Molecular portraits of tumor mutational and micro-environmental sculpting by immune checkpoint blockade therapy
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ABSTRACT: Immune checkpoint blockade (ICB) has demonstrated significant promise for the treatment of advanced malignancies. Anti-CTLA4 and ant-PD1 therapy can activate the immune system and result in durable control in diseases such as melanoma and non-small cell lung cancer.
Project description:Immune checkpoint blockade (ICB) has improved outcome for patients with metastatic melanoma but not all benefit from treatment. Several immune- and tumor intrinsic features are associated with clinical response at baseline. However, we need to further understand the molecular changes occurring during development of ICB resistance. Here, we collected biopsies from a cohort of 44 melanoma patients after progression to anti-CTLA4 or anti-PD1 monotherapy. Genetic alterations of antigen presentation and interferon gamma signaling pathways were observed in approximately 25% of ICB resistant cases. Anti-CTLA4 resistant lesions had a sustained immune response, including immune-regulatory features, as suggested by multiplex spatial and TCR clonality analyses. One anti-PD1 resistant lesion harbored a distinct immune cell niche, however, anti-PD1 resistant tumors were generally immune poor with non-expanded TCR clones. Such immune poor microenvironments were associated with melanoma cells having a de-differentiated phenotype lacking expression of MHC-I molecules. In addition, anti-PD1 resistant tumors had reduced fractions of PD1+ CD8+ T cells as compared to ICB naïve metastases. Collectively, these data show the complexity of ICB resistance and highlight differences between anti-CTLA4 and anti-PD1 resistance that may underlie differential clinical outcomes of therapy sequence and combination.
Project description:Immune checkpoint blockade (ICB) has improved outcome for patients with metastatic melanoma but not all benefit from treatment. Several immune- and tumor intrinsic features are associated with clinical response at baseline. However, we need to further understand the molecular changes occurring during development of ICB resistance. Here, we collected biopsies from a cohort of 44 melanoma patients after progression to anti-CTLA4 or anti-PD1 monotherapy. Genetic alterations of antigen presentation and interferon gamma signaling pathways were observed in approximately 25% of ICB resistant cases. Anti-CTLA4 resistant lesions had a sustained immune response, including immune-regulatory features, as suggested by multiplex spatial and TCR clonality analyses. One anti-PD1 resistant lesion harbored a distinct immune cell niche, however, anti-PD1 resistant tumors were generally immune poor with non-expanded TCR clones. Such immune poor microenvironments were associated with melanoma cells having a de-differentiated phenotype lacking expression of MHC-I molecules. In addition, anti-PD1 resistant tumors had reduced fractions of PD1+ CD8+ T cells as compared to ICB naïve metastases. Collectively, these data show the complexity of ICB resistance and highlight differences between anti-CTLA4 and anti-PD1 resistance that may underlie differential clinical outcomes of therapy sequence and combination.
Project description:Background: Outcomes for locally advanced or recurrent/ metastatic head and neck squamous cell carcinomas (HNSCCs) remain unfavorable despite recent advances with immune checkpoint blockade (ICB). Preclinical studies using model antigens identified a critical role of CD8+TCF7+PD1+ T cells in anti-PD1 response. Studies on the heterogeneity and clonal dynamics of global tumor infiltrating T lymphocytes (TILs) in the HNSCC anti-PD1 and anti-CTLA4 response have not been explored. Results: In this study, we generated isogenic HNSCC anti-PD1 sensitive/resistant models that bore distinct cancer cell intrinsic transcriptomic programs. Tumor microenvironment characterization using mass cytometry and targeted depletion revealed the contribution of Tregs and M2-like macrophages in anti-PD1 resistance. Paired single-cell RNA and TCR sequencing on tumor infiltrating immune cells from ICB responsive and resistant HNSCC models identified a spectrum of CD8+ TIL subsets including TCF7+PD1- (naïve/memory-like), TCF7+PD1+ (progenitor exhausted), and TCF7-PD1+ (terminally exhausted). Mapping TCR shared fractions between these subsets identified that successful anti-PD1 or anti-CTLA4 therapy induced higher post-treatment T cell lineage transitions. A TIL differentiation gene signature was associated with better responses in multiple ICB clinical trials. Conclusions: Together, analyses integrating scRNAseq and TCRseq demonstrate distinct differentiation dynamics of CD8+ TILs in novel ICB responsive and resistant HNSCC models, highlighting critical aspects of CD8+ TIL differentiation in response to ICB.
Project description:Immune checkpoint blockade (ICB) has improved outcomes in some cancers. A major limitation of ICB is that a majority of patients fail to respond, which is partly attributable to immunosuppression. Obesity appears to improve immune checkpoint therapies in some cancers but impacts on breast cancer (BC) remain unknown. In obese mice fed an obesogenic or lean controls on a low fat diet, mice are injected with BC cells andtreated with anti-PD-1 or control. Obesity leads to immunosuppression systemically in tumor-free mice that is exacerbated in tumor-bearing mice. Obesity augments tumor incidence and progression. Anti-PD-1 induces regression in lean mice and potently abrogates progression in obese mice. Anti PD-1 significantly reduces immunosuppressive cells and elevates anti-tumor immune cells. Lamb2, downregulated by anti-PD1, significantly predict patient survival. Last, we identify a microbial signature associated with anti-PD-1 efficacy. In sum, anti-PD-1 is highly efficacious in obese mice by reinvigorating durable antitumor immunity.
Project description:Immune checkpoint blockade (ICB) has improved outcomes in some cancers. A major limitation of ICB is that a majority of patients fail to respond, which is partly attributable to immunosuppression. Obesity appears to improve immune checkpoint therapies in some cancers but impacts on breast cancer (BC) remain unknown. In obese mice fed an obesogenic or lean controls on a low fat diet, mice are injected with BC cells andtreated with anti-PD-1 or control. Obesity leads to immunosuppression systemically in tumor-free mice that is exacerbated in tumor-bearing mice. Obesity augments tumor incidence and progression. Anti-PD-1 induces regression in lean mice and potently abrogates progression in obese mice. Anti PD-1 significantly reduces immunosuppressive cells and elevates anti-tumor immune cells. Lamb2, downregulated by anti-PD1, significantly predict patient survival. Last, we identify a microbial signature associated with anti-PD-1 efficacy. In sum, anti-PD-1 is highly efficacious in obese mice by reinvigorating durable antitumor immunity.
Project description:we performed bulk RNA sequencing assessing transcriptomics and pathways affected in our mouse model. In ICI-myocarditis mice (ctla4+/-pd1-/-), bulk RNA sequencing showed very distinct affected pathways in ICI-myocarditis mice compared to unaffected control mice (ctla4+/+ pd1-/-).
Project description:Non-inflamed (cold) tumors such as leiomyosarcoma (LMS) do not benefit from immune checkpoint blockade (ICB) monotherapy. Combining ICB with angiogenesis-, or poly-ADP ribose polymerase (PARP) inhibitors may increase tumor immunogenicity by altering the immune cell composition of the tumor microenvironment (TME). The DAPPER phase II study evaluated the safety, immunologic, and clinical activity of ICB-based combinations in pre-treated LMS patients.
Project description:Co-stimulatory molecules of the CD28 family on T lymphocytes integrate cues from innate immune system sensors, and modulate activation responses in conventional CD4+ T cells (Tconv) and their FoxP3+ regulatory counterparts (Treg). To better understand how costimulatory and co-inhibitory signals might be integrated, we profiled the changes in gene expression elicited in the hours and days after engagement of Treg and Tconv by anti-CD3 and either anti-CD28, -CTLA4, -ICOS, -PD1, -BTLA or -CD80. Total CD4+ T cells were stimulated by anti-CD3 and either anti-CD28, -CTLA4, -ICOS, -PD1, -BTLA or -CD80 antibodies for 1, 4, 20 and 48 hrs and Tconv and Treg were separated by flowcytometry. The 1 and 4 hr lysates were pooled [the 'early' samples] before RNA purification and profiling, as were the 20 and 48 hr samples [the 'late' samples] (note; for Treg cells, only the 20 hr sample was used). RNA was amplified, labeled and hybridized to Mouse Gene 1.0 ST arrays with the data generation and quality control pipeline of 19 the Immunological Genome Project (www.immgen.org), in biological triplicates (duplicates only for ICOS and CD80). Raw data were background-corrected and normalized using the RMA algorithm.
Project description:Immune checkpoint blockade (ICB) has led to durable clinical responses in multiple cancer types; however, biomarkers that identify which patients are most likely to respond to ICB are not well defined. Many putative biomarkers developed from a small number of samples often fail to maintain their predictive status in larger validation cohorts. We show across multiple human malignancies and syngeneic murine tumor models that neither pre-treatment T cell receptor (TCR) clonality nor changes in clonality after ICB correlate with response. Dissection of tumor infiltrating lymphocytes pre- and post-ICB by paired single-cell RNA sequencing and single-cell TCR sequencing reveals conserved and distinct transcriptomic features in expanded TCR clonotypes between anti-PD1 responder and non-responder murine tumor models. Overall, our results indicate a productive anti-tumor response is agnostic of TCR clonal expansion. Further, we used single-cell transcriptomics to develop a CD8+ T cell specific gene signature for a productive anti-tumor response and show the response signature to be associated with clinical outcomes to nivolumab monotherapy in CheckMate-067, a phase 3 clinical trial in metastatic melanoma. These results highlight the value of leveraging single-cell assays to dissect heterogeneous tumors and T cell subsets and define cell-type specific transcriptomic biomarkers of ICB response.