Project description:The regulatory circuits dictating CD8+ T cell responsiveness vs. exhaustion during anti-tumor immunity are incompletely understood. Here, we report that tumor-infiltrating antigen-specific PD-1+ TCF-1- CD8+ T cells express the immunosuppressive cytokine Fgl2. Conditional deletion of Fgl2 from antigen-specific CD8+ T cells prolonged CD8+ T cell persistence, decreased phenotypic and transcriptomic signatures of T cell exhaustion, and improved tumor control. Melanoma patients who died of their disease exhibited increased expression of Fgl2 in tumor-infiltrating CD8+ T cells as compared to those who survived. PD-1+CD8+ T cell-derived Fgl2 also negatively regulated virus-specific T cell responses in a model of chronic viral infection. Mechanistically, the enhanced responsiveness of Fgl2-deficient CD8+ T cells is underpinned by the interaction of Fgl2 with CD8+ T cell-expressed FcγRIIB, ligation of which results in caspase 3/7-mediated apoptosis. These data illuminate a novel cell-autonomous regulatory axis by which PD-1+ CD8+ T cell responses are regulated in vivo.
Project description:We use scRNA-seq to show the differences in tumor-infiltrating immune cells among IgG, anti-PD-1, anti-PSGL-1, and combination anti-PD-1 and anti-PSGL-1 treated mice. We show that anti-PSGL-1 treatment resulted in an increase in neutrophil and T cells, anti-PD-1 treatment resulted in an increase in macrophages, and the combination resulted in an increase in T cells and macrophages when compared to the tumors of IgG treated mice. Additionally, we show that Tregulatory cells are decreased in the tumors of anti-PSGL-1 and combination treated mice. Further, we find that anti-PSGL-1 treated CD8 T cells show upregulation of activation and survival genes, while combination treatment increased effector gene expression in CD8 T cells. Both anti-PSGL-1 treatment and combination treatment increase effector gene expression in CD4 T cells when compared to IgG. This scRNA-seq study shows the impact of IgG, anti-PD-1, anti-PSGL-1, and combination anti-PSGL-1 and anti-PD-1 antibody tteatment on tumor-infiltrating immune cells in B16-GP33 melnoma tumor bearing mice.
Project description:Targeting checkpoint blockade to rescue exhausted regulatory T cells (Tregs) has become an essential immunotherapy strategy in treating cancer. Until now, the CD4+ Tregs and PD-1+CD8+ T cells were demonstrated to reduce immunogenic responses. In contrast, little is known about the PD-L1 graphic pattern and characteristics in CD8+ T cells. We performed two high-throughput analysis approaches on tumor-infiltrating CD8+ T cells in lung cancers. We discovered PD-L1+CD8+ T cells enriched in tumor lesions, localized with PD-1+CD8+ affected T cells, and owned regulatory functions. Moreover, tumor-derived IL-27 promoted the development of PD-L1+CD8+ T cells through STAT1/STAT3 signaling. Single-cell RNA sequencing data analysis further clarified the enrichment of PD-L1+CD8+ T cells related to the downregulation of adaptive immune response. Additionally, enrichment of this subset was correlated with poor survival of lung cancer patients. Our data collectively demonstrated that PD-L1+CD8+ T cells potentially become a prognostic biomarker in lung cancer.
Project description:T cell exhaustion is a progressive loss of effector function and memory potential due to persistent antigen exposure, which occurs in chronic viral infections and cancer. Here we investigate the relation between gene expression and chromatin accessibility in CD8+ tumor-infiltrating lymphocytes (TIL) that recognize a model tumor antigen and have features of both activation and functional exhaustion. By filtering out accessible regions observed in bystander, non-exhausted, TIL and in acutely restimulated CD8+ T cells, we define a pattern of chromatin accessibility specific for T cell exhaustion, characterized by enrichment for consensus binding motifs for Nr4a and NFAT transcription factors. Anti-PD-L1 treatment of tumor-bearing mice results in cessation of tumor growth and partial rescue of cytokine production by the dysfunctional TIL, with only limited changes in gene expression and chromatin accessibility. Our studies provide a valuable resource for the molecular understanding of T cell exhaustion in cancer and other inflammatory settings.
Project description:T cell exhaustion is a progressive loss of effector function and memory potential due to persistent antigen exposure, which occurs in chronic viral infections and cancer. Here we investigate the relation between gene expression and chromatin accessibility in CD8+ tumor-infiltrating lymphocytes (TIL) that recognize a model tumor antigen and have features of both activation and functional exhaustion. By filtering out accessible regions observed in bystander, non-exhausted, TIL and in acutely restimulated CD8+ T cells, we define a pattern of chromatin accessibility specific for T cell exhaustion, characterized by enrichment for consensus binding motifs for Nr4a and NFAT transcription factors. Anti-PD-L1 treatment of tumor-bearing mice results in cessation of tumor growth and partial rescue of cytokine production by the dysfunctional TIL, with only limited changes in gene expression and chromatin accessibility. Our studies provide a valuable resource for the molecular understanding of T cell exhaustion in cancer and other inflammatory settings.
Project description:T cell exhaustion is a progressive loss of effector function and memory potential due to persistent antigen exposure, which occurs in chronic viral infections and cancer. Here we investigate the relation between gene expression and chromatin accessibility in CD8+ tumor-infiltrating lymphocytes (TIL) that recognize a model tumor antigen and have features of both activation and functional exhaustion. By filtering out accessible regions observed in bystander, non-exhausted, TIL and in acutely restimulated CD8+ T cells, we define a pattern of chromatin accessibility specific for T cell exhaustion, characterized by enrichment for consensus binding motifs for Nr4a and NFAT transcription factors. Anti-PD-L1 treatment of tumor-bearing mice results in cessation of tumor growth and partial rescue of cytokine production by the dysfunctional TIL, with only limited changes in gene expression and chromatin accessibility. Our studies provide a valuable resource for the molecular understanding of T cell exhaustion in cancer and other inflammatory settings.
Project description:T cell exhaustion is a progressive loss of effector function and memory potential due to persistent antigen exposure, which occurs in chronic viral infections and cancer. Here we investigate the relation between gene expression and chromatin accessibility in CD8+ tumor-infiltrating lymphocytes (TIL) that recognize a model tumor antigen and have features of both activation and functional exhaustion. By filtering out accessible regions observed in bystander, non-exhausted, TIL and in acutely restimulated CD8+ T cells, we define a pattern of chromatin accessibility specific for T cell exhaustion, characterized by enrichment for consensus binding motifs for Nr4a and NFAT transcription factors. Anti-PD-L1 treatment of tumor-bearing mice results in cessation of tumor growth and partial rescue of cytokine production by the dysfunctional TIL, with only limited changes in gene expression and chromatin accessibility. Our studies provide a valuable resource for the molecular understanding of T cell exhaustion in cancer and other inflammatory settings.
Project description:TGFb signaling is a major pathway associated with poor clinical outcome in patients with
advanced metastatic cancers and non-response to immune checkpoint blockade, particularly in the immune-excluded tumor phenotype. While previous pre-clinical studies demonstrated that converting tumors from an excluded to an inflamed phenotype and curative anti-tumor immunity require attenuation of both PD-L1 and TGFb signaling, the underlying cellular mechanisms remain unclear. Recent studies suggest that stem cell-like CD8 T cells (TSCL) can differentiate into non-exhausted CD8 T effector cells that drive durable anti-tumor immunity. Here, we show that TGFb and PD-L1 restrain TSCL expansion as well as replacement of progenitor exhausted and dysfunctional CD8 T cells with non-exhausted IFNghi CD8 T effector cells in the tumor microenvironment (TME). Blockade of TGFb and PD-L1 generated IFNghi CD8 T effector cells with enhanced motility, enabling both their accumulation in the TME and increased interaction with other cell types. Ensuing IFNg signaling markedly transformed myeloid, stromal, and tumor niches to yield a broadly immune-supportive ecosystem. Blocking IFNg completely abolished the effect of anti-PD-L1/ TGFb combination therapy. Our data suggest that TGFb works in concert with PD-L1 to prevent TSCL expansion and replacement of exhausted CD8 T cells with fresh CD8
T effector cells, thereby maintaining the CD8 T cell compartment in a dysfunctional state.
Project description:Programmed cell death 1 ligand 1 (PD-L1) is known to suppress immune system and to be an unfavorable prognostic factor in ovarian cancer. The purpose of this study was to elucidate the function of PD-L1 in peritoneal dissemination. Tumor cell lysis by CTLs was attenuated when PD-L1 on tumor cells was overexpressed and promoted when it was silenced. PD-L1 overexpression also inhibited gathering and degranulation of CTLs. Gene expression profile of mouse CTLs caused by PD-L1-overexpressing ovarian cancer was related to human CTLs exhaustion. In mouse ovarian cancer dissemination models, depleting PD-L1 expression on tumor cells resulted in inhibited tumor growth in the peritoneal cavity and prolonged survival. Restoring immune function by inhibiting immune-suppressive factors such as PD-L1 may be a promising therapeutic strategy for peritoneal dissemination. Genome-wide transcriptional changes in OT-1 mouse CD8+ T cells that were co-incubated with OVA peptide-loaded ID8 mouse ovarian cancer cell lines. CTLs from 4 mice were devided into 2 groups, and co-incubated with PD-L1-overexpressed ID8 or PD-L1-depleted ID8.