This disclosure relates to in vivo methods of identifying lipid nanoparticles that are specifically suitable for a cell of interest.
In humans, lipid nanoparticles (LNPs) have delivered mRNA to antigen-presenting cells after intramuscular administration1, 2, mRNA encoding Cas9 and sgRNA to hepatocytes after systemic administration3, and siRNA to hepatocytes after systemic administration4. These advances are tempered by clinical setbacks in which nanoparticle-mediated mRNA delivery was insufficient to treat disease5-7, underscoring the potential impact of LNPs with improved efficacy. To improve LNPs, scientists formulate them with chemically diverse lipids identified in vitro8 (cell culture) or in vivo9 (adult mammals). These efforts have led to LNPs that deliver mRNA to the lung, spleen, and immune cells in preclinical models10-15.
In addition to lipid design, clinical RNA delivery has required scientists to understand genes that influence drug delivery in vivo. In one example, LNPs were shown to deliver siRNA into hepatocytes expressing low-density lipoprotein receptor by interacting with serum apolipoprotein E in mice16. This endogenous apolipoprotein E-mediated mechanism was used in a Food and Drug Administration (FDA)-approved LNP-siRNA therapy17 and in a recent phase 1 clinical trial3. Similarly, after siRNA conjugated to modified N-Acetylgalactosamine (GalNAc) was shown to enter hepatocytes by binding asialoglycoprotein receptor (ASGPR) in mice18, GalNAc conjugates were used in FDA- and/or European Medicines Agency-approved medicines19-21 and to generate other promising clinical data22, 23. Taken together, these data demonstrate that preclinical studies revealing the biological mechanism of delivery are often necessary for clinical RNA delivery. More recently, preclinical LNP-mediated mRNA delivery has been doubled24 or reduced to nearly zero25, 26 by treating cells with small molecules that manipulate endocytic, inflammatory, or metabolic signaling, indicating that these cellular processes affect LNP delivery via yet-to-be-determined mechanisms.
Research into the biology of LNP delivery faces two key limitations, however. First, candidate genes are often identified using in vitro nanoparticle delivery. Since in vitro nanoparticle delivery does not always recapitulate in vivo nanoparticle delivery27, it was reasoned that an unbiased in vivo approach could reveal alternative gene candidates. Second, the extent to which cell heterogeneity influences LNP delivery is understudied. Several lines of evidence led us to hypothesize that cells exhibit heterogeneous responses to LNPs and that these responses influence the efficiency of mRNA therapeutics. One line of evidence is that cell heterogeneity can drive metabolic28 or immunological responses29. Metabolic changes can increase24 or decrease25 LNP delivery and increasing the robustness of immunological responses decreases LNP delivery26. Another line of evidence is that cells heterogeneously respond to hydrogels30, which are synthetic biomaterials. Finally, LNP tropism to hepatocytes, endothelial cells, and Kupffer cells can be tuned10, 11, 31, 32 by modifying LNP chemistry without using targeting ligands such as antibodies, peptides, or aptamers.
An ideal way to test this hypothesis would be to measure LNP biodistribution (i.e., LNPs entering cells), functional delivery (i.e., delivered mRNA translated into functional protein), and the cellular response to LNPs, all in single cells. An ideal readout would also be generated in transcriptionally distinct single cells, thereby enabling analysis of on- and off-target delivery in any combination of cells, including rare cell types or cell types without validated fluorescence-activated cell sorting (FACS) markers. However, techniques to generate multiomic readouts of nanoparticle delivery, let alone at the single-cell level, are not well established. Accordingly, what is needed is a screening method that can be used to identify LNPs that are uniquely suitable for specific cell or cell types based on in vivo measurements.
Other features and advantages of the inventions will be apparent from the detailed description and examples that follow.
One aspect of the disclosure is directed to in vivo methods of identifying a lipid nanoparticle optimized based on cellular state and delivery profile for delivery into a specific single cell. The methods comprise:
In another aspect, the present disclosure provides in vivo methods of identifying a lipid nanoparticle optimized based on cellular state, delivery profile, or both, for delivery into a specific single cell comprising:
The disclosure also provides beads for characterizing a lipid nanoparticle having a capture sequence with a poly-T end (a PolyA binding site) and a capture sequence with a DNA barcode capture site linked to the bead. In certain embodiments, the bead is carboxyl-coated magnetic polymer bead coated with an amine reactive oligo composed of three bead barcodes (BC1-3), a sequencing adapter (GT), two linker sequences (L1-2), an UMI and Poly A binding site and/or DNA barcode binding site comprising the nucleotide sequence of SEQ ID NO: 1 or the sequence shown in
The summary, as well as the following detailed description, is further understood when read in conjunction with the appended drawings. For the purpose of illustrating, there are shown in the drawings' exemplary embodiments of the inventions. However, the inventions are not limited to the specific methods and compositions disclosed and the inventions are not limited to the precise arrangements and instrumentalities of the embodiments depicted in the drawings. In addition, the drawings are not necessarily drawn to scale. In the drawings:
In the following detailed description of the illustrative embodiments, reference is made to the accompanying drawings that form a part hereof. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized, and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the embodiments described herein, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense.
An ideal drug delivery readout would measure LNP biodistribution (i.e., LNPs entering cells), functional delivery (i.e., delivered mRNA translated into functional protein), and the cellular response to LNPs. Moreover, it would generate these data in single cells, alongside the transcriptome of each cell, thereby creating two key advantages. First, measuring delivery in transcriptionally defined single cells makes it possible to quantify rare cell types, cell subtypes, and cells defined by a specific gene of interest (e.g., a transcription factor). In addition, since these assays do not require FACS markers, this approach could enable high-throughput screens with detailed on-/off-target delivery in animals such as non-human primates (NHPs), which do not have established FACS panels for all desired cell types. Second, since delivery is measured alongside cell response to the delivery vehicle, this approach could lead to novel insights regarding the genes and pathways that affect drug delivery. To that end, this disclosure provides for in vivo method of identifying a lipid nanoparticle that has been optimized based on cellular state and delivery profile for delivery into a specific single cell.
The in vivo method of the disclosure are unique in that they allow detection of a lipid nanoparticle in a specific cell and the response of that specific cell. The methods of disclosure thus function at the single cell level. The in vivo methods allow for simultaneous detection of the lipid nanoparticle and the cell's response by using sequencing.
The Single-Cell Nanoparticle Targeting-sequencing (SENT-seq) methods of the disclosure use uses (i) DNA barcodes to quantify how many chemically distinct LNPs target cells in the same animal, (ii) DNA tagged antibodies to measure the functional translation of LNP-delivered mRNA, and (iii) RNA sequencing to measure the transcriptome all with single-cell resolution. This disclosure uniquely provides a high-throughput in vivo drug delivery assay with single-cell resolution as well as the simultaneous determining (i) and (i). By using SENT-seq to quantify how many LNPs deliver to 17transcriptionally defined cell subtypes within the liver, the inventors have generated a newly detailed readout of on- and off-target delivery.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although any methods and materials similar or equivalent to those described herein may be used in the practice for testing of the present invention, the preferred materials and methods are described herein. In describing and claiming the present invention, the following terminology will be used.
It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
As used herein, the articles “a” and “an” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element.
As used herein when referring to a measurable value such as an amount, a temporal duration, and the like, the term “about” is meant to encompass variations of ±20% or ±10%, more preferably ±5%, even more preferably ±1%, and still more preferably ±0.1% from the specified value, as such variations are appropriate to perform the disclosed methods.
As used herein, the terms “comprising,” “including,” “containing” and “characterized by” are exchangeable, inclusive, open-ended and do not exclude additional, unrecited elements or method steps. Any recitation herein of the term “comprising,” particularly in a description of components of a composition or in a description of elements of a device, is understood to encompass those compositions and methods consisting essentially of and consisting of the recited components or elements.
As used herein, the term “consisting of” excludes any element, step, or ingredient not specified in the claim element.
Ranges: throughout this disclosure, various aspects of the invention can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, and 6. This applies regardless of the breadth of the range.
One aspect of the disclosure is directed to in vivo methods of identifying a lipid nanoparticle that has been optimized based on cellular state and delivery profile for delivery into a specific single cell. In certain embodiments, the methods identify lipid nanoparticles that do not induce toxicity or immune activation, such as e.g. during the screening method.
The methods of disclosure use lipid nanoparticles having different chemical compositions. Each of the different lipid nanoparticle comprises a DNA barcode which identifies the chemical composition of the lipid nanoparticle and a VHH antibody. These lipid nanoparticles are administered to mammalian cells in vivo.
The methods of the disclosure also include determining the cellular state in one or more cells at a single cell level that have administered the lipid nanoparticle. In certain embodiments, the methods include simultaneously determining the cellular state in one or more cells at a single cell level that have administered the lipid nanoparticle.
The determining the cellular state is achieved by measuring by sequencing expression of one or more of an inflammatory gene, a toxicity gene, and/or a cell state gene in the one or more viable cells that have been administered the lipid nanoparticle. These cells are identified based on the presence of the DNA barcode and the VHH antibody. Based on comparing the cell state and a nanoparticles, it is possible to identify which nanoparticle is optimal for delivery into the cell. When the cells have reduced expression of the one or more one of an inflammatory gene, a toxicity gene, and a cell state gene compared to a cell not administered the lipid nanoparticle are cells, the nanoparticle is optimal for delivery into the cell. In one embodiment, the method includes measuring by sequencing expression of one or more of an inflammatory gene, a toxicity gene, and a cell state gene in the one or more viable cells.
In certain embodiments, the methods also include measuring by sequencing the expression of the same one or more of an inflammatory gene, a toxicity gene, and a cell state gene in a cell that has not been contacted in the lipid nanoparticles. In other embodiments, the methods include provide the previous measurements of the same one or more of an inflammatory gene, a toxicity gene, and a cell state gene in a cell that has not been contacted in the lipid nanoparticles.
In certain embodiments, the methods include measuring the expression of at least one inflammatory gene, at least one toxicity gene, and at least one cell state gene. Alternatively, the methods include measuring (i) one or more, 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, eleven or more, twelve or more inflammatory genes; (ii) one or more, 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, eleven or more, twelve or more toxicity genes; and/or (iii) one or more, 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, eleven or more, twelve or more cell state genes.
In certain embodiments, the inflammatory gene is Apoa2, CD163, Dnajb9, Traf3, and/or combinations thereof. In other embodiments, the toxicity gene is Gsk3b, Rpto, Dnm1, Casp3, and/or combinations thereof. In alternate embodiments, the cell state gene is CDk9, Rdx, Ldir, Atm, and/or combinations thereof. In yet another embodiment, the inflammatory gene is Apoa2, CD163, Dnajb9, Traf3, and/or combinations thereof, the toxicity gene is Gsk3b, Rpto, Dnm1, Casp3, and/or combinations thereof, and/or the cell state gene is CDk9, Rdx, Ldir, Atm, and/or combinations thereof.
In addition to measuring expression of one or more of an inflammatory gene, a toxicity gene, and/or a cell state gene, the methods may include measuring by sequencing expression of one or more gene indicative of endocytosis. In certain embodiments, increased expression of one more gene indicative of endocytosis when compared to a cell not administered the lipid nanoparticle is indicative of a lipid nanoparticle having improved uptake in the cell. In certain embodiments, increased expression of one more gene indicative of endocytosis when compared to a cell not administered the lipid nanoparticle is indicative of a lipid nanoparticle having improved uptake in the cell.
The methods of the disclosure do not comprise measuring protein levels. In certain embodiments, the methods include quantifying the lipid nanoparticles in the single cell (i.e. at the single cell level). In other embodiments, the methods simultaneously identify the DNA barcode in the cell and measure expression (by sequencing) of the one or more of an inflammatory gene, a toxicity gene, and a cell state gene in the viable cells having the DNA barcode and the VHH antibody.
Additional examples of inflammatory genes that may be measured in the methods of the invention are shown in Table 1 below. In certain embodiments of the disclosure, the methods of the invention may measure expression of one or more, 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, eleven or more, twelve or more of the inflammatory genes shown in Table 1 below.
Examples of toxicity genes that may be used in the methods of the invention are shown in Table 2 below. In certain embodiments of the disclosure, the methods of the invention may measure expression of one or more, 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, eleven or more, twelve or more of the toxicity genes shown in Table 2 below.
Examples of suitable cell state genes that may be used in the methods of the invention are shown in the table below. In certain embodiments of the disclosure, the methods of the invention may measure expression of one or more, 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, eleven or more, twelve or more of the cell state genes shown in Table 3 below.
Examples of suitable endocytosis genes that may be used in the methods of the invention are shown in Table 4 below. In certain embodiments of the disclosure, the methods of the invention may measure expression of one or more, 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, eleven or more, twelve or more of the endocytosis genes shown below.
In certain embodiments of the methods, the agent that simultaneously detects the DNA barcode, the VHH antibody, and the endogenous mRNA of the cells is a bead having a capture sequence with a poly-T end (a PolyA binding site) and a capture sequence with a DNA barcode capture site. In these beads, the DNA barcode capture site is capable of binding a universal sequence found in all of the DNA barcodes. Furthermore, in certain embodiments, the poly-T end detects the VHH antibody and endogenous mRNA of the cell. In other embodiments, the bead is a carboxyl-coated magnetic polymer bead. In other embodiments, the agent is a bead as described below are as used in the Examples.
One embodiment of the disclosure is an in vivo method of identify a lipid nanoparticle that has been optimized based on cellular state and delivery profile for delivery into a specific single cell which includes the steps of:
In one embodiment, the method includes measuring the expression of one or more of an inflammatory gene, a toxicity gene, and a cell state gene in a cell that has not been contacted in the lipid nanoparticles. In another embodiment, the method includes measuring the expression of at least one inflammatory gene, at least one toxicity gene, and at least one cell state gene.
In certain embodiments, the inflammatory gene measured in the methods is selected from the group consisting of Apoa2, CD163, Dnajb9, Traf3, and combinations thereof. In other embodiments, the inflammatory gene is one or more gene shown in Table 1. In other embodiments, the toxicity gene is selected from the group consisting of Gsk3b, Rpto, Dnm1, Casp3, and combinations thereof. In additional embodiments, the toxicity gene is one or more gene shown in Table 2. In yet further embodiments, the cell state gene is selected from the group consisting of CDk9, Rdx, Ldir, Atm, and combinations thereof. In yet alternate embodiments, the cell state gene is one or more gene shown in Table 3.
In certain embodiments, the method includes measuring expression of one or more gene indicative of endocytosis and measuring the expression of one or more of an inflammatory gene, a toxicity gene, and a cell state gene in the viable cells having the DNA barcode and the VHH antibody. In some embodiments, increased expression of one more gene indicative of endocytosis when compared to a cell not administered the lipid nanoparticle is indicative of a lipid nanoparticle having improved uptake in the cell. In other embodiments, the one of more gene indicative of endocytosis is one or more gene shown in Table 4.
In one embodiment, the method identifies lipid nanoparticles that do not induce toxicity or immune activation during the screening method. In another embodiment, the method comprises simultaneously identifying the DNA barcode in the cell and measuring expression of the one or more of an inflammatory gene, a toxicity gene, and a cell state gene in the viable cells having the DNA barcode and the VHH antibody.
In certain embodiments of the method the agent that simultaneously detects the DNA barcode, the VHH antibody, and the endogenous mRNA of the cells is a bead having a capture sequence with a poly-T end (a PolyA binding site) and a capture sequence with a DNA barcode capture site. In one embodiment, the DNA barcode capture site is capable of binding a universal sequence found in all of the DNA barcodes. In another embodiment, the poly-T end detects the VHH antibody and endogenous mRNA of the cell.
In yet another embodiment, the bead is a carboxyl-coated magnetic polymer bead. In certain embodiments, the method also includes administering a lipid nanoparticle identified by the method, which contains a therapeutic agent, to a patient in need of the therapeutic agent such as e.g. a cancer patient.
The disclosure also provides beads for characterizing a lipid nanoparticle having a capture sequence with a poly-T end (a PolyA binding site) and a capture sequence with a DNA barcode capture site linked to the bead.
The DNA barcode capture site of the beads is capable of binding a universal sequence DNA sequence found in DNA barcodes for lipid nanoparticles. In certain embodiments, the DNA barcode capture site of the beads comprises the LNP barcode capture site shown in
In certain embodiments, the bead has a structure as shown in
In certain embodiments, the bead is carboxyl-coated magnetic polymer bead coated with an amine reactive oligo composed of three bead barcodes (BC1-3), a sequencing adapter (GT), two linker sequences (L1-2), an UMI and PolyA binding site and/or DNA barcode binding site comprising the nucleotide sequence of SEQ ID NO: 1 or the sequence shown in
In other embodiments, the disclosure provides for kits for characterizing a lipid nanoparticles for in vivo delivery of an agents. The kits include the beads for characterizing a lipid nanoparticles and optionally instructions for use.
The invention is now described with reference to the following Examples. These Examples are provided for the purpose of illustration only and the invention should in no way be construed as being limited to these Examples, but rather should be construed to encompass any and all variations which become evident as a result of the teaching provided herein. The described embodiments and following examples are for illustrative purposes and are not intended to limit the scope of the claims. Other modifications, uses, or combinations with respect to the compositions described herein will be apparent to a person of ordinary skill in the art without departing from the spirit and scope of the claimed subject matter.
Without further description, it is believed that one of ordinary skill in the art can, using the preceding description and the following illustrative examples, make and utilize the compounds of the present invention and practice the claimed methods. The following working examples, therefore, specifically point out the preferred embodiments of the present invention and are not to be construed as limiting in any way the remainder of the disclosure.
Cells that were previously described as homogenous are composed of subsets with distinct transcriptional states. However, it remains unclear whether this cell heterogeneity influences the efficiency with which lipid nanoparticles (LNPs) deliver mRNA therapies in vivo. To test the hypothesis that cell heterogeneity influences LNP-mediated mRNA delivery, anew method of testing multiomic nanoparticle delivery system called Single-cell Nanoparticle Targeting-sequencing (SENT-seq) was devised. SENT-seq quantifies how dozens of LNPs deliver DNA barcodes and mRNA into cells, subsequent protein production, and the transcriptome, with single-cell resolution. Using SENT-seq, it is possible to identify cell subtypes that exhibit particularly high or low LNP uptake as well as genes associated with those subtypes.
Single-Cell Readouts of Gene Expression, mRNA Delivery, and DNA Barcode Delivery
Single-cell Nanoparticle Targeting-sequencing (SENT-seq) quantifies the biodistribution of many chemically distinct LNPs, measured with DNA barcodes; the functional delivery of mRNA, measured as protein using DNA-encoded antibodies; and the transcriptome of transfected cells, measured with single-cell RNA sequencing (scRNA-seq) (see
SENT-seq was initiated by formulating LNP-1, with chemical structure 1, to carry mRNA encoding a glycosylphosphatidylinositol (GPI)-anchored camelid VHH antibody (anchored-VHH, aVHH) and DNA barcode 1 at a lipid:nucleic acid mass ratio of 10:1 using microfluidic mixing33. This process was repeated N times so that LNP-N, with chemical structure N, was formulated to carry aVHH mRNA and DNA barcode N. With DNA barcodes used to quantify biodistribution from many LNPs simultaneously, SENT-seq can test a large, chemically diverse LNP library without the need to sacrifice, sort, and sequence single cells from hundreds of mice. The aVHH, barcode, and mass ratio were rationally designed:the VHH domain was linked with a GPI anchor to induce cell-surface aVHH expression, allowing aVHH+ cells to be detected with an anti-camelid VHH antibody34; the DNA barcode (
After administering the barcoded LNP library to mice, the liver was isolated and digested into a single-cell suspension which was then mixed with 20 μm carboxyl-coated magnetic polymer beads conjugated to DNA via an amine-reactive oligo using N-hydroxysulfosuccinimide sodium salt (Sulfo-NHS). The beads were designed with two orthogonal capture sequences: one bound a universal sequence in all the LNP-carried DNA barcodes, while the other, a poly-T, captured poly-A tagged cell hash oligo antibodies36 and endogenous mRNA with poly-A tails (
SENT-seq utilizes orthogonal capture sequences to generate tunable multiomic readouts (
SENT-seq was then used to analyze the presence of LNP-delivered DNA barcodes, functional LNP-mediated mRNA delivery, and the transcriptome, using 24 chemically distinct LNPs in vivo. To create the 24 LNPs (
Fifteen hours after administration, which is sufficient time for LNP-mediated aVHH mRNA delivery to produce aVHH protein, cells were isolated from the liver, digested into a single-cell suspension, and live cells were sorted using FACS (
It was observed that hepatocytes, endothelial cells, Kupffer cells, hepatic stellate (Ito) cells, and other hepatic cell types separated into transcriptionally distinct subtypes when plotted using t-SNE (
aVHH protein was observed in all 17 cell subtypes (
After characterizing SENT-seq and using it to generate multiomic nanoparticle readouts, the data was used to test the hypothesis that cell heterogeneity influences LNP delivery. LNP-mediated DNA barcode delivery was quantified by quantifying the barcode counts in each cell, binning those counts by increments of 100, and plotting a histogram of cells with counts within each bin. Notably, different cell subtypes exhibited distinct levels of barcode reads. For example, endothelial cell subtype three (EC3) had a sharp peak (mean: 367 counts, median: 420 counts), whereas endothelial cell subtype one (EC1) had a broader peak (mean: 845 counts, median: 799 counts) but included cells generating as few as 100 counts and cells generating as many as 1,700 counts (
Transcriptional Analysis of Cells that Exhibit Differential LNP Delivery
These data led to focus on endothelial cells, which had the most distinct subtype-dependent LNP delivery and the largest statistically significant differences in the percentage of aVHH+ cells (
Although these analyses revealed subtypes that were transcriptionally distinct, they could not identify genes that may drive differences in LNP delivery. For example, if all cells in EC1 are compared to all cells in EC3, including cells that were not targeted by LNPs, the data include differences in basal gene expression that are unrelated to LNP delivery; this basal gene expression problem limits all RNA sequencing-based analyses of nanoparticle delivery. SENT-seq was specifically engineered to alleviate this issue by enabling us to perform three key analytical steps (
Table 1-2 shows the 11 differentially regulated genes in aVHH+EC1 and EC2, relative to EC3, that were not differentially expressed in aVHH− cells, and the current putative roles for those genes in Mus musculus.
Of these genes, the nodal molecules were CDKT13 and CDK14, which are part of the cyclin-dependent kinase family41. This family of molecules has been shown to be important in regulating cell cycle and mRNA processing42, which may explain the increased level of functional delivery in these endothelial cell clusters. To confirm that these genes were in fact expressed differently, the overall expression levels within each cluster was compared using a dot map. It was found that the expression levels were much higher in EC1 and EC2 and much lower or even downregulated in EC3 (
Quantifying LNP Tropism with Single-Cell Resolution
These data demonstrate that cell subsets differentially interact with LNPs, which led us to hypothesize that chemically distinct LNPs could exhibit different tropisms. Therefore the normalized barcode counts for all 17 cell subtypes as both an average (
LNP-7 was enriched in KCl, cholangiocytes, ITO1, and BC1 (
cKK-E15 was prepared as previously described 26 (
avhh mRNA Synthesis.
mRNA was synthesized as previously described34. Briefly, the GPI-anchored VHH sequence was ordered as a DNA gBlock from IDT (Integrated DNA Technologies) containing a 5′ UTR with Kozak sequence, a 3′ UTR derived from the mouse alpha-globin sequence, and extensions to allow for Gibson assembly. The sequence was human codon optimized using the IDT website. The gBlock was then cloned into a PCR amplified pMA7 vector through Gibson assembly using NEB Builder with 3 molar excess of insert. Gibson assembly reaction transcripts were 0.8% agarose gel purified prior to assembly reaction. Subsequent plasmids from each colony were Sanger sequenced to ensure sequence identity. Plasmids were digested into a linear template using NotI-HF (New England BioLabs) overnight at 37° C. Linearized templates were purified by ammonium acetate (Thermo Fisher Scientific) precipitation before being resuspended with nuclease-free water. In vitro transcription was performed overnight at 37° C. using the HiScribe T7 kit (NEB) following the manufacturer's instructions (full replacement of uracil with N1-methyl-pseudouridine). RNA product was treated with DNase I (Aldevron) for 30 min to remove template and purified using lithium chloride precipitation (Thermo Fisher Scientific). RNA transcripts were heat denatured at 65° C. for 10 min before being capped with a Cap1 structure using guanylyl transferase (Aldevron) and 2′-O-methyltransferase (Aldevron). Transcripts were then polyadenylated enzymatically (Aldevron). mRNA was then purified by lithium chloride precipitation, treated with alkaline phosphatase (NEB), and purified a final time. Concentrations were measured using a NanoDrop and mRNA stock concentrations were between 2 and 4 mg/mL. Purified RNA products were analyzed by gel electrophoresis to ensure purity. mRNA stocks were stored at −80° C.
Nanoparticles were formulated in a microfluidic device by mixing aVHH mRNA, DNA, the ionizable lipid, PEG, and cholesterol as previously described33. Nanoparticles were made with variable mole ratios of these constituents. The nucleic acid (e.g., DNA barcode, mRNA) was diluted in 10 mM citrate buffer (Teknova) and loaded into a syringe (Hamilton Company). The materials making up the nanoparticles (CKK-E12, CKK-E15, cholesterol, 20a-hydroxycholesterol, C14PEG2K, C18PEG2K, DOPE) were diluted in ethanol and loaded into a second syringe. The citrate phase and ethanol phase were mixed in a microfluidic device using syringe pumps.
Each chemically distinct LNP was formulated to carry its own distinct DNA barcode. For example, LNP-1 carried aVHH mRNA and DNA barcode 1, whereas the chemically distinct LNP-2 carried aVHH mRNA and DNA barcode 2. The DNA barcodes were designed rationally with universal primer sites and a specific 8-nucleotide (nt) barcode sequence, similar to what was previously described50. DNA barcodes were single stranded, 91 nucleotides long, and purchased from Integrated DNA Technologies. Briefly, the barcodes had the following characteristics and modifications: i) nucleotides on the 5′ and 3′ ends were modified with a phosphorothioate to reduce exonuclease degradation, ii) universal forward and reverse primer regions were included to ensure equal amplification of each sequence, iii) 7 random nucleotides were included to monitor PCR bias, iv) a droplet digital PCR (ddPCR) probe site was included for ddPCR compatibility, and v) each barcode had a unique 8-nt barcode. An 8-nt sequence can generate over 48 (65,536) distinct barcodes. Only the 8-nucleotide sequences designed to prevent sequence bleaching and reading errors on the Illumina MiniSeg™ sequencing machine were used.
LNP hydrodynamic diameter and polydispersity index were measured using dynamic light scattering (DLS). LNPs were diluted in sterile 1× PBS to a concentration of ˜0.06 μg/mL and analyzed. LNPs were included if they met three criteria: diameter>20 nm, diameter<200 nm, and autocorrelation function with only one inflection point. Particles that met these criteria were pooled and dialyzed in 1× phosphate buffered saline (PBS, Invitrogen), and sterile filtered with a 0.22 μm filter. The nanoparticle concentration was determined using NanoDrop (Thermo Scientific).
Using two replicates for each LNP, 50 μL of a 6 ng/μL LNP-encapsulated RNA solution was added to 50 μL of a solution of 1× TE (Thermo Fisher) or a solution containing a 1:50 dilution of Triton X-100 (Sigma Aldrich). After incubating at 37° C. for 10 mn, 100 μL of a solution of 1:100 of RiboGreen reagent (Thermo Fisher) was added to each well. Fluorescence and absorbance were measured at an excitation wavelength of 485 nm and an emission wavelength of 528 nm with a plate reader (BioTek Synergy H4 Hybrid).
All animal experiments were performed in accordance with the Georgia Institute of Technology's Institutional Animal Care and Use Committee (IACUC). C57BL/6J (#000664) mice were purchased from the Jackson Laboratory. In all experiments, mice were aged 5-8 weeks, and N=4 mice per group were injected intravenously via the lateral tail vein. Weights for all mice for all experiments are included in
In all cases, mice were sacrificed 1 day after administration of LNPs and immediately perfused with 20 mL of 1×PBS through the right atrium. The liver was isolated immediately following perfusion, minced with scissors, and then placed in a digestive enzyme solution with collagenase type I (Sigma Aldrich), collagenase XI (Sigma Aldrich), and hyaluronidase (Sigma Aldrich) at 37° C. and 750 rpm for 45 minutes. Digested tissues were passed through a 70 μm filter and red blood cells were lysed.
Cells were stained to identify specific cell populations and sorted using a BD FacsFusion cell sorter. Antibody clones used for staining were anti-CD31 (390, BioLegend), anti-CD45.2 (104, BioLegend), anti-CD68 (FA-11, BioLegend), anti-aVHH (17A2, GenScript), live/dead (Thermo Fisher). Representative gating strategies for liver cell populations are included in
All samples were amplified and prepared for sequencing using a nested PCR protocol as previously described 51. More specifically, 1 μL of each primer (10 M reverse/forward) were added to 5 μL of Kapa HiFi 2× master mix, 2 μL sterile H2O, and 1 μL DNA template. The second PCR added Nextera XT chemistry, indices, and i5/i7 adapter regions and used the product from PCR 1 as template.
Illumina deep sequencing was performed on Illumina MiniSeg™ using standard protocols suggested by Illumina. The sequencing was conducted in the Georgia Tech Molecular Evolution core.
Sequencing results were processed using a custom Python-based tool to extract raw barcode counts for each tissue. These raw counts were then normalized with an R script prior to further analysis. Counts for each particle were normalized to the barcoded LNP mixture injected into mice, as previously described9. Statistical analyses were done using GraphPad Prism 7. Data is plotted as mean±standard error mean unless otherwise stated.
To generate orthogonal beads containing 10% barcode binding sequences, the following protocol was used. Two milliliters of 50 M amine modified oligo (table 1) was conjugated to 150 mg of 20 μm carboxyl coated magnetic beads (kbspheretech) using 200 mg of EDC and NHS-ester (Sigma Aldrich) in 6 ml of 0.1M MES overnight. The conjugated beads were then washed once in 0.1M PBS containing 0.02% Tween-20 and two more times in TE (pH 8.0) using a magnet.
To add the three unique bead barcodes the conjugated beads were subjected to 3 rounds of split-pool PCR using the cell barcode oligos with the following protocol. The beads were washed once in ddH2O and resuspended in 4.5 mL of 1× Kappa HF master mix, and 45 μL were aliquoted into a 96 well plate. Five microliters of 50 μM of a unique cell barcode oligo, with a complementary sequence to the amine modified oligo, was added, and amplified using the following PCR program: 94° C. for 5 min, 5 cycles of 94° C. for 15s, 50° C. for 4 min and 72° C. for 4 min and a final 4° C. hold. The beads were then pooled and washed twice with ddH2O and repeated twice more with the additional plates of cell barcodes. The final set of cell barcodes also contained a unique molecular identifier (UMI) as well as a 15-nucleotide poly-T region for mRNA binding (
The generation of the microwell device and subsequent library preparation was performed following the protocol from Han et al. with a few modifications to accommodate CITE-seq and LNP barcode. The microwell device was generated using a PDMS 1 million-well device (iBioChips) to create a positive imprint mold for generation of a 5% agarose in PBS disposable device. One hundred thousand of the isolated and pooled cells were loaded onto the agarose device and allowed to settle for 10 minutes until most of the cells had fallen into the bottoms of the wells. Two washes were performed with ice-cold PBS to remove any cells that did not fall into a single well. The device was then placed on a strong magnet, and 1 million barcoded beads were slowly distributed over the device and allowed to incubate for 10 minutes so that most of the beads were immobilized into each well. Two more washes were performed to remove any unbound beads, and 1 mL of cold lysis buffer (0.1M Tris-HCL pH7.5, 0.5 M LiCl, 1% SDS, 10 mM EDTA and 5 mM dithiothreitol) was added and allowed to incubate on ice for 10 minutes. After lysis the device was cut out and flipped over, and the magnet was used to remove the beads from the wells. The beads were pooled, washed twice with 6×SSC, and given one final wash in 50 mM Tris-HCL pH 8.0.
The pooled beads were then placed in a reverse transcription reaction containing 200 U M-MLV Reverse Transcriptase (BioChain Institute), 1× RT buffer, 20 U RNAse inhibitor (NEB), 1 M betaine (Sigma), 6 mM MgCl2 (Sigma), 2.5 mM DTT (Thermo Fisher), 1 mM dNTP (NEB), and 1 μM TSO primer. The beads were incubated for 90 minutes at 42° C. followed by a hold at 4° C. with constant shaking at 500 RPM. After the reverse transcriptase step, enzyme was removed using 1×TE with 0.5% SDS followed by a wash in 1×TE with 0.01% Tween 20 and finally a wash in 100 mM Tris-HCl pH 8.0.
To remove any unused single-stranded oligo from the beads, they were treated with 200 U of exonuclease I (NEB) in 1× ExoI buffer for 60 minutes at 37° C. with 500 RPM shaking. Following the digestion, excess ExoI was removed using the previously described TE-SDS, TE-Tween 20 and Tris-HCL pH 8.0 washes. After removal of ExoI, the beads were resuspended in 200 μL of Platinum II hot-start master mix (Thermo Fisher) with IS-PCR, p7 Multi Barcode Rvs and Hash p7 Rvs primers, and the first-round PCR was performed using the following cycling conditions: one cycle at 94° C. for 2 minutes, 12 cycles of 94° C. for 15 seconds, 60° C. for 15 seconds, and 68° C. for 2 minutes. The sample was pooled, the beads were removed and discarded, and the sample was purified using 0.6× SPRI beads. The long RNA fragments were collected on the SPRI beads, while the shorter barcode and hash reads remained in the PCR supernatant; these were purified using 2.0× SPRI beads and saved for use during the final round PCR. The RNA sample was then treated with TN5 transposase to fragment and add on sequencing handles for subsequent PCR. Both the DNA and fragmented RNA sample were then amplified using a second round of PCR with non-hot-start Q5 high-fidelity polymerase (NEB), P7 Nextera index adapters, and Microwell P5 primer using the following cycling conditions: one cycle at 70° C. for 5 minutes, 12 cycles of 98° C. for 30 seconds, 58° C. for 30 seconds, and 72° C. for 90 seconds, with a final extension at 72° C. for 2 minutes. The samples were then purified using 0.8× SPRI beads, pooled at a 10:1 molar ratio of RNA to DNA, and finally sequenced on an Illumina HiSeq paired-end 150-cycle run.
The data were processed using zUMIs (v 2.9.7) for the RNA mapping and counting and Salmon Alevin (v1.5.2) for the DNA barcode and cell hashes52, 53. All samples were mapped to GRCm39, and only Exonic regions were counted. All output files were loaded into Seurat (v 4.0.4), and in summary, cells were log normalized to a scale factor of 10,000, then scaled using a linear transformation54. This was followed by PCA dimensional reduction and t-SNE clustering and then exported using rBCS for further analysis in BBrowser2 (v2.9.23). Once in BBrowser2, the cell search tool was used to identify the cell types within each cluster, and gene expression profiles were compared within cell types of interest. Barcode counts were combined with RNA counts in Seurat and treated in a similar manner to other multimodal datasets such as CITE-seq.
After synthesizing new lipids for LNPs, scientists typically formulate them into nanoparticles and test their ability to deliver drugs in vitro or in vivo. However, both FDA-approved, systemically administered siRNA therapies3, 4 that use delivery vehicles have required scientists to understand the genes that enable and enhance drug delivery. These findings, coupled with recent data demonstrating that LNP delivery substantially increases24 or decreases25, 26 depending on cell state, strongly suggest that further insights into the biology of delivery are needed to improve clinical nanoparticles.
The testing shown in this example establishes a sequencing-based multiomic system capable of performing high-throughput in vivo nanoparticle delivery assays and analyzing the cellular response to nanoparticles, all with single-cell resolution. By marrying empirical drug delivery datasets to biological readouts, SENT-seq generated several lines of evidence that cell heterogeneity influences LNP-mediated mRNA delivery. These lines of evidence were enabled by one key advantage to SENT-seq: cells are defined by their transcriptional state instead of cell surface markers.
In this case, delivery to 17 cell subtypes in the liver was quantified; it is believed that such delivery has not been previously measured in these subtypes. But the same advantage can also serve to quantify delivery to, and therefore target, (i) rare cells including hematopoietic stem cells, basal cells, and circulating tumor cells, or (ii) cells defined by a particular, even complicated, transcriptional state, such as exhausted T cells46. A second, related advantage is that SENT-seq may be helpful in quantifying delivery in larger animals that do not have established flow antibodies for cells of interest. This is distinct from previous assays, which rely on tissue-level delivery readouts or require FACS antibody panels to isolate cells of interest; these antibody panels are far less common for non-human primates (NHPs) and other large animals.
It is anticipated that SENT-seq may help elucidate the genes driving non-liver targeting to the lung10, 12, spleen10, 13, and bone marrow32 using LNP-based delivery vehicles. Although additional work needs to be completed, this ability to simultaneously read out high throughput nanoparticle delivery and the cellular response to nanoparticles may lead to new datasets and insights that improve mRNA therapeutics.
The present disclosure also pertains to and includes at least the following aspects:
Aspect 1. An in vivo method of identifying a lipid nanoparticle optimized based on cellular state, delivery profile, or both cellular state and delivery profile, for delivery into a specific single cell comprising:
It is to be understood that while the disclosure has been described in conjunction with the preferred specific embodiments thereof, that the foregoing description and the examples that follow are intended to illustrate and not limit the scope of the disclosure. It will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted without departing from the scope of the disclosure, and further that other aspects, advantages and modifications will be apparent to those skilled in the art to which the disclosure pertains. In addition to the embodiments described herein, the present disclosure contemplates and claims those inventions resulting from the combination of features of the disclosure cited herein and those of the cited prior art references which complement the features of the present disclosure. Similarly, it will be appreciated that any described material, feature, or article may be used in combination with any other material, feature, or article, and such combinations are considered within the scope of this disclosure.
The disclosures of each patent, patent application, and publication cited or described herein are hereby incorporated herein by reference, each in its entirely, for all purposes.
The present application claims the benefit of priority to U.S. Provisional Application No. 63/314,166, filed Feb. 25, 2022, the entire contents of which are hereby incorporated by reference.
This invention was made with government support under National Institutes of Health Grant UG3-TR002855 and R01DE0269. The government has certain rights in the invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2023/063221 | 2/24/2023 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63314166 | Feb 2022 | US |