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:Increases in terminally exhausted T cells in the tumor are associated with poor responses to immunotherapy, yet the mechanisms that promote progression to terminal exhaustion remain undefined. We profiled the chromatin landscape of subsets of tumor-infiltrating CD8+ T cells using CUT&RUN. CD8 T cells were sorted from the murine B16 melanoma tumor using PD1 and Tim3 expression to define four subsets: PD1lo, PD1mid, PD1hi, and PD1hiTim3+. Additional control samples include paired CD44+ cells from the tumor-draining lymph node of tumor bearing mice, and OT-I effector CD8 T cells isolated from Vaccinia-ova infection. We performed CUT&RUN for H3K4me3, H3K27me3, H3K27ac, and H3K9ac, as well as the transcription factors Tox and Batf.
Project description:Increases in terminally exhausted T cells in the tumor are associated with poor responses to immunotherapy, yet the mechanisms that promote progression to terminal exhaustion remain undefined. To understand the effect of epigenetic changes in subsets of tumor-infiltrating CD8+ T cells, we performed RNA-seq to understand changes in gene expression. CD8 T cells were sorted from the murine B16 melanoma tumor using PD1 and Tim3 expression to define four subsets: PD1lo, PD1mid, PD1hi, and PD1hiTim3+. Additional control samples include paired CD44+ cells from the tumor-draining lymph node of tumor bearing mice, and OT-I effector CD8 T cells isolated from Vaccinia-ova infection. CD8 TIL PD1hi Tim3+ from B16 tumors treated with IgG control, anti-PD1 or anti-41BB agonist immunotherapies were also isolated for RNAseq.
Project description:High amount of Eomes might drive T cell exhaustion. In order to understand how Eomes contributes to exhaustion of CD8+ T cell in the TME, we conducted transcriptional analysis of control OT-I cells and Eomes-overexpressing OT-I cells
Project description:High amount of Eomes might drive T cell exhaustion. In order to understand how Eomes contributes to exhaustion of CD8+ T cell in the TME as a transcription factor, we conducted anti-Eomes ChIPseq analysis of control OT-I cells and Eomes-overexpressing OT-I cells.
Project description:In patients with pancreatic ductal adenocarcinoma (PDAC), we show that response to radiation therapy (RT) is characterized by increased IL2R and IL2R expression, decreased ILR2 and exhaustion markers. The bispecific PD-1-targeted IL-2 variant (IL2v) immunocytokine with engineered IL-2 cis-targeted to PD-1 and abolished IL2R binding targets the activation of tumor-antigen specific T cells while rescuing them from Treg suppression. Using aPD1-IL2v in orthotopic PDAC KPC-driven tumor models, we show marked improvement in local and metastatic survival along with profound increase in tumor-infiltrating polyfunctional CD8 T cell subsets with a transcriptionally and metabolically active phenotype, and preferential activation of antigen-specific CD8 T cells. In combination with single dose RT, aPD1-IL2v treatment results in a robust, durable expansion of polyfunctional CD8 T cells, T cell stemness, tumor-specific memory immune response, NK cell activation, and decreased Tregs. These data show that the novel aPD1-IL2v, leads to profound local and distant response in PDAC.
