Patent Application
20190263912
The subject matter disclosed herein is generally directed to compositions and methods for modulating, controlling or otherwise influencing enteric cell differentiation, homeostasis and activation. Manipulation of T cell balance and activity drives intestinal epithelial cell (IEC) differentiation and activity. This invention also relates generally to identifying and exploiting target genes and/or target gene products that modulate, control or otherwise influence T cell balance and enteric cell balance in a variety of therapeutic and/or diagnostic indications. This invention also relates generally to a gut atlas identifying novel cell types and markers for detecting, quantitating and isolating said cell types.
The functional balance between the epithelium and the constituents within the lumen plays a central role in both maintaining the normal mucosa and in disease. Intestinal epithelial cells (IECs) of the small intestinal epithelium comprise two major lineages—absorptive and secretory1—reflecting its dual roles to absorb nutrients and form a flexible barrier, monitoring and titrating responses to a variety of noxious substances or pathogens2. Enterocytes of the absorptive lineage comprise approximately 80% of the epithelium and are specialized for digestion and transport of nutrients3. The secretory lineage comprises five further terminally differentiated types of IECs: goblet, Paneth, enteroendocrine, tuft and microfold (M) cells4-6—each with distinct and specialized sensory and effector functions.
The epithelium is organized in a repeating structure of villi, which project toward the lumen, and nearby crypts (
Epithelial tissue turns over rapidly (˜5 days)8, allowing it to dynamically shift its composition in response to stress or pathogens. For example, parasitic infection typically induces hyperplasia of goblet cells, which produce and secrete mucins to prevent pathogen attachment, strengthening the epithelial barrier and facilitating parasite expulsion10. Rare (0.5-1%) enteroendocrine cells (EECs) secrete over 20 individual hormones and are key mediators of intestinal response to nutrients11,12 by directly detecting fluctuations in luminal nutrient concentrations via G-protein-coupled receptors (GPCRs)11. Finally, IECs communicate with immune cells to initiate either inflammatory responses or tolerance in response to lumen signals2,13. Tuft cells5, a rare IEC population, promote type-2 immunity in response to intestinal parasites by expressing interleukin-25 (Il25), which in turn mediates the recruitment of group 2 of innate lymphoid cells (ILC2s) that initiate the expansion of T-helper type 2 (Th2) cells upon parasite infection14-16. M cells, which reside exclusively in follicle-associated epithelia (FAE)17, play an important role in immune sensing by transporting luminal content to immune cells found directly below them18 in Peyer's patches, gut associated lymphoid follicles. Disruption in any of the major innate immune sensors and proximity effector functions of IECs may result in increased antigenic load through weakening of the epithelial barrier, and may lead to the onset of acute or chronic inflammation.
Despite this extensive knowledge, given the complexity of the epithelial cellular ecosystem, many questions remain open. First, do we know all the discrete epithelial cell types of the gut, or are there additional types, or new sub-types that have eluded previous studies. Second, what are the molecular characteristics of each type. For example, mapping the GPCRs and hormones expressed by EECs has important therapeutic applications; charting known and new specific cell surface markers would provide handles for specific cell isolation, and help assess the validity of legacy ones; and finding differentially expressed transcription factors (TFs) will open the way to study the molecular processes that accompany the differentiation of IECs, such as tuft or enteroendocrine cells. Third, we still know little about the response of individual cell populations to pathogenic insult, both in terms of changes in cellular proportions and cell-intrinsic responses.
A systematic atlas of single-cell RNA profiles can help address these questions, as the gene-expression program of a given cell closely reflects both its identity and function19,20. Most previous studies have examined the gene-expression profiles of IECs, but relied on known markers to purify cell populations6,15,21,22, which may isolate either a mixed population if marker expression is more promiscuous than assumed, or a subset of a larger group if overly specific. They may further fail to detect rare cellular populations or intermediate, transient states on a continuum. A recent study23 attempted to overcome these limitations using single-cell RNAseq (scRNA-seq), but analyzed only several hundred single cells, which may be insufficient to address the diversity of IECs, especially for subtypes that occur at a frequency of less than 0.1%11,12. Additional, studies53,30,145 also attempted to overcome these limitations using single-cell RNAseq (scRNA-seq). All of these studies have not yet extensively characterized intestinal epithelial cellular diversity.
The intestinal mucosa maintains a functional equilibrium with the complex luminal milieu, which is dominated by a spectrum of gut microbial species and their products. The functional balance between the epithelium and the lumen plays a central role in maintaining the normal mucosa and in the pathophysiology of many gastrointestinal disorders2. To maintain barrier integrity and tissue homeostasis in response to immune signals and luminal contents2, the gut epithelium constantly regenerates by rapid proliferation and differentiation49. This process is initiated by intestinal stem cells (ISCs), which give rise to committed progenitors that in turn differentiate to specific IEC types103,39.
ISC differentiation depends on external signals from an ecosystem of non-epithelial cells in the gut niche. In particular, canonical signal transduction pathways, such as Wnt and Notch113,114, are essential to ISC maintenance and differentiation, and rely on signals from stromal cells15,150. The intestinal tract is also densely populated by innate and adaptive immune cells, which maintain the balance between immune activation and tolerance2,151. However, it is unknown if and how immune cells and the adjacent ISCs interact.
Several studies suggest an important role for immune cells in tissue homeostasis. Tissue-resident innate immune cells, such as macrophages and type 3 innate lymphoid cells (ILC3s), can play a role in regeneration of the gut115,116 and other tissues117,119. Among adaptive immune cells, recent studies have implicated T regulatory cells (Tregs) in regeneration within muscles, lungs, and the central nervous system118,152,153. Skin-resident Tregs were very recently shown to be involved in maintaining hair follicle stem cell (HFSC) renewal through Jagged1-mediated Notch signaling54. In the gut, mouse models of intestinal infection, T cell depletion, and inflammatory bowel disease (IBD) all display aberrant epithelial cell composition, such as goblet cell hypoplasia or tuft cell expansion13,14,155. These phenotypes have been primarily interpreted as reflecting intestinal epithelial cell dysfunction and changes in gut microbial populations13,151,156,157.
The small intestinal mucosa is a complex system. The mucosa comprises multiple cell types involved in absorption, defense, secretion and more. These cell types are rapidly renewed from intestinal stem cells. The types of cells, their differentiation, and signals controlling differentiation and activation are poorly understood. The small intestinal mucosa also possesses a large and active immune system, poised to detect antigens and bacteria at the mucosal surface and to drive appropriate responses of tolerance or an active immune response. Finally, there is complex luminal milieu which comprises a combination of diverse microbial species and their products as well as derivative products of the diet. It is increasingly clear that a functional balance between the epithelium and the constituents within the lumen plays a central role in both maintaining the normal mucosa and the pathophysiology of many gastrointestinal disorders. Many disorders, such as irritable bowel disease, Crohn's disease, and food allergies, have proven difficult to treat. The manner in which these multiple factors interact remains unclear.
Applicants have identified novel markers and networks driving the regulation and differentiation of stem cells and intestinal epithelial cells, have identified markers capable of identifying new subpopulations of cells, have developed an atlas of the cells in the small intestine, and identified the crucial role of intestinal T cells in controlling epithelial stem cell differentiation and regulation. The present invention provides methods for modulating intestinal cells for the treatment gastrointestinal disorders, such as irritable bowel disease, Crohn's disease, and food allergies.
In some embodiments, the invention provides a method of modulating intestinal epithelial cell differentiation, maintenance and/or function, the method comprising contacting an intestinal T cell or a population of intestinal T cells with a T cell modulating agent in an amount sufficient to modify differentiation, maintenance and/or function of the T cell or population of T cells as compared to differentiation, maintenance and/or function of the T cell or population of T cells in the absence of the T cell modulating agent, whereby the differentiation, maintenance and/or function of the T cell directly influences intestinal epithelial cell differentiation, maintenance and/or function.
In some embodiments, such modulating of intestinal epithelial cell differentiation, maintenance and/or function modulates inflammation of the gut. In other embodiments, modulating can increase the immune response, or shape the immune response to treat disease.
In another embodiment, provided is a method of modulating intestinal epithelial cell differentiation, maintenance and/or function by administering an agent that modulates MHCII. In a related embodiment, provided is method of modulating differentiation, maintenance and/or function of MHC II-expressing cells in the intestines, particularly of MHC II-expressing intestinal epithelial cells, comprising administering to a subject in need thereof an agent that modulates differentiation, maintenance and/or function of T cells. In the foregoing, the T cell or population of T cells includes, without limitation, Th1 cells, Th2 cells, Th17 cells, and regulatory T cells (Tregs).
In other embodiments, provided is method of modulating intestinal epithelial cell differentiation, maintenance and/or function by administering an agent that modulates one or more of H2-Ab1, H2-DMb1, H2-DMa, H2-Aa, H2-Eb1, Cd74, Sectm1a, Sectm1b, Defa197, Defa24, Lyz1, Itln1, Mmp7, Ang4, Tslp, CD45, Rntlb, Wars, Pnlipr2, Muc2, Mptx1, Mptx2, Reg3b, Reg3g, Gfra3, Gpbar1, Gpr119 Neurog3, Sox4, Sct, Cck, Klf15, Grm4, Gal, Nts, Nucb2, Iapp, Sst, Nr1h4, Nr1h3, Nr1i2, Nr1i, Ffar, Ffar2, Ffar4, Ghrl, GIP, Gcg, Ghrl, Cd24a, Batf2, Mxd3, Foxa3, Gata5, Creb3l3, Osr2, Nfe2l2, Gata4, mKi67, Lgr5, Cyp2e1, Psrc1, and Kdm5.
In related embodiments the invention is a method of proliferating intestinal stem cells comprising contacting the stem cells with an agent that increases expression of MHC II genes. Such a method of regulating the proliferation rate of intestinal stem cells may, in some embodiments, comprise contacting the stem cells with (i) an agent that regulates expression of MHC II genes and/or proteins, and/or (ii) an agent that binds to MHC II proteins. Such an agent may be an MHC II blocking antibody or an infectious agent.
In the foregoing, the expression of MHC genes includes, without limitation, one or more of H2-Ab1, H2-DMb1, H2-DMa, H2-Aa, H2-Eb1, Cd74, Sectm1a, and Sectm1b.
In further embodiments, provided is a method of enhancing expression of one or more of Defa197, Defa24, Lyz1, Itln1, Mmp7, and Ang4 in intestinal cells, comprising administering to a subject in need thereof an agent that increases the presence of Th1 cells in the intestines.
In further embodiments, provided is a method of enhancing Th2 cell responses, comprising administering an agent that increases enteric levels of at least one of Tslp, CD45, Rntlb, Wars, Pnlipr2, and Muc2 protein and/or mRNA; preferably Tslp and/or CD45 protein and/or mRNA.
In further embodiments, provided is a method of treating an enteric condition, comprising inducing enterocyte and Paneth cell differentiation.
In an additional embodiment, provided is a method of treating an enteric condition, comprising administering Mptx2 protein and/or an agent that increases Mptx2 expression to a subject in need thereof. Such a method may further comprise administering at least one treatment selected from
a) Mptx1 and/or an agent that increases Mptx1 expression;
b) CRP and/or an agent that increases CRP expression;
c) Reg3b and/or an agent that increases Reg3b expression; and
d) Reg3g and/or an agent that increases Reg3g expression.
In view of the identification of the role of T cells in gut differentiation and modulation, provide also is a method of inducing intestinal stem cell differentiation comprising incubating stem cells in the presence of T cells (such as Th1, Th17 and Treg) or a cytokine selected from T-bet, FNγ, IL-13, IL-17A, and IL-10. Such a method may be in vitro or in vivo. Also encompassed is a stem cell produced by foregoing stimulation by T cells or T cell cytokines.
The foregoing method is useful for the modulation of gut function and in the related treatment of an enteric disease or condition. Such diseases include cancer, an infection (such as caused by a bacterial or parasitic infection, such as Salmonella), inflammation (such as inflammatory bowel disease, Crohn's disease, ulcerative colitis, and food allergies) or an immune dysfunction.
The inventors have identified a number of markers to identify disease. In some embodiments, provided is a method of diagnosing enteric bacterial infection in a subject comprising detecting protein or mRNA of at least one of Mptx1, Mptx2, Reg3b and Reg3g in an intestinal or fecal sample, wherein expression, such as elevated expression indicates bacterial infection.
Another embodiment comprises a method of diagnosing an enteric parasitic infection in a subject comprising detecting expression of Tslp and CD45 protein and/or mRNA in an intestinal or fecal sample, wherein expression, such as an elevated level thereof indicates parasitic infection. The method may further comprise detecting expression of protein and/or mRNA for Rntlb, Wars, Pnlipr2, and Muc2, wherein the expression, such as an elevated level thereof, indicates parasitic infection.
The inventors have also identified markers to identify cell types, metabolic state, age, and the like. A method for identifying Paneth cells in a sample, comprising detecting expression of protein or mRNA of one or more of Klf15, Mptx1 or Mptx2, wherein the expression, such as elevated expression, indicates Paneth cells.
Accordingly, in some embodiments provided is a method for identifying gut enteroendocrine cells in a sample, comprising detecting expression of protein or mRNA of one or more of Gfra3 protein or mRNA wherein the expression, such as elevated expression, indicates enteroendocrine cells.
In another embodiment provided is a method for identifying gut enteroendocrine cells in a sample, comprising detecting expression of protein or mRNA of at least 2 of Gfra3 Gpbar1, Gpr119 Neurog3, Sox4, Sct, and Cck, wherein expression, such as elevated expression, indicates enteroendocrine cells.
In another embodiment provided is a method for identifying gut enterochromaffin cells in a sample, comprising detecting expression of protein or mRNA of any one or more of Grm4 or Chrm4, wherein expression, such as elevated expression, indicates enterochromaffin cells.
In another embodiment provided is a method for identifying enteroendocrine cell subtypes, comprising detecting expression of one or more protein or mRNA selected from Galanin (Gal), Neurotensin (Nts), Nesfatin-1 (Nucb2), Amylin (Iapp) and Somatostatin (Sst).
In another embodiment provided is a method for identifying gut enterocytes in a sample, comprising detecting expression of protein or mRNA of any one or more of Nr1h4, Nr1h3, Nr1i2, or Nr1i in the sample, wherein expression thereof, such as elevated expression, indicates enterocytes. Such a method may be further comprising detecting the expression of at least one of Ffar, Ffar2, Ffar4, Ghrl, GIP, Gcg, Ghrl and Cd24a.
In another embodiment provided is a method for identifying the developmental lineage of an enteric cell, particularly of an enterocyte, comprising measuring the expression of mRNA or protein of any one or more of Batf2 or Mxd3. Such a method may further comprise measuring any one or more of Sox4, or Foxa3.
In another embodiment provided is a method for identifying the proximal or distal (in terms of location in the intestinal tract) identity of an enteric cell, particularly of an enterocyte, comprising measuring the levels of mRNA or protein of any one or more of Gata5, Creb3l3, Osr2, or Nfe2l2, optionally further comprising measuring any one or more of Gata4 or Nr1h4.
In another embodiment provided is a method of identifying the cell cycle state in an intestinal stem cell, comprising detecting the expression of protein or mRNA of one or more of Cyp2e1 and Psrc1 and optionally also mKi67, Lgr5, in a cell.
In another embodiment provided is a method of decreasing cell cycle rate in an intestinal stem cell comprising administering to a subject in need thereof an agent that increases the expression of Kdm5b protein or mRNA.
In another embodiment provided is a method for identifying tuft cells in a sample, comprising detecting expression of any one or more of Cd24a, Tas1r3, Ffar3, Sucnr1, Gabbr1 or Drd3 protein or mRNA, wherein the expression indicates tuft cells. Such a method may further comprise detecting expression of any one or more of Ptprc or Tslp protein or mRNA, wherein the expression indicates a subset of tuft cells, and may further comprise detecting expression of any one or more of Nrep, Nradd, Ninj1, and Plekhg5 protein or mRNA, wherein the expression indicates a subset of tuft cells.
In another embodiment provided is a method for identifying enteroendocrine cell subtypes in a sample, comprising detecting expression of a gene or gene product signature, the signature comprising or consisting of one or more genes or gene products as set forth in this application.
In another embodiment provided is a method for identifying enterochromaffin cell subtypes in a sample, comprising detecting expression, such as elevated expression, of protein or mRNA of Reg4.
In another embodiment provided is an isolated gastrointestinal tract cell characterized by expression of one or markers for a cell type selected from any of Tables 3 to 10 or 15 A to D.
In another embodiment provided is a method for detecting or quantifying gastrointestinal tract cells in a biological sample of a subject, the method comprising detecting or quantifying in the biological sample gastrointestinal tract cells as defined in herein. The gastrointestinal tract cell may be detected or quantified using one or more markers for a cell type selected from any of Tables 3 to 10 or 15 A to D.
In another embodiment provided is a method of isolating a gastrointestinal tract cell from a biological sample of a subject, the method comprising isolating from the biological sample gastrointestinal tract cells as defined herein. The gastrointestinal tract cell may be isolated using one or more surface markers for a cell type selected from any of Tables 3 to 10 or 15 A to D.
The gastrointestinal tract cells may be isolated, detected or quantified using a technique selected from the group consisting of RT-PCR, RNA-seq, single cell RNA-seq, western blot, ELISA, flow cytometry, mass cytometry, fluorescence activated cell sorting, fluorescence microscopy, affinity separation, magnetic cell separation, microfluidic separation, and combinations thereof.
The ability to identify cell types, metabolic state, cycling state and the like has many utilities—for example, identifying the source of a cancer cell type; identifying disease states; screening for drug effects; and applied and basic research.
These and other aspects, objects, features, and advantages of the example embodiments will become apparent to those having ordinary skill in the art upon consideration of the following detailed description of illustrated example embodiments.
Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Definitions of common terms and techniques in molecular biology may be found in Molecular Cloning: A Laboratory Manual, 2nd edition (1989) (Sambrook, Fritsch, and Maniatis); Molecular Cloning: A Laboratory Manual, 4th edition (2012) (Green and Sambrook); Current Protocols in Molecular Biology (1987) (F. M. Ausubel et al. eds.); the series Methods in Enzymology (Academic Press, Inc.): PCR 2: A Practical Approach (1995) (M. J. MacPherson, B. D. Hames, and G. R. Taylor eds.): Antibodies, A Laboraotry Manual (1988) (Harlow and Lane, eds.): Antibodies A Laboraotry Manual, 2nd edition 2013 (E. A. Greenfield ed.); Animal Cell Culture (1987) (R. I. Freshney, ed.); Benjamin Lewin, Genes IX, published by Jones and Bartlet, 2008 (ISBN 0763752223); Kendrew et al. (eds.), The Encyclopedia of Molecular Biology, published by Blackwell Science Ltd., 1994 (ISBN 0632021829); Robert A. Meyers (ed.), Molecular Biology and Biotechnology: a Comprehensive Desk Reference, published by VCH Publishers, Inc., 1995 (ISBN 9780471185710); Singleton et al., Dictionary of Microbiology and Molecular Biology 2nd ed., J. Wiley & Sons (New York, N.Y. 1994), March, Advanced Organic Chemistry Reactions, Mechanisms and Structure 4th ed., John Wiley & Sons (New York, N.Y. 1992); and Marten H. Hofker and Jan van Deursen, Transgenic Mouse Methods and Protocols, 2nd edition (2011).
As used herein, the singular forms “a”, “an”, and “the” include both singular and plural referents unless the context clearly dictates otherwise.
The term “optional” or “optionally” means that the subsequent described event, circumstance or substituent may or may not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.
The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.
The terms “about” or “approximately” as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, are meant to encompass variations of and from the specified value, such as variations of +/−10% or less, +/−5% or less, +/−1% or less, and +/−0.1% or less of and from the specified value, insofar such variations are appropriate to perform in the disclosed invention. It is to be understood that the value to which the modifier “about” or “approximately” refers is itself also specifically, and preferably, disclosed.
Reference throughout this specification to “one embodiment”, “an embodiment,” “an example embodiment,” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” or “an example embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention. For example, in the appended claims, any of the claimed embodiments can be used in any combination.
Whereas the terms “one or more” or “at least one”, such as one or more members or at least one member of a group of members, is clear per se, by means of further exemplification, the term encompasses inter alia a reference to any one of the members, or to any two or more of the members, such as, e.g., any ≥3, ≥4, ≥5, ≥6 or ≥7 etc. of the members, and up to all members. In another example, “one or more” or “at least one” may refer to 1, 2, 3, 4, 5, 6, 7 or more.
The term “optional” or “optionally” means that the subsequent described event, circumstance or substituent may or may not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.
The term “isolated” as used throughout this specification with reference to a particular component generally denotes that such component exists in separation from—for example, has been separated from or prepared and/or maintained in separation from—one or more other components of its natural environment. More particularly, the term “isolated” as used herein in relation to a cell or cell population denotes that such cell or cell population does not form part of an animal or human body.
All publications, published patent documents, and patent applications cited herein are hereby incorporated by reference to the same extent as though each individual publication, published patent document, or patent application was specifically and individually indicated as being incorporated by reference.
Embodiments disclosed herein provide markers and gene signatures for identifying, isolating and modulating cells for the treatment of diseases and disorders associated with the gut. Understanding the development, differentiation and function of an organ, such as the intestine, requires the identification and characterization of all of its component cell types. In the small bowel, intestinal epithelial cells (IECs) sense and respond to microbial stimuli and noxious substances, provide crucial barrier function and participate in the coordination of immune responses. Here, Applicants profiled 53,193 individual IECs from mouse small intestine and intestinal organoid cultures. Using unsupervised clustering, Applicants defined specific gene signatures for major IEC lineages, including the identification of Mptx2, a mucosal pentraxin, as a novel Paneth cell marker. In addition, Applicants identified unexpected diversity of hormone-secreting enteroendocrine populations, revealing co-expression programs of gut hormone genes, previously thought to represent different enteroendocrine subtypes, and constructed a novel hierarchical taxonomy of these cells. Applicants also distinguished two subtypes of Dclk1-positive tuft cells, one of which (Tuft-2) expresses both the epithelial cytokine Tslp and the pan-immune cell marker Ptprc (CD45), which has not been previously associated with any non-hematopoietic cell type. Finally, Applicants characterized how the intrinsic states and proportions of these cell types are reshaped in response to Salmonella enterica and Heligmosomoides polygyrus infections. Salmonella infection led to an increased number of Paneth cells and enterocytes, and Paneth cell-specific up-regulation of both defensins and Mptx2. In addition, an absorptive enterocyte-specific antimicrobial program was broadly activated across all IEC types, demonstrating previously uncharacterized cellular response to pathogens. In contrast, H. polygyrus led to expansion of goblet and tuft cell populations, with a particular expansion of the Cd45+ Tuft-2 group. The high-resolution atlas highlights new markers and transcriptional programs, novel allocation of sensory molecules to cell types and organizational principles of gut homeostasis and physiology.
Here, Applicants use scRNA-seq to chart a comprehensive atlas of the epithelial cells of the small intestine. Applicants identified gene signatures, key TFs and specific GPCRs for each of the major small intestinal differentiated cell types, and traced their differentiation from ISCs. Applicants identified and characterized cellular heterogeneity within specific cell-types, and validated individual genes and signatures in situ. Applicants found a transcriptional signature distinguishing proximal and distal enterocytes, established a novel classification of the different subtypes of the enteroendocrine cells and their differential deployment at different locations, and identified a previously unrecognized separation of tuft cells to two sub-types, one with a neuron-like and one with an immune-like gene signature, expressing Ptprc (CD45) and TSLP, a pan-immune cell marker and epithelial cytokine, respectively. Finally, Applicants demonstrated how these cell types and states change dynamically as the small intestine adapts to infection by distinct classes of pathogens. The high resolution cell atlas better defines the composition of the gut, highlights novel key molecules, TFs and GPCRs that can impact gut function and shows how changes in gut composition can play a key role in maintaining homeostasis in response to pathogens.
In the small intestine, a cellular niche of diverse accessory cell types supports the rapid generation of mature epithelial cell types through self-renewal, proliferation, and differentiation of intestinal stem cells (ISCs). However, not much is known about interactions between immune cells and ISCs, and it is unclear if and how immune cell dynamics affect eventual ISC fate or the balance between self-renewal and differentiation. Here, Applicants used single-cell RNA-seq (scRNA-Seq) of intestinal epithelial cells (IECs) to identify new mechanisms for ISC-immune cell interactions. Surprisingly, MHC class II (MHCII) is enriched in two distinct subsets of Lgr5+ crypt base columnar ISCs, which are also distinguished by higher proliferation rates. Using co-culture of T cells with intestinal organoids, cytokine stimulations, and in vivo mouse models, Applicants confirm that CD4+ T helper (Th) cells communicate with ISCs and affect their differentiation, in a manner specific to the Th subtypes and their signature cytokines and dependent on MHCII expression by ISCs. Specific inducible knockout of MHCII in intestinal epithelial cells in mice in vivo results in expansion of the ISC pool. Mice lacking T cells have expanded ISC pools, whereas specific depletion of Treg cells in vivo results in substantial reduction of ISC numbers. The findings show that interactions between Th cells and ISCs mediated via MHCII expressed in intestinal epithelial stem cells help orchestrate tissue-wide responses to external signals. The mechanisms discovered can be leveraged to treat disease in the gut.
Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine, principally including Crohn's disease and ulcerative colitis, with other forms of IBD representing far fewer cases (e.g., collagenous colitis, lymphocytic colitis, diversion colitis, Behçet's disease and indeterminate colitis). Pathologically, Crohn's disease affects the full thickness of the bowel wall (e.g., transmural lesions) and can affect any part of the gastrointestinal tract, while ulcerative colitis is restricted to the mucosa (epithelial lining) of the colon and rectum.
Graft-versus-host disease (GVHD) is an immune-related disease that can occur following an allogeneic tissue transplant. It is commonly associated with stem cell or bone marrow transplants, but GVHD also applies to other forms of tissue graft. In GVHD immune cells of the tissue graft recognize the recipient host as foreign and attack the host's cells.
It has long been recognized that IBD and GVHD are diseases associated with increased immune activity. The causes of IBD, while not well understood, may be related to an aberrant immune response to the microbiota in genetically susceptible individuals. IBD affects over 1.4 million people in the United States and over 2.2 million in Europe and is on the increase. With both environmental and genetic factors playing a role in the development and progression of IBD, response to current treatments (e.g., anti-inflammatory drugs, immune system suppressors, antibiotics, surgery, and other symptom specific medications) are unpredictable.
Similarly, a fundamental feature of GVHD is increased immune activity. As yet, the pathophysiology underlying GVHD is not well understood. It is a significant cause of morbidity and mortality following allogenic haematopoietic stem-cell transplantation and thus the focus of much ongoing research. Despite the advances in understanding the pathophysiology (e.g., predisposing factors), a standardized therapeutic strategy is still lacking. Currently both acute and chronic forms of GVHD are treated using corticosteroids (e.g., anti-inflammatory treatments). There is a need for new approaches to treating IBD and GVHD.
Some of the genetic factors predisposing one to IBD are known, as explored in Daniel B. Graham and Ramnik J. Xavier “From Genetics of Inflammatory Bowel Disease Towards Mechanistic Insights” Trends Immunol. 2013 August; 34(8): 371-378 (incorporated herein). This disclosure provides a rationale for modulating intestinal epithelial cell balance, function, differentiation and/or activity for the treatment of both IBD and GVHD, and other disorders.
In certain embodiments, the IBD is Crohn's disease or ulcerative colitis. In certain embodiments, the IBD is collagenous colitis, lymphocytic colitis, diversion colitis, Behçet's disease, or indeterminate colitis.
In other embodiments, the GVHD is acute graft-versus-host disease (aGVHD) or chronic graft-versus-host disease (cGVHD).
In yet other embodiments, the methods of the disclosure include administering to a subject in need thereof an effective amount (e.g., therapeutically effective amount or prophylactically effective amount) of the treatments provided herein. Such treatment may be supplemented with other known treatments, such as surgery on the subject. In certain embodiments, the surgery is strictureplasty, resection (e.g., bowel resection, colon resection), colectomy, surgery for abscesses and fistulas, proctocolectomy, restorative proctocolectomy, vaginal surgery, cataract surgery, or a combination thereof.
The small intestinal mucosa is at equipoise with a complex luminal milieu which comprises a combination of diverse microbial species and their products as well as derivative products of the diet. It is increasingly clear that the functional balance between the epithelium and the constituents within the lumen plays a central role in both maintaining the normal mucosa and the pathophysiology of many gastrointestinal disorders. The barrier function is part fulfilled by anatomic features that partly impede penetration of macromolecules and diverse set of specialized cells that monitor and titrate responses to a variety of noxious substances or pathogens (Peterson and Artis, 2014). The underlying mucosal immune system is poised to detect antigens and bacteria at the mucosal surface and to drive appropriate responses of tolerance or an active immune response.
IECs of the small intestinal epithelium comprise two major lineages—absorptive and secretory (Clevers, 2006)—reflecting its dual roles. Enterocytes of the absorptive lineage comprise approximately 80% of the epithelium and are specialized for digestion and transport of nutrients (Ferraris et al., 1992). The secretory lineage comprises five further terminally differentiated types of IECs: goblet, Paneth, enteroendocrine, tuft and microfold (M) cells (Barker et al., 2007; Gerbe et al., 2012; Sato et al., 2009)—each with distinct and specialized sensory and effector functions.
The epithelium is organized in a repeating structure of villi, which project toward the lumen, and nearby crypts (
For example, parasitic infection typically induces hyperplasia of goblet cells, which produce and secrete mucins to prevent pathogen attachment, strengthening the epithelial barrier and facilitating parasite expulsion (Pelaseyed et al., 2014). Rare (0.5-1%) enteroendocrine cells (EECs) secrete over 20 individual hormones and are key mediators of intestinal response to nutrients (Furness et al., 2013; Gribble and Reimann, 2016) by directly detecting fluctuations in luminal nutrient concentrations via G-protein-coupled receptors (GPCRs)(Gribble and Reimann, 2016). Mapping these GPCRs and hormones has important therapeutic applications. Finally, IECs communicate with immune cells to initiate either inflammatory responses or tolerance in response to lumen signals (Biton et al., 2011; Peterson and Artis, 2014).
A rare IEC population, tuft cells (Gerbe et al., 2012) promote type-2 immunity in response to intestinal parasites by expressing interleukin-25 (Il25), which in turn mediates the recruitment of group 2 of innate lymphoid cells (ILC2s) that initiate the expansion of T-helper type 2 cells upon parasite infection (Gerbe et al., 2016; Howitt et al., 2016; von Moltke et al., 2016). Furthermore, M cells reside exclusively in follicle-associated epithelia found only above Peyer's patches, which are gut associated lymphoid follicles (de Lau et al., 2012). M cells play an important role in immune sensing by transporting luminal content to immune cells found directly below them (Mabbott et al., 2013). Disruption in any of the major innate immune sensors and proximity effector functions of IECs may result in increased antigenic load through weakening of the epithelial barrier, and may lead to the onset of acute or chronic inflammation. Despite this extensive knowledge, given the complexity of the epithelial cellular ecosystem, many questions remain open.
It is an objective of the present invention to determine all the discrete epithelial cell types of the gut, additional types, or new sub-types that have eluded previous studies. It is another objective of the present invention to determine the molecular characteristics of each type. For example, mapping the GPCRs and hormones expressed by EECs has important therapeutic applications; charting known and new specific cell surface markers can provide handles for specific cell isolation, and help assess the validity of legacy ones; and finding differentially expressed transcription factors (TFs) can open the way to study the molecular processes that accompany the differentiation of IECs, such as tuft or enteroendocrine cells. It is another objective of the present invention to understand the response of individual cell populations to pathogenic insult, both in terms of changes in cellular proportions and cell-intrinsic responses.
In some aspects the present disclosure refers to a method of identifying a cell or cell marker, comprising: a) isolating target cells based on a marker specifically expressed in or on the cell or by label-free imaging flow cytometry; b) quantifying gene expression in the target cells by single cell sequencing, and c) clustering the target cells based on the gene expression by application of one or more algorithms, d) optionally determining a transcription signature for each cluster based at least in part on identifying differentially expressed genes between two or more clusters and between each cluster and the remaining cells as background, and e) optionally validating gene expression against cellular morphology.
In some examples of the present disclosure identifying differentially expressed transcripts comprises application of a supervised or unsupervised machine-learning model. A supervised machine learning model is for example selected from the group consisting of an analytical learning model, an artificial neural network model, a back propagation model, a boosting model, a Bayesian statistics model, a case-based model, a decision tree learning model, an inductive logic programming model, a Gaussian process regression model, a group method of data handling model, a kernel estimator model, a learning automata model, a minimum message length model, a multilinear subspace learning, a naïve bayes classifer model, a nearest neighbor model, a probably approximately correct (PAC) learning model, a ripple down rules model, a symbolic machine learning model, a subsymbolic machine learning model, a support vector machine learning model, a minimum complexity machine model, a random forest model, an ensemble of classifiers model, an ordinal classification model, a data pre-processing model, a handling imbalanced datasets model, a statistical relational learning model, a Proaftn model. An unsupervised machine learning model is for example selected from the group consisting of a k-means model, a mixture model, a hierarchical clustering model, an anomaly detection model, a neural network model, an expectation-maximization (EM) model, a method of moments model, or a blind signal separation technique.
These models are used separately or in combination with each other or in combination with any other machine-learning model, wherein a supervised model is combined with a supervised model, or an unsupervised model is combined with an unsupervised model or a supervised model is combined with an unsupervised model.
In other examples of the previous aspects (optional) validating gene expression against cellular morphology comprises sparse labeling the cell to enhance the expression of a fluorescent protein in the cell and combining the sparse labeling with fluorescent in situ hybridization (FISH) to validate the marker against cellular morphology in step e). In examples of the previous aspects FISH is for example combined with a specific antibody, double FISH or a transgenic reporter mouse line directed to a previously identified marker in the cell. For example an enhancer element is inserted into a lentivirus or an adeno-associated virus (AAV) vector upstream of the fluorescent protein to enhance its expression.
The term “marker” is widespread in the art and commonly broadly denotes a biological molecule, more particularly an endogenous biological molecule, and/or a detectable portion thereof, whose qualitative and/or quantitative evaluation in a tested object (e.g., in or on a cell, cell population, tissue, organ, or organism, e.g., in a biological sample of a subject) is predictive or informative with respect to one or more aspects of the tested object's phenotype and/or genotype. The terms “marker” and “biomarker” may be used interchangeably throughout this specification.
Preferably, markers as intended herein may be peptide-, polypeptide- and/or protein-based, or may be nucleic acid-based. For example, a marker may be comprised of peptide(s), polypeptide(s) and/or protein(s) encoded by a given gene, or of detectable portions thereof. Further, whereas the term “nucleic acid” generally encompasses DNA, RNA and DNA/RNA hybrid molecules, in the context of markers the term may typically refer to heterogeneous nuclear RNA (hnRNA), pre-mRNA, messenger RNA (mRNA), or copy DNA (cDNA), or detectable portions thereof. Such nucleic acid species are particularly useful as markers, since they contain qualitative and/or quantitative information about the expression of the gene. Particularly preferably, a nucleic acid-based marker may encompass mRNA of a given gene, or cDNA made of the mRNA, or detectable portions thereof. Any such nucleic acid(s), peptide(s), polypeptide(s) and/or protein(s) encoded by or produced from a given gene are encompassed by the term “gene product(s)”.
Preferably, markers as intended herein may be extracellular or cell surface markers, as methods to measure extracellular or cell surface marker(s) need not disturb the integrity of the cell membrane and may not require fixation/permeabilisation of the cells.
The term “protein” as used throughout this specification generally encompasses macromolecules comprising one or more polypeptide chains, i.e., polymeric chains of amino acid residues linked by peptide bonds. The term may encompass naturally, recombinantly, semi-synthetically or synthetically produced proteins. The term also encompasses proteins that carry one or more co- or post-expression-type modifications of the polypeptide chain(s), such as, without limitation, glycosylation, acetylation, phosphorylation, sulfonation, methylation, ubiquitination, signal peptide removal, N-terminal Met removal, conversion of pro-enzymes or pre-hormones into active forms, etc. The term further also includes protein variants or mutants which carry amino acid sequence variations vis-à-vis corresponding native proteins, such as, e.g., amino acid deletions, additions and/or substitutions. The term contemplates both full-length proteins and protein parts or fragments, e.g., naturally-occurring protein parts that ensue from processing of such full-length proteins.
The term “polypeptide” as used throughout this specification generally encompasses polymeric chains of amino acid residues linked by peptide bonds. Hence, insofar a protein is only composed of a single polypeptide chain, the terms “protein” and “polypeptide” may be used interchangeably herein to denote such a protein. The term is not limited to any minimum length of the polypeptide chain. The term may encompass naturally, recombinantly, semi-synthetically or synthetically produced polypeptides. The term also encompasses polypeptides that carry one or more co- or post-expression-type modifications of the polypeptide chain, such as, without limitation, glycosylation, acetylation, phosphorylation, sulfonation, methylation, ubiquitination, signal peptide removal, N-terminal Met removal, conversion of pro-enzymes or pre-hormones into active forms, etc. The term further also includes polypeptide variants or mutants which carry amino acid sequence variations vis-à-vis a corresponding native polypeptide, such as, e.g., amino acid deletions, additions and/or substitutions. The term contemplates both full-length polypeptides and polypeptide parts or fragments, e.g., naturally-occurring polypeptide parts that ensue from processing of such full-length polypeptides.
The term “peptide” as used throughout this specification preferably refers to a polypeptide as used herein consisting essentially of 50 amino acids or less, e.g., 45 amino acids or less, preferably 40 amino acids or less, e.g., 35 amino acids or less, more preferably 30 amino acids or less, e.g., 25 or less, 20 or less, 15 or less, 10 or less or 5 or less amino acids.
The term “nucleic acid” as used throughout this specification typically refers to a polymer (preferably a linear polymer) of any length composed essentially of nucleoside units. A nucleoside unit commonly includes a heterocyclic base and a sugar group. Heterocyclic bases may include inter alia purine and pyrimidine bases such as adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U) which are widespread in naturally-occurring nucleic acids, other naturally-occurring bases (e.g., xanthine, inosine, hypoxanthine) as well as chemically or biochemically modified (e.g., methylated), non-natural or derivatised bases. Exemplary modified nucleobases include without limitation 5-substituted pyrimidines, 6-azapyrimidines and N-2, N-6 and 0-6 substituted purines, including 2-aminopropyladenine, 5-propynyluracil and 5-propynylcytosine. In particular, 5-methylcytosine substitutions have been shown to increase nucleic acid duplex stability and may be preferred base substitutions in for example antisense agents, even more particularly when combined with 2′-O-methoxyethyl sugar modifications. Sugar groups may include inter alia pentose (pentofuranose) groups such as preferably ribose and/or 2-deoxyribose common in naturally-occurring nucleic acids, or arabinose, 2-deoxyarabinose, threose or hexose sugar groups, as well as modified or substituted sugar groups (such as without limitation 2′-O-alkylated, e.g., 2′-O-methylated or 2′-O-ethylated sugars such as ribose; 2′-O-alkyloxyalkylated, e.g., 2′-O-methoxyethylated sugars such as ribose; or 2′-O,4′-C-alkylene-linked, e.g., 2′-O,4′-C-methylene-linked or 2′-O,4′-C-ethylene-linked sugars such as ribose; 2′-fluoro-arabinose, etc.).
Nucleoside units may be linked to one another by any one of numerous known inter-nucleoside linkages, including inter alia phosphodiester linkages common in naturally-occurring nucleic acids, and further modified phosphate- or phosphonate-based linkages such as phosphorothioate, alkyl phosphorothioate such as methyl phosphorothioate, phosphorodithioate, alkylphosphonate such as methylphosphonate, alkylphosphonothioate, phosphotriester such as alkylphosphotriester, phosphoramidate, phosphoropiperazidate, phosphoromorpholidate, bridged phosphoramidate, bridged methylene phosphonate, bridged phosphorothioate; and further siloxane, carbonate, sulfamate, carboalkoxy, acetamidate, carbamate such as 3′-N-carbamate, morpholino, borano, thioether, 3′-thioacetal, and sulfone internucleoside linkages. Preferably, inter-nucleoside linkages may be phosphate-based linkages including modified phosphate-based linkages, such as more preferably phosphodiester, phosphorothioate or phosphorodithioate linkages or combinations thereof. The term “nucleic acid” also encompasses any other nucleobase containing polymers such as nucleic acid mimetics, including, without limitation, peptide nucleic acids (PNA), peptide nucleic acids with phosphate groups (PHONA), locked nucleic acids (LNA), morpholino phosphorodiamidate-backbone nucleic acids (PMO), cyclohexene nucleic acids (CeNA), tricyclo-DNA (tcDNA), and nucleic acids having backbone sections with alkyl linkers or amino linkers (see, e.g., Kurreck 2003 (Eur J Biochem 270: 1628-1644)). “Alkyl” as used herein particularly encompasses lower hydrocarbon moieties, e.g., C1-C4 linear or branched, saturated or unsaturated hydrocarbon, such as methyl, ethyl, ethenyl, propyl, 1-propenyl, 2-propenyl, and isopropyl. Nucleic acids as intended herein may include naturally occurring nucleosides, modified nucleosides or mixtures thereof.
A modified nucleoside may include a modified heterocyclic base, a modified sugar moiety, a modified inter-nucleoside linkage or a combination thereof. The term “nucleic acid” further preferably encompasses DNA, RNA and DNA/RNA hybrid molecules, specifically including hnRNA, pre-mRNA, mRNA, cDNA, genomic DNA, amplification products, oligonucleotides, and synthetic (e.g., chemically synthesised) DNA, RNA or DNA/RNA hybrids. A nucleic acid can be naturally occurring, e.g., present in or isolated from nature, can be recombinant, i.e., produced by recombinant DNA technology, and/or can be, partly or entirely, chemically or biochemically synthesised. A “nucleic acid” can be double-stranded, partly double stranded, or single-stranded. Where single-stranded, the nucleic acid can be the sense strand or the antisense strand. In addition, nucleic acid can be circular or linear.
Unless otherwise apparent from the context, reference herein to any marker, such as a peptide, polypeptide, protein, or nucleic acid, may generally also encompass modified forms of the marker, such as bearing post-expression modifications including, for example, phosphorylation, glycosylation, lipidation, methylation, cysteinylation, sulphonation, glutathionylation, acetylation, oxidation of methionine to methionine sulphoxide or methionine sulphone, and the like.
The reference to any marker, including any peptide, polypeptide, protein, or nucleic acid, corresponds to the marker commonly known under the respective designations in the art. The terms encompass such markers of any organism where found, and particularly of animals, preferably warm-blooded animals, more preferably vertebrates, yet more preferably mammals, including humans and non-human mammals, still more preferably of humans.
The terms particularly encompass such markers, including any peptides, polypeptides, proteins, or nucleic acids, with a native sequence, i.e., ones of which the primary sequence is the same as that of the markers found in or derived from nature. A skilled person understands that native sequences may differ between different species due to genetic divergence between such species. Moreover, native sequences may differ between or within different individuals of the same species due to normal genetic diversity (variation) within a given species. Also, native sequences may differ between or even within different individuals of the same species due to somatic mutations, or post-transcriptional or post-translational modifications. Any such variants or isoforms of markers are intended herein. Accordingly, all sequences of markers found in or derived from nature are considered “native”. The terms encompass the markers when forming a part of a living organism, organ, tissue or cell, when forming a part of a biological sample, as well as when at least partly isolated from such sources. The terms also encompass markers when produced by recombinant or synthetic means.
In certain embodiments, markers, including any peptides, polypeptides, proteins, or nucleic acids, may be human, i.e., their primary sequence may be the same as a corresponding primary sequence of or present in a naturally occurring human markers. Hence, the qualifier “human” in this connection relates to the primary sequence of the respective markers, rather than to their origin or source. For example, such markers may be present in or isolated from samples of human subjects or may be obtained by other means (e.g., by recombinant expression, cell-free transcription or translation, or non-biological nucleic acid or peptide synthesis).
The terms “orthologue” (also referred to as “ortholog” herein) and “homologue” (also referred to as “homolog” herein) are well known in the art. By means of further guidance, a “homologue” of a protein as used herein is a protein of the same species which performs the same or a similar function as the protein it is a homologue of. Homologous proteins may but need not be structurally related, or are only partially structurally related. An “orthologue” of a protein as used herein is a protein of a different species which performs the same or a similar function as the protein it is an orthologue of. Orthologous proteins may but need not be structurally related, or are only partially structurally related. Thus, when reference is made to mouse genes and proteins, it is understood that the same is believed to apply to the corresponding ortholog in humans or other species.
Likewise, when referencing Cas9 and other proteins, it is understood to likewise apply to orthologs and homologs.
The CRISPR-CRISPR associated (Cas) systems of bacterial and archaeal adaptive immunity are some such systems that show extreme diversity of protein composition and genomic loci architecture. The CRISPR-Cas system loci has more than 50 gene families and there is no strictly universal genes indicating fast evolution and extreme diversity of loci architecture. So far, adopting a multi-pronged approach, there is comprehensive cas gene identification of about 395 profiles for 93 Cas proteins. Classification includes signature gene profiles plus signatures of locus architecture. A new classification of CRISPR-Cas systems is proposed in which these systems are broadly divided into two classes, Class 1 with multisubunit effector complexes and Class 2 with single-subunit effector modules exemplified by the Cas9 protein. Novel effector proteins associated with Class 2 CRISPR-Cas systems may be developed as powerful genome engineering tools and the prediction of putative novel effector proteins and their engineering and optimization is important.
The effector protein may comprise a chimeric effector protein comprising a first fragment from a first effector protein ortholog and a second fragment from a second effector protein ortholog, and wherein the first and second effector protein orthologs are different. At least one of the first and second effector protein orthologs may comprise an effector protein from an organism comprising Bergeyella, Prevotella, Porphyromonas, Bacteroides, Alistipes, Riemerella, Myroides, Flavobacterium, Capnocytophaga, Chryseobacterium, Paludibacter, Phaeodactylibacter or Psychroflexus.
In certain embodiments, the effector protein, particularly a Group 29 or Group 30 effector protein effector protein may be at least 700 amino acids long. In preferred embodiments, the effector protein may be about 1100 to about 1500 amino acids long, e.g., about 1100 to about 1200 amino acids long, or about 1200 to about 1300 amino acids long, or about 1300 to about 1400 amino acids long, or about 1400 to about 1500 amino acids long, e.g., about 900, about 1000, about 1100, about 1200, about 1300, about 1400, about 1500, about 1600, about 1700, or about 1800 amino acids long.
In certain embodiments, the Group 29 or Group 30 effector proteins as intended herein may be associated with a locus comprising short CRISPR repeats between 30 and 40 bp long, more typically between 34 and 38 bp long, even more typically between 36 and 37 bp long, e.g., 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 bp long. In certain embodiments the CRISPR repeats are long or dual repeats between 80 and 350 bp long such as between 80 and 200 bp long, even more typically between 86 and 88 bp long, e.g., 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, or 90 bp long
Orthologous proteins may but need not be structurally related, or are only partially structurally related. In particular embodiments, the homologue or orthologue of a Group 29 or Group 30 protein as referred to herein has a sequence homology or identity of at least 80%, more preferably at least 85%, even more preferably at least 90%, such as for instance at least 95% with the Group 29 or Group 30 effector protein. In a preferred embodiment, the Group 29 or Group 30 effector protein may be an ortholog of an organism of a genus which includes but is not limited to Bergeyella, Prevotella, Porphyromonas, Bacteroides, Alistipes, Riemerella, Myroides, Flavobacterium, Capnocytophaga, Chryseobacterium, Phaeodactylibacter, Paludibacter or Psychroflexus. Some methods of identifying orthologs of CRISPRsystem enzymes may involve identifying tracr sequences in genomes of interest. Identification of tracr sequences may relate to the following steps: Search for the direct repeats or tracr mate sequences in a database to identify a CRISPR region comprising a CRISPR enzyme. Search for homologous sequences in the CRISPR region flanking the CRISPR enzyme in both the sense and antisense directions. Look for transcriptional terminators and secondary structures. Identify any sequence that is not a direct repeat or a tracr mate sequence but has more than 50% identity to the direct repeat or tracr mate sequence as a potential tracr sequence. Take the potential tracr sequence and analyze for transcriptional terminator sequences associated therewith.
It will be appreciated that any of the functionalities described herein may be engineered into CRISPR enzymes from other orthologs, including chimeric enzymes comprising fragments from multiple orthologs. Examples of such orthologs are described elsewhere herein. Thus, chimeric enzymes may comprise fragments of CRISPR enzyme orthologs of an organism which includes but is not limited to Bergeyella, Prevotella, Porphyromonas, Bacteroides, Alistipes, Riemerella, Myroides, Flavobacterium, Capnocytophaga, Chryseobacterium, Phaeodactylibacter, Paludibacter or Psychroflexus. A chimeric enzyme can comprise a first fragment and a second fragment, and the fragments can be of CRISPR enzyme orthologs of organisms of genuses herein mentioned or of species herein mentioned; advantageously the fragments are from CRISPR enzyme orthologs of different species.
Paludibacter propionicigenes
Prevotella sp. P5-60
Prevotella sp. P4-76
Prevotella sp. P5-125
Prevotella sp. P5-119
Capnocytophaga canimorsus
Phaeodactylibacter xiamenensis
Porphyromonas gingivalis W83
Porphyromonas gingivalis
Porphyromonas gingivalis ATCC
Porphyromonas gingivalis
Porphyromonas gingivalis
Porphyromonas gingivalis SJD2
Porphyromonas gingivalis
Porphyromonas gingivalis
Porphyromonas gingivalis
Porphyromonas gingivalis
Porphyromonas gingivalis
Porphyromonas gulae
Bacteroides pyogenes F0041
Bacteroides pyogenes JCM
Alistipes sp. ZOR0009
Flavobacterium branchiophilum
Prevotella sp. MA2016
Myroides odoratimimus CCUG
Myroides odoratimimus CCUG
Myroides odoratimimus CCUG
Myroides odoratimimus CCUG
Myroides odoratimimus CCUG
Myroides odoratimimus
Bergeyella zoohelcum ATCC
Capnocytophaga cynodegmi
Bergeyella zoohelcum ATCC
Flavobacterium sp. 316
Psychroflexus torquis ATCC
Flavobacterium columnare ATCC
Flavobacterium columnare
Flavobacterium columnare
Flavobacterium columnare
Chryseobacterium sp. YR477
Riemerella anatipestifer ATCC
Riemerella anatipestifer RA-CH-
Riemerella anatipestifer
Riemerella anatipestifer
Riemerella anatipestifer
Prevotella saccharolytica F0055
Prevotella saccharolytica JCM
Prevotella buccae ATCC 33574
Prevotella buccae ATCC 33574
Prevotella buccae D17
Prevotella sp. MSX73
Prevotella pallens ATCC 700821
Prevotella pallens ATCC 700821
Prevotella intermedia ATCC
Prevotella intermedia
Prevotella intermedia 17
Prevotella intermedia
Prevotella intermedia
Prevotella intermedia ZT
Prevotella aurantiaca JCM 15754
Prevotella pleuritidis F0068
Prevotella pleuritidis JCM 14110
Prevotella falsenii DSM 22864 =
Porphyromonas gulae
Porphyromonas sp. COT-052
Porphyromonas gulae
Porphyromonas gulae
Porphyromonas gulae
Porphyromonas gulae
Porphyromonas gulae
Porphyromonas gulae
Porphyromonas gulae
Porphyromonas gingivalis
Porphyromonas gingivalis ATCC
Porphyromonas gingivalis
Porphyromonas gingivalis JCVI
Porphyromonas gingivalis W50
Porphyromonas gingivalis
Porphyromonas gingivalis AJW4
Porphyromonas gingivalis
Porphyromonas gingivalis
The reference herein to any marker, including any peptide, polypeptide, protein, or nucleic acid, also encompasses fragments thereof. Hence, the reference herein to measuring (or measuring the quantity of) any one marker may encompass measuring the marker and/or measuring one or more fragments thereof.
For example, any marker and/or one or more fragments thereof may be measured collectively, such that the measured quantity corresponds to the sum amounts of the collectively measured species. In another example, any marker and/or one or more fragments thereof may be measured each individually.
The term “fragment” as used throughout this specification with reference to a peptide, polypeptide, or protein generally denotes a portion of the peptide, polypeptide, or protein, such as typically an N- and/or C-terminally truncated form of the peptide, polypeptide, or protein. Preferably, a fragment may comprise at least about 30%, e.g., at least about 50% or at least about 70%, preferably at least about 80%, e.g., at least about 85%, more preferably at least about 90%, and yet more preferably at least about 95% or even about 99% of the amino acid sequence length of the peptide, polypeptide, or protein. For example, insofar not exceeding the length of the full-length peptide, polypeptide, or protein, a fragment may include a sequence of ≥5 consecutive amino acids, or ≥10 consecutive amino acids, or ≥20 consecutive amino acids, or ≥30 consecutive amino acids, e.g., ≥40 consecutive amino acids, such as for example ≥50 consecutive amino acids, e.g., ≥60, ≥70, ≥80, ≥90, ≥100, ≥200, ≥300, ≥400, ≥500 or ≥600 consecutive amino acids of the corresponding full-length peptide, polypeptide, or protein.
The term “fragment” with reference to a nucleic acid (polynucleotide) generally denotes a 5′- and/or 3′-truncated form of a nucleic acid. Preferably, a fragment may comprise at least about 30%, e.g., at least about 50% or at least about 70%, preferably at least about 80%, e.g., at least about 85%, more preferably at least about 90%, and yet more preferably at least about 95% or even about 99% of the nucleic acid sequence length of the nucleic acid. For example, insofar not exceeding the length of the full-length nucleic acid, a fragment may include a sequence of ≥5 consecutive nucleotides, or ≥10 consecutive nucleotides, or ≥20 consecutive nucleotides, or ≥30 consecutive nucleotides, e.g., ≥40 consecutive nucleotides, such as for example ≥50 consecutive nucleotides, e.g., ≥60, ≥70, ≥80, ≥90, ≥100, ≥200, ≥300, ≥400, ≥500 or ≥600 consecutive nucleotides of the corresponding full-length nucleic acid.
The terms encompass fragments arising by any mechanism, in vivo and/or in vitro, such as, without limitation, by alternative transcription or translation, exo- and/or endo-proteolysis, exo- and/or endo-nucleolysis, or degradation of the peptide, polypeptide, protein, or nucleic acid, such as, for example, by physical, chemical and/or enzymatic proteolysis or nucleolysis. The phrase “gene or gene product signature” as intended throughout this specification refers to a set, group or collection of one or more, preferably two or more markers, such as genes or gene products, the expression status or profile of which is associated with or identifies a specific cell type, cell subtype, or cell state of a specific cell type or subtype. Such gene or gene product signatures can be used for example to indicate the presence of a specific cell type, cell subtype, or cell state of a specific cell type or subtype in a population of cells, and/or the overall cell type composition or status of an entire cell population. Such gene or gene product signatures may be indicative of cells within a population of cells in vivo. Preferably, a reference herein to a gene or gene product signature comprising or consisting of one or more genes or gene products from a discrete list of genes or gene products may denote that the genes or gene products said to be comprised by or constituting the signature are expressed in a specific cell type, cell subtype, or cell state of a specific cell type or subtype, i.e., that cells of the specific cell type, cell subtype, or cell state of the specific cell type or subtype are positive for the genes or gene products comprised by the signature.
Typically, a gene signature may comprise or consist of two or more, three or more, four or more, five or more, six or more, seven or more, eight or more, nine or more, ten or more, 15 or more, 20 or more, 25 or more, 30 or more, 35 or more, 40 or more, 45 or more, 50 or more, 60 or more, 70 or more, 80 or more, 90 or more, or 100 or more, or 200 or more, or 300 or more, or 400 or more, or 500 or more genes or gene products. Where the present specification refers to a signature as comprising or consisting of one or more genes set forth in a given Table, the signature may comprise of consist of, by means of example and without limitation, one, or two or more, three or more, four or more, five or more, six or more, seven or more, eight or more, nine or more, ten or more, 15 or more, 20 or more, 25 or more, 30 or more, 35 or more, 40 or more, 45 or more, 50 or more, 60 or more, 70 or more, 80 or more, 90 or more, or 100 or more (provided that the recited number does not exceed the number of genes or gene products listed in the Table) or substantially all or all genes or gene products as set forth in the Table. In certain embodiments, the signature may comprise or consist of at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90%, or at least 95%, e.g., 96%, 97%, 98%, 99%, or up to 100% (by number) of the genes or gene products set forth in the Table (rounded up or down as conventional to the closest integer).
As used herein a signature may encompass any gene or genes, or protein or proteins, whose expression profile or whose occurrence is associated with a specific cell type, subtype, or cell state of a specific cell type or subtype within a population of cells. Increased or decreased expression or activity or prevalence may be compared between different cells in order to characterize or identify for instance specific cell (sub)populations. A gene signature as used herein, may thus refer to any set of up- and down-regulated genes between different cells or cell (sub)populations derived from a gene-expression profile. For example, a gene signature may comprise a list of genes differentially expressed in a distinction of interest. It is to be understood that also when referring to proteins (e.g. differentially expressed proteins), such may fall within the definition of “gene” signature.
The signatures as defined herein (be it a gene signature, protein signature or other genetic signature) can be used to indicate the presence of a cell type, a subtype of the cell type, the state of the microenvironment of a population of cells, a particular cell type population or subpopulation, and/or the overall status of the entire cell (sub)population. Furthermore, the signature may be indicative of cells within a population of cells in vivo. The signature may also be used to suggest for instance particular therapies, or to follow up treatment, or to suggest ways to further modulate intestinal epithelial cells. The signatures of the present invention may be discovered by analysis of expression profiles of single-cells within a population of cells from isolated samples (e.g. biopsy), thus allowing the discovery of novel cell subtypes or cell states that were previously invisible or unrecognized.
The presence of subtypes or cell states may be determined by subtype specific or cell state specific signatures. The presence of these specific cell (sub)types or cell states may be determined by applying the signature genes to bulk sequencing data in a sample. Not being bound by a theory, a combination of cell subtypes having a particular signature may indicate an outcome. Not being bound by a theory, the signatures can be used to deconvolute the network of cells present in a particular pathological condition. Not being bound by a theory the presence of specific cells and cell subtypes are indicative of a particular response to treatment, such as including increased or decreased susceptibility to treatment. The signature may indicate the presence of one particular cell type. In one embodiment, the novel signatures are used to detect multiple cell states or hierarchies that occur in subpopulations of cells that are linked to particular pathological condition (e.g. cancer), or linked to a particular outcome or progression of the disease, or linked to a particular response to treatment of the disease.
The signature according to certain embodiments of the present invention may comprise or consist of one or more genes and/or proteins, such as for instance 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more. In certain embodiments, the signature may comprise or consist of two or more genes and/or proteins, such as for instance 2, 3, 4, 5, 6, 7, 8, 9, 10 or more. In certain embodiments, the signature may comprise or consist of three or more genes and/or proteins, such as for instance 3, 4, 5, 6, 7, 8, 9, 10 or more. In certain embodiments, the signature may comprise or consist of four or more genes and/or proteins, such as for instance 4, 5, 6, 7, 8, 9, 10 or more. In certain embodiments, the signature may comprise or consist of five or more genes and/or proteins, such as for instance 5, 6, 7, 8, 9, 10 or more. In certain embodiments, the signature may comprise or consist of six or more genes and/or proteins, such as for instance 6, 7, 8, 9, 10 or more. In certain embodiments, the signature may comprise or consist of seven or more genes and/or proteins, such as for instance 7, 8, 9, 10 or more. In certain embodiments, the signature may comprise or consist of eight or more genes and/or proteins, such as for instance 8, 9, 10 or more. In certain embodiments, the signature may comprise or consist of nine or more genes and/or proteins, such as for instance 9, 10 or more. In certain embodiments, the signature may comprise or consist of ten or more genes and/or proteins, such as for instance 10, 11, 12, 13, 14, 15, or more. It is to be understood that a signature according to the invention may for instance also include a combination of genes or proteins.
It is to be understood that “differentially expressed” genes/proteins include genes/proteins which are up- or down-regulated as well as genes/proteins which are turned on or off. When referring to up- or down-regulation, in certain embodiments, such up- or down-regulation is preferably at least two-fold, such as two-fold, three-fold, four-fold, five-fold, or more, such as for instance at least ten-fold, at least 20-fold, at least 30-fold, at least 40-fold, at least 50-fold, or more. Alternatively, or in addition, differential expression may be determined based on common statistical tests, as is known in the art.
As discussed herein, differentially expressed genes/proteins may be differentially expressed on a single cell level, or may be differentially expressed on a cell population level. Preferably, the differentially expressed genes/proteins as discussed herein, such as constituting the gene signatures as discussed herein, when as to the cell population level, refer to genes that are differentially expressed in all or substantially all cells of the population (such as at least 80%, preferably at least 90%, such as at least 95% of the individual cells). This allows one to define a particular subpopulation of cells. As referred to herein, a “subpopulation” of cells preferably refers to a particular subset of cells of a particular cell type which can be distinguished or are uniquely identifiable and set apart from other cells of this cell type. The cell subpopulation may be phenotypically characterized, and is preferably characterized by the signature as discussed herein. A cell (sub)population as referred to herein may constitute of a (sub)population of cells of a particular cell type characterized by a specific cell state.
When referring to induction, or alternatively suppression of a particular signature, preferable is meant induction or alternatively suppression (or upregulation or downregulation) of at least one gene/protein of the signature, such as for instance at least to, at least three, at least four, at least five, at least six, or all genes/proteins of the signature.
Signatures may be functionally validated as being uniquely associated with a particular phenotype of an intestinal epithelial cell, intestinal epithelial stem cell, or intestinal immune cell. Induction or suppression of a particular signature may consequentially be associated with or causally drive a particular phenotype.
Various aspects and embodiments of the invention may involve analyzing gene signature(s), protein signature(s), and/or other genetic signature(s) based on single cell analyses (e.g. single cell RNA sequencing) or alternatively based on cell population analyses, as is defined herein elsewhere.
As used herein the term “signature gene” means any gene or genes whose expression profile is associated with a specific cell type, subtype, or cell state of a specific cell type or subtype within a population of cells. The signature gene can be used to indicate the presence of a cell type, a subtype of the cell type, the state of the microenvironment of a population of cells, and/or the overall status of the entire cell population. Furthermore, the signature genes may be indicative of cells within a population of cells in vivo. Not being bound by a theory, the signature genes can be used to deconvolute the cells present in a tumor based on comparing them to data from bulk analysis of a tumor sample. The signature gene may indicate the presence of one particular cell type.
Markers as taught herein or genes or gene products comprised by or constituting gene or gene product signatures as taught herein, or the gene or gene product signatures as taught herein, may display AUC (area under the receiver-operating curve (ROC) as well-established in the art) value of 0.70 or more, e.g., 0.75 or more, preferably 0.80 or more, more preferably 0.85 or more, even more preferably 0.90 or more, and still more preferably 0.95 or more, e.g., 0.96, 0.97, 0.98, 0.99, or 1.00. An AUC value of 1 implies that the marker, gene, gene product or signature is a perfect classifier for a given outcome (e.g., a cell type or cluster). An AUC value of 0.50 implies no predictive value for the outcome.
A marker, for example a gene or gene product, for example a peptide, polypeptide, protein, or nucleic acid, or a group of two or more markers, is “measured” in a tested object (e.g., in or on a cell, cell population, tissue, organ, or organism, e.g., in a biological sample of a subject) when the presence or absence and/or quantity of the marker or the group of markers is detected or determined in the tested object, preferably substantially to the exclusion of other molecules and analytes, e.g., other genes or gene products.
Depending on factors that can be evaluated and decided on by a skilled person, such as inter alia the type of a marker (e.g., peptide, polypeptide, protein, or nucleic acid), the type of the tested object (e.g., a cell, cell population, tissue, organ, or organism, e.g., the type of biological sample of a subject, e.g., whole blood, plasma, serum, tissue biopsy), the expected abundance of the marker in the tested object, the type, robustness, sensitivity and/or specificity of the detection method used to detect the marker, etc., the marker may be measured directly in the tested object, or the tested object may be subjected to one or more processing steps aimed at achieving an adequate measurement of the marker.
The terms “quantity”, “amount” and “level” are synonymous and generally well-understood in the art. The terms as used throughout this specification may particularly refer to an absolute quantification of a marker in a tested object (e.g., in or on a cell, cell population, tissue, organ, or organism, e.g., in a biological sample of a subject), or to a relative quantification of a marker in a tested object, i.e., relative to another value such as relative to a reference value, or to a range of values indicating a base-line of the marker. Such values or ranges may be obtained as conventionally known.
An absolute quantity of a marker may be advantageously expressed as weight or as molar amount, or more commonly as a concentration, e.g., weight per volume or mol per volume. A relative quantity of a marker may be advantageously expressed as an increase or decrease or as a fold-increase or fold-decrease relative to another value, such as relative to a reference value. Performing a relative comparison between first and second variables (e.g., first and second quantities) may but need not require determining first the absolute values of the first and second variables. For example, a measurement method may produce quantifiable readouts (such as, e.g., signal intensities) for the first and second variables, wherein the readouts are a function of the value of the variables, and wherein the readouts may be directly compared to produce a relative value for the first variable vs. the second variable, without the actual need to first convert the readouts to absolute values of the respective variables.
Where a marker is detected in or on a cell, the cell may be conventionally denoted as positive (+) or negative (−) for the marker. Semi-quantitative denotations of marker expression in cells are also commonplace in the art, such as particularly in flow cytometry quantifications, for example, “dim” vs. “bright”, or “low” vs. “medium”/“intermediate” vs. “high”, or “−” vs. “+” vs. “++”, commonly controlled in flow cytometry quantifications by setting of the gates. Where a marker is quantified in or on a cell, absolute quantity of the marker may also be expressed for example as the number of molecules of the marker comprised by the cell.
Where a marker is detected and/or quantified on a single cell level in a cell population, the quantity of the marker may also be expressed for example as a percentage or fraction (by number) of cells comprised in the population that are positive for the marker, or as percentages or fractions (by number) of cells comprised in the population that are “dim” or “bright”, or that are “low” or “medium”/“intermediate” or “high”, or that are “−” or “+” or “++”. By means of an example, a sizeable proportion of the tested cells of the cell population may be positive for the marker, e.g., at least about 20%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%, or up to 100%.
Any existing, available or conventional separation, detection and/or quantification methods may be used to measure the presence or absence (e.g., readout being present vs. absent; or detectable amount vs. undetectable amount) and/or quantity (e.g., readout being an absolute or relative quantity) of markers in a tested object (e.g., in or on a cell, cell population, tissue, organ, or organism, e.g., in a biological sample of a subject).
In certain examples, such methods may include biochemical assay methods, including inter alia assays of enzymatic activity, membrane channel activity, substance-binding activity, gene regulatory activity, or cell signalling activity of a marker, e.g., peptide, polypeptide, protein, or nucleic acid.
In other examples, such methods may include immunological assay methods, wherein the ability of an assay to separate, detect and/or quantify a marker (such as, preferably, peptide, polypeptide, or protein) is conferred by specific binding between a separable, detectable and/or quantifiable immunological binding agent (antibody) and the marker. Immunological assay methods include without limitation immunohistochemistry, immunocytochemistry, flow cytometry, mass cytometry, fluorescence activated cell sorting (FACS), fluorescence microscopy, fluorescence based cell sorting using microfluidic systems, immunoaffinity adsorption based techniques such as affinity chromatography, magnetic particle separation, magnetic activated cell sorting or bead based cell sorting using microfluidic systems, enzyme-linked immunosorbent assay (ELISA) and ELISPOT based techniques, radioimmunoassay (RIA), Western blot, etc.
In further examples, such methods may include mass spectrometry analysis methods. Generally, any mass spectrometric (MS) techniques that are capable of obtaining precise information on the mass of peptides, and preferably also on fragmentation and/or (partial) amino acid sequence of selected peptides (e.g., in tandem mass spectrometry, MS/MS; or in post source decay, TOF MS), may be useful herein for separation, detection and/or quantification of markers (such as, preferably, peptides, polypeptides, or proteins). Suitable peptide MS and MS/MS techniques and systems are well-known per se (see, e.g., Methods in Molecular Biology, vol. 146: “Mass Spectrometry of Proteins and Peptides”, by Chapman, ed., Humana Press 2000, ISBN 089603609x; Biemann 1990. Methods Enzymol 193: 455-79; or Methods in Enzymology, vol. 402: “Biological Mass Spectrometry”, by Burlingame, ed., Academic Press 2005, ISBN 9780121828073) and may be used herein. MS arrangements, instruments and systems suitable for biomarker peptide analysis may include, without limitation, matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) MS; MALDI-TOF post-source-decay (PSD); MALDI-TOF/TOF; surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF) MS; electrospray ionization mass spectrometry (ESI-MS); ESI-MS/MS; ESI-MS/(MS)n (n is an integer greater than zero); ESI 3D or linear (2D) ion trap MS; ESI triple quadrupole MS; ESI quadrupole orthogonal TOF (Q-TOF); ESI Fourier transform MS systems; desorption/ionization on silicon (DIOS); secondary ion mass spectrometry (SIMS); atmospheric pressure chemical ionization mass spectrometry (APCI-MS); APCI-MS/MS; APCI-(MS)n; atmospheric pressure photoionization mass spectrometry (APPI-MS); APPI-MS/MS; and APPI-(MS)n. Peptide ion fragmentation in tandem MS (MS/MS) arrangements may be achieved using manners established in the art, such as, e.g., collision induced dissociation (CID). Detection and quantification of markers by mass spectrometry may involve multiple reaction monitoring (MRM), such as described among others by Kuhn et al. 2004 (Proteomics 4: 1175-86). MS peptide analysis methods may be advantageously combined with upstream peptide or protein separation or fractionation methods, such as for example with the chromatographic and other methods.
In other examples, such methods may include chromatography methods. The term “chromatography” encompasses methods for separating substances, such as chemical or biological substances, e.g., markers, such as preferably peptides, polypeptides, or proteins, referred to as such and vastly available in the art. In a preferred approach, chromatography refers to a process in which a mixture of substances (analytes) carried by a moving stream of liquid or gas (“mobile phase”) is separated into components as a result of differential distribution of the analytes, as they flow around or over a stationary liquid or solid phase (“stationary phase”), between the mobile phase and the stationary phase. The stationary phase may be usually a finely divided solid, a sheet of filter material, or a thin film of a liquid on the surface of a solid, or the like. Chromatography is also widely applicable for the separation of chemical compounds of biological origin, such as, e.g., amino acids, proteins, fragments of proteins or peptides, etc.
Chromatography may be preferably columnar (i.e., wherein the stationary phase is deposited or packed in a column), preferably liquid chromatography, and yet more preferably HPLC. While particulars of chromatography are well known in the art, for further guidance see, e.g., Meyer M., 1998, ISBN: 047198373X, and “Practical HPLC Methodology and Applications”, Bidlingmeyer, B. A., John Wiley & Sons Inc., 1993. Exemplary types of chromatography include, without limitation, high-performance liquid chromatography (HPLC), normal phase HPLC (NP-HPLC), reversed phase HPLC (RP-HPLC), ion exchange chromatography (IEC), such as cation or anion exchange chromatography, hydrophilic interaction chromatography (HILIC), hydrophobic interaction chromatography (HIC), size exclusion chromatography (SEC) including gel filtration chromatography or gel permeation chromatography, chromatofocusing, affinity chromatography such as immunoaffinity, immobilised metal affinity chromatography, and the like.
Further techniques for separating, detecting and/or quantifying markers, such as preferably peptides, polypeptides, or proteins, may be used, optionally in conjunction with any of the above described analysis methods. Such methods include, without limitation, chemical extraction partitioning, isoelectric focusing (IEF) including capillary isoelectric focusing (CIEF), capillary isotachophoresis (CITP), capillary electrochromatography (CEC), and the like, one-dimensional polyacrylamide gel electrophoresis (PAGE), two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), capillary gel electrophoresis (CGE), capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), free flow electrophoresis (FFE), etc.
In certain examples, such methods may include separating, detecting and/or quantifying markers at the nucleic acid level, more particularly RNA level, e.g., at the level of hnRNA, pre-mRNA, mRNA, or cDNA. Standard quantitative RNA or cDNA measurement tools known in the art may be used. Non-limiting examples include hybridisation-based analysis, microarray expression analysis, digital gene expression profiling (DGE), RNA-in-situ hybridisation (RISH), Northern-blot analysis and the like; PCR, RT-PCR, RT-qPCR, end-point PCR, digital PCR or the like; supported oligonucleotide detection, pyrosequencing, polony cyclic sequencing by synthesis, simultaneous bi-directional sequencing, single-molecule sequencing, single molecule real time sequencing, true single molecule sequencing, hybridization-assisted nanopore sequencing, sequencing by synthesis, single-cell RNA sequencing (sc-RNA seq), or the like. By means of an example, methods to profile the RNA content of large numbers of individual cells have been recently developed. To do so, special microfluidic devices have been developed to encapsulate each cell in an individual drop, associate the RNA of each cell with a ‘cell barcode’ unique to that cell/drop, measure the expression level of each RNA with sequencing, and then use the cell barcodes to determine which cell each RNA molecule came from. In particular, methods of Macosko et al. (Cell. 2015, vol. 161, 1202-1214) and Klein et al. (Cell. 2015, vol. 161, 1187-1201) are contemplated for the present invention.
In further examples, any combinations of methods such as discussed herein may be employed.
A further aspect of the invention thus relates to a method for detecting or quantifying intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells in a biological sample of a subject, or for isolating such cells from a biological sample of a subject, the method comprising: a) providing a biological sample of a subject; and b) detecting or quantifying in the biological sample intestinal epithelial cells, intestinal epithelial stem cells, or preferably intestinal epithelial cells as disclosed herein, or isolating from the biological sample such cells as disclosed herein.
The terms “subject”, “individual” or “patient” are used interchangeably throughout this specification, and typically and preferably denote humans, but may also encompass reference to non-human animals, preferably warm-blooded animals, even more preferably mammals, such as, e.g., non-human primates, rodents, canines, felines, equines, ovines, porcines, and the like. The term “non-human animals” includes all vertebrates, e.g., mammals, such as non-human primates, (particularly higher primates), sheep, dog, rodent (e.g. mouse or rat), guinea pig, goat, pig, cat, rabbits, cows, and non-mammals such as chickens, amphibians, reptiles etc. In one embodiment, the subject is a non-human mammal. In another embodiment, the subject is human. In another embodiment, the subject is an experimental animal or animal substitute as a disease model. The term does not denote a particular age or sex. Thus, adult and newborn subjects, as well as fetuses, whether male or female, are intended to be covered. Examples of subjects include humans, dogs, cats, cows, goats, and mice. The term subject is further intended to include transgenic species.
The terms “sample” or “biological sample” as used throughout this specification include any biological specimen obtained from a subject. Particularly preferred are samples from the intestinal tissue, but may also include samples from intestinal lumen, faeces, or blood. The term “tissue” as used throughout this specification refers to any animal tissue types, but particularly preferred is intestinal tissue. The tissue may be healthy or affected by pathological alterations. The tissue may be from a living subject or may be cadaveric tissue. The tissue may be autologous tissue or syngeneic tissue or may be allograft or xenograft tissue.
The method may allow to detect or conclude the presence or absence of the specified intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) in a tested object (e.g., in a cell population, tissue, organ, organism, or in a biological sample of a subject). The method may also allow to quantify the specified intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) in a tested object (e.g., in a cell population, tissue, organ, organism, or in a biological sample of a subject). The quantity of the specified cells in the tested object such as the biological sample may be suitably expressed for example as the number (count) of the specified cells per standard unit of volume (e.g., ml, μl or nl) or weight (e.g., g or mg or ng) of the tested object such as the biological sample or may also be suitably expressed as a percentage or fraction (by number) of all cells comprised in the tested object such as the biological sample, or as a percentage or fraction (by number) of a select subset of the cells comprised in the tested object such as the biological sample, e.g., as a percentage or fraction (by number) intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells), and of different (sub) types comprised in the tested object such as the biological sample. The quantity of the specified cells in the tested object such as the biological sample may also be suitably represented by an absolute or relative quantity of a suitable surrogate analyte, such as a peptide, polypeptide, protein, or nucleic acid expressed or comprised by the specified cells.
The method may allow to isolate or purify the specified intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) from the tested object such as the biological sample. The terms “isolating” or “purifying” as used throughout this specification with reference to a particular component of a composition or mixture (e.g., the tested object such as the biological sample) encompass processes or techniques whereby such component is separated from one or more or (substantially) all other components of the composition or mixture (e.g., the tested object such as the biological sample). The terms do not require absolute purity. Instead, isolating or purifying the component will produce a discrete environment in which the abundance of the component relative to one or more or all other components is greater than in the starting composition or mixture (e.g., the tested object such as the biological sample). A discrete environment may denote a single medium, such as for example a single solution, dispersion, gel, precipitate, etc.
Isolating or purifying the specified intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells from the tested object such as the biological sample may increase the abundance of the specified cells relative to all other cells comprised in the tested object such as the biological sample, or relative to other cells of a select subset of the cells comprised in the tested object such as the biological sample.
By means of example, isolating or purifying the specified cells from the tested object such as the biological sample may yield a cell population, in which the specified cells constitute at least 40% (by number) of all cells of the cell population, for example, at least 45%, preferably at least 50%, at least 55%, more preferably at least 60%, at least 65%, still more preferably at least 70%, at least 75%, even more preferably at least 80%, at least 85%, and yet more preferably at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100% of all cells of the cell population.
The intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) disclosed herein are generally described or characterised with reference to certain marker(s) or combination(s) of markers (such as genes or gene products, e.g., peptides, polypeptides, proteins, or nucleic acids) expressed or not expressed by the cells, or with reference to certain gene or gene product signature(s) comprised by the cells. Accordingly, the present methods for detecting, quantifying or isolating the specified cells may be marker-based or gene or gene product signature-based, i.e., may involve detection, quantification or isolation of cells expressing or not expressing marker(s) or combination(s) of markers the expression or lack of expression of which is taught herein as typifying or characterising the specified cells, or may involve detection, quantification or isolation of cells comprising gene or gene product signature(s) taught herein as typifying or characterising the specified cells.
Any existing, available or conventional separation, detection and/or quantification methods may be used to measure the presence or absence (e.g., readout being present vs. absent; or detectable amount vs. undetectable amount) and/or quantity (e.g., readout being an absolute or relative quantity) of the specified intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) in, or to isolate the specified cells from, a tested object (e.g., a cell population, tissue, organ, organism, or a biological sample of a subject). Such methods allow to detect, quantify or isolate the specified cells in or from the tested object (e.g., a cell population, tissue, organ, organism, or a biological sample of a subject) substantially to the exclusion of other cells comprised in the tested object.
Such methods may allow to detect, quantify or isolate the specified cells with sensitivity of at least 50%, at least 55%, at least 60%, at least 65%, preferably at least 70%, at least 75%, more preferably at least 80%, at least 85%, even more preferably at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100%, and/or with specificity of at least 50%, at least 55%, at least 60%, at least 65%, preferably at least 70%, at least 75%, more preferably at least 80%, at least 85%, even more preferably at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100%. By means of example, at least 40% (by number), for example at least 45%, preferably at least 50%, at least 55%, more preferably at least 60%, at least 65%, still more preferably at least 70%, at least 75%, even more preferably at least 80%, at least 85%, and yet more preferably at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100% of all cells detected, quantified or isolated by such methods may correspond to the specified cells.
In certain embodiments, methods for detecting, quantifying or isolating the specified cells may comprise treatment(s) or step(s) which diminish or eliminate the viability of the cells. For example, methods which comprise measuring intracellular marker(s) typically necessitate permeabilisation of the cell membrane and possibly fixation of the cells; and methods which comprise measuring nucleic acid marker(s) may typically necessitate obtaining nucleic acids (such as particularly RNA, more particularly mRNA) from the cells. In certain other embodiments, methods for detecting, quantifying or isolating the specified cells may substantially preserve the viability of the cells. For example, methods which comprise measuring extracellular or cell surface marker(s) need not disturb the integrity of the cell membrane and may not require fixation/permeabilisation of the cells. By means of an example, methods for detecting, quantifying or isolating the specified cells may be configured such that at least 40% (by number), for example, at least 45%, preferably at least 50%, at least 55%, more preferably at least 60%, at least 65%, still more preferably at least 70%, at least 75%, even more preferably at least 80%, at least 85%, and yet more preferably at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100% of the detected, quantified or isolated cells remain viable. The term “viable cells” as used throughout this specification refers to cells that can be qualified as viable by tests and assays known per se. For instance, the viability of cells may be measured using conventional dye exclusion assays, such as Trypan Blue exclusion assay or propidium iodide exclusion assay. In such assays, viable cells exclude the dye and hence remain unstained, while non-viable cells take up the dye and are stained. The cells and their uptake of the dye can be visualised and revealed by suitable techniques (e.g., conventional light microscopy, fluorescence microscopy, or flow cytometry), and viable (unstained) and non-viable (stained) cells in the tested sample can be counted.
In certain embodiments, methods for detecting, quantifying or isolating the specified intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) may be single-cell-based, i.e., may allow to discretely detect, quantify or isolate the specified cells as individual cells. In other embodiments, methods for detecting, quantifying or isolating the specified cells may be cell population-based, i.e., may only allow to detect, quantify or isolate the specified cells as a group or collection of cells, without providing information on or allowing to isolate individual cells.
Methods for detecting, quantifying or isolating the specified intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) may employ any of the above-described techniques for measuring markers, insofar the separation or the qualitative and/or quantitative measurement of the marker(s) can be correlated with or translated into detection, quantification or isolation of the specified cells. For example, any of the above-described biochemical assay methods, immunological assay methods, mass spectrometry analysis methods, chromatography methods, or nucleic acid analysis method, or combinations thereof for measuring markers, may be employed for detecting, quantifying or isolating the specified cells.
In certain embodiments, the intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) are detected, quantified or isolated using a technique selected from the group consisting of flow cytometry, fluorescence activated cell sorting, mass cytometry, fluorescence microscopy, affinity separation, magnetic cell separation, microfluidic separation, and combinations thereof.
Flow cytometry encompasses methods by which individual cells of a cell population are analysed by their optical properties (e.g., light absorbance, light scattering and fluorescence properties, etc.) as they pass in a narrow stream in single file through a laser beam. Flow cytometry methods include fluorescence activated cell sorting (FACS) methods by which a population of cells having particular optical properties are separated from other cells.
Elemental mass spectrometry-based flow cytometry, or mass cytometry, offers an approach to analyse cells by replacing fluorochrome-labelled binding reagents with mass tagged binding reagents, i.e., tagged with an element or isotope having a defined mass. In these methods, labelled particles are introduced into a mass cytometer, where they are individually atomised and ionised. The individual particles are then subjected to elemental analysis, which identifies and measures the abundance of the mass tags used. The identities and the amounts of the isotopic elements associated with each particle are then stored and analysed. Due to the resolution of elemental analysis and the number of elemental isotopes that can be used, it is possible to simultaneously measure up to 100 or more parameters on a single particle.
Fluorescence microscopy broadly encompasses methods by which individual cells of a cell population are microscopically analysed by their fluorescence properties. Fluorescence microscopy approaches may be manual or preferably automated.
Affinity separation also referred to as affinity chromatography broadly encompasses techniques involving specific interactions of cells present in a mobile phase, such as a suitable liquid phase (e.g., cell population in an aqueous suspension) with, and thereby adsorption of the cells to, a stationary phase, such as a suitable solid phase; followed by separation of the stationary phase from the remainder of the mobile phase; and recovery (e.g., elution) of the adsorbed cells from the stationary phase. Affinity separation may be columnar, or alternatively, may entail batch treatment, wherein the stationary phase is collected/separated from the liquid phases by suitable techniques, such as centrifugation or application of magnetic field (e.g., where the stationary phase comprises magnetic substrate, such as magnetic particles or beads). Accordingly, magnetic cell separation is also envisaged herein.
Microfluidic systems allow for accurate and high throughput cell detection, quantification and/or sorting, exploiting a variety of physical principles. Cell sorting on microchips provides numerous advantages by reducing the size of necessary equipment, eliminating potentially biohazardous aerosols, and simplifying the complex protocols commonly associated with cell sorting. The term “microfluidic system” as used throughout this specification broadly refers to systems having one or more fluid microchannels. Microchannels denote fluid channels having cross-sectional dimensions the largest of which are typically less than 1 mm, preferably less than 500 μm, more preferably less than 400 μm, more preferably less than 300 μm, more preferably less than 200 μm, e.g., 100 μm or smaller. Such microfluidic systems can be used for manipulating fluid and/or objects such as droplets, bubbles, capsules, particles, cells and the like. Microfluidic systems may allow for example for fluorescent label-based (e.g., employing fluorophore-conjugated binding agent(s), such as fluorophore-conjugated antibody(ies)), bead-based (e.g., bead-conjugated binding agent(s), such as bead-conjugated antibody(ies)), or label-free cell sorting (reviewed in Shields et al., Lab Chip. 2015, vol. 15: 1230-1249).
In certain embodiments, the aforementioned methods and techniques may employ agent(s) capable of specifically binding to one or more gene products, e.g., peptides, polypeptides, proteins, or nucleic acids, expressed or not expressed by the intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) as taught herein. In certain preferred embodiments, such one or more gene products, e.g., peptides, polypeptides, or proteins, may be expressed on the cell surface (i.e., cell surface markers, e.g., transmembrane peptides, polypeptides or proteins, or secreted peptides, polypeptides or proteins which remain associated with the cell surface). Hence, further disclosed are binding agents capable of specifically binding to markers, such as genes or gene products, e.g., peptides, polypeptides, proteins, or nucleic acids as taught herein. Binding agents as intended throughout this specification may include inter alia antibodies, aptamers, spiegelmers (L-aptamers), photoaptamers, protein, peptides, peptidomimetics, nucleic acids such as oligonucleotides (e.g., hybridisation probes or amplification or sequencing primers and primer pairs), small molecules, or combinations thereof.
Binding agents may be in various forms, e.g., lyophilised, free in solution, or immobilised on a solid phase. They may be, e.g., provided in a multi-well plate or as an array or microarray, or they may be packaged separately, individually, or in combination.
The term “specifically bind” as used throughout this specification means that an agent (denoted herein also as “specific-binding agent”) binds to one or more desired molecules or analytes (e.g., peptides, polypeptides, proteins, or nucleic acids) substantially to the exclusion of other molecules which are random or unrelated, and optionally substantially to the exclusion of other molecules that are structurally related. The term “specifically bind” does not necessarily require that an agent binds exclusively to its intended target(s). For example, an agent may be said to specifically bind to target(s) of interest if its affinity for such intended target(s) under the conditions of binding is at least about 2-fold greater, preferably at least about 5-fold greater, more preferably at least about 10-fold greater, yet more preferably at least about 25-fold greater, still more preferably at least about 50-fold greater, and even more preferably at least about 100-fold, or at least about 1000-fold, or at least about 104-fold, or at least about 105-fold, or at least about 106-fold or more greater, than its affinity for a non-target molecule, such as for a suitable control molecule (e.g., bovine serum albumin, casein).
Preferably, the specific binding agent may bind to its intended target(s) with affinity constant (KA) of such binding KA≥1×106 M−1, more preferably KA≥1×107 M−1, yet more preferably KA≥1×108 M−1, even more preferably KA≥1×109 M−1, and still more preferably KA≥1×1010 M−1 or KA≥1×1011 M−1 or KA≥1×1012 M−1, wherein KA=[SBA_T]/[SBA][T], SBA denotes the specific-binding agent, T denotes the intended target. Determination of KA can be carried out by methods known in the art, such as for example, using equilibrium dialysis and Scatchard plot analysis.
As used herein, the term “antibody” is used in its broadest sense and generally refers to any immunologic binding agent. The term specifically encompasses intact monoclonal antibodies, polyclonal antibodies, multivalent (e.g., 2-, 3- or more-valent) and/or multi-specific antibodies (e.g., bi- or more-specific antibodies) formed from at least two intact antibodies, and antibody fragments insofar they exhibit the desired biological activity (particularly, ability to specifically bind an antigen of interest, i.e., antigen-binding fragments), as well as multivalent and/or multi-specific composites of such fragments. The term “antibody” is not only inclusive of antibodies generated by methods comprising immunisation, but also includes any polypeptide, e.g., a recombinantly expressed polypeptide, which is made to encompass at least one complementarity-determining region (CDR) capable of specifically binding to an epitope on an antigen of interest. Hence, the term applies to such molecules regardless whether they are produced in vitro or in vivo.
An antibody may be any of IgA, IgD, IgE, IgG and IgM classes, and preferably IgG class antibody. An antibody may be a polyclonal antibody, e.g., an antiserum or immunoglobulins purified there from (e.g., affinity-purified). An antibody may be a monoclonal antibody or a mixture of monoclonal antibodies. Monoclonal antibodies can target a particular antigen or a particular epitope within an antigen with greater selectivity and reproducibility. By means of example and not limitation, monoclonal antibodies may be made by the hybridoma method first described by Kohler et al. 1975 (Nature 256: 495), or may be made by recombinant DNA methods (e.g., as in U.S. Pat. No. 4,816,567). Monoclonal antibodies may also be isolated from phage antibody libraries using techniques as described by Clackson et al. 1991 (Nature 352: 624-628) and Marks et al. 1991 (J Mol Biol 222: 581-597), for example.
Antibody binding agents may be antibody fragments. “Antibody fragments” comprise a portion of an intact antibody, comprising the antigen-binding or variable region thereof. Examples of antibody fragments include Fab, Fab′, F(ab′)2, Fv and scFv fragments, single domain (sd) Fv, such as VH domains, VL domains and VHH domains; diabodies; linear antibodies; single-chain antibody molecules, in particular heavy-chain antibodies; and multivalent and/or multispecific antibodies formed from antibody fragment(s), e.g., dibodies, tribodies, and multibodies. The above designations Fab, Fab′, F(ab′)2, Fv, scFv etc. are intended to have their art-established meaning.
The term antibody includes antibodies originating from or comprising one or more portions derived from any animal species, preferably vertebrate species, including, e.g., birds and mammals. Without limitation, the antibodies may be chicken, turkey, goose, duck, guinea fowl, quail or pheasant. Also without limitation, the antibodies may be human, murine (e.g., mouse, rat, etc.), donkey, rabbit, goat, sheep, guinea pig, camel (e.g., Camelus bactrianus and Camelus dromaderius), llama (e.g., Lama paccos, Lama glama or Lama vicugna) or horse. An antibody can include one or more amino acid deletions, additions and/or substitutions (e.g., conservative substitutions), insofar such alterations preserve its binding of the respective antigen. An antibody may also include one or more native or artificial modifications of its constituent amino acid residues (e.g., glycosylation, etc.).
Methods of producing polyclonal and monoclonal antibodies as well as fragments thereof are well known in the art, as are methods to produce recombinant antibodies or fragments thereof (see for example, Harlow and Lane, “Antibodies: A Laboratory Manual”, Cold Spring Harbour Laboratory, New York, 1988; Harlow and Lane, “Using Antibodies: A Laboratory Manual”, Cold Spring Harbour Laboratory, New York, 1999, ISBN 0879695447; “Monoclonal Antibodies: A Manual of Techniques”, by Zola, ed., CRC Press 1987, ISBN 0849364760; “Monoclonal Antibodies: A Practical Approach”, by Dean & Shepherd, eds., Oxford University Press 2000, ISBN 0199637229; Methods in Molecular Biology, vol. 248: “Antibody Engineering: Methods and Protocols”, Lo, ed., Humana Press 2004, ISBN 1588290921).
The term “aptamer” refers to single-stranded or double-stranded oligo-DNA, oligo-RNA or oligo-DNA/RNA or any analogue thereof that specifically binds to a target molecule such as a peptide. Advantageously, aptamers display fairly high specificity and affinity (e.g., KA in the order 1×109 M−1) for their targets. Aptamer production is described inter alia in U.S. Pat. No. 5,270,163; Ellington & Szostak 1990 (Nature 346: 818-822); Tuerk & Gold 1990 (Science 249: 505-510); or “The Aptamer Handbook: Functional Oligonucleotides and Their Applications”, by Klussmann, ed., Wiley-VCH 2006, ISBN 3527310592, incorporated by reference herein. The term “photoaptamer” refers to an aptamer that contains one or more photoreactive functional groups that can covalently bind to or crosslink with a target molecule. The term “spiegelmer” refers to an aptamer which includes L-DNA, L-RNA, or other left-handed nucleotide derivatives or nucleotide-like molecules. Aptamers containing left-handed nucleotides are resistant to degradation by naturally occurring enzymes, which normally act on substrates containing right-handed nucleotides. The term “peptidomimetic” refers to a non-peptide agent that is a topological analogue of a corresponding peptide. Methods of rationally designing peptidomimetics of peptides are known in the art. For example, the rational design of three peptidomimetics based on the sulphated 8-mer peptide CCK26-33, and of two peptidomimetics based on the 11-mer peptide Substance P, and related peptidomimetic design principles, are described in Horwell 1995 (Trends Biotechnol 13: 132-134).
The term “oligonucleotide” as used throughout this specification refers to a nucleic acid (including nucleic acid analogues and mimetics) oligomer or polymer as defined herein. Preferably, an oligonucleotide, such as more particularly an antisense oligonucleotide, is (substantially) single-stranded. Oligonucleotides as intended herein may be preferably between about 10 and about 100 nucleoside units (i.e., nucleotides or nucleotide analogues) in length, preferably between about 15 and about 50, more preferably between about 20 and about 40, also preferably between about 20 and about 30. Oligonucleotides as intended herein may comprise one or more or all non-naturally occurring heterocyclic bases and/or one or more or all non-naturally occurring sugar groups and/or one or more or all non-naturally occurring inter-nucleoside linkages, the inclusion of which may improve properties such as, for example, increased stability in the presence of nucleases and increased hybridization affinity, increased tolerance for mismatches, etc. The reference to oligonucleotides may in particular but without limitation include hybridisation probes and/or amplification primers and/or sequencing primers, etc., as commonly used in nucleic acid detection technologies.
Nucleic acid binding agents, such as oligonucleotide binding agents, are typically at least partly antisense to a target nucleic acid of interest. The term “antisense” generally refers to an agent (e.g., an oligonucleotide) configured to specifically anneal with (hybridise to) a given sequence in a target nucleic acid, such as for example in a target DNA, hnRNA, pre-mRNA or mRNA, and typically comprises, consist essentially of or consist of a nucleic acid sequence that is complementary or substantially complementary to the target nucleic acid sequence. Antisense agents suitable for use herein, such as hybridisation probes or amplification or sequencing primers and primer pairs) may typically be capable of annealing with (hybridising to) the respective target nucleic acid sequences at high stringency conditions, and capable of hybridising specifically to the target under physiological conditions. The terms “complementary” or “complementarity” as used throughout this specification with reference to nucleic acids, refer to the normal binding of single-stranded nucleic acids under permissive salt (ionic strength) and temperature conditions by base pairing, preferably Watson-Crick base pairing. By means of example, complementary Watson-Crick base pairing occurs between the bases A and T, A and U or G and C. For example, the sequence 5′-A-G-U-3′ is complementary to sequence 5′-A-C-U-3′.
The term “small molecule” refers to compounds, preferably organic compounds, with a size comparable to those organic molecules generally used in pharmaceuticals. The term excludes biological macromolecules (e.g., proteins, peptides, nucleic acids, etc.). Preferred small organic molecules range in size up to about 5000 Da, e.g., up to about 4000, preferably up to 3000 Da, more preferably up to 2000 Da, even more preferably up to about 1000 Da, e.g., up to about 900, 800, 700, 600 or up to about 500 Da.
Binding agents as discussed herein may suitably comprise a detectable label. The term “label” refers to any atom, molecule, moiety or biomolecule that may be used to provide a detectable and preferably quantifiable read-out or property, and that may be attached to or made part of an entity of interest, such as a binding agent. Labels may be suitably detectable by for example mass spectrometric, spectroscopic, optical, colourimetric, magnetic, photochemical, biochemical, immunochemical or chemical means. Labels include without limitation dyes; radiolabels such as 32P, 33P, 35S, 125I, 131I; electron-dense reagents; enzymes (e.g., horse-radish peroxidase or alkaline phosphatase as commonly used in immunoassays); binding moieties such as biotin-streptavidin; haptens such as digoxigenin; luminogenic, phosphorescent or fluorogenic moieties; mass tags; and fluorescent dyes alone or in combination with moieties that may suppress or shift emission spectra by fluorescence resonance energy transfer (FRET).
In certain embodiments, the one or more binding agents may be one or more antibodies. In other embodiments, binding agents may be provided with a tag that permits detection with another agent (e.g., with a probe binding partner). Such tags may be, for example, biotin, streptavidin, his-tag, myc tag, maltose, maltose binding protein or any other kind of tag known in the art that has a binding partner. Example of associations which may be utilised in the probe:binding partner arrangement may be any, and includes, for example biotin:streptavidin, his-tag:metal ion (e.g., Ni2+), maltose:maltose binding protein, etc. In certain embodiments, the one or more binding agents are configured for use in a technique selected from the group consisting of flow cytometry, fluorescence activated cell sorting, mass cytometry, fluorescence microscopy, affinity separation, magnetic cell separation, microfluidic separation, and combinations thereof. In certain embodiments, the one or more binding agents are one or more antibodies.
A marker-binding agent conjugate may be associated with or attached to a detection agent to facilitate detection. Examples of detection agents include, but are not limited to, luminescent labels; colourimetric labels, such as dyes; fluorescent labels; or chemical labels, such as electroactive agents (e.g., ferrocyanide); enzymes; radioactive labels; or radiofrequency labels. The detection agent may be a particle. Examples of such particles include, but are not limited to, colloidal gold particles; colloidal sulphur particles; colloidal selenium particles; colloidal barium sulfate particles; colloidal iron sulfate particles; metal iodate particles; silver halide particles; silica particles; colloidal metal (hydrous) oxide particles; colloidal metal sulfide particles; colloidal lead selenide particles; colloidal cadmium selenide particles; colloidal metal phosphate particles; colloidal metal ferrite particles; any of the above-mentioned colloidal particles coated with organic or inorganic layers; protein or peptide molecules; liposomes; or organic polymer latex particles, such as polystyrene latex beads. Preferable particles may be colloidal gold particles.
The terms “kit” and “kit of parts” as used throughout this specification refer to a product containing components necessary for carrying out the specified methods (e.g., methods for detecting, quantifying or isolating intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) as taught herein), packed so as to allow their transport and storage. Materials suitable for packing the components comprised in a kit include crystal, plastic (e.g., polyethylene, polypropylene, polycarbonate), bottles, flasks, vials, ampules, paper, envelopes, or other types of containers, carriers or supports. Where a kit comprises a plurality of components, at least a subset of the components (e.g., two or more of the plurality of components) or all of the components may be physically separated, e.g., comprised in or on separate containers, carriers or supports. The components comprised in a kit may be sufficient or may not be sufficient for carrying out the specified methods, such that external reagents or substances may not be necessary or may be necessary for performing the methods, respectively.
Typically, kits and kit of parts are employed in conjunction with standard laboratory equipment, such as liquid handling equipment, environment (e.g., temperature) controlling equipment, analytical instruments, etc. In addition to the recited binding agents(s) as taught herein, such as for example, antibodies, hybridisation probes, amplification and/or sequencing primers, optionally provided on arrays or microarrays, the present kits may also include some or all of solvents, buffers (such as for example but without limitation histidine-buffers, citrate-buffers, succinate-buffers, acetate-buffers, phosphate-buffers, formate buffers, benzoate buffers, TRIS (Tris(hydroxymethyl)-aminomethan) buffers or maleate buffers, or mixtures thereof), enzymes (such as for example but without limitation thermostable DNA polymerase), detectable labels, detection reagents, and control formulations (positive and/or negative), useful in the specified methods. Typically, the kits and kit of parts may also include instructions for use thereof, such as on a printed insert or on a computer readable medium. The terms may be used interchangeably with the term “article of manufacture”, which broadly encompasses any man-made tangible structural product, when used in the present context.
In certain embodiments, the kit of parts or article of manufacture may comprise a microfluidic system.
Another aspect of the invention provides a composition, pharmaceutical composition or vaccine comprising the intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) or populations thereof as taught herein.
A “pharmaceutical composition” refers to a composition that usually contains an excipient, such as a pharmaceutically acceptable carrier that is conventional in the art and that is suitable for administration to cells or to a subject.
The term “pharmaceutically acceptable” as used throughout this specification is consistent with the art and means compatible with the other ingredients of a pharmaceutical composition and not deleterious to the recipient thereof.
As used herein, “carrier” or “excipient” includes any and all solvents, diluents, buffers (such as, e.g., neutral buffered saline or phosphate buffered saline), solubilisers, colloids, dispersion media, vehicles, fillers, chelating agents (such as, e.g., EDTA or glutathione), amino acids (such as, e.g., glycine), proteins, disintegrants, binders, lubricants, wetting agents, emulsifiers, sweeteners, colorants, flavourings, aromatisers, thickeners, agents for achieving a depot effect, coatings, antifungal agents, preservatives, stabilisers, antioxidants, tonicity controlling agents, absorption delaying agents, and the like. The use of such media and agents for pharmaceutical active components is well known in the art. Such materials should be non-toxic and should not interfere with the activity of the cells or active components.
The precise nature of the carrier or excipient or other material will depend on the route of administration. For example, the composition may be in the form of a parenterally acceptable aqueous solution, which is pyrogen-free and has suitable pH, isotonicity and stability. For general principles in medicinal formulation, the reader is referred to Cell Therapy: Stem Cell Transplantation, Gene Therapy, and Cellular Immunotherapy, by G. Morstyn & W. Sheridan eds., Cambridge University Press, 1996; and Hematopoietic Stem Cell Therapy, E. D. Ball, J. Lister & P. Law, Churchill Livingstone, 2000.
The pharmaceutical composition can be applied parenterally, rectally, orally or topically. Preferably, the pharmaceutical composition may be used for intravenous, intramuscular, subcutaneous, peritoneal, peridural, rectal, nasal, pulmonary, mucosal, or oral application. In a preferred embodiment, the pharmaceutical composition according to the invention is intended to be used as an infuse. The skilled person will understand that compositions which are to be administered orally or topically will usually not comprise cells, although it may be envisioned for oral compositions to also comprise cells, for example when gastro-intestinal tract indications are treated. Each of the cells or active components (e.g., modulants, immunomodulants, antigens) as discussed herein may be administered by the same route or may be administered by a different route. By means of example, and without limitation, cells may be administered parenterally and other active components may be administered orally.
Liquid pharmaceutical compositions may generally include a liquid carrier such as water or a pharmaceutically acceptable aqueous solution. For example, physiological saline solution, tissue or cell culture media, dextrose or other saccharide solution or glycols such as ethylene glycol, propylene glycol or polyethylene glycol may be included.
The composition may include one or more cell protective molecules, cell regenerative molecules, growth factors, anti-apoptotic factors or factors that regulate gene expression in the cells. Such substances may render the cells independent of their environment.
Such pharmaceutical compositions may contain further components ensuring the viability of the cells therein. For example, the compositions may comprise a suitable buffer system (e.g., phosphate or carbonate buffer system) to achieve desirable pH, more usually near neutral pH, and may comprise sufficient salt to ensure isoosmotic conditions for the cells to prevent osmotic stress. For example, suitable solution for these purposes may be phosphate-buffered saline (PBS), sodium chloride solution, Ringer's Injection or Lactated Ringer's Injection, as known in the art. Further, the composition may comprise a carrier protein, e.g., albumin (e.g., bovine or human albumin), which may increase the viability of the cells.
Further suitably pharmaceutically acceptable carriers or additives are well known to those skilled in the art and for instance may be selected from proteins such as collagen or gelatine, carbohydrates such as starch, polysaccharides, sugars (dextrose, glucose and sucrose), cellulose derivatives like sodium or calcium carboxymethylcellulose, hydroxypropyl cellulose or hydroxypropylmethyl cellulose, pregeletanized starches, pectin agar, carrageenan, clays, hydrophilic gums (acacia gum, guar gum, arabic gum and xanthan gum), alginic acid, alginates, hyaluronic acid, polyglycolic and polylactic acid, dextran, pectins, synthetic polymers such as water-soluble acrylic polymer or polyvinylpyrrolidone, proteoglycans, calcium phosphate and the like.
If desired, cell preparation can be administered on a support, scaffold, matrix or material to provide improved tissue regeneration. For example, the material can be a granular ceramic, or a biopolymer such as gelatine, collagen, or fibrinogen. Porous matrices can be synthesized according to standard techniques (e.g., Mikos et al., Biomaterials 14: 323, 1993; Mikos et al., Polymer 35:1068, 1994; Cook et al., J. Biomed. Mater. Res. 35:513, 1997). Such support, scaffold, matrix or material may be biodegradable or non-biodegradable. Hence, the cells may be transferred to and/or cultured on suitable substrate, such as porous or non-porous substrate, to provide for implants.
For example, cells that have proliferated, or that are being differentiated in culture dishes, can be transferred onto three-dimensional solid supports in order to cause them to multiply and/or continue the differentiation process by incubating the solid support in a liquid nutrient medium of the invention, if necessary. Cells can be transferred onto a three-dimensional solid support, e.g. by impregnating the support with a liquid suspension containing the cells. The impregnated supports obtained in this way can be implanted in a human subject. Such impregnated supports can also be re-cultured by immersing them in a liquid culture medium, prior to being finally implanted. The three-dimensional solid support needs to be biocompatible so as to enable it to be implanted in a human. It may be biodegradable or non-biodegradable.
The cells or cell populations can be administered in a manner that permits them to survive, grow, propagate and/or differentiate towards desired cell types (e.g. differentiation) or cell states. The cells or cell populations may be grafted to or may migrate to and engraft within the intended organ.
In certain embodiments, a pharmaceutical cell preparation as taught herein may be administered in a form of liquid composition. In embodiments, the cells or pharmaceutical composition comprising such can be administered systemically, topically, within an organ or at a site of organ dysfunction or lesion.
Preferably, the pharmaceutical compositions may comprise a therapeutically effective amount of the specified intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) and/or other active components. The term “therapeutically effective amount” refers to an amount which can elicit a biological or medicinal response in a tissue, system, animal or human that is being sought by a researcher, veterinarian, medical doctor or other clinician, and in particular can prevent or alleviate one or more of the local or systemic symptoms or features of a disease or condition being treated.
A further aspect of the invention provides a population of the intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) as taught herein. The terms “cell population” or “population” denote a set of cells having characteristics in common. The characteristics may include in particular the one or more marker(s) or gene or gene product signature(s) as taught herein. The intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) cells as taught herein may be comprised in a cell population. By means of example, the specified cells may constitute at least 40% (by number) of all cells of the cell population, for example, at least 45%, preferably at least 50%, at least 55%, more preferably at least 60%, at least 65%, still more preferably at least 70%, at least 75%, even more preferably at least 80%, at least 85%, and yet more preferably at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or even 100% of all cells of the cell population.
The isolated intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) of populations thereof as disclosed throughout this specification may be suitably cultured or cultivated in vitro. The term “in vitro” generally denotes outside, or external to, a body, e.g., an animal or human body. The term encompasses “ex vivo”. The terms “culturing” or “cell culture” are common in the art and broadly refer to maintenance of cells and potentially expansion (proliferation, propagation) of cells in vitro. Typically, animal cells, such as mammalian cells, such as human cells, are cultured by exposing them to (i.e., contacting them with) a suitable cell culture medium in a vessel or container adequate for the purpose (e.g., a 96-, 24-, or 6-well plate, a T-25, T-75, T-150 or T-225 flask, or a cell factory), at art-known conditions conducive to in vitro cell culture, such as temperature of 37° C., 5% v/v CO2 and >95% humidity.
The term “medium” as used herein broadly encompasses any cell culture medium conducive to maintenance of cells, preferably conducive to proliferation of cells. Typically, the medium will be a liquid culture medium, which facilitates easy manipulation (e.g., decantation, pipetting, centrifugation, filtration, and such) thereof.
Within the present specification, the terms “differentiation”, “differentiating” or derivatives thereof, denote the process by which an unspecialised or relatively less specialised cell becomes relatively more specialised. In the context of cell ontogeny, the adjective “differentiated” is a relative term. Hence, a “differentiated cell” is a cell that has progressed further down a certain developmental pathway than the cell it is being compared with. The differentiated cell may, for example, be a terminally differentiated cell, i.e., a fully specialised cell capable of taking up specialised functions in various tissues or organs of an organism, which may but need not be post-mitotic; or the differentiated cell may itself be a progenitor cell within a particular differentiation lineage which can further proliferate and/or differentiate.
A relatively more specialised cell may differ from an unspecialised or relatively less specialised cell in one or more demonstrable phenotypic characteristics, such as, for example, the presence, absence or level of expression of particular cellular components or products, e.g., RNA, proteins or other substances, activity of certain biochemical pathways, morphological appearance, proliferation capacity and/or kinetics, differentiation potential and/or response to differentiation signals, electrophysiological behaviour, etc., wherein such characteristics signify the progression of the relatively more specialised cell further along the developmental pathway. Non-limiting examples of differentiation may include, e.g., the change of a pluripotent stem cell into a given type of multipotent progenitor or stem cell, the change of a multipotent progenitor or stem cell into a given type of unipotent progenitor or stem cell, or the change of a unipotent progenitor or stem cell to more specialised cell types or to terminally specialised cells within a given cell lineage.
The terms “diagnosis” and “monitoring” are commonplace and well-understood in medical practice. By means of further explanation and without limitation the term “diagnosis” generally refers to the process or act of recognising, deciding on or concluding on a disease or condition in a subject on the basis of symptoms and signs and/or from results of various diagnostic procedures (such as, for example, from knowing the presence, absence and/or quantity of one or more biomarkers characteristic of the diagnosed disease or condition).
The term “monitoring” generally refers to the follow-up of a disease or a condition in a subject for any changes which may occur over time.
The terms “prognosing” or “prognosis” generally refer to an anticipation on the progression of a disease or condition and the prospect (e.g., the probability, duration, and/or extent) of recovery. A good prognosis of the diseases or conditions taught herein may generally encompass anticipation of a satisfactory partial or complete recovery from the diseases or conditions, preferably within an acceptable time period. A good prognosis of such may more commonly encompass anticipation of not further worsening or aggravating of such, preferably within a given time period. A poor prognosis of the diseases or conditions as taught herein may generally encompass anticipation of a substandard recovery and/or unsatisfactorily slow recovery, or to substantially no recovery or even further worsening of such.
The terms also encompass prediction of a disease. The terms “predicting” or “prediction” generally refer to an advance declaration, indication or foretelling of a disease or condition in a subject not (yet) having the disease or condition. For example, a prediction of a disease or condition in a subject may indicate a probability, chance or risk that the subject will develop the disease or condition, for example within a certain time period or by a certain age. The probability, chance or risk may be indicated inter alia as an absolute value, range or statistics, or may be indicated relative to a suitable control subject or subject population (such as, e.g., relative to a general, normal or healthy subject or subject population). Hence, the probability, chance or risk that a subject will develop a disease or condition may be advantageously indicated as increased or decreased, or as fold-increased or fold-decreased relative to a suitable control subject or subject population. As used herein, the term “prediction” of the conditions or diseases as taught herein in a subject may also particularly mean that the subject has a ‘positive’ prediction of such, i.e., that the subject is at risk of having such (e.g., the risk is significantly increased vis-à-vis a control subject or subject population). The term “prediction of no” diseases or conditions as taught herein as described herein in a subject may particularly mean that the subject has a ‘negative’ prediction of such, i.e., that the subject's risk of having such is not significantly increased vis-à-vis a control subject or subject population.
As used throughout this specification, the terms “treat”, “treating” and “treatment” refer to the alleviation or measurable lessening of one or more symptoms or measurable markers of a pathological condition such as a disease or disorder. Measurable lessening includes any statistically significant decline in a measurable marker or symptom. Generally, the terms encompass both curative treatments and treatments directed to reduce symptoms and/or slow progression of the disease. The terms encompass both the therapeutic treatment of an already developed pathological condition, as well as prophylactic or preventative measures, wherein the aim is to prevent or lessen the chances of incidence of a pathological condition. In certain embodiments, the terms may relate to therapeutic treatments. In certain other embodiments, the terms may relate to preventative treatments. Treatment of a chronic pathological condition during the period of remission may also be deemed to constitute a therapeutic treatment. The term may encompass ex vivo or in vivo treatments as appropriate in the context of the present invention.
As used throughout this specification, the terms “prevent”, “preventing” and “prevention” refer to the avoidance or delay in manifestation of one or more symptoms or measurable markers of a pathological condition, such as a disease or disorder. A delay in the manifestation of a symptom or marker is a delay relative to the time at which such symptom or marker manifests in a control or untreated subject with a similar likelihood or susceptibility of developing the pathological condition. The terms “prevent”, “preventing” and “prevention” include not only the avoidance or prevention of a symptom or marker of the pathological condition, but also a reduced severity or degree of any one of the symptoms or markers of the pathological condition, relative to those symptoms or markers in a control or non-treated individual with a similar likelihood or susceptibility of developing the pathological condition, or relative to symptoms or markers likely to arise based on historical or statistical measures of populations affected by the disease or disorder. By “reduced severity” is meant at least a 10% reduction in the severity or degree of a symptom or measurable marker relative to a control or reference, e.g., at least 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99% or even 100% (i.e., no symptoms or measurable markers).
The terms “disease” or “disorder” are used interchangeably throughout this specification, and refer to any alternation in state of the body or of some of the organs, interrupting or disturbing the performance of the functions and/or causing symptoms such as discomfort, dysfunction, distress, or even death to the person afflicted or those in contact with a person. A disease or disorder can also be related to a distemper, ailing, ailment, malady, disorder, sickness, illness, complaint, indisposition, or affliction.
In certain embodiments, the pathological condition may be an infection, inflammation, proliferative disease, autoimmune disease, or allergy.
The term “infection” as used herein refers to presence of an infective agent, such as a pathogen, e.g., a microorganism, in or on a subject, which, if its presence or growth were inhibited, would result in a benefit to the subject. Hence, the term refers to the state produced by the establishment, more particularly invasion and multiplication, of an infective agent, such as a pathogen, e.g., a microorganism, in or on a suitable host. An infection may produce tissue injury and progress to overt disease through a variety of cellular and toxic mechanisms.
The term “inflammation” generally refers to a response in vasculated tissues to cellular or tissue injury usually caused by physical, chemical and/or biological agents, that is marked in the acute form by the classical sequences of pain, heat, redness, swelling, and loss of function, and serves as a mechanism initiating the elimination, dilution or walling-off of noxious agents and/or of damaged tissue. Inflammation histologically involves a complex series of events, including dilation of the arterioles, capillaries, and venules with increased permeability and blood flow, exudation of fluids including plasma proteins, and leukocyte migration into the inflammatory focus.
Further, the term encompasses inflammation caused by extraneous physical or chemical injury or by biological agents, e.g., viruses, bacteria, fungi, protozoan or metazoan parasite infections, as well as inflammation which is seemingly unprovoked, e.g., which occurs in the absence of demonstrable injury or infection, inflammation responses to self-antigens (auto-immune inflammation), inflammation responses to engrafted xenogeneic or allogeneic cells, tissues or organs, inflammation responses to allergens, etc. The term covers both acute inflammation and chronic inflammation. Also, the term includes both local or localised inflammation, as well as systemic inflammation, i.e., where one or more inflammatory processes are not confined to a particular tissue but occur generally in the endothelium and/or other organ systems.
Systemic inflammatory conditions may particularly encompass systemic inflammatory response syndrome (SIRS) or sepsis. “SIRS” is a systemic inflammatory response syndrome with no signs of infection. It can be characterised by the presence of at least two of the four following clinical criteria: fever or hypothermia (temperature of 38.0° C.) or more, or temperature of 36.0° C. or less); tachycardia (at least 90 beats per minute); tachypnea (at least 20 breaths per minute or PaCO2 less than 4.3 kPa (32.0 mm Hg) or the need for mechanical ventilation); and an altered white blood cell (WBC) count of 12×106 cells/mL or more, or an altered WBC count of 4×106 cells/mL or less, or the presence of more than 10% band forms. “Sepsis” can generally be defined as SIRS with a documented infection, such as for example a bacterial infection. Infection can be diagnosed by standard textbook criteria or, in case of uncertainty, by an infectious disease specialist. Bacteraemia is defined as sepsis where bacteria can be cultured from blood. Sepsis may be characterised or staged as mild sepsis, severe sepsis (sepsis with acute organ dysfunction), septic shock (sepsis with refractory arterial hypotension), organ failure, multiple organ dysfunction syndrome and death.
The term “proliferative disease” generally refers to any disease or disorder characterised by neoplastic cell growth and proliferation, whether benign, pre-malignant, or malignant. The term proliferative disease generally includes all transformed cells and tissues and all cancerous cells and tissues. Proliferative diseases or disorders include, but are not limited to abnormal cell growth, benign tumours, premalignant or precancerous lesions, malignant tumors, and cancer.
The terms “tumor” or “tumor tissue” refer to an abnormal mass of tissue resulting from excessive cell division. A tumor or tumor tissue comprises “tumor cells” which are neoplastic cells with abnormal growth properties and no useful bodily function. Tumors, tumor tissue and tumor cells may be benign, pre-malignant or malignant, or may represent a lesion without any cancerous potential. A tumor or tumor tissue may also comprise “tumor-associated non-tumor cells”, e.g., vascular cells which form blood vessels to supply the tumor or tumor tissue. Non-tumor cells may be induced to replicate and develop by tumor cells, for example, the induction of angiogenesis in a tumor or tumor tissue.
The term “cancer” refers to a malignant neoplasm characterised by deregulated or unregulated cell growth. The term “cancer” includes primary malignant cells or tumors (e.g., those whose cells have not migrated to sites in the subject's body other than the site of the original malignancy or tumor) and secondary malignant cells or tumors (e.g., those arising from metastasis, the migration of malignant cells or tumor cells to secondary sites that are different from the site of the original tumor. The term “metastatic” or “metastasis” generally refers to the spread of a cancer from one organ or tissue to another non-adjacent organ or tissue. The occurrence of the proliferative disease in the other non-adjacent organ or tissue is referred to as metastasis.
As used throughout the present specification, the terms “autoimmune disease” or “autoimmune disorder” used interchangeably refer to a diseases or disorders caused by an immune response against a self-tissue or tissue component (self-antigen) and include a self-antibody response and/or cell-mediated response. The terms encompass organ-specific autoimmune diseases, in which an autoimmune response is directed against a single tissue, as well as non-organ specific autoimmune diseases, in which an autoimmune response is directed against a component present in two or more, several or many organs throughout the body.
Non-limiting examples of autoimmune diseases include but are not limited to acute disseminated encephalomyelitis (ADEM); Addison's disease; ankylosing spondylitis; antiphospholipid antibody syndrome (APS); aplastic anemia; autoimmune gastritis; autoimmune hepatitis; autoimmune thrombocytopenia; Behçet's disease; coeliac disease; dermatomyositis; diabetes mellitus type I; Goodpasture's syndrome; Graves' disease; Guillain-Barré syndrome (GBS); Hashimoto's disease; idiopathic thrombocytopenic purpura; inflammatory bowel disease (IBD) including Crohn's disease and ulcerative colitis; mixed connective tissue disease; multiple sclerosis (MS); myasthenia gravis; opsoclonus myoclonus syndrome (OMS); optic neuritis; Ord's thyroiditis; pemphigus; pernicious anaemia; polyarteritis nodosa; polymyositis; primary biliary cirrhosis; primary myoxedema; psoriasis; rheumatic fever; rheumatoid arthritis; Reiter's syndrome; scleroderma; Sjögren's syndrome; systemic lupus erythematosus; Takayasu's arteritis; temporal arteritis; vitiligo; warm autoimmune hemolytic anemia; or Wegener's granulomatosis.
“Activation” generally refers to the state of a cell, such as preferably T cell, following sufficient cell surface moiety ligation (e.g., interaction between the T cell receptor on the surface of a T cell (such as naturally-occurring TCR or genetically engineered TCR, e.g., chimeric antigen receptor, CAR) and MHC-bound antigen peptide presented on the surface of the immune cell as taught herein) to induce a noticeable biochemical or morphological change of the cell, such as preferably T cell. In particular, “activation” may refer to the state of a T cell that has been sufficiently stimulated to induce detectable cellular proliferation of the T cell. Activation can also encompass induced cytokine production, and detectable T cell effector functions, e.g., regulatory or cytolytic effector functions. The T cells and immune cells may be may be suitably contacted by admixing the T cells and immune cells in an aqueous composition, e.g., in a culture medium, in sufficient numbers and for a sufficient duration of time to produce the desired T cell activation.
The terms “increased” or “increase” or “upregulated” or “upregulate” as used herein generally mean an increase by a statically significant amount. For avoidance of doubt, “increased” means a statistically significant increase of at least 10% as compared to a reference level, including an increase of at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 100% or more, including, for example at least 2-fold, at least 3-fold, at least 4-fold, at least 5-fold, at least 10-fold increase or greater as compared to a reference level, as that term is defined herein.
The term “reduced” or “reduce” or “decrease” or “decreased” or “downregulate” or “downregulated” as used herein generally means a decrease by a statistically significant amount relative to a reference. For avoidance of doubt, “reduced” means statistically significant decrease of at least 10% as compared to a reference level, for example a decrease by at least 20%, at least 30%, at least 40%, at least t 50%, or least 60%, or least 70%, or least 80%, at least 90% or more, up to and including a 100% decrease (i.e., absent level as compared to a reference sample), or any decrease between 10-100% as compared to a reference level, as that term is defined herein. The term “abolish” or “abolished” may in particular refer to a decrease by 100%, i.e., absent level as compared to a reference sample.
Any one or more of the several successive molecular mechanisms involved in the expression of a given gene or polypeptide may be targeted by the intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) cell modification as intended herein. Without limitation, these may include targeting the gene sequence (e.g., targeting the polypeptide-encoding, non-coding and/or regulatory portions of the gene sequence), the transcription of the gene into RNA, the polyadenylation and where applicable splicing and/or other post-transcriptional modifications of the RNA into mRNA, the localisation of the mRNA into cell cytoplasm, where applicable other post-transcriptional modifications of the mRNA, the translation of the mRNA into a polypeptide chain, where applicable post-translational modifications of the polypeptide, and/or folding of the polypeptide chain into the mature conformation of the polypeptide. For compartmentalised polypeptides, such as secreted polypeptides and transmembrane polypeptides, this may further include targeting trafficking of the polypeptides, i.e., the cellular mechanism by which polypeptides are transported to the appropriate sub-cellular compartment or organelle, membrane, e.g. the plasma membrane, or outside the cell. Functional genomics can be used to modify cells for therapeutic purposes, and identify networks and pathways. For example, Graham et al (“Functional genomics identifies negative regulatory nodes controlling phagocyte oxidative burst,” Nature Communications 6, Article number: 7838 (2015)) describes functional genetic screens to identify the phagocytic oxidative burst. With the rapid advancement of genomic technology, it is now possible to associate genetic variation with phenotypes of intestinal epithelial cells, intestinal epithelial stem cells, or intestinal immune cells (preferably intestinal epithelial cells) at the population level. In particular, genome-wide association studies (GWAS) have implicated genetic loci associated with risk for IBD and allowed for inference of new biological processes that contribute to disease. These studies highlight innate defense mechanisms such as antibacterial autophagy, superoxide generation during oxidative burst and reactive nitrogen species produced by iNOS. However GWAS requires functional analysis to unlock new insights. For example, many risk loci are densely populated with coding genes, which complicates identification of causal genes. Even when fine mapping clearly identifies key genes, a majority have poorly defined functions in host immunity. Moreover, any given gene may have multiple functions depending on the cell type in which it is expressed as well as environmental cues. Such context-specific functions of regulatory genes are largely unexplored. Thus, human genetics offers an opportunity to leverage insight from large amounts of genetic variation within healthy and patient populations to interrogate mechanisms of immunity. Irrespective of their putative roles in IBD pathology, genes within risk loci are likely to be highly enriched for genes controlling signalling pathways.
With respect to general information on CRISPR-Cas Systems, components thereof, the DNA binding protein is a (endo)nuclease or a variant thereof having altered or modified activity (i.e. a modified nuclease, as described herein elsewhere). In certain embodiments, the nuclease is a targeted or site-specific or homing nuclease or a variant thereof having altered or modified activity. In certain embodiments, the nuclease or targeted/site-specific/homing nuclease is, comprises, consists essentially of, or consists of a (modified) CRISPR/Cas system or complex, a (modified) Cas protein, a (modified) zinc finger, a (modified) zinc finger nuclease (ZFN), a (modified) transcription factor-like effector (TALE), a (modified) transcription factor-like effector nuclease (TALEN), or a (modified) meganuclease.
In certain embodiments, the (modified) nuclease or targeted/site-specific/homing nuclease is, comprises, consists essentially of, or consists of a (modified) RNA-guided nuclease. As used herein, the term “Cas” generally refers to a (modified) effector protein of the CRISPR/Cas system or complex, and can be without limitation a (modified) Cas9, or other enzymes such as Cpf1, The term “Cas” may be used herein interchangeably with the terms “CRISPR” protein, “CRISPR/Cas protein”, “CRISPR effector”, “CRISPR/Cas effector”, “CRISPR enzyme”, “CRISPR/Cas enzyme” and the like, unless otherwise apparent, such as by specific and exclusive reference to Cas9. It is to be understood that the term “CRISPR protein” may be used interchangeably with “CRISPR enzyme”, irrespective of whether the CRISPR protein has altered, such as increased or decreased (or no) enzymatic activity, compared to the wild type CRISPR protein. Likewise, as used herein, in certain embodiments, where appropriate and which will be apparent to the skilled person, the term “nuclease” may refer to a modified nuclease wherein catalytic activity has been altered, such as having increased or decreased nuclease activity, or no nuclease activity at all, as well as nickase activity, as well as otherwise modified nuclease as defined herein elsewhere, unless otherwise apparent, such as by specific and exclusive reference to unmodified nuclease.
As used herein, the term “targeting” of a selected nucleic acid sequence means that a nuclease or nuclease complex is acting in a nucleotide sequence specific manner. For instance, in the context of the CRISPR/Cas system, the guide RNA is capable of hybridizing with a selected nucleic acid sequence. As uses herein, “hybridization” or “hybridizing” refers to a reaction in which one or more polynucleotides react to form a complex that is stabilized via hydrogen bonding between the bases of the nucleotide residues. The hydrogen bonding may occur by Watson Crick base pairing, Hoogstein binding, or in any other sequence specific manner. The complex may comprise two strands forming a duplex structure, three or more strands forming a multi stranded complex, a single self-hybridizing strand, or any combination of these. A hybridization reaction may constitute a step in a more extensive process, such as the initiation of PGR, or the cleavage of a polynucleotide by an enzyme. A sequence capable of hybridizing with a given sequence is referred to as the “complement” of the given sequence.
In certain embodiments, the DNA binding protein is a (modified) transcription activator-like effector nuclease (TALEN) system. Transcription activator-like effectors (TALEs) can be engineered to bind practically any desired DNA sequence. Exemplary methods of genome editing using the TALEN system can be found for example in Cermak T. Doyle E L. Christian M. Wang L. Zhang Y. Schmidt C, et al. Efficient design and assembly of custom TALEN and other TAL effector-based constructs for DNA targeting. Nucleic Acids Res. 2011; 39:e82; Zhang F. Cong L. Lodato S. Kosuri S. Church G M. Arlotta P Efficient construction of sequence-specific TAL effectors for modulating mammalian transcription. Nat Biotechnol. 2011; 29:149-153 and U.S. Pat. Nos. 8,450,471, 8,440,431 and 8,440,432, all of which are specifically incorporated by reference. By means of further guidance, and without limitation, naturally occurring TALEs or “wild type zincs” are nucleic acid binding proteins secreted by numerous species of proteobacteria. TALE polypeptides contain a nucleic acid binding domain composed of tandem repeats of highly conserved monomer polypeptides that are predominantly 33, 34 or 35 amino acids in length and that differ from each other mainly in amino acid positions 12 and 13. In advantageous embodiments the nucleic acid is DNA. As used herein, the term “polypeptide monomers”, or “TALE monomers” will be used to refer to the highly conserved repetitive polypeptide sequences within the TALE nucleic acid binding domain and the term “repeat variable di-residues” or “RVD” will be used to refer to the highly variable amino acids at positions 12 and 13 of the polypeptide monomers. As provided throughout the disclosure, the amino acid residues of the RVD are depicted using the IUPAC single letter code for amino acids. A general representation of a TALE monomer which is comprised within the DNA binding domain is X1-11-(X12X13)-X14-33 or 34 or 35, where the subscript indicates the amino acid position and X represents any amino acid. X12X13 indicate the RVDs. In some polypeptide monomers, the variable amino acid at position 13 is missing or absent and in such polypeptide monomers, the RVD consists of a single amino acid. In such cases the RVD may be alternatively represented as X*, where X represents X12 and (*) indicates that X13 is absent. The DNA binding domain comprises several repeats of TALE monomers and this may be represented as (X1-11-(X12X13)-X14-33 or 34 or 35)z, where in an advantageous embodiment, z is at least 5 to 40. In a further advantageous embodiment, z is at least 10 to 26. The TALE monomers have a nucleotide binding affinity that is determined by the identity of the amino acids in its RVD. For example, polypeptide monomers with an RVD of NI preferentially bind to adenine (A), polypeptide monomers with an RVD of NG preferentially bind to thymine (T), polypeptide monomers with an RVD of HD preferentially bind to cytosine (C) and polypeptide monomers with an RVD of NN preferentially bind to both adenine (A) and guanine (G). In yet another embodiment of the invention, polypeptide monomers with an RVD of IG preferentially bind to T. Thus, the number and order of the polypeptide monomer repeats in the nucleic acid binding domain of a TALE determines its nucleic acid target specificity. In still further embodiments of the invention, polypeptide monomers with an RVD of NS recognize all four base pairs and may bind to A, T, G or C. The structure and function of TALEs is further described in, for example, Moscou et al., Science 326:1501 (2009); Boch et al., Science 326:1509-1512 (2009); and Zhang et al., Nature Biotechnology 29:149-153 (2011), each of which is incorporated by reference in its entirety.
In certain embodiments, the nucleic acid modification is effected by a (modified) zinc-finger nuclease (ZFN) system. The ZFN system uses artificial restriction enzymes generated by fusing a zinc finger DNA-binding domain to a DNA-cleavage domain that can be engineered to target desired DNA sequences. Exemplary methods of genome editing using ZFNs can be found for example in U.S. Pat. Nos. 6,534,261, 6,607,882, 6,746,838, 6,794,136, 6,824,978, 6,866,997, 6,933,113, 6,979,539, 7,013,219, 7,030,215, 7,220,719, 7,241,573, 7,241,574, 7,585,849, 7,595,376, 6,903,185, and 6,479,626, all of which are specifically incorporated by reference. By means of further guidance, and without limitation, artificial zinc-finger (ZF) technology involves arrays of ZF modules to target new DNA-binding sites in the genome. Each finger module in a ZF array targets three DNA bases. A customized array of individual zinc finger domains is assembled into a ZF protein (ZFP). ZFPs can comprise a functional domain. The first synthetic zinc finger nucleases (ZFNs) were developed by fusing a ZF protein to the catalytic domain of the Type IIS restriction enzyme FokI. (Kim, Y. G. et al., 1994, Chimeric restriction endonuclease, Proc. Natl. Acad. Sci. U.S.A. 91, 883-887; Kim, Y. G. et al., 1996, Hybrid restriction enzymes: zinc finger fusions to Fok I cleavage domain. Proc. Natl. Acad. Sci. U.S.A. 93, 1156-1160). Increased cleavage specificity can be attained with decreased off target activity by use of paired ZFN heterodimers, each targeting different nucleotide sequences separated by a short spacer. (Doyon, Y. et al., 2011, Enhancing zinc-finger-nuclease activity with improved obligate heterodimeric architectures. Nat. Methods 8, 74-79). ZFPs can also be designed as transcription activators and repressors and have been used to target many genes in a wide variety of organisms.
In certain embodiments, the nucleic acid modification is effected by a (modified) meganuclease, which are endodeoxyribonucleases characterized by a large recognition site (double-stranded DNA sequences of 12 to 40 base pairs). Exemplary method for using meganucleases can be found in U.S. Pat. Nos. 8,163,514; 8,133,697; 8,021,867; 8,119,361; 8,119,381; 8,124,369; and 8,129,134, which are specifically incorporated by reference.
In certain embodiments, the nucleic acid modification is effected by a (modified) CRISPR/Cas complex or system. With respect to general information on CRISPR/Cas Systems, components thereof, and delivery of such components, including methods, materials, delivery vehicles, vectors, particles, and making and using thereof, including as to amounts and formulations, as well as Cas9CRISPR/Cas-expressing eukaryotic cells, Cas-9 CRISPR/Cas expressing eukaryotes, such as a mouse, reference is made to: U.S. Pat. Nos. 8,999,641, 8,993,233, 8,697,359, 8,771,945, 8,795,965, 8,865,406, 8,871,445, 8,889,356, 8,889,418, 8,895,308, 8,906,616, 8,932,814, 8,945,839, 8,993,233 and 8,999,641; US Patent Publications US 2014-0310830 (U.S. application Ser. No. 14/105,031), US 2014-0287938 A1 (U.S. application Ser. No. 14/213,991), US 2014-0273234 A1 (U.S. application Ser. No. 14/293,674), US2014-0273232 A1 (U.S. application Ser. No. 14/290,575), US 2014-0273231 (U.S. application Ser. No. 14/259,420), US 2014-0256046 A1 (U.S. application Ser. No. 14/226,274), US 2014-0248702 A1 (U.S. application Ser. No. 14/258,458), US 2014-0242700 A1 (U.S. application Ser. No. 14/222,930), US 2014-0242699 A1 (U.S. application Ser. No. 14/183,512), US 2014-0242664 A1 (U.S. application Ser. No. 14/104,990), US 2014-0234972 A1 (U.S. application Ser. No. 14/183,471), US 2014-0227787 A1 (U.S. application Ser. No. 14/256,912), US 2014-0189896 A1 (U.S. application Ser. No. 14/105,035), US 2014-0186958 (U.S. application Ser. No. 14/105,017), US 2014-0186919 A1 (U.S. application Ser. No. 14/104,977), US 2014-0186843 A1 (U.S. application Ser. No. 14/104,900), US 2014-0179770 A1 (U.S. application Ser. No. 14/104,837) and US 2014-0179006 A1 (U.S. application Ser. No. 14/183,486), US 2014-0170753 (U.S. application Ser. No. 14/183,429); US 2015-0184139 (U.S. application Ser. No. 14/324,960); Ser. No. 14/054,414 European Patent Applications EP 2 771 468 (EP13818570.7), EP 2 764 103 (EP13824232.6), and EP 2 784 162 (EP14170383.5); and PCT Patent Publications WO 2014/093661 (PCT/US2013/074743), WO 2014/093694 (PCT/US2013/074790), WO 2014/093595 (PCT/US2013/074611), WO 2014/093718 (PCT/US2013/074825), WO 2014/093709 (PCT/US2013/074812), WO 2014/093622 (PCT/US2013/074667), WO 2014/093635 (PCT/US2013/074691), WO 2014/093655 (PCT/US2013/074736), WO 2014/093712 (PCT/US2013/074819), WO 2014/093701 (PCT/US2013/074800), WO 2014/018423 (PCT/US2013/051418), WO 2014/204723 (PCT/US2014/041790), WO 2014/204724 (PCT/US2014/041800), WO 2014/204725 (PCT/US2014/041803), WO 2014/204726 (PCT/US2014/041804), WO 2014/204727 (PCT/US2014/041806), WO 2014/204728 (PCT/US2014/041808), WO 2014/204729 (PCT/US2014/041809), WO 2015/089351 (PCT/US2014/069897), WO 2015/089354 (PCT/US2014/069902), WO 2015/089364 (PCT/US2014/069925), WO 2015/089427 (PCT/US2014/070068), WO 2015/089462 (PCT/US2014/070127), WO 2015/089419 (PCT/US2014/070057), WO 2015/089465 (PCT/US2014/070135), WO 2015/089486 (PCT/US2014/070175), WO2015/058052 (PCT/US2014/061077), WO2015070083 (PCT/US2014/064663), WO2015/089354 (PCT/US2014/069902), WO2015/089351 (PCT/US2014/069897), WO2015/089364 (PCT/US2014/069925), WO2015/089427 (PCT/US2014/070068), WO2015/089473 (PCT/US2014/070152), WO2015/089486 (PCT/US2014/070175), WO/2016/04925 (PCT/US2015/051830), WO/2016/094867 (PCT/US2015/065385), WO/2016/094872 (PCT/US2015/065393), WO/2016/094874 (PCT/US2015/065396), WO/2016/106244 (PCT/US2015/067177)
Reference is further made to Multiplex genome engineering using CRISPR/Cas systems. Cong, L., Ran, F. A., Cox, D., Lin, S., Barretto, R., Habib, N., Hsu, P. D., Wu, X., Jiang, W., Marraffini, L. A., & Zhang, F. Science February 15; 339(6121):819-23 (2013); RNA-guided editing of bacterial genomes using CRISPR-Cas systems. Jiang W., Bikard D., Cox D., Zhang F, Marraffini L A. Nat Biotechnol March; 31(3):233-9 (2013); One-Step Generation of Mice Carrying Mutations in Multiple Genes by CRISPR/Cas-Mediated Genome Engineering. Wang H., Yang H., Shivalila C S., Dawlaty M M., Cheng A W., Zhang F., Jaenisch R. Cell May 9; 153(4):910-8 (2013); Optical control of mammalian endogenous transcription and epigenetic states. Konermann S, Brigham M D, Trevino A E, Hsu P D, Heidenreich M, Cong L, Platt R J, Scott D A, Church G M, Zhang F. Nature. 2013 Aug. 22; 500(7463):472-6. doi: 10.1038/Naturel2466. Epub 2013 Aug. 23; Double Nicking by RNA-Guided CRISPR Cas9 for Enhanced Genome Editing Specificity. Ran, F A., Hsu, P D., Lin, C Y., Gootenberg, J S., Konermann, S., Trevino, A E., Scott, D A., Inoue, A., Matoba, S., Zhang, Y., & Zhang, F. Cell August 28. pii: S0092-8674(13)01015-5. (2013); DNA targeting specificity of RNA-guided Cas9 nucleases. Hsu, P., Scott, D., Weinstein, J., Ran, F A., Konermann, S., Agarwala, V., Li, Y., Fine, E., Wu, X., Shalem, O., Cradick, T J., Marraffini, L A., Bao, G., & Zhang, F. Nat Biotechnol doi:10.1038/nbt.2647 (2013); Genome engineering using the CRISPR-Cas9 system. Ran, F A., Hsu, P D., Wright, J., Agarwala, V., Scott, D A., Zhang, F. Nature Protocols November; 8(11):2281-308. (2013); Genome-Scale CRISPR-Cas9 Knockout Screening in Human Cells. Shalem, O., Sanjana, N E., Hartenian, E., Shi, X., Scott, D A., Mikkelson, T., Heckl, D., Ebert, B L., Root, D E., Doench, J G., Zhang, F. Science Dec. 12. (2013). [Epub ahead of print]; Crystal structure of cas9 in complex with guide RNA and target DNA. Nishimasu, H., Ran, F A., Hsu, P D., Konermann, S., Shehata, S I., Dohmae, N., Ishitani, R., Zhang, F., Nureki, O. Cell Feb. 27. (2014). 156(5):935-49; Genome-wide binding of the CRISPR endonuclease Cas9 in mammalian cells. Wu X., Scott D A., Kriz A J., Chiu A C., Hsu P D., Dadon D B., Cheng A W., Trevino A E., Konermann S., Chen S., Jaenisch R., Zhang F., Sharp P A. Nat Biotechnol. (2014) Apr. 20. doi: 10.1038/nbt.2889; CRISPR-Cas9 Knockin Mice for Genome Editing and Cancer Modeling, Platt et al., Cell 159(2): 440-455 (2014) DOI: 10.1016/j.cell.2014.09.014; Development and Applications of CRISPR-Cas9 for Genome Engineering, Hsu et al, Cell 157, 1262-1278 (Jun. 5, 2014) (Hsu 2014); Genetic screens in human cells using the CRISPR/Cas9 system, Wang et al., Science. 2014 Jan. 3; 343(6166): 80-84. doi:10.1126/science.1246981; Rational design of highly active sgRNAs for CRISPR-Cas9-mediated gene inactivation, Doench et al., Nature Biotechnology 32(12):1262-7 (2014) published online 3 Sep. 2014; doi:10.1038/nbt.3026, and In vivo interrogation of gene function in the mammalian brain using CRISPR-Cas9, Swiech et al, Nature Biotechnology 33, 102-106 (2015) published online 19 Oct. 2014; doi:10.1038/nbt.3055, Cpf1 Is a Single RNA-Guided Endonuclease of a Class 2 CRISPR-Cas System, Zetsche et al., Cell 163, 1-13 (2015); Discovery and Functional Characterization of Diverse Class 2 CRISPR-Cas Systems, Shmakov et al., Mol Cell 60(3): 385-397 (2015); Each of these publications, patents, patent publications, and applications, and all documents cited therein or during their prosecution (“appln cited documents”) and all documents cited or referenced in the appln cited documents, together with any instructions, descriptions, product specifications, and product sheets for any products mentioned therein or in any document therein and incorporated by reference herein, are hereby incorporated herein by reference, and may be employed in the practice of the invention. All documents (e.g., these patents, patent publications and applications and the appln cited documents) are incorporated herein by reference to the same extent as if each individual document was specifically and individually indicated to be incorporated by reference.
Preferred DNA binding proteins are CRISPR/Cas enzymes or variants thereof. In certain embodiments, the CRISPR/Cas protein is a class 2 CRISPR/Cas protein. In certain embodiments, the CRISPR/Cas protein is a type II, type V, or type VI CRISPR/Cas protein. The CRISPR/Cas system does not require the generation of customized proteins to target specific sequences but rather a single Cas protein can be programmed by an RNA guide (gRNA) to recognize a specific nucleic acid target, in other words the Cas enzyme protein can be recruited to a specific nucleic acid target locus (which may comprise or consist of RNA and/or DNA) of interest using the short RNA guide.
In general, the CRISPR/Cas or CRISPR system is as used herein foregoing documents refers collectively to elements involved in the expression of or directing the activity of CRISPR-associated (“Cas”) proteins or genes, including sequences encoding a Cas protein and a guide RNA. In this context of the guide RNA this may include one or more of, a tracr (trans-activating CRISPR) sequence (e.g. tracrRNA or an active partial tracrRNA), a tracr-mate sequence (encompassing a “direct repeat” and a tracrRNA-processed partial direct repeat in the context of an endogenous CRISPR system), a guide sequence (also referred to as a “spacer” in the context of an endogenous CRISPR system), In general, a CRISPR system is characterized by elements that promote the formation of a CRISPR complex at the site of a target sequence. In the context of formation of a CRISPR complex, “target sequence” refers to a sequence to which a guide sequence is designed to have complementarity, where hybridization between a target DNA sequence and a guide sequence promotes the formation of a CRISPR complex.
In certain embodiments, the gRNA comprises a guide sequence fused to a tracr mate sequence (or direct repeat), and a tracr sequence In particular embodiments, the guide sequence fused to the tracr mate and the tracr sequence are provided or expressed as discrete RNA sequences. In preferred embodiments, the gRNA is a chimeric guide RNA or single guide RNA (sgRNA), comprising a guide sequence fused to the tracr mate which is itself linked to the tracr sequence. In particular embodiments, the CRISPR/Cas system or complex as described herein does not comprise and/or does not rely on the presence of a tracr sequence (e.g. if the Cas protein is Cpf1).
As used herein, the term “guide sequence” in the context of a CRISPR/Cas system, comprises any polynucleotide sequence having sufficient complementarity with a target nucleic acid sequence to hybridize with the target nucleic acid sequence and direct sequence-specific binding of a nucleic acid-targeting complex to the target nucleic acid sequence. In some embodiments, the degree of complementarity, when optimally aligned using a suitable alignment algorithm, is about or more than about 50%, 60%, 75%, 80%, 85%, 90%, 95%, 97.5%, 99%, or more. Optimal alignment may be determined with the use of any suitable algorithm for aligning sequences, non-limiting example of which include the Smith-Waterman algorithm, the Needleman-Wunsch algorithm, algorithms based on the Burrows-Wheeler Transform (e.g., the Burrows Wheeler Aligner), ClustalW, Clustal X, BLAT, Novoalign (Novocraft Technologies; available at www.novocraft.com), ELAND (Illumina, San Diego, Calif.), SOAP (available at soap.genomics.org.cn), and Maq (available at maq.sourceforge.net). The ability of a guide sequence (within a nucleic acid-targeting guide RNA) to direct sequence-specific binding of a nucleic acid-targeting complex to a target nucleic acid sequence may be assessed by any suitable assay.
A guide sequence, and hence a nucleic acid-targeting guide RNA may be selected to target any target nucleic acid sequence. The target sequence may be DNA. The target sequence may be genomic DNA. The target sequence may be mitochondrial DNA.
In certain embodiments, the gRNA comprises a stem loop, preferably a single stem loop. In certain embodiments, the direct repeat sequence forms a stem loop, preferably a single stem loop. In certain embodiments, the spacer length of the guide RNA is from 15 to 35 nt. In certain embodiments, the spacer length of the guide RNA is at least 15 nucleotides. In certain embodiments, the spacer length is from 15 to 17 nt, e.g., 15, 16, or 17 nt, from 17 to 20 nt, e.g., 17, 18, 19, or 20 nt, from 20 to 24 nt, e.g., 20, 21, 22, 23, or 24 nt, from 23 to 25 nt, e.g., 23, 24, or 25 nt, from 24 to 27 nt, e.g., 24, 25, 26, or 27 nt, from 27-30 nt, e.g., 27, 28, 29, or 30 nt, from 30-35 nt, e.g., 30, 31, 32, 33, 34, or 35 nt, or 35 nt or longer. In particular embodiments, the CRISPR/Cas system requires a tracrRNA. The “tracrRNA” sequence or analogous terms includes any polynucleotide sequence that has sufficient complementarity with a crRNA sequence to hybridize. In some embodiments, the degree of complementarity between the tracrRNA sequence and crRNA sequence along the length of the shorter of the two when optimally aligned is about or more than about 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 97.5%, 99%, or higher. In some embodiments, the tracr sequence is about or more than about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 40, 50, or more nucleotides in length. In some embodiments, the tracr sequence and gRNA sequence are contained within a single transcript, such that hybridization between the two produces a transcript having a secondary structure, such as a hairpin. In an embodiment of the invention, the transcript or transcribed polynucleotide sequence has at least two or more hairpins. In preferred embodiments, the transcript has two, three, four or five hairpins. In a further embodiment of the invention, the transcript has at most five hairpins. In a hairpin structure the portion of the sequence 5′ of the final “N” and upstream of the loop may correspond to the tracr mate sequence, and the portion of the sequence 3′ of the loop then corresponds to the tracr sequence. In a hairpin structure the portion of the sequence 5′ of the final “N” and upstream of the loop may alternatively correspond to the tracr sequence, and the portion of the sequence 3′ of the loop corresponds to the tracr mate sequence. In alternative embodiments, the CRISPR/Cas system does not require a tracrRNA, as is known by the skilled person.
In certain embodiments, the guide RNA (capable of guiding Cas to a target locus) may comprise (1) a guide sequence capable of hybridizing to a target locus and (2) a tracr mate or direct repeat sequence (in 5′ to 3′ orientation, or alternatively in 3′ to 5′ orientation, depending on the type of Cas protein, as is known by the skilled person). In particular embodiments, the CRISPR/Cas protein is characterized in that it makes use of a guide RNA comprising a guide sequence capable of hybridizing to a target locus and a direct repeat sequence, and does not require a tracrRNA. In particular embodiments, where the CRISPR/Cas protein is characterized in that it makes use of a tracrRNA, the guide sequence, tracr mate, and tracr sequence may reside in a single RNA, i.e. an sgRNA (arranged in a 5′ to 3′ orientation or alternatively arranged in a 3′ to 5′ orientation), or the tracr RNA may be a different RNA than the RNA containing the guide and tracr mate sequence. In these embodiments, the tracr hybridizes to the tracr mate sequence and directs the CRISPR/Cas complex to the target sequence.
In particular embodiments, the DNA binding protein is a catalytically active protein. In these embodiments, the formation of a nucleic acid-targeting complex (comprising a guide RNA hybridized to a target sequence results in modification (such as cleavage) of one or both DNA or RNA strands in or near (e.g., within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 50, or more base pairs from) the target sequence. As used herein the term “sequence(s) associated with a target locus of interest” refers to sequences near the vicinity of the target sequence (e.g. within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 50, or more base pairs from the target sequence, wherein the target sequence is comprised within a target locus of interest). The skilled person will be aware of specific cut sites for selected CRISPR/Cas systems, relative to the target sequence, which as is known in the art may be within the target sequence or alternatively 3′ or 5′ of the target sequence.
Accordingly, in particular embodiments, the DNA binding protein has nucleic acid cleavage activity. In some embodiments, the nuclease as described herein may direct cleavage of one or both nucleic acid (DNA, RNA, or hybrids, which may be single or double stranded) strands at the location of or near a target sequence, such as within the target sequence and/or within the complement of the target sequence or at sequences associated with the target sequence. In some embodiments, the nucleic acid-targeting effector protein may direct cleavage of one or both DNA or RNA strands within about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 50, 100, 200, 500, or more base pairs from the first or last nucleotide of a target sequence. In some embodiments, the cleavage may be blunt (e.g. for Cas9, such as SaCas9 or SpCas9). In some embodiments, the cleavage may be staggered (e.g. for Cpf1), i.e. generating sticky ends. In some embodiments, the cleavage is a staggered cut with a 5′ overhang. In some embodiments, the cleavage is a staggered cut with a 5′ overhang of 1 to 5 nucleotides, preferably of 4 or 5 nucleotides. In some embodiments, the cleavage site is upstream of the PAM. In some embodiments, the cleavage site is downstream of the PAM.
In certain embodiments, the target sequence should be associated with a PAM (protospacer adjacent motif) or PFS (protospacer flanking sequence or site); that is, a short sequence recognized by the CRISPR complex. The precise sequence and length requirements for the PAM differ depending on the CRISPR enzyme used, but PAMs are typically 2-5 base pair sequences adjacent the protospacer (that is, the target sequence). Examples of PAM sequences are given in the examples section below, and the skilled person will be able to identify further PAM sequences for use with a given CRISPR enzyme. Further, engineering of the PAM Interacting (PI) domain may allow programing of PAM specificity, improve target site recognition fidelity, and increase the versatility of the Cas, e.g. Cas9, genome engineering platform. Cas proteins, such as Cas9 proteins may be engineered to alter their PAM specificity, for example as described in Kleinstiver B P et al. Engineered CRISPR-Cas9 nucleases with altered PAM specificities. Nature. 2015 Jul. 23; 523(7561):481-5. doi: 10.1038/nature14592. In some embodiments, the method comprises allowing a CRISPR complex to bind to the target polynucleotide to effect cleavage of the target polynucleotide thereby modifying the target polynucleotide, wherein the CRISPR complex comprises a CRISPR enzyme complexed with a guide sequence hybridized to a target sequence within the target polynucleotide, wherein the guide sequence is linked to a tracr mate sequence which in turn hybridizes to a tracr sequence. The skilled person will understand that other Cas proteins may be modified analogously.
In some embodiments, the nucleic acid-targeting effector protein may be mutated with respect to a corresponding wild-type enzyme such that the mutated nucleic acid-targeting effector protein lacks the ability to cleave one or both DNA strands of a target polynucleotide containing a target sequence. As a further example, two or more catalytic domains of a Cas protein (e.g. RuvC I, RuvC II, and RuvC III or the HNH domain of a Cas9 protein) may be mutated to produce a mutated Cas protein which cleaves only one DNA strand of a target sequence.
In particular embodiments, the nucleic acid-targeting effector protein may be mutated with respect to a corresponding wild-type enzyme such that the mutated nucleic acid-targeting effector protein lacks substantially all DNA cleavage activity. In some embodiments, a nucleic acid-targeting effector protein may be considered to substantially lack all DNA and/or RNA cleavage activity when the cleavage activity of the mutated enzyme is about no more than 25%, 10%, 5%, 1%, 0.1%, 0.01%, or less of the nucleic acid cleavage activity of the non-mutated form of the enzyme; an example can be when the nucleic acid cleavage activity of the mutated form is nil or negligible as compared with the non-mutated form.
As used herein, the term “modified” Cas generally refers to a Cas protein having one or more modifications or mutations (including point mutations, truncations, insertions, deletions, chimeras, fusion proteins, etc.) compared to the wild type Cas protein from which it is derived. By derived is meant that the derived enzyme is largely based, in the sense of having a high degree of sequence homology with, a wildtype enzyme, but that it has been mutated (modified) in some way as known in the art or as described herein.
As detailed above, in certain embodiments, the nuclease as referred to herein is modified. As used herein, the term “modified” refers to which may or may not have an altered functionality. By means of example, and in particular with reference to Cas proteins, modifications which do not result in an altered functionality include for instance codon optimization for expression into a particular host, or providing the nuclease with a particular marker (e.g. for visualization). Modifications with may result in altered functionality may also include mutations, including point mutations, insertions, deletions, truncations (including split nucleases), etc., as well as chimeric nucleases (e.g. comprising domains from different orthologues or homologues) or fusion proteins. Fusion proteins may without limitation include for instance fusions with heterologous domains or functional domains (e.g. localization signals, catalytic domains, etc.). Accordingly, in certain embodiments, the modified nuclease may be used as a generic nucleic acid binding protein with fusion to or being operably linked to a functional domain. In certain embodiments, various different modifications may be combined (e.g. a mutated nuclease which is catalytically inactive and which further is fused to a functional domain, such as for instance to induce DNA methylation or another nucleic acid modification, such as including without limitation a break (e.g. by a different nuclease (domain)), a mutation, a deletion, an insertion, a replacement, a ligation, a digestion, a break or a recombination). As used herein, “altered functionality” includes without limitation an altered specificity (e.g. altered target recognition, increased (e.g. “enhanced” Cas proteins) or decreased specificity, or altered PAM recognition), altered activity (e.g. increased or decreased catalytic activity, including catalytically inactive nucleases or nickases), and/or altered stability (e.g. fusions with destalilization domains). Suitable heterologous domains include without limitation a nuclease, a ligase, a repair protein, a methyltransferase, (viral) integrase, a recombinase, a transposase, an argonaute, a cytidine deaminase, a retron, a group II intron, a phosphatase, a phosphorylase, a sulpfurylase, a kinase, a polymerase, an exonuclease, etc. Examples of all these modifications are known in the art. It will be understood that a “modified” nuclease as referred to herein, and in particular a “modified” Cas or “modified” CRISPR/Cas system or complex preferably still has the capacity to interact with or bind to the polynucleic acid (e.g. in complex with the gRNA).
By means of further guidance and without limitation, in certain embodiments, the nuclease may be modified as detailed below. As already indicated, more than one of the indicated modifications may be combined. For instance, codon optimization may be combined with NLS or NES fusions, catalytically inactive nuclease modifications or nickase mutants may be combined with fusions to functional (heterologous) domains, etc.
In certain embodiments, the nuclease, and in particular the Cas proteins of prokaryotic origin, may be codon optimized for expression into a particular host (cell). An example of a codon optimized sequence, is in this instance a sequence optimized for expression in a eukaryote, e.g., humans (i.e. being optimized for expression in humans), or for another eukaryote, animal or mammal as herein discussed; see, e.g., SaCas9 human codon optimized sequence in WO 2014/093622 (PCT/US2013/074667). Whilst this is preferred, it will be appreciated that other examples are possible and codon optimization for a host species other than human, or for codon optimization for specific organs is known. In some embodiments, an enzyme coding sequence encoding a Cas is codon optimized for expression in particular cells, such as eukaryotic cells. The eukaryotic cells may be those of or derived from a particular organism, such as a mammal, including but not limited to human, or non-human eukaryote or animal or mammal as herein discussed, e.g., mouse, rat, rabbit, dog, livestock, or non-human mammal or primate. In some embodiments, processes for modifying the germ line genetic identity of human beings and/or processes for modifying the genetic identity of animals which are likely to cause them suffering without any substantial medical benefit to man or animal, and also animals resulting from such processes, may be excluded. In general, codon optimization refers to a process of modifying a nucleic acid sequence for enhanced expression in the host cells of interest by replacing at least one codon (e.g. about or more than about 1, 2, 3, 4, 5, 10, 15, 20, 25, 50, or more codons) of the native sequence with codons that are more frequently or most frequently used in the genes of that host cell while maintaining the native amino acid sequence. Various species exhibit particular bias for certain codons of a particular amino acid. Codon bias (differences in codon usage between organisms) often correlates with the efficiency of translation of messenger RNA (mRNA), which is in turn believed to be dependent on, among other things, the properties of the codons being translated and the availability of particular transfer RNA (tRNA) molecules. The predominance of selected tRNAs in a cell is generally a reflection of the codons used most frequently in peptide synthesis. Accordingly, genes can be tailored for optimal gene expression in a given organism based on codon optimization. Codon usage tables are readily available, for example, at the “Codon Usage Database” available at www.kazusa.orjp/codon/and these tables can be adapted in a number of ways. See Nakamura, Y., et al. “Codon usage tabulated from the international DNA sequence databases: status for the year 2000” Nucl. Acids Res. 28:292 (2000). Computer algorithms for codon optimizing a particular sequence for expression in a particular host cell are also available, such as Gene Forge (Aptagen; Jacobus, Pa.), are also available. In some embodiments, one or more codons (e.g. 1, 2, 3, 4, 5, 10, 15, 20, 25, 50, or more, or all codons) in a sequence encoding a Cas correspond to the most frequently used codon for a particular amino acid. Codon optimization may be for expression into any desired host (cell), including mammalian, plant, algae, or yeast.
In certain embodiments, the nuclease, in particular the Cas protein, may comprise one or more modifications resulting in enhanced activity and/or specificity, such as including mutating residues that stabilize the targeted or non-targeted strand (e.g. eCas9; “Rationally engineered Cas9 nucleases with improved specificity”, Slaymaker et al. (2016), Science, 351(6268):84-88, incorporated herewith in its entirety by reference). In certain embodiments, the altered or modified activity of the engineered CRISPR protein comprises increased targeting efficiency or decreased off-target binding. In certain embodiments, the altered activity of the engineered CRISPR protein comprises modified cleavage activity. In certain embodiments, the altered activity comprises increased cleavage activity as to the target polynucleotide loci. In certain embodiments, the altered activity comprises decreased cleavage activity as to the target polynucleotide loci. In certain embodiments, the altered activity comprises decreased cleavage activity as to off-target polynucleotide loci. In certain embodiments, the altered or modified activity of the modified nuclease comprises altered helicase kinetics. In certain embodiments, the modified nuclease comprises a modification that alters association of the protein with the nucleic acid molecule comprising RNA (in the case of a Cas protein), or a strand of the target polynucleotide loci, or a strand of off-target polynucleotide loci. In an aspect of the invention, the engineered CRISPR protein comprises a modification that alters formation of the CRISPR complex. In certain embodiments, the altered activity comprises increased cleavage activity as to off-target polynucleotide loci. Accordingly, in certain embodiments, there is increased specificity for target polynucleotide loci as compared to off-target polynucleotide loci. In other embodiments, there is reduced specificity for target polynucleotide loci as compared to off-target polynucleotide loci. In certain embodiments, the mutations result in decreased off-target effects (e.g. cleavage or binding properties, activity, or kinetics), such as in case for Cas proteins for instance resulting in a lower tolerance for mismatches between target and gRNA. Other mutations may lead to increased off-target effects (e.g. cleavage or binding properties, activity, or kinetics). Other mutations may lead to increased or decreased on-target effects (e.g. cleavage or binding properties, activity, or kinetics). In certain embodiments, the mutations result in altered (e.g. increased or decreased) helicase activity, association or formation of the functional nuclease complex (e.g. CRISPR/Cas complex). In certain embodiments, the mutations result in an altered PAM recognition, i.e. a different PAM may be (in addition or in the alternative) be recognized, compared to the unmodified Cas protein (see e.g. “Engineered CRISPR-Cas9 nucleases with altered PAM specificities”, Kleinstiver et al. (2015), Nature, 523(7561):481-485, incorporated herein by reference in its entirety). Particularly preferred mutations include positively charged residues and/or (evolutionary) conserved residues, such as conserved positively charged residues, in order to enhance specificity. In certain embodiments, such residues may be mutated to uncharged residues, such as alanine.
In certain embodiments, the nuclease, in particular the Cas protein, may comprise one or more modifications resulting in a nuclease that has reduced or no catalytic activity, or alternatively (in case of nucleases that target double stranded nucleic acids) resulting in a nuclease that only cleaves one strand, i.e. a nickase. By means of further guidance, and without limitation, for example, an aspartate-to-alanine substitution (D10A) in the RuvC I catalytic domain of Cas9 from S. pyogenes converts Cas9 from a nuclease that cleaves both strands to a nickase (cleaves a single strand). Other examples of mutations that render Cas9 a nickase include, without limitation, H840A, N854A, and N863A. As further guidance, where the enzyme is not SpCas9, mutations may be made at any or all residues corresponding to positions 10, 762, 840, 854, 863 and/or 986 of SpCas9 (which may be ascertained for instance by standard sequence comparison tools). In particular, any or all of the following mutations are preferred in SpCas9: D10A, E762A, H840A, N854A, N863A and/or D986A; as well as conservative substitution for any of the replacement amino acids is also envisaged. As a further example, two or more catalytic domains of Cas9 (RuvC I, RuvC II, and RuvC III or the HNH domain) may be mutated to produce a mutated Cas9 substantially lacking all DNA cleavage activity. In some embodiments, a D10A mutation is combined with one or more of H840A, N854A, or N863A mutations to produce a Cas9 enzyme substantially lacking all DNA cleavage activity. In some embodiments, a Cas is considered to substantially lack all DNA cleavage activity when the DNA cleavage activity of the mutated enzyme is about no more than 25%, 10%, 5%, 1%, 0.1%, 0.01%, or less of the DNA cleavage activity of the non-mutated form of the enzyme; an example can be when the DNA cleavage activity of the mutated form is nil or negligible as compared with the non-mutated form. Thus, the Cas may comprise one or more mutations and may be used as a generic DNA binding protein with or without fusion to a functional domain. The mutations may be artificially introduced mutations or gain- or loss-of-function mutations. The mutations may include but are not limited to mutations in one of the catalytic domains (e.g., D10 and H840) in the RuvC and HNH catalytic domains respectively; or the CRISPR enzyme can comprise one or more mutations selected from the group consisting of D10A, E762A, H840A, N854A, N863A or D986A and/or one or more mutations in a RuvC1 or HNH domain of the Cas or has a mutation as otherwise as discussed herein.
In certain embodiments, the nuclease is a split nuclease (see e.g. “A split-Cas9 architecture for inducible genome editing and transcription modulation”, Zetsche et al. (2015), Nat Biotechnol. 33(2):139-42, incorporated herein by reference in its entirety). In a split nuclease, the activity (which may be a modified activity, as described herein elsewhere), relies on the two halves of the split nuclease to be joined, i.e. each half of the split nuclease does not possess the required activity, until joined. As further guidance, and without limitation, with specific reference to Cas9, a split Cas9 may result from splitting the Cas9 at any one of the following split points, according or with reference to SpCas9: a split position between 202A/203S; a split position between 255F/256D; a split position between 310E/311I; a split position between 534R/535K; a split position between 572E/573C; a split position between 713S/714G; a split position between 1003L/104E; a split position between 1054G/1055E; a split position between 1114N/1115S; a split position between 1152K/1153S; a split position between 1245K/1246G; or a split between 1098 and 1099. Identifying potential split sides is most simply done with the help of a crystal structure. For Sp mutants, it should be readily apparent what the corresponding position for, for example, a sequence alignment. For non-Sp enzymes one can use the crystal structure of an ortholog if a relatively high degree of homology exists between the ortholog and the intended Cas9. Ideally, the split position should be located within a region or loop. Preferably, the split position occurs where an interruption of the amino acid sequence does not result in the partial or full destruction of a structural feature (e.g. alpha-helixes or beta-sheets). Unstructured regions (regions that did not show up in the crystal structure because these regions are not structured enough to be “frozen” in a crystal) are often preferred options. In certain embodiments, a functional domain may be provided on each of the split halves, thereby allowing the formation of homodimers or heterodimers. The functional domains may be (inducible) interact, thereby joining the split halves, and reconstituting (modified) nuclease activity. By means of example, an inducer energy source may inducibly allow dimerization of the split halves, through appropriate fusion partners. An inducer energy source may be considered to be simply an inducer or a dimerizing agent. The term ‘inducer energy source’ is used herein throughout for consistency. The inducer energy source (or inducer) acts to reconstitute the Cas9. In some embodiments, the inducer energy source brings the two parts of the Cas9 together through the action of the two halves of the inducible dimer. The two halves of the inducible dimer therefore are brought tougher in the presence of the inducer energy source. The two halves of the dimer will not form into the dimer (dimerize) without the inducer energy source. Thus, the two halves of the inducible dimer cooperate with the inducer energy source to dimerize the dimer. This in turn reconstitutes the Cas9 by bringing the first and second parts of the Cas9 together. The CRISPR enzyme fusion constructs each comprise one part of the split Cas9. These are fused, preferably via a linker such as a GlySer linker described herein, to one of the two halves of the dimer. The two halves of the dimer may be substantially the same two monomers that together that form the homodimer, or they may be different monomers that together form the heterodimer. As such, the two monomers can be thought of as one half of the full dimer. The Cas9 is split in the sense that the two parts of the Cas9 enzyme substantially comprise a functioning Cas9. That Cas9 may function as a genome editing enzyme (when forming a complex with the target DNA and the guide), such as a nickase or a nuclease (cleaving both strands of the DNA), or it may be a deadCas9 which is essentially a DNA-binding protein with very little or no catalytic activity, due to typically two or more mutations in its catalytic domains as described herein further.
In certain embodiments, the nuclease may comprise one or more additional (heterologous) functional domains, i.e. the modified nuclease is a fusion protein comprising the nuclease itself and one or more additional domains, which may be fused C-terminally or N-terminally to the nuclease, or alternatively inserted at suitable and appropriate sited internally within the nuclease (preferably without perturbing its function, which may be an otherwise modified function, such as including reduced or absent catalytic activity, nickase activity, etc.). any type of functional domain may suitably be used, such as without limitation including functional domains having one or more of the following activities: (DNA or RNA) methyltransferase activity, methylase activity, demethylase activity, DNA hydroxylmethylase domain, histone acetylase domain, histone deacetylases domain, transcription or translation activation activity, transcription or translation repression activity, transcription or translation release factor activity, histone modification activity, nuclease activity, single-strand RNA cleavage activity, double-strand RNA cleavage activity, single-strand DNA cleavage activity, double-strand DNA cleavage activity, nucleic acid binding activity, a protein acetyltransferase, a protein deacetylase, a protein methyltransferase, a protein deaminase, a protein kinase, a protein phosphatase, transposase domain, integrase domain, recombinase domain, resolvase domain, invertase domain, protease domain, repressor domain, activator domain, nuclear-localization signal domains, transcription-regulatory protein (or transcription complex recruiting) domain, cellular uptake activity associated domain, nucleic acid binding domain, antibody presentation domain, histone modifying enzymes, recruiter of histone modifying enzymes; inhibitor of histone modifying enzymes, histone methyltransferase, histone demethylase, histone kinase, histone phosphatase, histone ribosylase, histone deribosylase, histone ubiquitinase, histone deubiquitinase, histone biotinase, histone tail protease, HDACs, histone methyltransferases (HMTs), and histone acetyltransferase (HAT) inhibitors, as well as HDAC and HMT recruiting proteins, HDAC Effector Domains, HDAC Recruiter Effector Domains, Histone Methyltransferase (HMT) Effector Domains, Histone Methyltransferase (HMT) Recruiter Effector Domains, or Histone Acetyltransferase Inhibitor Effector Domains. In some embodiments, the functional domain is an epigenetic regulator; see, e.g., Zhang et al., U.S. Pat. No. 8,507,272 (incorporated herein by reference in its entirety). In some embodiments, the functional domain is a transcriptional activation domain, such as VP64, p65, MyoD1, HSF1, RTA, SET7/9 or a histone acetyltransferase. In some embodiments, the functional domain is a transcription repression domain, such as KRAB. In some embodiments, the transcription repression domain is SID, or concatemers of SID (eg SID4X), NuE, or NcoR. In some embodiments, the functional domain is an epigenetic modifying domain, such that an epigenetic modifying enzyme is provided. In some embodiments, the functional domain is an activation domain, which may be the P65 activation domain. In some embodiments, the functional domain comprises nuclease activity. In one such embodiment, the functional domain may comprise Fok1. Mention is made of U.S. Pat. Pub. 2014/0356959, U.S. Pat. Pub. 2014/0342456, U.S. Pat. Pub. 2015/0031132, and Mali, P. et al., 2013, Science 339(6121):823-6, doi: 10.1126/science.1232033, published online 3 Jan. 2013 and through the teachings herein the invention comprehends methods and materials of these documents applied in conjunction with the teachings herein. It is to be understood that also destabilization domains or localization domains as described herein elsewhere are encompassed by the generic term “functional domain”. In certain embodiments, one or more functional domains are associated with the nuclease itself. In some embodiments, one or more functional domains are associated with an adaptor protein, for example as used with the modified guides of Konnerman et al. (Nature 517(7536): 583-588, 2015; incorporated herein by reference in its entirety), and gene form part of a Synergistic activator mediator (SAM) complex. The adaptor proteins may include but are not limited to orthogonal RNA-binding protein/aptamer combinations that exist within the diversity of bacteriophage coat proteins. A list of such coat proteins includes, but is not limited to: Qβ, F2, GA, fr, JP501, M12, R17, BZ13, JP34, JP500, KU1, M11, MX1, TW18, VK, SP, FI, ID2, NL95, TW19, AP205, ϕCb5, ϕCb8r, ϕCb12r, ϕCb23r, 7s and PRR1. These adaptor proteins or orthogonal RNA binding proteins can further recruit effector proteins or fusions which comprise one or more functional domains.
In certain embodiments, the nuclease, in particular the Cas protein, may comprise one or more modifications resulting in a destabilized nuclease when expressed in a host (cell). Such may be achieved by fusion of the nuclease with a destabilization domain (DD). Destabilizing domains have general utility to confer instability to a wide range of proteins; see, e.g., Miyazaki, J Am Chem Soc. Mar. 7, 2012; 134(9): 3942-3945, incorporated herein by reference. CMP8 or 4-hydroxytamoxifen can be destabilizing domains. More generally, A temperature-sensitive mutant of mammalian DHFR (DHFRts), a destabilizing residue by the N-end rule, was found to be stable at a permissive temperature but unstable at 37° C. The addition of methotrexate, a high-affinity ligand for mammalian DHFR, to cells expressing DHFRts inhibited degradation of the protein partially. This was an important demonstration that a small molecule ligand can stabilize a protein otherwise targeted for degradation in cells. A rapamycin derivative was used to stabilize an unstable mutant of the FRB domain of mTOR (FRB*) and restore the function of the fused kinase, GSK-3β.6,7 This system demonstrated that ligand-dependent stability represented an attractive strategy to regulate the function of a specific protein in a complex biological environment. A system to control protein activity can involve the DD becoming functional when the ubiquitin complementation occurs by rapamycin induced dimerization of FK506-binding protein and FKBP12. Mutants of human FKBP12 or ecDHFR protein can be engineered to be metabolically unstable in the absence of their high-affinity ligands, Shield-1 or trimethoprim (TMP), respectively. These mutants are some of the possible destabilizing domains (DDs) useful in the practice of the invention and instability of a DD as a fusion with a CRISPR enzyme confers to the CRISPR protein degradation of the entire fusion protein by the proteasome. Shield-1 and TMP bind to and stabilize the DD in a dose-dependent manner. The estrogen receptor ligand binding domain (ERLBD, residues 305-549 of ERS 1) can also be engineered as a destabilizing domain. Since the estrogen receptor signaling pathway is involved in a variety of diseases such as breast cancer, the pathway has been widely studied and numerous agonist and antagonists of estrogen receptor have been developed. Thus, compatible pairs of ERLBD and drugs are known. There are ligands that bind to mutant but not wild-type forms of the ERLBD. By using one of these mutant domains encoding three mutations (L384M, M421G, G521R)12, it is possible to regulate the stability of an ERLBD-derived DD using a ligand that does not perturb endogenous estrogen-sensitive networks. An additional mutation (Y537S) can be introduced to further destabilize the ERLBD and to configure it as a potential DD candidate. This tetra-mutant is an advantageous DD development. The mutant ERLBD can be fused to a CRISPR enzyme and its stability can be regulated or perturbed using a ligand, whereby the CRISPR enzyme has a DD. Another DD can be a 12-kDa (107-amino-acid) tag based on a mutated FKBP protein, stabilized by Shieldl ligand; see, e.g., Nature Methods 5, (2008). For instance a DD can be a modified FK506 binding protein 12 (FKBP12) that binds to and is reversibly stabilized by a synthetic, biologically inert small molecule, Shield-1; see, e.g., Banaszynski L A, Chen L C, Maynard-Smith L A, Ooi A G, Wandless T J. A rapid, reversible, and tunable method to regulate protein function in living cells using synthetic small molecules. Cell. 2006; 126:995-1004; Banaszynski L A, Sellmyer M A, Contag C H, Wandless T J, Thorne S H. Chemical control of protein stability and function in living mice. Nat Med. 2008; 14:1123-1127; Maynard-Smith L A, Chen L C, Banaszynski L A, Ooi A G, Wandless T J. A directed approach for engineering conditional protein stability using biologically silent small molecules. The Journal of biological chemistry. 2007; 282:24866-24872; and Rodriguez, Chem Biol. Mar. 23, 2012; 19(3): 391-398—all of which are incorporated herein by reference and may be employed in the practice of the invention in selected a DD to associate with a CRISPR enzyme in the practice of this invention. As can be seen, the knowledge in the art includes a number of DDs, and the DD can be associated with, e.g., fused to, advantageously with a linker, to a CRISPR enzyme, whereby the DD can be stabilized in the presence of a ligand and when there is the absence thereof the DD can become destabilized, whereby the CRISPR enzyme is entirely destabilized, or the DD can be stabilized in the absence of a ligand and when the ligand is present the DD can become destabilized; the DD allows the CRISPR enzyme and hence the CRISPR-Cas complex or system to be regulated or controlled—turned on or off so to speak, to thereby provide means for regulation or control of the system, e.g., in an in vivo or in vitro environment. For instance, when a protein of interest is expressed as a fusion with the DD tag, it is destabilized and rapidly degraded in the cell, e.g., by proteasomes. Thus, absence of stabilizing ligand leads to a D associated Cas being degraded. When a new DD is fused to a protein of interest, its instability is conferred to the protein of interest, resulting in the rapid degradation of the entire fusion protein. Peak activity for Cas is sometimes beneficial to reduce off-target effects. Thus, short bursts of high activity are preferred. The present invention is able to provide such peaks. In some senses the system is inducible. In some other senses, the system repressed in the absence of stabilizing ligand and de-repressed in the presence of stabilizing ligand. By means of example, and without limitation, in some embodiments, the DD is ER50. A corresponding stabilizing ligand for this DD is, in some embodiments, 4HT. As such, in some embodiments, one of the at least one DDs is ER50 and a stabilizing ligand therefor is 4HT or CMP8. In some embodiments, the DD is DHFR50. A corresponding stabilizing ligand for this DD is, in some embodiments, TMP. As such, in some embodiments, one of the at least one DDs is DHFR50 and a stabilizing ligand therefor is TMP. In some embodiments, the DD is ER50. A corresponding stabilizing ligand for this DD is, in some embodiments, CMP8. CMP8 may therefore be an alternative stabilizing ligand to 4HT in the ER50 system. While it may be possible that CMP8 and 4HT can/should be used in a competitive matter, some cell types may be more susceptible to one or the other of these two ligands, and from this disclosure and the knowledge in the art the skilled person can use CMP8 and/or 4HT. More than one (the same or different) DD may be present, and may be fused for instance C-terminally, or N-terminally, or even internally at suitable locations. Having two or more DDs which are heterologous may be advantageous as it would provide a greater level of degradation control.
In some embodiments, the fusion protein as described herein may comprise a linker between the nuclease and the fusion partner (e.g. functional domain). In some embodiments, the linker is a GlySer linker.
In some embodiments, the nuclease is fused to one or more localization signals, such as nuclear localization sequences (NLSs), such as about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more NLSs. In some embodiments, the nuclease comprises about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more NLSs at or near the amino-terminus, about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more NLSs at or near the carboxy-terminus, or a combination of these (e.g. zero or at least one or more NLS at the amino-terminus and zero or at one or more NLS at the carboxy terminus). When more than one NLS is present, each may be selected independently of the others, such that a single NLS may be present in more than one copy and/or in combination with one or more other NLSs present in one or more copies. In a preferred embodiment of the invention, the nuclease comprises at most 6 NLSs. In some embodiments, an NLS is considered near the N- or C-terminus when the nearest amino acid of the NLS is within about 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 40, 50, or more amino acids along the polypeptide chain from the N- or C-terminus. Non-limiting examples of NLSs include an NLS sequence derived from: the NLS of the SV40 virus large T-antigen; the NLS from nucleoplasmin (e.g. the nucleoplasmin bipartite NLS; the c-myc NLS; the hRNPA1 M9 NLS; or the IBB domain from importin-alpha.
With particular reference to the CRISPR/Cas system as described herein, besides the Cas protein, in addition or in the alternative, the gRNA and/or tracr (where applicable) and/or tracr mate (or direct repeat) may be modified. Suitable modifications include, without limitation dead guides, escorted guides, protected guides, or guides provided with aptamers, suitable for ligating to, binding or recruiting functional domains (see e.g. also elsewhere herein the reference to synergistic activator mediators (SAM)). Mention is also made of WO/2016/049258 (FUNCTIONAL SCREENING WITH OPTIMIZED FUNCTIONAL CRISPR-CAS SYSTEMS (SAM)), WO/2016/094867 (PROTECTED GUIDE RNAS (PGRNAS); WO/2016/094872 (DEAD GUIDES FOR CRISPR TRANSCRIPTION FACTORS); WO/2016/094874 (ESCORTED AND FUNCTIONALIZED GUIDES FOR CRISPR-CAS SYSTEMS); all incorporated herein by reference. In certain embodiments, the tracr sequence (where appropriate) and/or tracr mate sequence (direct repeat), may comprise one or more protein-interacting RNA aptamers. The one or more aptamers may be located in the tetraloop and/or stemloop 2 of the tracr sequence. The one or more aptamers may be capable of binding MS2 bacteriophage coat protein. In certain embodiments, the gRNA (or trace or tracr mate) is modified by truncations, and/or incorporation of one or more mismatches vis-à-vis the intended target sequence or sequence to hybridize with.
By means of further guidance, and without limitation, in certain embodiments, the gRNA is a dead gRNA (dgRNA), which are guide sequences which are modified in a manner which allows for formation of the CRISPR complex and successful binding to the target, while at the same time, not allowing for successful nuclease activity (i.e. without nuclease activity/without indel activity). These dead guides or dead guide sequences can be thought of as catalytically inactive or conformationally inactive with regard to nuclease activity. Several structural parameters allow for a proper framework to arrive at such dead guides. Dead guide sequences are shorter than respective guide sequences which result in active Cas-specific indel formation. Dead guides are 5%, 10%, 20%, 30%, 40%, 50%, shorter than respective guides directed to the same Cas protein leading to active Cas-specific indel formation. Guide RNA comprising a dead guide may be modified to further include elements in a manner which allow for activation or repression of gene activity, in particular protein adaptors (e.g. aptamers) as described herein elsewhere allowing for functional placement of gene effectors (e.g. activators or repressors of gene activity). One example is the incorporation of aptamers, as explained herein and in the state of the art. By engineering the gRNA comprising a dead guide to incorporate protein-interacting aptamers (Konermann et al., “Genome-scale transcription activation by an engineered CRISPR-Cas9 complex,” doi:10.1038/nature14136, incorporated herein by reference), one may assemble a synthetic transcription activation complex consisting of multiple distinct effector domains. Such may be modeled after natural transcription activation processes. For example, an aptamer, which selectively binds an effector (e.g. an activator or repressor; dimerized MS2 bacteriophage coat proteins as fusion proteins with an activator or repressor), or a protein which itself binds an effector (e.g. activator or repressor) may be appended to a dead gRNA tetraloop and/or a stem-loop 2. In the case of MS2, the fusion protein MS2-VP64 binds to the tetraloop and/or stem-loop 2 and in turn mediates transcriptional up-regulation, for example for Neurog2. Other transcriptional activators are, for example, VP64. P65, HSF1, and MyoD1. By mere example of this concept, replacement of the MS2 stem-loops with PP7-interacting stem-loops may be used to recruit repressive elements.
By means of further guidance, and without limitation, in certain embodiments, the gRNA is an escorted gRNA (egRNA). By “escorted” is meant that the CRISPR-Cas system or complex or guide is delivered to a selected time or place within a cell, so that activity of the CRISPR-Cas system or complex or guide is spatially or temporally controlled. For example, the activity and destination of the CRISPR-Cas system or complex or guide may be controlled by an escort RNA aptamer sequence that has binding affinity for an aptamer ligand, such as a cell surface protein or other localized cellular component. Alternatively, the escort aptamer may for example be responsive to an aptamer effector on or in the cell, such as a transient effector, such as an external energy source that is applied to the cell at a particular time. The escorted Cpf1 CRISPR-Cas systems or complexes have a gRNA with a functional structure designed to improve gRNA structure, architecture, stability, genetic expression, or any combination thereof. Such a structure can include an aptamer. Aptamers are biomolecules that can be designed or selected to bind tightly to other ligands, for example using a technique called systematic evolution of ligands by exponential enrichment (SELEX; Tuerk C, Gold L: “Systematic evolution of ligands by exponential enrichment: RNA ligands to bacteriophage T4 DNA polymerase.” Science 1990, 249:505-510). Nucleic acid aptamers can for example be selected from pools of random-sequence oligonucleotides, with high binding affinities and specificities for a wide range of biomedically relevant targets, suggesting a wide range of therapeutic utilities for aptamers (Keefe, Anthony D., Supriya Pai, and Andrew Ellington. “Aptamers as therapeutics.” Nature Reviews Drug Discovery 9.7 (2010): 537-550). These characteristics also suggest a wide range of uses for aptamers as drug delivery vehicles (Levy-Nissenbaum, Etgar, et al. “Nanotechnology and aptamers: applications in drug delivery.” Trends in biotechnology 26.8 (2008): 442-449; and, Hicke B J, Stephens A W. “Escort aptamers: a delivery service for diagnosis and therapy.” J Clin Invest 2000, 106:923-928.). Aptamers may also be constructed that function as molecular switches, responding to a que by changing properties, such as RNA aptamers that bind fluorophores to mimic the activity of green flourescent protein (Paige, Jeremy S., Karen Y. Wu, and Samie R. Jaffrey. “RNA mimics of green fluorescent protein.” Science 333.6042 (2011): 642-646). It has also been suggested that aptamers may be used as components of targeted siRNA therapeutic delivery systems, for example targeting cell surface proteins (Zhou, Jiehua, and John J. Rossi. “Aptamer-targeted cell-specific RNA interference.” Silence 1.1 (2010): 4).
By means of further guidance, and without limitation, in certain embodiments, the gRNA is a protected guide. Protected guides are designed to enhance the specificity of a Cas protein given individual guide RNAs through thermodynamic tuning of the binding specificity of the guide RNA to target nucleic acid. This is a general approach of introducing mismatches, elongation or truncation of the guide sequence to increase/decrease the number of complimentary bases vs. mismatched bases shared between a target and its potential off-target loci, in order to give thermodynamic advantage to targeted genomic loci over genomic off-targets. In certain embodiments, the guide sequence is modified by secondary structure to increase the specificity of the CRISPR-Cas system and whereby the secondary structure can protect against exonuclease activity and allow for 3′ additions to the guide sequence. In certain embodiments, a “protector RNA” is hybridized to a guide sequence, wherein the “protector RNA” is an RNA strand complementary to the 5′ end of the guide RNA (gRNA), to thereby generate a partially double-stranded gRNA. In an embodiment of the invention, protecting the mismatched bases with a perfectly complementary protector sequence decreases the likelihood of target binding to the mismatched basepairs at the 3′ end. In certain embodiments, additional sequences comprising an extented length may also be present.
Guide RNA (gRNA) extensions matching the genomic target provide gRNA protection and enhance specificity. Extension of the gRNA with matching sequence distal to the end of the spacer seed for individual genomic targets is envisaged to provide enhanced specificity. Matching gRNA extensions that enhance specificity have been observed in cells without truncation. Prediction of gRNA structure accompanying these stable length extensions has shown that stable forms arise from protective states, where the extension forms a closed loop with the gRNA seed due to complimentary sequences in the spacer extension and the spacer seed. These results demonstrate that the protected guide concept also includes sequences matching the genomic target sequence distal of the 20mer spacer-binding region. Thermodynamic prediction can be used to predict completely matching or partially matching guide extensions that result in protected gRNA states. This extends the concept of protected gRNAs to interaction between X and Z, where X will generally be of length 17-20 nt and Z is of length 1-30 nt. Thermodynamic prediction can be used to determine the optimal extension state for Z, potentially introducing small numbers of mismatches in Z to promote the formation of protected conformations between X and Z. Throughout the present application, the terms “X” and seed length (SL) are used interchangeably with the term exposed length (EpL) which denotes the number of nucleotides available for target DNA to bind; the terms “Y” and protector length (PL) are used interchangeably to represent the length of the protector; and the terms “Z”, “E”, “E′” and EL are used interchangeably to correspond to the term extended length (ExL) which represents the number of nucleotides by which the target sequence is extended. An extension sequence which corresponds to the extended length (ExL) may optionally be attached directly to the guide sequence at the 3′ end of the protected guide sequence. The extension sequence may be 2 to 12 nucleotides in length. Preferably ExL may be denoted as 0, 2, 4, 6, 8, 10 or 12 nucleotides in length. In a preferred embodiment the ExL is denoted as 0 or 4 nucleotides in length. In a more preferred embodiment the ExL is 4 nucleotides in length. The extension sequence may or may not be complementary to the target sequence. An extension sequence may further optionally be attached directly to the guide sequence at the 5′ end of the protected guide sequence as well as to the 3′ end of a protecting sequence. As a result, the extension sequence serves as a linking sequence between the protected sequence and the protecting sequence. Without wishing to be bound by theory, such a link may position the protecting sequence near the protected sequence for improved binding of the protecting sequence to the protected sequence. Addition of gRNA mismatches to the distal end of the gRNA can demonstrate enhanced specificity. The introduction of unprotected distal mismatches in Y or extension of the gRNA with distal mismatches (Z) can demonstrate enhanced specificity. This concept as mentioned is tied to X, Y, and Z components used in protected gRNAs. The unprotected mismatch concept may be further generalized to the concepts of X, Y, and Z described for protected guide RNAs.
In certain embodiments, any of the nucleases, including the modified nucleases as described herein, may be used in the methods, compositions, and kits according to the invention. In particular embodiments, nuclease activity of an unmodified nuclease may be compared with nuclease activity of any of the modified nucleases as described herein, e.g. to compare for instance off-target or on-target effects. Alternatively, nuclease activity (or a modified activity as described herein) of different modified nucleases may be compared, e.g. to compare for instance off-target or on-target effects.
Also provided herein are compositions for use in carrying out the methods of the invention. More particularly, non-naturally occurring or engineered compositions are provided which comprise one or more of the elements required to ensure genomic perturbation. In particular embodiments, the compositions comprise one or more of the (modified) DNA binding protein, and/or a guide RNA. In particular embodiments, the composition comprises a vector. In further particular embodiments, the vector comprises a polynucleotide encoding a gRNA. In particular embodiments, the vector comprises two or more guide RNAs. The two or more guide RNAs may target a different target (so as to ensure multiplex targeting) or the same target, in which case the different guide RNAs will target different sequences within the same target sequence. Where provided in a vector the different guide RNAs may be under common control of the same promotor, or may be each be under control of the same or different promoters.
In certain embodiments, a modulant may comprise silencing one or more endogenous genes.
As used herein, “gene silencing” or “gene silenced” in reference to an activity of an RNAi molecule, for example a siRNA or miRNA refers to a decrease in the mRNA level in a cell for a target gene by at least about 5%, about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 95%, about 99%, about 100% of the mRNA level found in the cell without the presence of the miRNA or RNA interference molecule. In one preferred embodiment, the mRNA levels are decreased by at least about 70%, about 80%, about 90%, about 95%, about 99%, about 100%.
As used herein, the term “RNAi” refers to any type of interfering RNA, including but not limited to, siRNAi, shRNAi, endogenous microRNA and artificial microRNA. For instance, it includes sequences previously identified as siRNA, regardless of the mechanism of down-stream processing of the RNA (i.e. although siRNAs are believed to have a specific method of in vivo processing resulting in the cleavage of mRNA, such sequences can be incorporated into the vectors in the context of the flanking sequences described herein). The term “RNAi” can include both gene silencing RNAi molecules, and also RNAi effector molecules which activate the expression of a gene.
As used herein, a “siRNA” refers to a nucleic acid that forms a double stranded RNA, which double stranded RNA has the ability to reduce or inhibit expression of a gene or target gene when the siRNA is present or expressed in the same cell as the target gene. The double stranded RNA siRNA can be formed by the complementary strands. In one embodiment, a siRNA refers to a nucleic acid that can form a double stranded siRNA. The sequence of the siRNA can correspond to the full-length target gene, or a subsequence thereof. Typically, the siRNA is at least about 15-50 nucleotides in length (e.g., each complementary sequence of the double stranded siRNA is about 15-50 nucleotides in length, and the double stranded siRNA is about 15-50 base pairs in length, preferably about 19-30 base nucleotides, preferably about 20-25 nucleotides in length, e.g., 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 nucleotides in length).
As used herein “shRNA” or “small hairpin RNA” (also called stem loop) is a type of siRNA. In one embodiment, these shRNAs are composed of a short, e.g. about 19 to about 25 nucleotide, antisense strand, followed by a nucleotide loop of about 5 to about 9 nucleotides, and the analogous sense strand. Alternatively, the sense strand can precede the nucleotide loop structure and the antisense strand can follow.
The terms “microRNA” or “miRNA” are used interchangeably herein are endogenous RNAs, some of which are known to regulate the expression of protein-coding genes at the posttranscriptional level. Endogenous microRNAs are small RNAs naturally present in the genome that are capable of modulating the productive utilization of mRNA. The term artificial microRNA includes any type of RNA sequence, other than endogenous microRNA, which is capable of modulating the productive utilization of mRNA. MicroRNA sequences have been described in publications such as Lim, et al., Genes & Development, 17, p. 991-1008 (2003), Lim et al Science 299, 1540 (2003), Lee and Ambros Science, 294, 862 (2001), Lau et al., Science 294, 858-861 (2001), Lagos-Quintana et al, Current Biology, 12, 735-739 (2002), Lagos Quintana et al, Science 294, 853-857 (2001), and Lagos-Quintana et al, RNA, 9, 175-179 (2003), which are incorporated by reference. Multiple microRNAs can also be incorporated into a precursor molecule. Furthermore, miRNA-like stem-loops can be expressed in cells as a vehicle to deliver artificial miRNAs and short interfering RNAs (siRNAs) for the purpose of modulating the expression of endogenous genes through the miRNA and or RNAi pathways.
As used herein, “double stranded RNA” or “dsRNA” refers to RNA molecules that are comprised of two strands. Double-stranded molecules include those comprised of a single RNA molecule that doubles back on itself to form a two-stranded structure. For example, the stem loop structure of the progenitor molecules from which the single-stranded miRNA is derived, called the pre-miRNA (Bartel et al. 2004. Cell 1 16:281-297), comprises a dsRNA molecule.
In certain embodiments, a modulant may comprise (i) a DNA-binding portion configured to specifically bind to the endogenous gene and (ii) an effector domain mediating a biological activity.
In certain embodiments, the DNA-binding portion may comprises a zinc finger protein or DNA-binding domain thereof, a transcription activator-like effector (TALE) protein or DNA-binding domain thereof, or an RNA-guided protein or DNA-binding domain thereof.
In certain embodiments, the DNA-binding portion may comprise (i) Cas9 or Cpf1 or any Cas protein described herein modified to eliminate its nuclease activity, or (ii) DNA-binding domain of Cas9 or Cpf1 or any Cas protein described herein.
In some embodiments the effector domain may be a transcriptional inhibitor (i.e., a repressor domain), such as an mSin interaction domain (SID). SID4X domain or a Krüppel-associated box (KRAB) or fragments of the KRAB domain. In some embodiments the effector domain may be an enhancer of transcription (i.e. an activation domain), such as the VP16, VP64 or p65 activation domain. In some embodiments, the nucleic acid binding portion may be linked, for example, with an effector domain that includes but is not limited to a transposase, integrase, recombinase, resolvase, invertase, protease, DNA methyltransferase, DNA demethylase, histone acetylase, histone deacetylase, nuclease, transcriptional repressor, transcriptional activator, transcription factor recruiting, protein nuclear-localization signal or cellular uptake signal. In some embodiments, the effector domain may be a protein domain which exhibits activities which include but are not limited to transposase activity, integrase activity, recombinase activity, resolvase activity, invertase activity, protease activity, DNA methyltransferase activity, DNA demethylase activity, histone acetylase activity, histone deacetylase activity, nuclease activity, nuclear-localization signaling activity, transcriptional repressor activity, transcriptional activator activity, transcription factor recruiting activity, or cellular uptake signaling activity. Other preferred embodiments of the invention may include any combination the activities described herein. In certain embodiments, a modulant may comprise introducing one or more endogenous genes and/or one or more exogenous genes in expressible format into the immune cell, in accordance with the practice of transgenesis as taught elsewhere in this specification.
The term “immune cell” as used throughout this specification generally encompasses any cell derived from a hematopoietic stem cell that plays a role in the immune response. The term is intended to encompass immune cells both of the innate or adaptive immune system. The immune cell as referred to herein may be a leukocyte, at any stage of differentiation (e.g., a stem cell, a progenitor cell, a mature cell) or any activation stage. Immune cells include lymphocytes (such as natural killer cells, T cells (including, e.g., thymocytes, Th or Tc; Th1, Th2, Th17, Thαβ, CD4+, CD8+, effector Th, memory Th, regulatory Th, CD4+/CD8+ thymocytes, CD4−/CD8− thymocytes, γδ T cells, etc.) or B-cells (including, e.g., pro-B cells, early pro-B cells, late pro-B cells, pre-B cells, large pre-B cells, small pre-B cells, immature or mature B-cells, producing antibodies of any isotype, T1 B-cells, T2, B-cells, naïve B-cells, GC B-cells, plasmablasts, memory B-cells, plasma cells, follicular B-cells, marginal zone B-cells, B-1 cells, B-2 cells, regulatory B cells, etc.), such as for instance, monocytes (including, e.g., classical, non-classical, or intermediate monocytes), (segmented or banded) neutrophils, eosinophils, basophils, mast cells, histiocytes, microglia, including various subtypes, maturation, differentiation, or activation stages, such as for instance hematopoietic stem cells, myeloid progenitors, lymphoid progenitors, myeloblasts, promyelocytes, myelocytes, metamyelocytes, monoblasts, promonocytes, lymphoblasts, prolymphocytes, small lymphocytes, macrophages (including, e.g., Kupffer cells, stellate macrophages, M1 or M2 macrophages), (myeloid or lymphoid) dendritic cells (including, e.g., Langerhans cells, conventional or myeloid dendritic cells, plasmacytoid dendritic cells, mDC-1, mDC-2, Mo-DC, HP-DC, veiled cells), granulocytes, polymorphonuclear cells, antigen-presenting cells (APC), etc.
The invention provides compositions and methods for modulating T cell and intestinal epithelial cell balance. As used herein, the term “modulating” includes up-regulation of, or otherwise increasing, the expression of one or more genes, down-regulation of, or otherwise decreasing, the expression of one or more genes, inhibiting or otherwise decreasing the expression, activity and/or function of one or more gene products, and/or enhancing or otherwise increasing the expression, activity and/or function of one or more gene products. The term “modulate” broadly denotes a qualitative and/or quantitative alteration, change or variation in that which is being modulated. Where modulation can be assessed quantitatively—for example, where modulation comprises or consists of a change in a quantifiable variable such as a quantifiable property of a cell or where a quantifiable variable provides a suitable surrogate for the modulation—modulation specifically encompasses both increase (e.g., activation) or decrease (e.g., inhibition) in the measured variable. The term encompasses any extent of such modulation, e.g., any extent of such increase or decrease, and may more particularly refer to statistically significant increase or decrease in the measured variable. By means of example, modulation may encompass an increase in the value of the measured variable by at least about 10%, e.g., by at least about 20%, preferably by at least about 30%, e.g., by at least about 40%, more preferably by at least about 50%, e.g., by at least about 75%, even more preferably by at least about 100%, e.g., by at least about 150%, 200%, 250%, 300%, 400% or by at least about 500%, compared to a reference situation without the modulation; or modulation may encompass a decrease or reduction in the value of the measured variable by at least about 10%, e.g., by at least about 20%, by at least about 30%, e.g., by at least about 40%, by at least about 50%, e.g., by at least about 60%, by at least about 70%, e.g., by at least about 80%, by at least about 90%, e.g., by at least about 95%, such as by at least about 96%, 97%, 98%, 99% or even by 100%, compared to a reference situation without the modulation. Preferably, modulation may be specific or selective, hence, one or more desired phenotypic aspects of a cell or cell population may be modulated without substantially altering other (unintended, undesired) phenotypic aspect(s).
In certain embodiments, an modulant may comprise altering expression and/or activity of one or more endogenous genes of the cell. The term “altered expression” denotes that the modification of the cell alters, i.e., changes or modulates, the expression of the recited gene(s) or polypeptides(s). The term “altered expression” encompasses any direction and any extent of the alteration. Hence, “altered expression” may reflect qualitative and/or quantitative change(s) of expression, and specifically encompasses both increase (e.g., activation or stimulation) or decrease (e.g., inhibition) of expression.
As used herein, the term “modulating T cell balance” includes the modulation of any of a variety of T cell-related functions and/or activities, including by way of non-limiting example, controlling or otherwise influencing the networks that regulate T cell differentiation; controlling or otherwise influencing the networks that regulate T cell maintenance, for example, over the lifespan of a T cell; controlling or otherwise influencing the networks that regulate T cell function; controlling or otherwise influencing the networks that regulate helper T cell (Th cell) differentiation; controlling or otherwise influencing the networks that regulate Th cell maintenance, for example, over the lifespan of a Th cell; controlling or otherwise influencing the networks that regulate Th cell function; controlling or otherwise influencing the networks that regulate Th17 cell differentiation; controlling or otherwise influencing the networks that regulate Th17 cell maintenance, for example, over the lifespan of a Th17 cell; controlling or otherwise influencing the networks that regulate Th17 cell function; controlling or otherwise influencing the networks that regulate regulatory T cell (Treg) differentiation; controlling or otherwise influencing the networks that regulate Treg cell maintenance, for example, over the lifespan of a Treg cell; controlling or otherwise influencing the networks that regulate Treg cell function; controlling or otherwise influencing the networks that regulate other CD4+ T cell differentiation; controlling or otherwise influencing the networks that regulate other CD4+ T cell maintenance; controlling or otherwise influencing the networks that regulate other CD4+ T cell function; manipulating or otherwise influencing the ratio of T cells such as, for example, manipulating or otherwise influencing the ratio of Th17 cells to other T cell types such as Tregs or other CD4+ T cells; manipulating or otherwise influencing the ratio of different types of Th17 cells such as, for example, pathogenic Th17 cells and non-pathogenic Th17 cells; manipulating or otherwise influencing at least one function or biological activity of a T cell; manipulating or otherwise influencing at least one function or biological activity of Th cell; manipulating or otherwise influencing at least one function or biological activity of a Treg cell; manipulating or otherwise influencing at least one function or biological activity of a Th17 cell; and/or manipulating or otherwise influencing at least one function or biological activity of another CD4+ T cell.
As used herein, the term “modulating enteric cell balance” comprises cell differentiation types, rates, activity levels, death rate, and more.
The invention provides T cell modulating agents that modulate T cell balance. For example, in some embodiments, the invention provides T cell modulating agents and methods of using these T cell modulating agents to regulate, influence or otherwise impact the level(s) of and/or balance between T cell types, e.g., between Th17 and other T cell types, for example, regulatory T cells (Tregs), and/or Th17 activity and inflammatory potential.
As used herein, terms such as “Th17 cell” and/or “Th17 phenotype” and all grammatical variations thereof refer to a differentiated T helper cell that expresses one or more cytokines selected from the group the consisting of interleukin 17A (IL-17A), interleukin 17F (IL-17F), and interleukin 17A/F heterodimer (IL17-AF). As used herein, terms such as “Th1 cell” and/or “Th1 phenotype” and all grammatical variations thereof refer to a differentiated T helper cell that expresses interferon gamma (IFNγ). As used herein, terms such as “Th2 cell” and/or “Th2 phenotype” and all grammatical variations thereof refer to a differentiated T helper cell that expresses one or more cytokines selected from the group the consisting of interleukin 4 (IL-4), interleukin 5 (IL-5) and interleukin 13 (IL-13). As used herein, terms such as “Treg cell” and/or “Treg phenotype” and all grammatical variations thereof refer to a differentiated T cell that expresses Foxp3.
For example, in some embodiments, the invention provides T cell modulating agents and methods of using these T cell modulating agents to regulate, influence or otherwise impact the level of and/or balance between Th17 phenotypes, and/or Th17 activity and inflammatory potential. Suitable T cell modulating agents include an antibody, a soluble polypeptide, a polypeptide agent, a peptide agent, a nucleic acid agent, a nucleic acid ligand, or a small molecule agent.
For example, in some embodiments, the invention provides T cell modulating agents and methods of using these T cell modulating agents to regulate, influence or otherwise impact the level of and/or balance between Th17 cell types, e.g., between pathogenic and non-pathogenic Th17 cells. For example, in some embodiments, the invention provides T cell modulating agents and methods of using these T cell modulating agents to regulate, influence or otherwise impact the level of and/or balance between pathogenic and non-pathogenic Th17 activity.
For example, in some embodiments, the invention provides T cell modulating agents and methods of using these T cell modulating agents to influence or otherwise impact the differentiation of a population of T cells, for example toward Th17 cells, with or without a specific pathogenic distinction, or away from Th17 cells, with or without a specific pathogenic distinction.
For example, in some embodiments, the invention provides T cell modulating agents and methods of using these T cell modulating agents to influence or otherwise impact the differentiation of a population of T cells, for example toward a non-Th17 T cell subset or away from a non-Th17 cell subset. For example, in some embodiments, the invention provides T cell modulating agents and methods of using these T cell modulating agents to induce T cell plasticity, i.e., converting Th17 cells into a different subtype, or into a new state.
For example, in some embodiments, the invention provides T cell modulating agents and methods of using these T cell modulating agents to induce T cell plasticity, e.g., converting Th17 cells into a different subtype, or into a new state.
For example, in some embodiments, the invention provides T cell modulating agents and methods of using these T cell modulating agents to achieve any combination of the above.
The terms “pathogenic” or “non-pathogenic” as used herein are not to be construed as implying that one cell phenotype is more desirable than the other.
In some embodiments, the invention provides a method of activating therapeutic immunity by exploiting the blockade of immune checkpoints. The progression of a productive immune response requires that a number of immunological checkpoints be passed. Immunity response is regulated by the counterbalancing of stimulatory and inhibitory signal. One skilled in the art will appreciate that the T cell modulating agents have a variety of uses. For example, the T cell modulating agents are used as therapeutic agents as described herein. The T cell modulating agents can be used as reagents in screening assays, diagnostic kits or as diagnostic tools, or these T cell modulating agents can be used in competition assays to generate therapeutic reagents.
Given the linkage between T cells and intestinal epithelial cell differentiation, function and activity, the invention also contemplates the adoptive cell transfer for the modulation of epithelial cells. Adoptive cell therapy or adoptive cell transfer (ACT) can refer to the transfer of cells, most commonly immune-derived cells, back into the same patient or into a new recipient host with the goal of transferring the immunologic functionality and characteristics into the new host. If possible, use of autologous cells helps the recipient by minimizing GVHD issues. The adoptive transfer of autologous tumor infiltrating lymphocytes (TIL) (Besser et al., (2010) Clin. Cancer Res 16 (9) 2646-55; Dudley et al., (2002) Science 298 (5594): 850-4; and Dudley et al., (2005) Journal of Clinical Oncology 23 (10): 2346-57.) or genetically re-directed peripheral blood mononuclear cells (Johnson et al., (2009) Blood 114 (3): 535-46; and Morgan et al., (2006) Science 314(5796) 126-9) has been used to successfully treat patients with advanced solid tumors, including melanoma and colorectal carcinoma, as well as patients with CD19-expressing hematologic malignancies (Kalos et al., (2011) Science Translational Medicine 3 (95): 95ra73).
Aspects of the invention involve the adoptive transfer of immune system cells, such as T cells, specific for selected antigens, such as tumor associated antigens (see Maus et al., 2014, Adoptive Immunotherapy for Cancer or Viruses, Annual Review of Immunology, Vol. 32: 189-225; Rosenberg and Restifo, 2015, Adoptive cell transfer as personalized immunotherapy for human cancer, Science Vol. 348 no. 6230 pp. 62-68; Restifo et al., 2015, Adoptive immunotherapy for cancer: harnessing the T cell response. Nat. Rev. Immunol. 12(4): 269-281; and Jenson and Riddell, 2014, Design and implementation of adoptive therapy with chimeric antigen receptor-modified T cells. Immunol Rev. 257(1): 127-144). Various strategies may, for example, be employed to genetically modify T cells by altering the specificity of the T cell receptor (TCR), for example, by introducing new TCR a and 3 chains with selected peptide specificity (see U.S. Pat. No. 8,697,854; PCT Patent Publications: WO2003020763, WO2004033685, WO2004044004, WO2005114215, WO2006000830, WO2008038002, WO2008039818, WO2004074322, WO2005113595, WO2006125962, WO2013166321, WO2013039889, WO2014018863, WO2014083173; U.S. Pat. No. 8,088,379).
As an alternative to, or addition to, TCR modifications, chimeric antigen receptors (CARs) may be used in order to generate immunoresponsive cells, such as T cells, specific for selected targets, such as malignant cells, with a wide variety of receptor chimera constructs having been described (see U.S. Pat. Nos. 5,843,728; 5,851,828; 5,912,170; 6,004,811; 6,284,240; 6,392,013; 6,410,014; 6,753,162; 8,211,422; and, PCT Publication WO9215322).
In general, CARs are comprised of an extracellular domain, a transmembrane domain, and an intracellular domain, wherein the extracellular domain comprises an antigen-binding domain that is specific for a predetermined target. While the antigen-binding domain of a CAR is often an antibody or antibody fragment (e.g., a single chain variable fragment, scFv), the binding domain is not particularly limited so long as it results in specific recognition of a target. For example, in some embodiments, the antigen-binding domain may comprise a receptor, such that the CAR is capable of binding to the ligand of the receptor. Alternatively, the antigen-binding domain may comprise a ligand, such that the CAR is capable of binding the endogenous receptor of that ligand.
The antigen-binding domain of a CAR is generally separated from the transmembrane domain by a hinge or spacer. The spacer is also not particularly limited, and it is designed to provide the CAR with flexibility. For example, a spacer domain may comprise a portion of a human Fc domain, including a portion of the CH3 domain, or the hinge region of any immunoglobulin, such as IgA, IgD, IgE, IgG, or IgM, or variants thereof. Furthermore, the hinge region may be modified so as to prevent off-target binding by FcRs or other potential interfering objects. For example, the hinge may comprise an IgG4 Fc domain with or without a S228P, L235E, and/or N297Q mutation (according to Kabat numbering) in order to decrease binding to FcRs. Additional spacers/hinges include, but are not limited to, CD4, CD8, and CD28 hinge regions.
The transmembrane domain of a CAR may be derived either from a natural or from a synthetic source. Where the source is natural, the domain may be derived from any membrane-bound or transmembrane protein. Transmembrane regions of particular use in this disclosure may be derived from CD8, CD28, CD3, CD45, CD4, CD5, CDS, CD9, CD 16, CD22, CD33, CD37, CD64, CD80, CD86, CD 134, CD137, CD 154, TCR. Alternatively the transmembrane domain may be synthetic, in which case it will comprise predominantly hydrophobic residues such as leucine and valine. Preferably a triplet of phenylalanine, tryptophan and valine will be found at each end of a synthetic transmembrane domain. Optionally, a short oligo- or polypeptide linker, preferably between 2 and 10 amino acids in length may form the linkage between the transmembrane domain and the cytoplasmic signaling domain of the CAR. A glycine-serine doublet provides a particularly suitable linker.
Alternative CAR constructs may be characterized as belonging to successive generations. First-generation CARs typically consist of a single-chain variable fragment of an antibody specific for an antigen, for example comprising a VL linked to a VH of a specific antibody, linked by a flexible linker, for example by a CD8α hinge domain and a CD8α transmembrane domain, to the transmembrane and intracellular signaling domains of either CD3ζ or FcRγ (scFv-CD3ζ or scFv-FcRγ; see U.S. Pat. Nos. 7,741,465; 5,912,172; 5,906,936). Second-generation CARs incorporate the intracellular domains of one or more costimulatory molecules, such as CD28, OX40 (CD134), or 4-1BB (CD137) within the endodomain (for example scFv-CD28/OX40/4-1BB-CD3ζ; see U.S. Pat. Nos. 8,911,993; 8,916,381; 8,975,071; 9,101,584; 9,102,760; 9,102,761).
Third-generation CARs include a combination of costimulatory endodomains, such a CD3ζ-chain, CD97, GDI 1a-CD18, CD2, ICOS, CD27, CD2, CD7, LIGHT, LFA-1, NKG2C, B7-H3, CD30, CD40, PD-1, CD154, CDS, OX40, 4-1BB, or CD28 signaling domains (for example scFv-CD28-4-1BB-CD3ζ or scFv-CD28-OX40-CD3ζ; see U.S. Pat. Nos. 8,906,682; 8,399,645; 5,686,281; PCT Publication No. WO2014134165; PCT Publication No. WO2012079000). Alternatively, costimulation may be orchestrated by expressing CARs in antigen-specific T cells, chosen so as to be activated and expanded following engagement of their native αβTCR, for example by antigen on professional antigen-presenting cells, with attendant costimulation. In addition, additional engineered receptors may be provided on the immunoresponsive cells, for example to improve targeting of a T cell attack and/or minimize side effects.
Alternatively, T cells expressing CARs may be further modified to reduce or eliminate expression of endogenous TCRs in order to reduce off-target effects. Reduction or elimination of endogenous TCRs can reduce off-target effects and increase the effectiveness of the T cells (U.S. Pat. No. 9,181,527). T cells stably lacking expression of a functional TCR may be produced using a variety of approaches. T cells internalize, sort, and degrade the entire T cell receptor as a complex, with a half-life of about 10 hours in resting T cells and 3 hours in stimulated T cells (von Essen, M. et al. 2004. J. Immunol. 173:384-393). Proper functioning of the TCR complex requires the proper stoichiometric ratio of the proteins that compose the TCR complex. TCR function also requires two functioning TCR zeta proteins with ITAM motifs. The activation of the TCR upon engagement of its MHC-peptide ligand requires the engagement of several TCRs on the same T cell, which all must signal properly. Thus, if a TCR complex is destabilized with proteins that do not associate properly or cannot signal optimally, the T cell will not become activated sufficiently to begin a cellular response.
Accordingly, in some embodiments, TCR expression may be eliminated using RNA interference (e.g., shRNA, siRNA, miRNA, etc.), CRISPR, or other methods that target the nucleic acids encoding specific TCRs (e.g., TCR-α and TCR-β) and/or CD3 chains in primary T cells. By blocking expression of one or more of these proteins, the T cell will no longer produce one or more of the key components of the TCR complex, thereby destabilizing the TCR complex and preventing cell surface expression of a functional TCR.
In some instances, CAR may also comprise a switch mechanism for controlling expression and/or activation of the CAR. For example, a CAR may comprise an extracellular, transmembrane, and intracellular domain, in which the extracellular domain comprises a target-specific binding element that comprises a label, binding domain, or tag that is specific for a molecule other than the target antigen that is expressed on or by a target cell. In such embodiments, the specificity of the CAR is provided by a second construct that comprises a target antigen binding domain (e.g., an scFv or a bispecific antibody that is specific for both the target antigen and the label or tag on the CAR) and a domain that is recognized by or binds to the label, binding domain, or tag on the CAR. See, e.g., WO 2013/044225, WO 2016/000304, WO 2015/057834, WO 2015/057852, WO 2016/070061, U.S. Pat. No. 9,233,125, US 2016/0129109. In this way, a T cell that expresses the CAR can be administered to a subject, but the CAR cannot bind its target antigen until the second composition comprising an antigen-specific binding domain is administered.
Alternative switch mechanisms include CARs that require multimerization in order to activate their signaling function (see, e.g., US 2015/0368342, US 2016/0175359, US 2015/0368360) and/or an exogenous signal, such as a small molecule drug (US 2016/0166613, Yung et al., Science, 2015), in order to elicit a T cell response. Some CARs may also comprise a “suicide switch” to induce cell death of the CAR T cells following treatment (Buddee et al., PLoS One, 2013) or to downregulate expression of the CAR following binding to the target antigen (WO 2016/011210).
Various techniques may be used to transform target immunoresponsive cells, such as protoplast fusion, lipofection, transfection or electroporation. A wide variety of vectors may be used, such as retroviral vectors, lentiviral vectors, adenoviral vectors, adeno-associated viral vectors, plasmids or transposons, such as a Sleeping Beauty transposon (see U.S. Pat. Nos. 6,489,458; 7,148,203; 7,160,682; 7,985,739; 8,227,432), may be used to introduce CARs, for example using 2nd generation antigen-specific CARs signaling through CD3ζ and either CD28 or CD137. Viral vectors may for example include vectors based on HIV, SV40, EBV, HSV or BPV.
Cells that are targeted for transformation may for example include T cells, Natural Killer (NK) cells, cytotoxic T lymphocytes (CTL), regulatory T cells, human embryonic stem cells, tumor-infiltrating lymphocytes (TIL) or a pluripotent stem cell from which lymphoid cells may be differentiated. T cells expressing a desired CAR may for example be selected through co-culture with γ-irradiated activating and propagating cells (AaPC), which co-express the cancer antigen and co-stimulatory molecules. The engineered CAR T cells may be expanded, for example by co-culture on AaPC in presence of soluble factors, such as IL-2 and IL-21. This expansion may for example be carried out so as to provide memory CAR+ T cells (which may for example be assayed by non-enzymatic digital array and/or multi-panel flow cytometry). In this way, CAR T cells may be provided that have specific cytotoxic activity against antigen-bearing tumors (optionally in conjunction with production of desired chemokines such as interferon-γ). CAR T cells of this kind may for example be used in animal models, for example to treat tumor xenografts.
Approaches such as the foregoing may be adapted to provide methods of treating and/or increasing survival of a subject having a disease, such as a neoplasia, for example by administering an effective amount of an immunoresponsive cell comprising an antigen recognizing receptor that binds a selected antigen, wherein the binding activates the immunoreponsive cell, thereby treating or preventing the disease (such as a neoplasia, a pathogen infection, an autoimmune disorder, or an allogeneic transplant reaction).
In one embodiment, the treatment can be administrated into patients undergoing an immunosuppressive treatment. The cells or population of cells, may be made resistant to at least one immunosuppressive agent due to the inactivation of a gene encoding a receptor for such immunosuppressive agent. Not being bound by a theory, the immunosuppressive treatment should help the selection and expansion of the immunoresponsive or T cells according to the invention within the patient.
The administration of the cells or population of cells according to the present invention may be carried out in any convenient manner, including by aerosol inhalation, injection, ingestion, transfusion, implantation or transplantation. The cells or population of cells may be administered to a patient subcutaneously, intradermally, intratumorally, intranodally, intramedullary, intramuscularly, intrathecally, by intravenous or intralymphatic injection, or intraperitoneally. In some embodiments, the disclosed CARs may be delivered or administered into a cavity formed by the resection of tumor tissue (i.e. intracavity delivery) or directly into a tumor prior to resection (i.e. intratumoral delivery). In one embodiment, the cell compositions of the present invention are preferably administered by intravenous injection.
The administration of the cells or population of cells can consist of the administration of 104-109 cells per kg body weight, preferably 105 to 106 cells/kg body weight including all integer values of cell numbers within those ranges. Dosing in CAR T cell therapies may for example involve administration of from 106 to 109 cells/kg, with or without a course of lymphodepletion, for example with cyclophosphamide. The cells or population of cells can be administrated in one or more doses. In another embodiment, the effective amount of cells are administrated as a single dose. In another embodiment, the effective amount of cells are administrated as more than one dose over a period time. Timing of administration is within the judgment of managing physician and depends on the clinical condition of the patient. The cells or population of cells may be obtained from any source, such as a blood bank or a donor. While individual needs vary, determination of optimal ranges of effective amounts of a given cell type for a particular disease or conditions are within the skill of one in the art. An effective amount means an amount which provides a therapeutic or prophylactic benefit. The dosage administrated will be dependent upon the age, health and weight of the recipient, kind of concurrent treatment, if any, frequency of treatment and the nature of the effect desired.
In another embodiment, the effective amount of cells or composition comprising those cells are administrated parenterally. The administration can be an intravenous administration. The administration can be directly done by injection within a tumor.
To guard against possible adverse reactions, engineered immunoresponsive cells may be equipped with a transgenic safety switch, in the form of a transgene that renders the cells vulnerable to exposure to a specific signal. For example, the herpes simplex viral thymidine kinase (TK) gene may be used in this way, for example by introduction into allogeneic T lymphocytes used as donor lymphocyte infusions following stem cell transplantation (Greco, et al., Improving the safety of cell therapy with the TK-suicide gene. Front. Pharmacol. 2015; 6: 95). In such cells, administration of a nucleoside prodrug such as ganciclovir or acyclovir causes cell death. Alternative safety switch constructs include inducible caspase 9, for example triggered by administration of a small-molecule dimerizer that brings together two nonfunctional icasp9 molecules to form the active enzyme. A wide variety of alternative approaches to implementing cellular proliferation controls have been described (see U.S. Patent Publication No. 20130071414; PCT Patent Publication WO2011146862; PCT Patent Publication WO2014011987; PCT Patent Publication WO2013040371; Zhou et al. BLOOD, 2014, 123/25:3895-3905; Di Stasi et al., The New England Journal of Medicine 2011; 365:1673-1683; Sadelain M, The New England Journal of Medicine 2011; 365:1735-173; Ramos et al., Stem Cells 28(6):1107-15 (2010)).
In a further refinement of adoptive therapies, genome editing may be used to tailor immunoresponsive cells to alternative implementations, for example providing edited CAR T cells (see Poirot et al., 2015, Multiplex genome edited T cell manufacturing platform for “off-the-shelf” adoptive T cell immunotherapies, Cancer Res 75 (18): 3853). Cells may be edited using any CRISPR system and method of use thereof as described herein. CRISPR systems may be delivered to an immune cell by any method described herein. In preferred embodiments, cells are edited ex vivo and transferred to a subject in need thereof. Immunoresponsive cells, CAR T cells or any cells used for adoptive cell transfer may be edited. Editing may be performed to eliminate potential alloreactive T cell receptors (TCR), disrupt the target of a chemotherapeutic agent, block an immune checkpoint, activate a T cell, and/or increase the differentiation and/or proliferation of functionally exhausted or dysfunctional CD8+ T cells (see PCT Patent Publications: WO2013176915, WO2014059173, WO2014172606, WO2014184744, and WO2014191128). Editing may result in inactivation of a gene.
By inactivating a gene it is intended that the gene of interest is not expressed in a functional protein form. In a particular embodiment, the CRISPR system can specifically catalyze cleavage in one targeted gene thereby inactivating the targeted gene. The nucleic acid strand breaks caused are commonly repaired through the distinct mechanisms of homologous recombination or non-homologous end joining (NHEJ). However, NHEJ is an imperfect repair process that often results in changes to the DNA sequence at the site of the cleavage. Repair via NHEJ often results in small insertions or deletions (Indel) and can be used for the creation of specific gene knockouts. Cells in which a cleavage induced mutagenesis event has occurred can be identified and/or selected by well-known methods in the art.
T cell receptors (TCR) are cell surface receptors that participate in the activation of T cells in response to the presentation of antigen. The TCR is generally made from two chains, α and β, which assemble to form a heterodimer and associates with the CD3-transducing subunits to form the T cell receptor complex present on the cell surface. Each α and β chain of the TCR consists of an immunoglobulin-like N-terminal variable (V) and constant (C) region, a hydrophobic transmembrane domain, and a short cytoplasmic region. As for immunoglobulin molecules, the variable region of the α and β chains are generated by V(D)J recombination, creating a large diversity of antigen specificities within the population of T cells. However, in contrast to immunoglobulins that recognize intact antigen, T cells are activated by processed peptide fragments in association with an MHC molecule, introducing an extra dimension to antigen recognition by T cells, known as MHC restriction. Recognition of MHC disparities between the donor and recipient through the T cell receptor leads to T cell proliferation and the potential development of graft versus host disease (GVHD). The inactivation of TCRα or TCRβ can result in the elimination of the TCR from the surface of T cells preventing recognition of alloantigen and thus GVHD. However, TCR disruption generally results in the elimination of the CD3 signaling component and alters the means of further T cell expansion.
Allogeneic cells are rapidly rejected by the host immune system. It has been demonstrated that, allogeneic leukocytes present in non-irradiated blood products will persist for no more than 5 to 6 days (Boni, Muranski et al. 2008 Blood 1; 112(12):4746-54). Thus, to prevent rejection of allogeneic cells, the host's immune system usually has to be suppressed to some extent. However, in the case of adoptive cell transfer the use of immunosuppressive drugs also have a detrimental effect on the introduced therapeutic T cells. Therefore, to effectively use an adoptive immunotherapy approach in these conditions, the introduced cells would need to be resistant to the immunosuppressive treatment. Thus, in a particular embodiment, the present invention further comprises a step of modifying T cells to make them resistant to an immunosuppressive agent, preferably by inactivating at least one gene encoding a target for an immunosuppressive agent. An immunosuppressive agent is an agent that suppresses immune function by one of several mechanisms of action. An immunosuppressive agent can be, but is not limited to a calcineurin inhibitor, a target of rapamycin, an interleukin-2 receptor α-chain blocker, an inhibitor of inosine monophosphate dehydrogenase, an inhibitor of dihydrofolic acid reductase, a corticosteroid or an immunosuppressive antimetabolite. The present invention allows conferring immunosuppressive resistance to T cells for immunotherapy by inactivating the target of the immunosuppressive agent in T cells. As non-limiting examples, targets for an immunosuppressive agent can be a receptor for an immunosuppressive agent such as: CD52, glucocorticoid receptor (GR), a FKBP family gene member and a cyclophilin family gene member.
Immune checkpoints are inhibitory pathways that slow down or stop immune reactions and prevent excessive tissue damage from uncontrolled activity of immune cells. In certain embodiments, the immune checkpoint targeted is the programmed death-1 (PD-1 or CD279) gene (PDCD1). In other embodiments, the immune checkpoint targeted is cytotoxic T-lymphocyte-associated antigen (CTLA-4). In additional embodiments, the immune checkpoint targeted is another member of the CD28 and CTLA4 Ig superfamily such as BTLA, LAG3, ICOS, PDL1 or KIR. In further additional embodiments, the immune checkpoint targeted is a member of the TNFR superfamily such as CD40, OX40, CD137, GITR, CD27 or TIM-3.
Additional immune checkpoints include Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1) (Watson H A, et al., SHP-1: the next checkpoint target for cancer immunotherapy? Biochem Soc Trans. 2016 Apr. 15; 44(2):356-62). SHP-1 is a widely expressed inhibitory protein tyrosine phosphatase (PTP). In T-cells, it is a negative regulator of antigen-dependent activation and proliferation. It is a cytosolic protein, and therefore not amenable to antibody-mediated therapies, but its role in activation and proliferation makes it an attractive target for genetic manipulation in adoptive transfer strategies, such as chimeric antigen receptor (CAR) T cells. Immune checkpoints may also include T cell immunoreceptor with Ig and ITIM domains (TIGIT/Vstm3/WUCAM/VSIG9) and VISTA (Le Mercier I, et al., (2015) Beyond CTLA-4 and PD-1, the generation Z of negative checkpoint regulators. Front. Immunol. 6:418).
WO2014172606 relates to the use of MT1 and/or MT1 inhibitors to increase proliferation and/or activity of exhausted CD8+ T-cells and to decrease CD8+ T-cell exhaustion (e.g., decrease functionally exhausted or unresponsive CD8+ immune cells). In certain embodiments, metallothioneins are targeted by gene editing in adoptively transferred T cells.
In certain embodiments, targets of gene editing may be at least one targeted locus involved in the expression of an immune checkpoint protein. Such targets may include, but are not limited to CTLA4, PPP2CA, PPP2CB, PTPN6, PTPN22, PDCD1, ICOS (CD278), PDL1, KIR, LAG3, HAVCR2, BTLA, CD160, TIGIT, CD96, CRTAM, LAIR1, SIGLEC7, SIGLEC9, CD244 (2B4), TNFRSF10B, TNFRSF10A, CASP8, CASP10, CASP3, CASP6, CASP7, FADD, FAS, TGFBRII, TGFRBRI, SMAD2, SMAD3, SMAD4, SMAD10, SKI, SKIL, TGIF1, IL10RA, IL10RB, HMOX2, IL6R, IL6ST, EIF2AK4, CSK, PAG1, SIT1, FOXP3, PRDM1, BATF, VISTA, GUCY1A2, GUCY1A3, GUCY1B2, GUCY1B3, MT1, MT2, CD40, OX40, CD137, GITR, CD27, SHP-1 or TIM-3. In preferred embodiments, the gene locus involved in the expression of PD-1 or CTLA-4 genes is targeted. In other preferred embodiments, combinations of genes are targeted, such as but not limited to PD-1 and TIGIT. In preferred embodiments, the novel genes or gene combinations described herein are targeted or modulated.
In other embodiments, at least two genes are edited. Pairs of genes may include, but are not limited to PD1 and TCRα, PD1 and TCRβ, CTLA-4 and TCRα, CTLA-4 and TCRβ, LAG3 and TCRα, LAG3 and TCRβ, Tim3 and TCRα, Tim3 and TCRβ, BTLA and TCRα, BTLA and TCRβ, BY55 and TCRα, BY55 and TCRβ, TIGIT and TCRα, TIGIT and TCRβ, B7H5 and TCRα, B7H5 and TCRβ, LAIR1 and TCRα, LAIR1 and TCRβ, SIGLEC10 and TCRα, SIGLEC10 and TCRβ, 2B4 and TCRα, 2B4 and TCRβ.
Whether prior to or after genetic modification of the T cells, the T cells can be activated and expanded generally using methods as described, for example, in U.S. Pat. Nos. 6,352,694; 6,534,055; 6,905,680; 5,858,358; 6,887,466; 6,905,681; 7,144,575; 7,232,566; 7,175,843; 5,883,223; 6,905,874; 6,797,514; 6,867,041; and 7,572,631. T cells can be expanded in vitro or in vivo.
Immune cells may be obtained using any method known in the art. In one embodiment T cells that have infiltrated a tumor are isolated. T cells may be removed during surgery. T cells may be isolated after removal of tumor tissue by biopsy. T cells may be isolated by any means known in the art. In one embodiment the method may comprise obtaining a bulk population of T cells from a tumor sample by any suitable method known in the art. For example, a bulk population of T cells can be obtained from a tumor sample by dissociating the tumor sample into a cell suspension from which specific cell populations can be selected. Suitable methods of obtaining a bulk population of T cells may include, but are not limited to, any one or more of mechanically dissociating (e.g., mincing) the tumor, enzymatically dissociating (e.g., digesting) the tumor, and aspiration (e.g., as with a needle).
The bulk population of T cells obtained from a tumor sample may comprise any suitable type of T cell. Preferably, the bulk population of T cells obtained from a tumor sample comprises tumor infiltrating lymphocytes (TILs).
The tumor sample may be obtained from any mammal. Unless stated otherwise, as used herein, the term “mammal” refers to any mammal including, but not limited to, mammals of the order Logomorpha, such as rabbits; the order Carnivora, including Felines (cats) and Canines (dogs); the order Artiodactyla, including Bovines (cows) and Swines (pigs); or of the order Perssodactyla, including Equines (horses). The mammals may be non-human primates, e.g., of the order Primates, Ceboids, or Simoids (monkeys) or of the order Anthropoids (humans and apes). In some embodiments, the mammal may be a mammal of the order Rodentia, such as mice and hamsters. Preferably, the mammal is a non-human primate or a human. An especially preferred mammal is the human.
T cells can be obtained from a number of sources, including peripheral blood mononuclear cells, bone marrow, lymph node tissue, spleen tissue, and tumors. In certain embodiments of the present invention, T cells can be obtained from a unit of blood collected from a subject using any number of techniques known to the skilled artisan, such as Ficoll separation. In one preferred embodiment, cells from the circulating blood of an individual are obtained by apheresis or leukapheresis. The apheresis product typically contains lymphocytes, including T cells, monocytes, granulocytes, B cells, other nucleated white blood cells, red blood cells, and platelets. In one embodiment, the cells collected by apheresis may be washed to remove the plasma fraction and to place the cells in an appropriate buffer or media for subsequent processing steps. In one embodiment of the invention, the cells are washed with phosphate buffered saline (PBS). In an alternative embodiment, the wash solution lacks calcium and may lack magnesium or may lack many if not all divalent cations. Initial activation steps in the absence of calcium lead to magnified activation. As those of ordinary skill in the art would readily appreciate a washing step may be accomplished by methods known to those in the art, such as by using a semi-automated “flow-through” centrifuge (for example, the Cobe 2991 cell processor) according to the manufacturer's instructions. After washing, the cells may be resuspended in a variety of biocompatible buffers, such as, for example, Ca-free, Mg-free PBS. Alternatively, the undesirable components of the apheresis sample may be removed and the cells directly resuspended in culture media.
In another embodiment, T cells are isolated from peripheral blood lymphocytes by lysing the red blood cells and depleting the monocytes, for example, by centrifugation through a PERCOLL™ gradient. A specific subpopulation of T cells, such as CD28+, CD4+, CDC, CD45RA+, and CD45RO+ T cells, can be further isolated by positive or negative selection techniques. For example, in one preferred embodiment, T cells are isolated by incubation with anti-CD3/anti-CD28 (i.e., 3×28)-conjugated beads, such as DYNABEADS® M-450 CD3/CD28 T, or XCYTE DYNABEADS™ for a time period sufficient for positive selection of the desired T cells. In one embodiment, the time period is about 30 minutes. In a further embodiment, the time period ranges from 30 minutes to 36 hours or longer and all integer values there between. In a further embodiment, the time period is at least 1, 2, 3, 4, 5, or 6 hours. In yet another preferred embodiment, the time period is 10 to 24 hours. In one preferred embodiment, the incubation time period is 24 hours. For isolation of T cells from patients with leukemia, use of longer incubation times, such as 24 hours, can increase cell yield. Longer incubation times may be used to isolate T cells in any situation where there are few T cells as compared to other cell types, such in isolating tumor infiltrating lymphocytes (TIL) from tumor tissue or from immunocompromised individuals. Further, use of longer incubation times can increase the efficiency of capture of CD8+ T cells.
Enrichment of a T cell population by negative selection can be accomplished with a combination of antibodies directed to surface markers unique to the negatively selected cells. A preferred method is cell sorting and/or selection via negative magnetic immunoadherence or flow cytometry that uses a cocktail of monoclonal antibodies directed to cell surface markers present on the cells negatively selected. For example, to enrich for CD4+ cells by negative selection, a monoclonal antibody cocktail typically includes antibodies to CD14, CD20, CD11b, CD16, HLA-DR, and CD8.
Further, monocyte populations (i.e., CD14+ cells) may be depleted from blood preparations by a variety of methodologies, including anti-CD14 coated beads or columns, or utilization of the phagocytotic activity of these cells to facilitate removal. Accordingly, in one embodiment, the invention uses paramagnetic particles of a size sufficient to be engulfed by phagocytotic monocytes. In certain embodiments, the paramagnetic particles are commercially available beads, for example, those produced by Life Technologies under the trade name Dynabeads™. In one embodiment, other non-specific cells are removed by coating the paramagnetic particles with “irrelevant” proteins (e.g., serum proteins or antibodies). Irrelevant proteins and antibodies include those proteins and antibodies or fragments thereof that do not specifically target the T cells to be isolated. In certain embodiments the irrelevant beads include beads coated with sheep anti-mouse antibodies, goat anti-mouse antibodies, and human serum albumin.
In brief, such depletion of monocytes is performed by preincubating T cells isolated from whole blood, apheresed peripheral blood, or tumors with one or more varieties of irrelevant or non-antibody coupled paramagnetic particles at any amount that allows for removal of monocytes (approximately a 20:1 bead:cell ratio) for about 30 minutes to 2 hours at 22 to 37 degrees C., followed by magnetic removal of cells which have attached to or engulfed the paramagnetic particles. Such separation can be performed using standard methods available in the art. For example, any magnetic separation methodology may be used including a variety of which are commercially available, (e.g., DYNAL® Magnetic Particle Concentrator (DYNAL MPC®)). Assurance of requisite depletion can be monitored by a variety of methodologies known to those of ordinary skill in the art, including flow cytometric analysis of CD14 positive cells, before and after depletion.
For isolation of a desired population of cells by positive or negative selection, the concentration of cells and surface (e.g., particles such as beads) can be varied. In certain embodiments, it may be desirable to significantly decrease the volume in which beads and cells are mixed together (i.e., increase the concentration of cells), to ensure maximum contact of cells and beads. For example, in one embodiment, a concentration of 2 billion cells/ml is used. In one embodiment, a concentration of 1 billion cells/ml is used. In a further embodiment, greater than 100 million cells/ml is used. In a further embodiment, a concentration of cells of 10, 15, 20, 25, 30, 35, 40, 45, or 50 million cells/ml is used. In yet another embodiment, a concentration of cells from 75, 80, 85, 90, 95, or 100 million cells/ml is used. In further embodiments, concentrations of 125 or 150 million cells/ml can be used. Using high concentrations can result in increased cell yield, cell activation, and cell expansion. Further, use of high cell concentrations allows more efficient capture of cells that may weakly express target antigens of interest, such as CD28-negative T cells, or from samples where there are many tumor cells present (i.e., leukemic blood, tumor tissue, etc). Such populations of cells may have therapeutic value and would be desirable to obtain. For example, using high concentration of cells allows more efficient selection of CD8+ T cells that normally have weaker CD28 expression.
In a related embodiment, it may be desirable to use lower concentrations of cells. By significantly diluting the mixture of T cells and surface (e.g., particles such as beads), interactions between the particles and cells is minimized. This selects for cells that express high amounts of desired antigens to be bound to the particles. For example, CD4+ T cells express higher levels of CD28 and are more efficiently captured than CD8+ T cells in dilute concentrations. In one embodiment, the concentration of cells used is 5×106/ml. In other embodiments, the concentration used can be from about 1×105/ml to 1×106/ml, and any integer value in between.
T cells can also be frozen. Wishing not to be bound by theory, the freeze and subsequent thaw step provides a more uniform product by removing granulocytes and to some extent monocytes in the cell population. After a washing step to remove plasma and platelets, the cells may be suspended in a freezing solution. While many freezing solutions and parameters are known in the art and will be useful in this context, one method involves using PBS containing 20% DMSO and 8% human serum albumin, or other suitable cell freezing media, the cells then are frozen to −80° C. at a rate of 1° per minute and stored in the vapor phase of a liquid nitrogen storage tank. Other methods of controlled freezing may be used as well as uncontrolled freezing immediately at −20° C. or in liquid nitrogen.
T cells for use in the present invention may also be antigen-specific T cells. For example, tumor-specific T cells can be used. In certain embodiments, antigen-specific T cells can be isolated from a patient of interest, such as a patient afflicted with a cancer or an infectious disease. In one embodiment neoepitopes are determined for a subject and T cells specific to these antigens are isolated. Antigen-specific cells for use in expansion may also be generated in vitro using any number of methods known in the art, for example, as described in U.S. Patent Publication No. US 20040224402 entitled, Generation And Isolation of Antigen-Specific T Cells, or in U.S. Pat. No. 6,040,177. Antigen-specific cells for use in the present invention may also be generated using any number of methods known in the art, for example, as described in Current Protocols in Immunology, or Current Protocols in Cell Biology, both published by John Wiley & Sons, Inc., Boston, Mass.
In a related embodiment, it may be desirable to sort or otherwise positively select (e.g. via magnetic selection) the antigen specific cells prior to or following one or two rounds of expansion. Sorting or positively selecting antigen-specific cells can be carried out using peptide-MHC tetramers (Altman, et al., Science. 1996 Oct. 4; 274(5284):94-6). In another embodiment the adaptable tetramer technology approach is used (Andersen et al., 2012 Nat Protoc. 7:891-902). Tetramers are limited by the need to utilize predicted binding peptides based on prior hypotheses, and the restriction to specific HLAs. Peptide-MHC tetramers can be generated using techniques known in the art and can be made with any MHC molecule of interest and any antigen of interest as described herein. Specific epitopes to be used in this context can be identified using numerous assays known in the art. For example, the ability of a polypeptide to bind to MHC class I may be evaluated indirectly by monitoring the ability to promote incorporation of 125I labeled β2-microglobulin (β2m) into MHC class I/β2m/peptide heterotrimeric complexes (see Parker et al., J. Immunol. 152:163, 1994).
In one embodiment cells are directly labeled with an epitope-specific reagent for isolation by flow cytometry followed by characterization of phenotype and TCRs. In one T cells are isolated by contacting the T cell specific antibodies. Sorting of antigen-specific T cells, or generally any cells of the present invention, can be carried out using any of a variety of commercially available cell sorters, including, but not limited to, MoFlo sorter (DakoCytomation, Fort Collins, Colo.), FACSAria™, FACSArray™, FACSVantage™, BD™ LSR II, and FACSCalibur™ (BD Biosciences, San Jose, Calif.).
In a preferred embodiment, the method comprises selecting cells that also express CD3. The method may comprise specifically selecting the cells in any suitable manner. Preferably, the selecting is carried out using flow cytometry. The flow cytometry may be carried out using any suitable method known in the art. The flow cytometry may employ any suitable antibodies and stains. Preferably, the antibody is chosen such that it specifically recognizes and binds to the particular biomarker being selected. For example, the specific selection of CD3, CD8, TIM-3, LAG-3, 4-1BB, or PD-1 may be carried out using anti-CD3, anti-CD8, anti-TIM-3, anti-LAG-3, anti-4-1BB, or anti-PD-1 antibodies, respectively. The antibody or antibodies may be conjugated to a bead (e.g., a magnetic bead) or to a fluorochrome. Preferably, the flow cytometry is fluorescence-activated cell sorting (FACS). TCRs expressed on T cells can be selected based on reactivity to autologous tumors. Additionally, T cells that are reactive to tumors can be selected for based on markers using the methods described in patent publication Nos. WO2014133567 and WO2014133568, herein incorporated by reference in their entirety. Additionally, activated T cells can be selected for based on surface expression of CD107a.
In one embodiment of the invention, the method further comprises expanding the numbers of T cells in the enriched cell population. Such methods are described in U.S. Pat. No. 8,637,307 and is herein incorporated by reference in its entirety. The numbers of T cells may be increased at least about 3-fold (or 4-, 5-, 6-, 7-, 8-, or 9-fold), more preferably at least about 10-fold (or 20-, 30-, 40-, 50-, 60-, 70-, 80-, or 90-fold), more preferably at least about 100-fold, more preferably at least about 1,000 fold, or most preferably at least about 100,000-fold. The numbers of T cells may be expanded using any suitable method known in the art. Exemplary methods of expanding the numbers of cells are described in patent publication No. WO 2003057171, U.S. Pat. No. 8,034,334, and U.S. Patent Application Publication No. 2012/0244133, each of which is incorporated herein by reference.
In one embodiment, ex vivo T cell expansion can be performed by isolation of T cells and subsequent stimulation or activation followed by further expansion. In one embodiment of the invention, the T cells may be stimulated or activated by a single agent. In another embodiment, T cells are stimulated or activated with two agents, one that induces a primary signal and a second that is a co-stimulatory signal. Ligands useful for stimulating a single signal or stimulating a primary signal and an accessory molecule that stimulates a second signal may be used in soluble form. Ligands may be attached to the surface of a cell, to an Engineered Multivalent Signaling Platform (EMSP), or immobilized on a surface. In a preferred embodiment both primary and secondary agents are co-immobilized on a surface, for example a bead or a cell. In one embodiment, the molecule providing the primary activation signal may be a CD3 ligand, and the co-stimulatory molecule may be a CD28 ligand or 4-1BB ligand.
The invention provides biomarkers for the identification, diagnosis and manipulation of cell properties, for use in a variety of diagnostic and/or therapeutic indications. Biomarkers in the context of the present invention encompasses, without limitation nucleic acids, together with their polymorphisms, mutations, variants, modifications, subunits, fragments, and other analytes or sample-derived measures.
Biomarkers are useful in methods of diagnosing, prognosing and/or staging an immune response in a subject by detecting a first level of expression, activity and/or function of one or more biomarker and comparing the detected level to a control of level wherein a difference in the detected level and the control level indicates that the presence of an immune response in the subject.
These biomarkers are useful in methods of identifying patient populations at risk or suffering from an immune response based on a detected level of expression, activity and/or function of one or more biomarkers. These biomarkers are also useful in monitoring subjects undergoing treatments and therapies for suitable or abberant response(s) to determine efficaciousness of the treatment or therapy and for selecting or modifying therapies and treatments that would be efficacious in treating, delaying the progression of or otherwise ameliorating a symptom. The biomarkers provided herein are useful for selecting a group of patients at a specific state of a disease with accuracy that facilitates selection of treatments.
The present invention also may comprise a kit with a detection reagent that binds to one or more biomarkers.
Suitable T cell modulating agent(s) for use in any of the compositions and methods provided herein include an antibody, a soluble polypeptide, a polypeptide agent, a peptide agent, a nucleic acid agent, a nucleic acid ligand, or a small molecule agent. By way of non-limiting example, suitable T cell modulating agents or agents for use in combination with one or more T cell modulating agents are shown below in Table 1.
It will be appreciated that administration of therapeutic entities in accordance with the invention will be administered with suitable carriers, excipients, and other agents that are incorporated into formulations to provide improved transfer, delivery, tolerance, and the like. A multitude of appropriate formulations can be found in the formulary known to all pharmaceutical chemists: Remington's Pharmaceutical Sciences (15th ed, Mack Publishing Company, Easton, Pa. (1975)), particularly Chapter 87 by Blaug, Seymour, therein. These formulations include, for example, powders, pastes, ointments, jellies, waxes, oils, lipids, lipid (cationic or anionic) containing vesicles (such as Lipofectin™), DNA conjugates, anhydrous absorption pastes, oil-in-water and water-in-oil emulsions, emulsions carbowax (polyethylene glycols of various molecular weights), semi-solid gels, and semi-solid mixtures containing carbowax.
Any of the foregoing mixtures may be appropriate in treatments and therapies in accordance with the present invention, provided that the active ingredient in the formulation is not inactivated by the formulation and the formulation is physiologically compatible and tolerable with the route of administration. See also Baldrick P. “Pharmaceutical excipient development: the need for preclinical guidance.” Regul. Toxicol Pharmacol. 32(2):210-8 (2000), Wang W. “Lyophilization and development of solid protein pharmaceuticals.” Int. J. Pharm. 203(1-2):1-60 (2000), Charman W N “Lipids, lipophilic drugs, and oral drug delivery-some emerging concepts.” J Pharm Sci. 89(8):967-78 (2000), Powell et al. “Compendium of excipients for parenteral formulations” PDA J Pharm Sci Technol. 52:238-311 (1998) and the citations therein for additional information related to formulations, excipients and carriers well known to pharmaceutical chemists.
Diseases that may be treated by the foregoing include, without limitation, infection, inflammation, immune-related disorders or aberrant immune responses.
Diseases with an abberant or pathologic immune response include include, for example, Acquired Immunodeficiency Syndrome (AIDS, which is a viral disease with an autoimmune component), Crohn's disease, systemic lupus erythematosus, ulcerative colitis, multiple sclerosis (MS), inflammatory bowel disease and chronic and acute inflammatory disorders. Examples of inflammatory disorders include asthma, atopic allergy, allergy, eczema, glomerulonephritis, graft vs. host disease.
Administration of a modulating agent to a patient suffering from a disorder or aberrant or condition considered successful if any of a variety of laboratory or clinical objectives is achieved, such as if symptoms associated with the disorder or condition is alleviated, reduced, inhibited or does not progress to a further, i.e., worse, state.
A therapeutically effective amount of an agent relates generally to the amount needed to achieve a therapeutic objective, and will depend on the specificity of agent for its specific target, the rate and route of administration, and the like. Where polypeptide-based agents are used, the smallest fragment that specifically binds to the target and retains therapeutic function is preferred. Such fragments can be synthesized chemically and/or produced by recombinant DNA technology. (See, e.g., Marasco et al., Proc. Natl. Acad. Sci. USA, 90: 7889-7893 (1993)). The formulation can also contain more than one active compound as necessary for the particular indication being treated, preferably those with complementary activities that do not adversely affect each other.
The invention having now been described by way of written description, those of skill in the art will recognize that the invention can be practiced in a variety of embodiments and that the foregoing description and examples below are for purposes of illustration and not limitation of the claims that follow.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined in the appended claims.
The invention is further described in the following examples, which do not limit the scope of the invention described in the claims.
Here, Applicants performed an scRNA-seq survey of 53,193 epithelial cells of the small intestine (SI) in homeostasis and during infection. Applicants identified gene signatures, key transcription factors (TFs) and specific G protein-coupled receptors (GPCRs) for each major small intestinal differentiated cell type. Applicants distinguished proximal and distal enterocytes and their stem cells, established a novel classification of different enteroendocrine subtypes, and identified previously unrecognized heterogeneity within both Paneth and tuft cells. Finally, Applicants demonstrated how these cell types and states adaptively change is response to different infections.
Applicants profiled a total of 53,193 individual cells across this study (Table 2). Applicants estimated the required cell numbers using a general statistical model based on the negative binomial distribution for random sampling (Methods). There are seven known cell-types in the intestinal epithelium, and in order to provide an unbiased estimate, Applicants arbitrarily allow for as many as twice this number. The statistical framework suggested that to achieve a 99% probability of sampling at least 50 cells from each of 14 expected cell types, where the rarest cell type is present at a fraction of 1%, Applicants needed to sequence 7,500 cells (Methods).
Applicants used droplet-based massively-parallel single cell RNA-Seq24 (Methods) to transcriptionally profile EpCAM+ epithelial cells from the small intestine of C57BL/6 wild-type and Lgr5-GFP knock-in mice6 (
Unsupervised clustering of the data partitioned the cells into 15 distinct groups. First, Applicants built a k-nearest neighbor graph on a low-dimensional representation of the cellular expression data using principal component analysis (PCA), and partitioned this graph into 15 discrete clusters using the Infomap algorithm25,26, each comprising transcriptionally similar cells (Methods). The clusters, each of which contained cells from all mice and replicate experiments (
Applicants labeled the 15 clusters post hoc based on the expression of signatures of known marker genes (7
Applicants validated the atlas by independently profiling single epithelial cells that were sorted by FACS followed by an established full-length scRNA-seq protocol32 (
Relying on the high congruence between the two approaches, Applicants defined high-confidence consensus expression signatures for each cell type (Methods), highlighting known markers (corroborating the labels) and novel ones suggesting specific functions (
Next, leveraging the higher sensitivity of the plate-based, full-length scRNA-seq data, Applicants also identified enriched TFs, GPCRs and leucine-rich repeat (LRR) proteins (Methods) for each of the major cell types (
The largest components of variation (PC-1 and PC-2) between single cells in the atlas reflect the processes of proliferation and differentiation in the small intestine (
Focusing on the abundant population of enterocytes, Applicants used diffusion maps40 to place them in a pseudo-temporal order (
DC-2 captured a process of branching lineage commitment between enterocytes of the proximal (duodenum and jejunum) and distal (ileum) small intestine (
Finally, Applicants identified TFs with specific expression patterns in different regions of the diffusion map (Methods), associating regulators with early enterocyte lineage commitment (known: Sox444, and novel: Batf2, Mxd3 and Foxm1) (
Enteroendocrine cells (EECs) are key sensors of nutrients and microbial metabolites11,12 that secrete diverse hormones and function as metabolic signal transduction units146. Enteroendocrine cells (EECs) in the small intestine are a major site of hormone production, and were reported to comprise 8 distinct sub-classes, traditionally classified by the primary hormone they produce11,47,48, such that cells expressing Sct, Cck, Gcg or GIP were traditionally termed S, I, L and K cells, respectively12. However, significant crossover between traditional subtypes has been observed12,22, such that the same hormone may be expressed by more than one type. Thus, a classification based on a single “marker” hormone may not represent the true diversity and function of EECs (Gribble and Reimann, 2016), and may limit the ability in follow up studies based on these genes.
Applicants identified a cluster of EECs in both the whole SI (
Applicants then compared this ab initio taxonomy to the canonical classification by the expression of the marker hormones in each cluster (
Applicants placed each cluster of mature EECs in the new taxonomy (
Some EEC subsets are preferentially localized to specific regions of the small intestine. Specifically, SILA, expressing Ghrelin (Ghrl), the hunger hormone50, together with GCG, the incretin hormone51, are enriched in the duodenum (FDR <0.25, χ2 test, Methods), while SIL-P and SIK-P, both expressing the hormone Peptide YY, which reduces appetite upon feeding52, are found mainly in the ileum (FDR <0.1, χ2 test) (
Applicants note that a recent study53 used scRNA-seq of 145 organoid-derived EECs to identify seven subsets. The present taxonomy of 12 subsets from 533 in vivo cells includes all those mature identified subsets53, an additional three novel subsets (
Mature enterochromaffin cells (EC), EECs that secrete serotonin, regulate gut motility and secretory reflexes54 and are implicated in diverse pathologies55, partition into two clusters in the taxonomy. Both are readily identified by the expression of two canonical EC markers: Preprotachykinin-1 (Tac1), a precursor for neurokinin A and substance P, and Tryptophan hydroxylase 1 (Tph1), the rate-limiting enzyme in the biosynthesis of serotonin56 (
As enteroendocrine cells play a central role in sensing luminal nutrients, Applicants examined the expression of genes encoding GPCRs in these cells, identifying those expressed significantly higher (FDR <0.25, Mann-Whitney U-test) in a given subset (
Tuft cells are the chemosensory cells of the gut and are enriched for taste-sensing molecules148. Tuft cells, a relatively poorly characterized epithelial cell type, were recently shown to play a key role in the T helper 2 (Th2) response to parasitic worm infection, through secretion of the Interleukin-25 (Il25), a potent chemoattractant for type II innate lymphoid cells14-16.
This study obtained sets of marker genes distinguishing the absorptive and secretory lineages and noticed that the known secretory lineage marker Cd24a (Sato et al., 2009) was indeed one of the specific markers for the secretory lineage (
A previous study21 defined a tuft cell signature based on expression profiles of a bulk population of cells isolated using the cell surface marker Trpm5. The bulk signature had both neuronal and inflammation related gene modules; these could in principle be explained by either co-expression in the same cells or in distinct sub-types.
To distinguish these possibilities, Applicants re-clustered the 166 cells in the tuft cell cluster (
The Tuft-2 cell signature is enriched for immune-related genes (FDR <0.001,
As tuft cells were recently shown to be important for communication with gut-resident immune cells14-16, Applicants examined their expression of genes encoding epithelial cytokines. Both groups expressed Il25, consistent with recent findings14, but neither expressed Il33 (in both datasets) (
Finally, the Tuft-2 signature revealed that Ptprc, the gene encoding the pan-immune marker CD45, is expressed strongly and exclusively by Tuft-2 cells (
Taken together, the data suggests that tuft cells are a population of two distinct sub-types; Tuft-1 cells, with neuron-like features that may transmit taste-chemosensory signals to enteric neurons (Westphalen et al., 2014) and Tuft-2 cells with immune-like features that in addition to the taste-chemosensory ability, may communicate with immune cells, as suggested before (Gerbe et al., 2016; Howitt et al., 2016; von Moltke et al., 2016) to boost type-2 immunity upon signals from the lumen.
Surprisingly, the Tuft-2 subset expressed several of the genes previously reported to be specific to microfold (M) cells17,58, including Rac2, Siglecf and Gfi1b (Growth Factor Independent 1B Transcription Repressor), at a significantly higher mean level than Tuft-1 cells (p<1×10−5, Mann-Whitney U-test,
To distinguish between these possibilities, Applicants used both ex vivo and in vivo strategies, to determine an M cell signature at the single-cell level. First, Applicants used an ex vivo model of M cell differentiation, analyzing 5,434 cells from small intestinal organoids treated with RANKL17 for 0, 3, and 6 days (
Next, to confirm the relevance of these signatures to M cells in vivo, Applicants profiled 4,700 EpCAM+ cells from FAE of WT and Gfi1b-GFP labeled knock-in mice, a known marker for both tuft and M cells17,60 (n=5 mice). A cluster of 18 cells (
Immune and epithelial cell decisions to tolerate or elicit an immune response to specific gut pathogens play a key role in maintaining gut homeostasis2. Because the epithelial cells of the small intestine are generated in an ongoing, continuous and rapid process of differentiation from stem cells throughout life, it is likely that following infection with a pathogen, there are changes both in the relative composition of IEC sub-types and in the internal state of each type, as well as in global expression changes across multiple cell types. These three types of signals are challenging to distinguish in bulk analysis, whereas single-cell analysis can readily dissect each aspect.
Applicants therefore investigated the IEC responses to a common pathogenic bacterium, Salmonella enterica, which induces enteritis within hours61,62, and to the helminth Heligmosomoides polygyrus, a parasitic worm that damages the integrity of the small intestine and elicits a strong Th2 response63. Applicants profiled individual IECs using droplet-based 3′ scRNA-seq two days after Salmonella (n=2 mice, 1,770 cells) or 3 days (n=2 mice, 2,121 cells) and 10 days (n=2 mice, 2,711 cells) after H. polygyrus infections, as well as 3,240 cells from control mice (n=4 mice). Applicants profiled an additional 389 cells with the deeper, full-length scRNA-seq, which Applicants used to obtain high-confidence ‘consensus’ differentially expressed genes for all comparisons that are independent of cell-type.
First, Applicants investigated the global effects of infection with Salmonella. In infected IECs, 571 genes were up-regulated vs. control cells (FDR <0.25, likelihood-ratio test,
Second, Applicants identified cell-type-specific responses to Salmonella infection, most notably, an increase in the expression of both anti-microbial peptides and the mucosal pentraxin, Mptx2 (
Notably, as a result of infection, some anti-microbial genes, that are enterocyte-specific in homeostatic conditions, are induced at two levels: (1) further induction in enterocytes; and (2) global induction in non-enterocyte cells, generating an overall elevated response of the tissue. Specifically, in control mice, expression of the Reg3 gene-family (Reg3a-g) was mainly restricted to absorptive enterocytes (Table 3-4). Upon Salmonella infection not only was their expression further elevated in absorptive enterocytes (
Third, Applicants systematically distinguished the contribution of changes in cell intrinsic expression programs vs. shifts in cell composition. Applicants used unsupervised clustering to determine the proportion of each of the different IEC populations (
Next, analyzing IECs during infection with H. polygyrus, Applicants found a distinct recalibration of cell composition and cell states than in Salmonella. There are 299 genes up-regulated in H. polygyrus infected vs. control mice, 187 of which (62%) were specific to the H. polygyrus response (FDR <0.25, likelihood-ratio test,
In addition to changes in cell proportions, within goblet cells there was a strong induction (FDR <1×10−5, likelihood-ratio test;
Table 2|Summary of Single-Cell RNAseq Experiments.
This table provides the number (after quality filtering, see Methods) of individual intestinal epithelial cells profiled in each of the in this study.
Table 3|Cell-Type Specific Signature Genes—Droplet-Based Dataset.
This table provides the lists of genes specific to each of the identified clusters of intestinal epithelial cells, identified using 3′ droplet-based scRNA-seq data (
Table 4|Cell-Type Specific Signature Genes—Plate-Based Dataset.
This table provides the lists of genes specific to each of the identified clusters of intestinal epithelial cells, identified using full-length plate-based scRNA-seq data (Extended Data
Table 5|Consensus Cell-Type Specific Signature Genes—Both Datasets.
This table provides high-confidence lists of genes specific to each subtype of intestinal epithelial cells in both 3′ droplet-based and full-length plate-based scRNA-seq datasets.
Table 6|Cell-Type Specific TFs and Receptors.
This table provides lists of genes annotated as either transcription factors (TFs), G protein-coupled receptors (GPCRs), or leucine-rich repeat (LRR) proteins, enriched in each subtype of intestinal epithelial cells in full-length plate-based scRNA-seq data.
Table 7|Enteroendocrine Cell Subset Signature Genes.
This table provides the lists of genes specific to each of the identified clusters of enteroendocrine cells, identified using 3′ droplet-based scRNA-seq data.
Table 8|Consensus Tuft Cell Subset Signature Genes.
This table provides the lists of genes specific to each of the identified subsets of tuft cells, identified using both 3′ droplet-based and full-length plate-based scRNA-seq data.
Table 9|In Vitro and In Vivo M Cell Signature Genes.
This table provides the lists of genes specific to intestinal microfold (M) cells, using 3′ droplet-based scRNA-seq data from in vitro cells derived from RANKL-treated organoids, and in vivo cells derived from the follicle associated epithelia (FAE) of wild-type mice.
Table 10|Markers of Proximal and Distal Paneth Cells.
This table provides estimates of differential gene expression between two subsets of Paneth cells identified by clustering and interpreted (post-hoc) as derived from proximal and distal small intestine (
The intestinal epithelium is the most diverse epithelial tissue in the body, composed of functionally and molecularly specialized subtypes. Here, Applicants dissected it into its different components using massively parallel scRNA-seq, analyzing a total of 53,193 IECs, to create a high-resolution single-cell atlas of the mouse intestinal epithelium, and reveal even further diversity than was previously appreciated. Using unsupervised analyses, Applicants identified and characterized the transcriptomes of the major differentiated epithelial cell-types: enterocyte, goblet, Paneth, enteroendocrine, tuft and microfold. Applicants also derived specific gene signatures for intestinal stem, transit-amplifying and various enterocyte precursor cells. For each major cell-type Applicants obtained specific markers, TFs and GPCRs and high-confidence consensus signatures from two complementary scRNA-seq methods (3′ and full-length).
The single-cell profiling of tens of thousands of intestinal epithelial cells revealed coherent cell-specific transcriptional programs, some revising predicted marker expression, which Applicants validated in situ and in prospectively isolated cells. This emphasized the utility of unsupervised profiling of tissues to define new cell-type gene signatures, rather than solely relying on previously annotated individual marker genes, which may lead to biased isolation of subtypes. For example, Applicants discovered and validated that tuft cells are composed of two subsets, one of which expresses neuron-related genes which might mediate interaction with the enteric nervous system, while the other expresses genes related to inflammation and immunity, including the immune-cell marker gene Ptprc (CD45). This CD45+ tuft population expresses the epithelial cytokine TSLP, which may represent an additional mechanism by which epithelial cells communicate with gut-resident immune cells. Further studies would be required to determine whether the Tuft-1 and Tuft-2 cells represent two different developmental fates, or alternative cell states. In another example, Applicants found that several known tuft cell markers are also expressed by M cells, which may have confounded studies based on those markers. Using single-cell profiling Applicants resolve this ambiguity, providing novel specific markers and TFs to distinguish these rare cells, which may enable further insights into M cell biology.
The large number of cells profiled allowed Applicants to assess heterogeneity even within rare subpopulations such as enteroendocrine cells (EECs). From 533 EECs extracted from 18,881 epithelial cells (Table 2), Applicants identified and characterized the transcriptomes of 12 subsets, 8 of which are mature. Interestingly, EECs were more abundant than expected and partitioned into two main groups, enterochromaffin (2 subsets) and Secretinhigh (6 subsets) cells (
IECs play barrier roles, absorb nutrients, integrate and relay signals from the environment to the immune and enteric nervous systems12. The atlas resolves the cellular populations that are implicated in sensory pathways at unprecedented resolution. For example, Applicants found that two of the 10 most enterocyte-specific TFs were from the nuclear receptor (NR) family of proteins. These genes are crucial for sensing and metabolism of various substances. In particular, lipid homeostasis (Nr1h3), and sensing of endobiotic and xenobiotic substances, Nr1i3.
Similarly, Applicants provide an enhanced map of the GPCRs expressed by all cells, and particularly by EEC subsets. Most notably, the important cannabinoid receptor Gpr11937 was enriched in the novel SILA subset (FDR <0.05,
Although many studies have shown an expansion of goblet cells and recently tuft cells in response to parasites13-15, this analysis revealed that this dynamic restructuring of the epithelial barrier is specific to the identity of the individual pathogen and distinguished cell composition changes from changes in cell intrinsic programs. After infection with the parasitic worm H. polygyrus, there is, as reported, dramatic expansion of secretory cell types, initially an expansion of tuft cells, followed several days later by goblet cell metaplasia. While the overall Tuft cell population increased, the relative proportion of immune-like Tuft-2 subset was particularly expanded. In contrast, the pathogenic bacterium Salmonella enterica induced a strong expansion of absorptive enterocytes and Paneth cells. These dynamic shifts in epithelial composition constitute a generic response mechanism in which differentiation pathways are redirected to enhance the epithelial barrier under pathogenic insult.
These compositional changes are accompanied and enhanced by cell intrinsic changes to regulatory programs, both within specific cell types and across multiple cell types. During helminth infection, goblet cells induce the anti-parasitic molecules Retnlb, Wars and Pnliprp2. Upon Salmonella infection, Paneth cells not only increase in number, but also upregulate various genes encoding anti-microbial peptides (e.g., Lyz1, Defa5), and the mucosal pentraxin, Mptx2. Moreover, Applicants uncovered a novel epithelial cell response to Salmonella, where the expression of genes that are cell-type-specific in homeostatic conditions is broadened across multiple cell types during infection: the antimicrobial C-type lectins Reg3b and Reg3g, known to be crucial for preventing attachment of bacteria to the epithelium73, are expressed only by enterocytes in normal conditions, but were globally up-regulated by all cells following Salmonella infection. This could only be distinguished by single-cell analysis.
In single-cell RNA sequencing there is a trade-off between sequencing fewer cells deeply and sequencing many cells at a lower coverage. This study pursued both directions simultaneously for maximal information capture, and showed that the very large cell numbers achievable with droplet-based methods enabled the discovery of extremely rare subtypes (Shekhar et al., 2016), while the high coverage (an average of more than 6,000 genes detected per cell) obtained by the plate-based data enabled the detection of less abundant mRNA molecules such as transcription factors, which frequently play important regulatory roles in gut function. Further, the high number of cells this study obtained from the rapidly differentiating intestinal epithelium constitutes a dense sampling of a dynamic process, and therefore provided a high level of ‘pseudo-temporal’ resolution. This enabled Applicants to profile gradual shifts in differentiation of the absorptive enterocytes, subsequently identifying both known and novel TFs such as Gata4 (Bosse et al., 2006) and Gata5 which are expressed coherently during differentiation toward proximal or distal mature enterocyte, respectively.
This study provides a detailed reference dataset and specific hypotheses for follow-up studies, including cell-type specific gene markers, TFs and GPCRs that may open the possibilities for novel clinical interventions in pathologies such as obesity, type-2 diabetes, and allergies. For example, the Tuft-2 cells, which secrete Th2-recruiting epithelial cytokines, may provide insight into mechanisms underlying food allergies. Furthermore, the characterization of epithelial differentiation dynamics in response to two enteric pathogens, may help find ways to manipulate epithelial cell differentiation to minimize gut pathologies, such as acute or chronic gut inflammation, identify cell-specific epithelial cell markers for restitution and inflammation resolution.
Understanding the development, differentiation and function of an organ, such as the intestine, requires the identification and characterization of all of its component cell types. In the small bowel, intestinal epithelial cells (IECs) sense and respond to microbial stimuli and noxious substances, provide crucial barrier function and participate in the coordination of immune responses. Here, this study profiled 24,423 individual IECs from mouse small intestine and intestinal organoid cultures. Taken together, the examples above demonstrate that using unsupervised clustering, Applicants defined specific gene signatures for major IEC lineages, including the identification of Mptx2, a mucosal pentraxin, as a novel Paneth cell marker responsive to Salmonella infection. In addition, this study identified unexpected diversity of rare hormone-secreting enteroendocrine populations, revealing co-expression programs of gut hormone genes, previously thought to represent different enteroendocrine subtypes, and constructed a novel hierarchical classification of these cells. this study also distinguished two subtypes of Dclk1-positive tuft cells, one of which (Tuft-2) expresses both the epithelial cytokine Tslp and the pan-immune cell marker Ptprc (CD45), which has not been previously associated with any non-hematopoietic cell type.
Finally, this study characterized how the intrinsic state and proportion of these cell types are reshaped in response to Salmonella enterica and Heligmosomoides polygyrus infections. Salmonella infection led to an increased number of Paneth cells and enterocytes, and a Paneth cell-specific up-regulation of both defensins and pentraxins, including Mptx1 and Mptx2. An absorptive enterocyte-specific antimicrobial program was broadly activated across all IEC types, demonstrating a previously uncharacterized cellular plasticity in response to pathogens. In contrast, H. polygyrus led to expansion of goblet and tuft cell populations. This increase in tuft cells was driven by an expansion of the Cd45+ Tuft-2 group. The comprehensive atlas highlights new markers and transcriptional programs, novel allocation of sensory molecules to cell types and organizational principles of gut homeostasis and physiology.
Rapid generation of mature epithelial cell types in the small intestine occurs through continuous self-renewing, proliferation and differentiation of intestinal stem cells (ISCs)2. The niche that supports ISCs is composed of diverse cell types, including circulating immune cells96 However, little is known about interactions between immune cells and ISCs during homeostasis and disease, and it is unclear how niche dynamics affect eventual cell fate or the balance between self-renewal and differentiation.
Here, Applicants identify and characterize novel mechanisms for interaction between immune cells and ISCs. Using scRNA-seq, Applicants identified a putative molecular mechanism for CD4+ T cell interaction with specific subsets of Lgr5+ ISCs with enriched expression of MHC class II (MHCII) molecules and higher proliferation rates. Applicants characterized this putative interaction using scRNA-Seq and in situ analysis of canonical in vivo infection models, organoid assays, and T cell-depleted, Treg-depleted, and inducible epithelial-specific MHCII-KO mouse models. Applicants found that CD4+ T helper cells influence ISC renewal and epithelial differentiation via MHCII interaction. The study underscores the important anatomic positioning of CD4+ T cell-ISC interactions in the context of ISC renewal or contraction, gut inflammation, and tumorigenesis.
Applicants uncovered three distinct Lgr5+ crypt base columnar ISC6 states distinguished by specific proliferation rates: low-cycling (ISC-I), primed (ISC-II) and high-cycling (ISC-III). Surprisingly, MHC class II (MHCII) molecules are enriched in the two proliferative states (ISC-II and ISC-III), suggesting a novel T cell-ISC interaction. Using co-culture of intestinal organoids4 and T cells, cytokine stimulations, and in vivo mouse models, Applicants confirm that CD4+ T helper (Th) cells modulate ISCs and their differentiation, in a manner specific to the Th subtypes and their signature cytokines and that depends on MHCII expression by ISCs. In particular, mice lacking Th cells show expansion of the ISC pool, specific Treg depletion in vivo results in substantial reduction of ISC numbers, whereas specific inducible knockout of MHCII in epithelial cells in vivo results in expansion of the ISC pool. The findings show that interactions between ISCs and Th cells mediated via MHCII expressed in epithelial tissue helps orchestrate tissue-wide responses to external signals.
To identify potential mechanisms for ISC-immune cell interactions, Applicants searched for genes that are specifically expressed by ISCs compared to other gut epithelial cells and that encode cell surface or secreted proteins capable of interacting with cognate molecules on immune cells. Applicants collected full-length, high-coverage scRNA-seq (scRNA-seq) data of 1,522 EpCAM+ intestinal epithelial cells (IECs) (see above examples) from crypt-enriched small intestine of WT and Lgr5-GFP mouse models6 (Methods). Using unsupervised clustering (k-nearest neighbor (k-NN) graph-based clustering, Methods) of the 1,522 cells (table 11) Applicants identified 637 Lgr5-high (Lgr5High) stem cells (
Applicants found that CD74, the invariant chain of the MHCII complex, was highly expressed and specific to ISCs (
The three ISC subsets vary not only in their expression of the MHCII system, but also in their expression of signatures of the cell-cycle29,98 (
Applicants validated the association between the ISC subsets, MHC-II, and cell-cycle status by co-staining in situ (
Applicants hypothesized that ISCs may interact with CD4+ T helper (Th) cells via MHCII recognition and, as a consequence, CD4+ Th cells may affect ISC fate via cytokine-receptor interaction. Importantly, IECs, including ISCs, express receptors for Th cytokines interferon gamma (IFNγ), interleukin-10 (IL-10), IL-13, IL-4 and IL-17A. Furthermore, intra-vital imaging showed that CD4+ Th cells can be in very close proximity to stem cells in small intestinal crypts (
To dissect the potential interactions between T helper cells and ISCs independently of other contributions to the niche, Applicants therefore next used the intestinal organoid system4 in which immune cells are natively absent but can be added in a controlled manner123. Applicants introduced either specific CD4+ T helper subsets (
Each of the Th co-cultures or corresponding cytokine treatments resulted in a distinct modulation of the organoid ISC compartment (
The effects of Th cell subsets and cytokines on ISC numbers suggest that they affect ISC renewal potential, which in turn should affect the ability of ISCs to form organoid cultures. To test this hypothesis, Applicants assessed whether key cytokines affect ISC clonogenicity159. Applicants reseeded equal numbers of cytokine-treated organoids in new cultures and quantified the number of organoids after three days (n=6 replicates per each group, Methods). Consistent with the hypothesis, there was a significant reduction in the clonogenicity of organoids treated with the ISC-reducing cytokine L-13, whereas the ISC-expanding cytokine IL-10 induced higher clonogenicity (
Since the MHCII system is not expressed in organoids, Applicants next assessed its role in IECs in vivo by its conditional KO. Applicants crossed H2-Ab1fl/fl 132 to Villin-Cre-ERT2 133 mice, generating a mouse model of specific and inducible MHCII knockout in IECs (MHCIIΔgut). Applicants profiled 1,559 IECs from the MHCIIΔgut mice (n=5) 10 days after Tamoxifen induction and 1,617 IECs from floxed control (MHCIIfl/fl) littermates (n=5 mice). Applicants validated that MHCII is successfully knocked-out in EpCAM+ IECs (
Strikingly, the fraction of Lgr5+ cells was 31.3% higher in MHCIIΔgut mice (p<0.05, likelihood-ratio test,
Our organoid assays predicted that Th cell subsets have distinct effects on intestinal epithelial cell differentiation. To demonstrate the relevance of the T cell-ISC interaction in vivo, Applicants first assessed two T cell-deficient mouse models. First, Applicants profiled 2,967 individual IECs isolated from athymic B6 nude mice127 (n=2), characterized by T cell depletion. Unsupervised clustering revealed a markedly higher fraction of stem cells (52.5% increase, FDR<10−3, likelihood-ratio test, Methods) compared to control mice (n=6,
Our organoid assays also predicted that Treg cells promote renewal of the ISC pool. To test for this effect in vivo, Applicants used the Foxp3-DTR mouse129, in which Treg cells are specifically depleted upon application of diphtheria toxin (DT). Applicants profiled 3,387 IECs from both Foxp3-DTR (n=4) and matched control mice (n=5) treated with DT for 7 days and confirmed Treg ablation in the lamina propria (
All cell types in the Foxp3-DTR mice, including ISCs, showed strongly elevated expression of MHCII genes (p<5×10−4, likelihood-ratio test,
Previous studies of stem cell dynamics and differentiation processes136,137, focused on the role of the epithelial-intrinsic or stromal niche signals using lineage tracing. Here, Applicants investigated the possibility of interactions between adaptive immune cells and ISCs. Combining scRNA-seq with homeostatic or perturbed conditions that manipulate either T helper cells, their cytokines, or MHCII expression by epithelial cells allowed Applicants to assay comprehensive “snapshots” of ISC abundance and the fate of their progeny, followed by in silico inference of cell states and differentiation. In unperturbed mice, the expression of MHCII is high yet variable across ISCs, such that both ISC-II and III (ISCMHCII+) express high levels of the MHCII molecules, whereas ISC-I (ISCMHCII−) do not. Using controlled manipulation experiments in organoids and mice followed by scRNA-seq, Applicants established a crosstalk between Th cells and ISCs.
In particular, the in vitro and in vivo results support a model in which Th cells interact with ISCs via MHCII molecules, impacting the ISC pool and resultant differentiation pathways through their key cytokines (
Applicants assessed the potential role of MHCII in the changes in ISC state and subsequent differentiation, by again infecting mice with H. polygyrus for 3 days, but this time concurrently treating them with either MHCII-blocking or control anti-IgG antibodies, followed by scRNA-seq and cell-type identification using clustering (
Consistently, there was an increase in the fraction of cells expressing known stem cell marker genes (FDR<0.05) in iTreg-co-cultured organoids compared to control organoids. These included Soat1, Pdgfa and Glrx (
In organoids co-cultured with Th1 cells, there was a strong upregulation of Paneth cell-specific genes, especially anti-microbial peptides (AMPs) capable of enhancing type I immunity, namely Defa17, Defa24, Lyz1, Itln1, Mmp7, and Ang4 (FDR <10−4;
Based on the aformentioned observations in murine models, studies were conducted with human tissue. A biopsy was obtained from a human patient with ulcerative colitis. A separate biopsy was obtained from a patient control, i.e. without inflammatory disease. The biopsies were processed as before, on the basis of expression patterns, to identify cell types.
Applicants have generated a foundational resource in the healthy gut for: (1) Cell composition (i.e., changes in proportions of different cell types/states), (2) Cell intrinsic states (i.e., changes in gene expression within a cell type), (3) Cell-cell interactions (i.e., changes in cell-cell interaction mechanisms), and (4) the relevant cell types for each gene (e.g., GWAS genes).
Applicants used droplet-based scRNA-seq of colonoscopy samples from healthy individuals to generate the cell atlas. The samples were obtained from 10 healthy individuals (37,435 non-inflamed cells). The samples were small biopsies containing about <80,000 cells. The biopsies were fresh and dislocation and processing were performed by applicants.
Applicants were able to determine the cell of origin for genes associated with disease by genome wide association (GWAS) (e.g., IBD). Applicants show heatmaps for GWAS genes expressed in each cell type (
Applicants also show that the atlas may be used to determine cell-cell interaction mechanisms within the gut (
All mouse work was performed in accordance with the Institutional Animal Care and Use Committees (IACUC) and relevant guidelines at the Broad Institute and MIT, with protocols 0055-05-15 and 0612-058-15. Seven to ten weeks old female or male C57BL/6J wild-type, Lgr5-EGFP-IRES-CreERT2 (Lgr5-GFP), MHCII-KO, Foxp3-DTR, B6 Nude and TCRβ-KO mice, obtained from the Jackson Laboratory (Bar Harbor, Me.) or Gfi1beGFP/+ (Gfi1b-GFP) were housed under specific-pathogen-free (SPF) conditions at the Broad Institute, MIT or at the Harvard T. H. Chan School of Public Health animal facilities. MHCII-EGFP was obtained from Hidde Ploegh's lab and Lgr5-tdTomato-MHCII-EGFP and H2-Ab1fl/fl-Villin-CreERT2 (MHCIIDgut) mice were crossed for this study. All mice were housed under specific-pathogen-free (SPF) conditions at either the Broad Institute or MIT animal facilities; infection experiments were conducted at the laboratory of Dr. HN Shi, maintained under specific pathogen-free conditions at Massachusetts General Hospital (Charlestown, Mass.), with protocol 2003N000158. BrdU and EDU incorporation: EdU was injected intraperitoneally (IP) into Lgr5-GFP mice at 100 mg kg−1 for 2 or 4 hours before tissue collection.
Salmonella enterica and H. polygyrus Infection.
C57BL/6J mice (Jackson Laboratory) were infected with 200 third-stage larvae of H. polygyrus or 108 Salmonella enterica at the laboratory of Dr. HN Shi, maintained under specific pathogen-free conditions at Massachusetts General Hospital (Charlestown, Mass.), with protocol 2003N000158. H. polygyrus was propagated as previously described76. Mice were sacrificed 3 and 10 days after H. polygyrus infection. For the MHCII blocking experiment, mice infected with H. polygyrus were injected with 500 μg of blocking anti-mouse MHCII antibody (BioXCell) or Rat IgG2b isotype control (BioXCell) one-day prior to and for 2 consecutive days after H. polygyrus infection. For Salmonella enterica, mice were infected with a naturally streptomycin-resistant SL1344 strain of S. typhimurium (108 cells) as described76 and were sacrificed 48 hours after infection.
Foxp3-DTR. Foxp3 and wild-type C57BL/6J mice were injected intraperitoneally with diphtheria toxin (DT) at 22.5 ng/g body weight every other day for one week and then sacrificed.
MHCII deletion in intestinal epithelial cells. Cre activity was induced in 7-10 weeks old mice by intraperitoneal injection (IP) of Tamoxifen (SIGMA), diluted in corn oil, 4 mg per injection, 3 times, every other day. Mice were sacrificed 10 days after the first injection.
Crypt Isolation.
The small intestine of C57BL/6J wild-type, Lgr5-GFP or Gfi1b-GFP mice was isolated and rinsed in cold PBS. For all mice, crypts were isolated from the whole small intestine or the duodenum, jejunum and ileum compartment to account for regional distribution of Lgr5+ stem cells. The small intestine was extracted and rinsed in cold PBS. The tissue was opened longitudinally and sliced into small fragments roughly 0.2 cm long. The tissue was incubated in 20 mM EDTA-PBS on ice for 90 min, while shaking every 30 min. The tissue was then shaken vigorously and the supernatant was collected as fraction 1 in a new conical tube. The tissue was incubated in fresh EDTA-PBS and a new fraction was collected every 30 min. Fractions were collected until the supernatant consistent almost entirely of crypts. The final fraction (enriched for crypts) was washed twice in PBS, centrifuged at 300 g for 3 min, and dissociated with TrypLE express (Invitrogen) for 1 min at 37° C. The single cell suspension was then passed through a 40 μm filter and stained for FACS sorting for either scRNA-seq method (below) or used for organoid culture.
FAE Isolation.
Epithelial cells from the follicle associated epithelium were isolated by extracting small sections (0.5 cm) containing Peyer's patches from the small intestine of C57Bl/6J or Gfi1beGFP/+ mice.
Immune Cell Isolation.
Immune cells from the Lamina Propria were isolated enzymatically by incubating the small intestine with Liberase™ (100 ug/mL, Sigma) and DNasel (100 ug/mL, Sigma) for 30 min at 37° C. Immune cells were also isolated from the mesenteric lymph nodes (mLN). Cells were then incubated with CD3, CD4, CD45, or CD11b FACS-labeled antibodies and sorted for scRNA-seq.
For plate-based scRNA-seq experiments, a fluorescence-activated cell sorting (FACS) machine (Astrios) was used to sort a single cell into each well of a 96-well PCR plate containing 5 μl of TCL buffer with 1% 2-mercaptoethanol. For EpCAM+ isolation, cells were stained for 7AAD− (Life Technologies), CD45− (eBioscience), CD31− (eBioscience), Ter119− (eBioscience), EpCAM+ (eBioscience), and for specific epithelial cells Applicants also stained for CD24+/− (eBioscience) and c-Kit+/− (eBioscience). To enrich for specific IEC populations, cells were isolated from Lgr5-GFP mice, stained with the antibodies mentioned above and gated on GFP-high (stem cells), GFP-low (TAs), GFP−/CD24+/c-Kit+/− (secretory lineages) or GFP−/CD24−/EpCAM+ (epithelial cells). For Tuft-2 isolation, epithelial cells from 3 different mice were stained as above only this time Applicants used EpCAM+/CD45+ and sorted 2000 single cells. A population control of 200 cells was sorted into one well and a no-cell control was sorted into another well. After sorting, the plate was sealed tightly with a Microseal F and centrifuged at 800 g for 1 min. The plate was immediately frozen on dry ice and kept at −80° C. until ready for the lysate cleanup. Bulk population cells were sorted into an Eppendorf tube containing 100 μl solution of TCL with 1% 2-mercaptoethanol and stored at −80° C.
For droplet-based scRNA-seq, cells were sorted with the same parameters as described for plate-based scRNA-seq, but were sorted into an Eppendorf tube containing 50p of 0.4% BSA-PBS and stored on ice until proceeding to the GemCode Single Cell Platform or the Chromium Single Cell 3′ Library.
Plate-Based scRNA-Seq
Single Cells:
Libraries were prepared using a modified SMART-Seq2 protocol as previously reported32. Briefly, RNA lysate cleanup was preformed using RNAClean XP beads (Agencourt) followed by reverse transcription with Maxima Reverse Transcriptase (Life Technologies) and whole transcription amplification (WTA) with KAPA HotStart HIFI 2× ReadyMix (Kapa Biosystems) for 21 cycles. WTA products were purified with Ampure XP beads (Beckman Coulter), quantified with Qubit dsDNA HS Assay Kit (ThermoFisher), and assessed with a high sensitivity DNA chip (Agilent). RNA-seq libraries were constructed from purified WTA products using Nextera XT DNA Library Preparation Kit (Illumina). On each plate, the population and no-cell controls were processed using the same method as the single cells. The libraries were sequenced on an Illumina NextSeq 500.
Bulk Samples:
Bulk population samples were processed by extracting RNA with RNeasy Plus Micro Kit (Qiagen) per the manufacturer's recommendations, and then proceeding with the modified SMART-Seq2 protocol following lysate cleanup, as described above.
Droplet-Based scRNA-Seq
Single cells were processed through the GemCode Single Cell Platform using the GemCode Gel Bead, Chip and Library Kits (10× Genomics, Pleasanton, Calif.), or the Chromium Single Cell 3′ Library, Gel Bead and Chip Kits (10× Genomics, Pleasanton, Calif.), following the manufacturer's protocol. Briefly, single cells were sorted into 0.4% BSA-PBS. An input of 6,000 cells was added to each channel of a chip with a recovery rate of 1,500 cells. The cells were then partitioned into Gel Beads in Emulsion (GEMs) in the GemCode instrument, where cell lysis and barcoded reverse transcription of RNA occurred, followed by amplification, shearing and 5′ adaptor and sample index attachment. Libraries were sequenced on an Illumina NextSeq 500.
Lgr5-GFP mice were intraperitoneally (IP) injected with 100 mg kg·EdU (Click-iT Plus EdU Pacific Blue Flow Cytometry Assay Kit, Thermo Fisher Scientific) for 2 hours and then sacrificed. Crypts were isolated as described above and Lrg5hi cells were FACS sorted into PBS, spun down to remove the supernatant, flash frozen and stored in −80° C. Nuclei were then isolated using EZ Prep NUC-101 (Sigma) per manufacturer's recommendation, and then incubated in the Click-iT Cocktail per manufacturer's recommendations for 30 min, washed in 1% BSA-PBS and counterstained with Vybrant DyeCyle Ruby stain (Thermo Fisher Scientific) for 15 min. Nuclei were then individually sorted into the wells of 96 well plates with TCL+1% 2-mercaptoethanol as described before14 using FACS, based on positive Ruby and either EdUhigh or EdUlow. Plate-based single nucleus RNA-seq (snRNA-Seq) was then performed as described above for scRNA-seq.
Immunofluorescence and Single-Molecule Fluorescence In Situ Hybridization (smFISH)
Immunofluorescence (IFA) and Immunohistochemistry (IHC):
Staining of small intestinal tissues was conducted as described13. Briefly, tissues were fixed for 14 hours in formalin, embedded in paraffin and cut into 5 μm thick sections. Sections were deparaffinized with standard techniques, incubated with primary antibodies overnight at 4° C. and then with secondary antibodies at RT for 30 min. Slides were mounted with Slowfade Mountant+DAPI (Life Technologies, S36964) and sealed.
Single-Molecule Fluorescence In Situ Hybridization (smFISH):
RNAScope Multiplex Flourescent Kit (Advanced Cell Diagnostics) was used per manufacturer's recommendations with the following alterations. Target Retrieval boiling time was adjusted to 12 minutes and incubation with Protease IV at 40° C. was adjusted to 8 minutes. Slides were mounted with Slowfade Mountant+DAPI (Life Technologies, S36964) and sealed.
Combined IFA and smFISH was implemented by first performing smFISH as described above, with the following changes. After Amp 4, tissue sections were washed in washing buffer, incubated with primary antibodies overnight at 4° C., washed in 1×TBST 3 times and then incubated with secondary antibodies for 30 min at room temperature. Slides were mounted with Slowfade Mountant+DAPI (Life Technologies, S36964) and sealed.
Images of tissue sections were taken with a confocal microscope Fluorview FV1200 using Kalman and sequential laser emission to reduce noise and signal overlap. Scale bars were added to each image using the confocal software FV10-ASW 3.1 Viewer. Images were overlaid and visualized using Image J software77. Quantification of proliferating stem cells. Combined IFA and smFISH images of wildtype C57BL/6J small intestinal tissues were assessed by staining for E-Cadherin to mark cell borders, the canonical proliferation marker mKi67, and either the common ISC marker Lgr5, the predicted lcISC markers (Cyp2e1 or Fgfr4) or the predicted hcISC markers (Psrc1 or Cenpf). A line was drawn to establish the bottom of the crypt, termed “stem cell zone”, and quantification was only assessed within that zone. For each ISC subset marker, more than 10 randomly chosen intact crypts were analyzed. Cells were examined by double blind quantification and were determined double positive if they coexpressed mKi67 and one of the ISC subset markers. Proliferating cells in each ISC subset was measured by calculating the fraction of double positive cells out of all cells positive for the specific ISC subset marker. Automated quantification of Lgr5 mRNA molecules in smFISH images of intestinal crypts within different mouse models (
Antibodies Used for IFA:
rabbit anti-DCLK1 (1:200, Abcam ab31704), rat anti-CD45 (1:100, Biolegend 30-F11), goat anti-ChgA (1:100, Santa Cruz Sc-1488), mouse anti-E-cadherin (1:100, BD Biosciences 610181), rabbit anti-RELMI3 (1:200, Peprotech 500-p215), rat anti-Lysozyme (1:200, Dako A0099) and anti-mouse I-A/I-E (1:100, Biolegend 107601). Alexa Fluor 488-, 594-, and 647-conjugated secondary antibodies were used and obtained from Life Technologies.
Probes Used for Single-Molecule RNAscope (Advanced Cell Diagnostics):
Cck (C1), Ghrl (C2), GCG (C3), Tph1 (C1), Reg4 (C2), TSLP (C1), Ptprc (C1) and Mptx2 (C1). Probes used for single-molecule RNAscope (Advanced Cell Diagnostics): Lgr5 (C1,C3), Cyp2e1 (C2), Psrc1 (C1), Fgfr4 (C2), Cenpf (C3), mKi67 (C1,C3).
CD4+ naïve (CD44loCD62L+CD25−) T cells were isolated from spleen and lymph nodes of 7-10 weeks old C57BL/6J mice using flow cytometry cell sorting. The purity of isolated T cell populations routinely exceeded 98%. Naïve T cells were stimulated with plate-bound anti-CD3 (145-2C11, 1 mg/ml) and anti-CD28 (PV-1, 1 mg/ml) and polarizing cytokines (Th1: 4 ng/ml IL-12; Th2: 4 ng/ml IL-4; Th17: 10 ng/ml IL-6, 2 ng/ml TGF-β1; iTreg: 5 ng/ml TGF-β1; all cytokines from R&D).
Intestinal organoid cultures
Organoid Cultures.
Following crypt isolation from the whole small intestine142, the single cell suspension was resuspended in Matrigel (BD Bioscience) with 1 μM Jagged-1 peptide (Ana-Spec). Roughly 300 crypts embedded in 25 μl of Matrigel were seeded onto each well of a 24-well plate. Once solidified, the Matrigel was incubated in 600 μl culture medium (Advanced DMEM/F12, Invitrogen) with streptomycin/penicillin and glutamatax and supplemented with EGF (100 ng/mL, Peprotech), R-Spondin-1 (600 ng/mL, R&D), Noggin (100 ng/mL, Prepotech), Y-276432 dihydrochloride monohydrate (10 μM, Tochris), N-acetyl-1-cysteine (1 μM, Sigma-Aldrich), N2 (1×, Life Technologies), B27 (1×, Life Technologies) and Wnt3A (25 ng/mL, R&D Systems). Fresh media was replaced on day 3, and organoids were passaged by dissociation with TrypLE and resuspended in new Matrigel on day 6 with a 1:3 split ratio. For selected experiments, organoids were additionally treated with RANKL (100 ng/mL, Biolegends). For T helper cell co-culture experiments, organoids were cultured with Th1, Th2, Th17 or iTregs. Roughly 10,000 T helper cells were added to each well of 500 organoids and were supplemented either to the medium or suspended in the Matrigel. Treated organoids were dissociated and subjected to scRNA-seq using both methods.
Cytokine Treated Organoids.
Organoids were additionally treated with 0.5 U/ml IFNγ, 20 ng/ml IL-13, 20 ng/ml IL-17A or 10 ng/ml IL-10 in the culture medium for 3 days. Re-seeding after cytokine treatment. 500 organoids/well were treated with cytokines, as in the cytokine treated organoids above, collected after 3 days and then re-seeded at 500 organoids/well in media without cytokines. Each day, images were taken at 2× magnification and quantification of organoids number was performed with the ImageJ software.
To generate gut-homing T cells visualized by 2P-IVM, a combination of modified protocols143,144 was used. CD4+ T cells were isolated from spleen, pLN and mLN from β-actin-RFP mice using a MACS CD4 T cell positive-selection kit (Miltenyi clone L3T4) following the manufacturer's instructions. Plates were pre-treated with 5 ug/mL anti-CD3 (clone 145-2C11) and 1 ug/mL anti-CD28 (clone 37.51) and 1 Ř106 CD4+ T cells were added to each well for a final volume of 2.5 mL in complete RPMI1640 media supplemented with all-trans Retinoic Acid (100 nM, Sigma R2625). The T cells were cultured for 96 hours before replacing half of the volume with fresh media containing 20 U/mL of rIL-2 and then cultured for another 48 hours. Before adoptive transfer into Lgr5-GFP hosts, the gut-homing phenotype was validated with flow cytometry for 4037 and CCR9 expression. 1 Ř107 cells were then transferred into recipient mice for two hours, and treated with 20 ug of anti-CD3 (clone 2C11). 2P-IVM was performed 72 hours following transfer. The small intestine was surgically exposed through a laparotomy incision. Anesthetized mice were placed on a custom-built stage with a loop of the intact small intestine fixed to a temperature-controlled metallic support to facilitate exposure of the serosal aspect to a water-immersion 20× objective (0.95 numerical aperture) of an upright microscope (Prairie Technologies). A Mai Tai Ti:sapphire laser (Spectra-Physics) was tuned between 870 nm and 900 nm for multiphoton excitation and second-harmonic generation. For dynamic analysis of cell interaction in four dimensions, several X/Y sections (512×512) with Z spacing ranging from 2 μm to 4 μm were acquired every 15-20 seconds with an electronic zoom varying from 1× to 3×. Emitted light and second harmonic signals were directed through 450/80-nm, 525/50-nm and 630/120-nm bandpass filters and detected with non-descanned detectors. Post-acquisition image analysis, volume-rendering and four-dimensional time-lapse videos were performed using Imaris software (Bitplane scientific software).
Pre-Processing of Droplet (IOX) scRNA-Seq Data.
Demultiplexing, alignment to the mm10 transcriptome and UMI-collapsing were performed using the Cellranger toolkit (version 1.0.1) provided by 10× Genomics. For each cell, Applicants quantified the number of genes for which at least one read was mapped, and then excluded all cells with either fewer than 800 detected genes. Expression values Ei,j for gene i in cell j were calculated by dividing UMI count values for gene i by the sum of the UMI counts in cell j, to normalize for differences in coverage, and then multiplying by 10,000 to create TPM-like values, and finally calculating log2(TPM+1) values. Batch correction was performed using ComBat78 as implemented in the R package sva79, using the default parametric adjustment mode. The output was a corrected expression matrix, which was used as input to further analysis.
Selection of variable genes was performed by fitting a generalized linear model to the relationship between the squared co-efficient of variation (CV) and the mean expression level in log/log space, and selecting genes that significantly deviated (P<0.05) from the fitted curve, as previously described80.
Pre-Processing of SMART-Seq2 scRNA-Seq Data.
BAM files were converted to merged, demultiplexed FASTQs using the Illumina provided Bcl2Fastq software package v2.17.1.14. Paired-end reads were mapped to the UCSC hgl9 human transcriptome using Bowtie81 with parameters “-q --phred33-quals -n 1 -e 99999999-1 25 -I 1 -X 2000 -a -m 15 -S -p 6”, which allows alignment of sequences with one mismatch. Expression levels of genes were quantified as using transcript-per-million (TPM) values calculated by RSEM82 v1.2.3 in paired-end mode. For each cell, Applicants quantified the number of genes for which at least one read was mapped, and then excluded all cells with either fewer than 3,000 detected genes or a transcriptome-mapping of less than 40%.
Selection of variable genes was performed by fitting a generalized linear model to the relationship between the squared coefficient of variation (CV) and the mean expression level in log/log space, and selecting genes that significantly deviated (p<0.05) from the fitted curve, as previously described80.
For re-analysis of published data23 (
Dimensionality Reduction Using PCA and tSNE.
Applicants restricted the expression matrix to the subsets of variable genes and high quality cells noted above, and values were centered and scaled before input to PCA, which was implemented using the R function ‘prcomp’ from the ‘stats’ package for the SMART-seq2 dataset. For the droplet dataset, Applicants used a randomized approximation to PCA, implemented using the ‘rpca’ function from the ‘rsvd’ R package, with the parameter k set to 100. This low-rank approximation was used as it is several orders of magnitude faster to compute for very wide matrices. Given that many principal components (PCs) explain very little of the variance, the signal to noise ratio can be substantially improved by selecting a subset of n ‘significant’ PCs. After PCA, significant PCs were identified using the permutation test described in83, implemented using the ‘permutationPA’ function from the ‘jackstraw’ R package. This test identified 13 and 15 significant PCs in the 10× and SMART-Seq2 datasets of
For visualization, the dimensionality of the datasets was further reduced using the ‘Barnes-hut’ approximate version of the t-distributed stochastic neighbor embedding (tSNE)84,85. This was implemented using the ‘Rtsne’ function from the ‘Rtsne’ R package using 20,000 iterations and a perplexity setting that ranged from 10 to 30 depending on the size of the dataset. Scores from the first n PCs were used as the input to tSNE, where n was determined for each dataset using the permutation test described above.
Identifying Cell Differentiation Trajectories Using Diffusion Maps.
Prior to running diffusion-map dimensionality reduction Applicants selected highly variable genes in the data as follows. Applicants first fit a null model for baseline cell-cell gene expression variability in the data based on a power-law relationship between coefficient of variation (CV) and the mean of the UMI-counts of all the expressed genes, similar to86. Next, Applicants calculated for each gene the difference between the value of its observed CV and that expected by the null model (CVdiff). The histogram of CVdiff exhibited a “fat tail”. Applicants calculated the mean μ and standard deviation σ of this distribution, and selected all genes with CVdiff>μ+1.67σ, yielding 761 genes that were used for further analysis.
Applicants performed dimensionality reduction using the diffusion map approach40. Briefly, a cell-cell transition matrix was computed using the Gaussian kernel where the kernel width was adjusted to the local neighborhood of each cell, following87. This matrix was converted to a Markovian matrix after normalization. The right eigenvectors vi (i=0, 1, 2, 3, . . . ) of this matrix were computed and sorted in the order of decreasing eigenvalues λi (i=0, 1, 2, 3, . . . ) after excluding the top eigenvector v0, corresponding to λ0=1 (which reflects the normalization constraint of the Markovian matrix). The remaining eigenvectors vi (i=1, 2 . . . ) define the diffusion map embedding and are referred to as diffusion components (DCk (k=1, 2, . . . )). Applicants noticed a spectral gap between the λ4 and the λ5, and hence retained DC1-DC4.
Removing Contaminating Immune Cells and Doublets.
Although cells were sorted prior to sequencing using EpCAM, a small number of contaminating immune cells were observed in the 10× dataset. These 264 cells were removed by an initial round of unsupervised clustering (density-based clustering of the tSNE map using ‘dbscan’88 from the R package ‘fpc’) as they formed an extremely distinct cluster. In the case of the SMART-Seq2 dataset, several cells were outliers in terms of library complexity, which could possibly correspond to more than one individual cell per sequencing library or ‘doublets’. These cells were then removed by calculating the top quantile 1% of the distribution of genes detected per cell and removing any cells in this quantile.
Cluster Analysis (e.g., k-NN Graph Based Clustering).
To cluster single cells by their expression, Applicants used an unsupervised clustering approach, based on the Infomap graph-clustering algorithm25, following approaches recently described for single-cell CyTOF data89 and scRNA-seq26. Briefly, Applicants constructed a k-nearest-neighbor (k-NN) graph on the data using, for each pair of cells, the Euclidean distance between the scores of significant PCs to identify k nearest neighbors. The parameter k was chosen to be consistent with the size of the dataset.
Specifically, k was set to 200 and 80 for the droplet dataset of 7,216 cells (
Specifically, k was set to 600, 200 and 50 for the droplet dataset of 23,177, 4,332 and 1,090 cells from combined T cell and cytokines (
The nearest neighbor graph was computed using the function ‘nng’ from the R package ‘cccd’. The k-NN graph was then used as the input to Infomap25, implemented using the ‘infomap.community’ function from the ‘igraph’ R package.
Detected clusters were mapped to cell-types or intermediate states using known markers for intestinal epithelial cell subtypes. (7
For the cluster analysis of the follicle-associated epithelium (FAE) dataset of 4700 cells, the M cells were exceedingly rare (0.38%), and therefore the ‘ClusterDP’ method90 was used to identify them, as it empirically performed better than the kNN-graph algorithm on this dataset containing such a rare subgroup. As with the kNN methods, ClusterDP was run using significant (p<0.05) PC scores (19 in this case) as input, and was implemented using the ‘findClusters’ and ‘densityClust’ functions from the ‘densityClust’ R package using parameters rho=1.1 and delta=0.25.
Detected clusters were annotated by cell types or states using known markers for IEC subtypes. Specifically, for each known epithelial type Applicants selected five canonical marker genes (e.g., Lgr5, Ascl2, Slc12a2, Axin2 and Olfm4 for stem cells, or Lyz1, Defa17, Defa22, Defa24 and Ang4 for Paneth cells), and scored all clusters for their expression (see below for signature scoring procedure). In all cases, one cluster unambiguously expressed each cell-type signature, with two exceptions: in the plate-based dataset, two clusters both expressed high levels of ISC markers (
Extracting Rare Cell-Types for Further Analysis.
The initial clustering of the whole-gut dataset (7,216 cells,
Defining Cell-Type Signatures.
To identify maximally specific genes for cell-types, Applicants ran differential expression tests between each pair of clusters for all possible pairwise comparisons. Then, for a given cluster, putative signature genes were filtered using the maximum FDR Q-value and ranked by the minimum log2 fold-change. The minimum fold-change and maximum Q-value represent the weakest effect-size across all pairwise comparisons, therefore this a stringent criterion. Cell-type signature genes shown in (
In the case of signature genes for subtypes within cell-types (
Assigning the Three ISC States to Region of Origin Using Supervised Classification.
To study the anatomical distribution of ISCs in different parts of the small intestine, Applicants used a classification approach. First, Applicants sequenced a total of 11,665 cells drawn from each of the duodenum, jejunum and ileum, and identified 2,965 of them as ISCs using unsupervised clustering as described above. Next, Applicants developed a classifier for the anatomical origin of ISCs, by compiling a discriminative feature set using the expression levels of all genes differentially expressed (FDR <0.1, Mann-Whitney U-test, log, fold-change >0.25) between stem cells from the three regions, and also the scores along the first 25 PCs. A ‘random forest’ classifier was trained on these features, and subsequently distinguished between ISCs from the three regions with an average out-of-bag accuracy of 92.9%. Finally, Applicants used the trained classifier to classify the 637 ISCs (
Cell-Cell Similarity Matrix.
To visualize heterogeneity of ISCs within the ‘Stem’ cluster (637 cells), cell-cell similarities were computed. Principal component (PC) scores for each cell were computed across the 637 cells using the R function ‘prcomp’ as described above. The distance between cell i and j was calculated as the Pearson correlation between the scores of these two cells along the first 10 PCs. This distance matrix was then hierarchically clustered using Ward's method, implemented using the R function ‘hclust’ (with the ‘method’ argument set to ‘ward.D2’), and visualized as a heatmap using the R function ‘aheatmap’ (
Cell-Cycle and ISC Subset Signatures.
To identify maximally specific genes associated with the three ISC subsets, Applicants performed differential expression tests between each possible pairwise comparison between clusters. To ensure specificity of the detected marker genes to stem cells, the set of clusters included both the three ISC subsets (3 clusters), and all other detected IEC clusters (8 clusters;
Then, for a given cluster, putative signature genes were filtered using the maximum FDR Q-value and ranked by the minimum log2(fold-change). The minimum fold-change and maximum Q-value represent the weakest effect-size across all pairwise comparisons, therefore this is a stringent criterion. ISC subset signatures (Table 3) were obtained using a maximum FDR of 0.25 and a minimum log2(fold-change) of 0.25. To exclude the explicit effect of known cell-cycle genes on the gene signature of the ISC subsets Applicants filtered out any gene annotated as directly participating in cell-cycle regulation. Annotated cell-cycle genes were downloaded from the gene ontology (GO): amigo.geneontology.org/amigo/term/GO:0007049, and any gene appearing on this list was removed from the signature gene sets.
Gene sets associated with G1/S and G2/M phases of the cell-cycle were downloaded from www.cell.com/cms/attachment/2051395126/2059328514/mmc2.xlsx [Macosko 2015]. A set of cell-cycle genes to assess overall proliferation (see below for scoring procedure) was defined as the union of the G1/S and G2/M sets.
Scoring Cells Using Signature Gene Sets.
To obtain a score for a specific set of n genes in a given cell, a ‘background’ gene set was defined to control for differences in sequencing coverage and library complexity between cells in a manner similar to29. The background gene set was selected to be similar to the genes of interest in terms of expression level. Specifically, the 10n nearest neighbors in the 2-D space defined by mean expression and detection frequency across all cells were selected. The signature score for that cell was then defined as the mean expression of the n signature genes in that cell, minus the mean expression of the 10n background genes in that cell.
Estimates of Cell Type Sampling Frequencies.
For each cell-type the probability of observing at least n cells in a sample of size k is modeled using the cumulative distribution function of a negative binomial NBcdf(k, n, p), where p is the relative abundance of this cell type. For m cell types with the same parameter p the overall probability of seeing each type at least n times is NBcdf(k; n, p){circumflex over ( )}m. Such analysis can now be performed with user specified parameters at satijalab.org/howmanycells.
EEC Dendrogram.
Average expression vectors were calculated for all 12 EEC subset clusters, using log2(TPM+1) values, and restricted to the subset of 1,361 genes identified as significantly variable between EEC susbsets (p<0.05), as described above. The average expression vectors including these genes were hierarchically clustered using the R package pvclust (Spearman distance, ward.D2 clustering method), which provides bootstrap confidence estimates on every dendrogram node, as an empirical p-value over 100,000 trials (
Cell-Type Specific TFs, GPCRs and LRRs.
A list of all genes identified as acting as transcription factors in mice was obtained from AnimalTFDB93, downloaded from: www.bioguo.org/AnimalTFDB/BrowseAllTF.php?spe=Mus_musculus. The set of G-protein coupled receptors (GPCRs) was obtained from the UniProt database, downloaded from: www.uniprot.org/uniprot/?query=family%3A%22g+protein+coupled+receptor%22+AND+organism%3A%22Mouse+%5B10090%5D%22+AND+reviewed%3Ayes&sort=score. Functional annotations for each protein (
Cell-type enriched TFs, GPCRs and LRRs were then identified by intersecting the list of genes enriched in to each cell type with the lists of TFs, GPCRs and LRRs defined above. Cell-type enriched genes were defined using the SMART-Seq2 dataset, as those with a minimum log2 fold-change of 0 and a maximum FDR of 0.5, retaining a maximum of 10 genes per cell type in
Testing for Changes in Cell Type Proportions.
Applicants model the detected number of each cell-type in each analyzed mouse as a random count variable using a Poisson process. The rate of detection is then modeled by providing the total number of cells profiled in a given mouse as an offset variable, while the condition of each mouse (treatment or control) was provided as a covariate. The model was fit using the R command ‘glm’ from the ‘stats’ package. The p-value for the significance of the effect produced by the treatment was then assessed using a Wald test on the regression coefficient.
In the case of the assessment of the significance of spatial distributions of enteroendocrine (EEC) subsets (
Testing for Shifts in Cell Proportions in Intestinal Organoids.
Under several conditions, Applicants observed dramatic changes in the frequency of epithelial cell subtypes (
Specifically, given that m and n total cells (of all cell types) are sequenced in a treatment and control condition respectively, Applicants test, for a given cell type, whether the number of k and q of observed cells of type C in total and treatment condition respectively, significantly deviates from a null model given by the hypergeometric distribution. The probability of observing these values was calculated using the R function ‘phyper’ from the ‘stats’ package, using the command:
P=phyper(q,k,m,n)
and was reported as a hypergeometric p-value.
Testing for Shifts in Cell Proportions In Vivo.
In the case of in vivo perturbation experiments (
Gene Set Enrichment and GO Analysis.
GO analysis was performed using the ‘goseq’ R package95, using significantly differentially expressed genes (FDR <0.05) as target genes, and all genes expressed with log 2(TPM+1)>3 in at least 10 cells as background.
Various modifications and variations of the described methods, pharmaceutical compositions, and kits of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific embodiments, it will be understood that it is capable of further modifications and that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those skilled in the art are intended to be within the scope of the invention. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure come within known customary practice within the art to which the invention pertains and may be applied to the essential features herein before set forth.
This application claims the benefit of U.S. Provisional Application Nos. 62/421,204, filed Nov. 11, 2016 and 62/533,653, filed Jul. 17, 2017. The entire contents of the above-identified priority applications are hereby fully incorporated herein by reference.
This invention was made with government support under Grant Nos. OD020839, DK114784, DK043351 and DK097485 awarded by the National Institutes of Health. The government has certain rights in the invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2017/060469 | 11/7/2017 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62421204 | Nov 2016 | US | |
| 62533653 | Jul 2017 | US |
