The field of the invention is genetic analysis of tumor tissue, especially as it relates to immune cells signatures.
The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
All publications and patent applications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
Studies of the tumor microenvironment have surfaced promising avenues of exploration to better understand the clinical relevance of T cell immune biology. Regulatory T cells (Tregs) have keenly emerged in light of their ability to inhibit the adaptive immune response and provide a mechanism of immune escape for cancer cells within the tumor microenvironment across various cancer types. However, the relatively large number of studies exploring the clinical relevance of intratumoral Treg abundance has produced controversial results to date, with some studies finding a poor prognosis associated with Treg infiltration, and others suggesting a favorable Treg-associated prognosis. Not surprisingly, the recent efforts to account for these polarized clinical results have undermined the notion that FOXP3+ Tregs invariably suppress tumor immunity. To address this uncertainty, multiple gene markers were taken into account to more accurately identify Tregs, such as FOXP3+BLIMP1 or FOXP3+CTLA4. However, none of the known studies have produced results that were suitable to guide a clinician towards a rational-based therapy with high confidence in a predicted outcome.
Indeed, immune heterogeneity within the tumor microenvironment has added multiple layers of complexity to the understanding of chemosensitivity and survival across various cancer types. Within the tumor microenvironment, immunogenicity is a favorable clinical feature in part driven by the antitumor activity of CD8+ T cells. However, tumors often inhibit this antitumor activity by exploiting the suppressive function of Regulatory T cells (Tregs), thus suppressing an adaptive immune response.
Unfortunately, there are numerous mechanisms other than Tregs and CD8+ T involved in the immunogenicity of tumor cells, and an accurate prediction of immunogenicity of a tumor has remained elusive. Indeed, it has been reported that the immune infiltrate composition changes at each tumor stage and that particular immune cells have a major impact on survival. For example, densities of T follicular helper (Tfh) cells and innate cells increases, and most T cell densities decrease where tumor progression is observed. Moreover, the number of B cells, which are key players in the core immune network and are associated with prolonged survival, increase at a late stage and often show a dual effect on recurrence and tumor progression (see e.g., Immunity 2013 Oct 17;39(4):782-95).
Therefore, despite numerous findings in isolation, complex interactions between tumors and their microenvironment remain to be elucidated. Consequently, there is still a need for improved systems and methods to better characterize immunogenicity of a tumor.
The inventive subject matter is directed to various methods of genetic analysis, and especially quantitative and normalized RNA expression analysis of tumor tissue, to thereby allow for identification of infiltration and/or activity of various immune cells in a specific tumor. For example, in some embodiments, the inventors used various gene sets associated with various immune cells types and then correlated them with specific disease categories (e.g., ICD10 categories) to predict whether or not a tumor is immune-enriched. Moreover, immune cell-enrichment was found to be correlated with PDL1 high/normal/low cases, and molecular targets could also be identified for patients where PDL1 is low.
In one aspect of the inventive subject matter, the inventors contemplate a method of characterizing a tumor that includes a step of quantifying or obtaining expression levels for a plurality of distinct genes, wherein the distinct genes are associated with (e.g., expressed in, most typically specifically expressed in) respective distinct types of immune cells, and a further step of determining over-expression or under-expression for each of the distinct genes relative to respective reference ranges, wherein the reference ranges are specific for a specific tumor type. In yet another step the over-expression and/or under-expression of each of the distinct genes is then used to infer activity and/or infiltration by the immune cells in the tumor.
Most typically, but not necessarily, the expression level is measured via qPCR or RNAseq, and suitable genes for such analysis include BLK, CD19, CR2 (CD21), HLA-DOB, MS4A 1 (CD20), TNFRSF17 (CD269), CD2,CD3E,CD3G,CD6, ANP32B (APRIL), BATF, NUP107, CD28, ICOS (CD278), CD38, CSF2 (GM-CSF), IFNG, IL12RB2,LTA, CTLA4 (CD152), TXB21, STAT4, CXCR6 (CD186), GATA3, IL26, LAIR2 (CD306), PMCH, SMAD2, STATE, IL 17A, IL 17RA (CD217), RORC, CXCL13, MAF, PDCD1 (CD279), BCL6, FOXP3, ATM, DOCKS, NEFL, REPS1, USP9Y, AKT3, CCR2 (CD192), EWSR1 (EWS), LTK, NFATC4, CD8A, CD8B, FLT3LG, GZMM, MET1, PRF1, CD160, FEZ1, TARP (TCRG), BCL2, FUT5, NCR1 (CD335), ZNF205, FOXJ1, MPPED1, PLA2G6, RRAD, GTF3C1, GZMB, IL21R (CD360), CCL13, CCL17, CCL22 (MDC), CD209, HSD11B1, CD1A, CD1B, CD1E, F13A1, SYT17, CCL1, EBI3, IDO1 (INDO), LAMP3 (CD208), OAS3, IL3RA (CD123), APOE, CCL 7 (FIC), CD68, CHIT1, CXCL5, MARCO, MSR1 (CD204), CMA1, CTSG, KIT (CD117), MS4A2, PRG2, TPSAB1, CSF3R (CD114), FPR2, MME (CD10), CCR3 (CD193), IL5RA (CD125), PTGDR2, (CD294), SMPD3, and THBS1.
In further contemplated embodiments, a threshold for determination of over-expression or under-expression may be when the quantified expression level exceeds +/−2SD of the reference range. Most preferably, the reference range is specific for a particular tumor type as classified in ICD10. As will be readily appreciated, the immune status may then be associated with the tumor based on the inferred activity and/or infiltration. Consequently, immune therapy such as treatment with a checkpoint inhibitor, treatment with immune stimulatory compositions, and/or vaccination with a tumor associated antigen or tumor and patient specific may then be recommended or initiated. For example, checkpoint inhibitor treatment with a PDL1 inhibitor may be used for a PDL1-high tumor, while checkpoint inhibitor treatment with a TIM3 inhibitor or an IDO inhibitor may be recommended or initiated for a PDL1-low tumor.
Therefore, viewed from a different perspective, the inventor also contemplates a method of identifying a patient for immune therapy that will include a step of quantifying or obtaining expression levels for a plurality of distinct genes, wherein the distinct genes are associated with respective distinct types of immune cells. In a further step, over-expression or under-expression is determined for each of the distinct genes relative to respective reference ranges, wherein the reference ranges are specific for a specific tumor type, and in yet another step, the over-expression and/or under-expression of each of the distinct genes is used to infer activity and/or infiltration by the immune cells in the tumor. The so inferred activity is then used to predict an increased likelihood of positive treatment outcome where the inferred activity and/or infiltration of distinct immune cells in the tumor is increased relative to the respective reference ranges, and the patient is selected or identified as a suitable candidate for immune therapy upon prediction of the increased likelihood.
For example, the distinct immune cells in the tumor include pDC, aDC, TFH, NK cells, neutrophils, Treg, iDC, macrophages,Thelper cells, NK cells, CD8 T cells, T cells, and Th1 cells, and/or the increased number may be with respect to at least three or four distinct types of immune cells in the tumor. Suitable genes for such analysis include those noted above, and over-expression or under-expression may be ascertained when the quantified expression level exceeds +/−2SD of the reference range. As will be readily appreciated, suitable immune therapies include treatment with a checkpoint inhibitor, a vaccine composition, and/or an immune stimulatory cytokine.
Therefore, the inventor also contemplates the use of a plurality of distinct genes to characterize a tumor or to predict treatment outcome for immune therapy of the tumor, wherein the plurality of distinct genes are associated with respective distinct types of immune cells, and wherein the use comprises a quantification of expression levels of the distinct genes. Once more, suitable genes for such analysis include those noted above, and over-expression or under-expression for each of the distinct genes is preferably determined relative to respective reference ranges, wherein the reference ranges are specific for a specific tumor type. Thus, methods contemplated herein may also be used to characterize a tumor as being immunologically ‘hot’ or ‘cold’.
Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
The inventor has discovered that immune cell signatures can be obtained from a tumor tissue using gene expression signatures that are specific to or at least characteristic for various immune cells. Viewed from a different perspective the inventors conducted single-cell experiments to define gene sets that can differentiate between immune-cell types. By observing expression patterns of those gene sets within a tumor sample, the inventor was then able to make a determination as to whether a tumor tissue sample is enriched or suppressed in those cell types.
More specifically, based on single cell gene expression analysis of various immune cells, the inventor identified the following genes as being suitable for use in the analyses presented herein: BLK, CD19, CR2 (CD21 ), HLA-DOB, MS4A 1 (CD20), TNFRSF17 (CD269), which are commonly associated with B cells and are involved in several roles, including generating and presenting antibodies, cytokine, production, and lymphoid tissue organization, CD2,CD3E,CD3G,CD6, which are commonly associated with T cells, various genes associated with helper T cells, including ANP32B (APRIL), BATF, NUP107, CD28, ICOS (CD278) (associated with effector T cells), CD38, CSF2 (GM-CSF), IFNG, IL12B2, LTA, CTLA4 (CD152), TXB21, STAT4 (associated with TH1 cells), CXCR6 (CD186), GATA3, IL26, LAIR2 (CD306), PMCH, SMAD2, STATE (associated with TH2 cells), IL 17A, IL 17RA (CD217), RORC (associated with TH17 cells), CXCL13, MAF, PDCD1 (CD279), BCL6 (associated with TFH cells), FOXP3 (associated with Treg cells), ATM, DOCKS, NEFL, REPS1, USP9Y (associated with TCM cells), AKT3, CCR2 (CD192), EWSR1 (EWS), LTK, NFATC4 (associated with TEM cells), CD8A, CD8B, FLT3LG, GZMM, MET1, PRF1 (associated with CD8+ T cells), CD160, FEZ1, TARP (TCRG) (associated with Tγδ cells), BCL2, FUT5, NCR1 (CD335), ZNF205 (associated with NK cells), FOXJ1, MPPED1, PLA2G6, RRAD (associated with CD56bright cells), GTF3C1, GZMB, IL21R (CD360) (associated with CD56dim cells), CCL13, CCL17, CCL22 (MDC), CD209, HSD11B1 (associated with dendritic cells), CD1A, CD1B, CD1E, F13A1, SYT17 (associated with immature dendritic cells), CCL1, EBI3, IDO1 (INDO), LAMP3 (CD208), OAS3 (associated with activated dendritic cells), IL3RA (CD123) (associated with plasmacytoid dendritic cells), APOE, CCL 7 (FIC), CD68, CHIT1, CXCL5, MARCO, MSR1 (CD204) (associated with macrophages), CMA1, CTSG, KIT (CD117), MS4A2, PRG2, TPSAB1 (associated with mast cells), CSF3R (CD114), FPR2, MME (CD10) (associated with neutrophils), and CCR3 (CD193), IL5RA (CD125), PTGDR2, (CD294), SMPD3, and THB S1 (associated with eosinophils). These genes were identified to be preferentially or even selectively expressed in certain immune cells (see also e.g., Immunity 39, 782-795, Oct. 17, 2013).
Using these so identified genes, RNAseq analysis was performed on a total of 1037 tumor samples to investigate whether RNA expression levels of these genes would cluster.
The inventor then investigated whether specific immune cell types would be equally or differentially present or active in different types of tumors. Unexpectedly, as can be seen from the graphs in
The inventor then employed statistical analysis for the average gene expression of the particular immune cell and cancer type to identify threshold expression levels for the genes in specific immune cells with regard to a specific tumor cell type. Exemplary results are shown in the table of
For example, a tumor tissue belonging to ICD10 class C15-C26 (here: digestive organs malignant neoplasm) can be analyzed using RNAseq and gene expression data quantified, using the specific tumor tissue type and the tabulated results of
In still further studies, the inventor investigated whether or not immune marker co-expression patterns could be identified, and particularly checkpoint expression patterns and their correlations. For example, the inventors investigated if for a given PDL1 expression level in a tumor as measured by RNAseq any association could be identified with respect to other checkpoint related genes and their expression levels. More specifically,
Additionally, it was also observed that IDO and TIM3 had relatively high expression, particularly in the absence of PDL1 or in cases with low PDL1 expression. Expression levels of IDO and TIM3 were also highly correlated (R=0.78) when PDL1 is under-expressed, and that relationship seemed to be inversely proportional to PDL1 expression. LAG3 was also correlated with IDO and TIM3 in a low PDL1 setting, however, this relationship was not clear as PDL1 increased. Consequently, the data suggest that PDL1 itself is sufficient as a primary driver of immune suppression (as seen in the PDL1-high correlation plot), however when PDL1 is low there may be some differential role for IDO and TIM3.
When further investigating the role of PDL1 with respect to immune cell categories as noted above, the inventor discovered that the PDL1 high group is enriched for multiple immune-cell types, including multiple kinds of T-cells & T-helper cells as can be seen in
Therefore, it should be appreciated that immune cell specific gene expression analysis can be used in predictive analysis of immune therapy, particularly for immune therapy targeting the PD1/PDL1 axis. On the other hand, alternative immune therapy targeting IDO and/or TIM3 may also be indicated where the tumor tissue is PDL1 low.
In still further experiments, immune status was also correlated with MSI status on a total of 152 colorectal cancer tumor samples. Tumor/normal-paired DNAseq (WGS or WES) and deep RNAseq was performed and MSI-status was determined by both PCR and WGS/WES profiles. CMS types, checkpoint expression, and immune-infiltration deconvolution were calculated upon RNAseq data using above sequences, and significant enrichment for MSI, immune status, CMS types, and clinical covariates were analyzed.
It should still further be appreciated that contemplated methods and analyses may also be useful in determination of suitable treatment where location may provide a contributing factor. For example, the inventor discovered that upper and lower GI tumors are distinct in their tolerated immune cell infiltration. Immune therapies should therefore be tailored based on location to take advantage of the innate immune apparatus present. Specifically, upper GI cancers appear especially fit for checkpoint therapy despite having lower average TMB.
As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. Unless the context dictates the contrary, all ranges set forth herein should be interpreted as being inclusive of their endpoints, and open-ended ranges should be interpreted to include commercially practical values. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary.
Moreover, all methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.
It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the scope of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
This application claims priority to our copending US provisional patent application with the Ser. No. 62/647,621, which was filed Mar. 23, 2018.
Number | Date | Country | |
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62647621 | Mar 2018 | US |