Project description:De novo DNA methylation establishes T cell exhaustion and inhibits PD-1 blockade-mediated T-cell rejuvenation. Expression profiling of chronically stimulated WT and Dnmt3a cKO antigen-specific CD8 T cells.
Project description:Most bladder cancers are poorly responsive to immune checkpoint blockade (ICB) of PD-L1. Thus, there is a need to define mechanisms of de novo resistance including contributions from tumor infiltrating immune cells. In this study, we used single-cell transcriptional profiling to map and define infiltrating myeloid cells in 10 human bladder tumors. Human data sets were qualitatively compared with myeloid data sets from the carcinogen (BBN) induced mouse model of bladder cancer which we have demonstrated to be poorly responsive to PD-L1 blockade. We previously established a signature of acquired ICB resistance which we apply here to new human and murine tumor data sets that have not received prior ICB (or systemic treatment). In doing so, we reveal conservation in EMT-stromal core genes and TGF beta signaling between human and mouse myeloid cells consistent with signatures of de novo ICB resistance. Untreated BBN tumors were highly infiltrated with M0-M2 macrophages, low in T-NK infiltration and modeled a patient subpopulation with poor survival outcome. Concordantly, the combined targeting of TGFb + PD-L1 reverted immune cell exclusion and resulted in increased survival and delayed BBN mouse tumor progression. These data constitute the stromal and myeloid cell populations as providing a coordinate mechanism de novo resistance to PD-L1 blockade in a TGF-beta dependent manner.
Project description:T cell rejuvenation by PD-1/PD-L1 blockade, despite emerging as a highly promising therapy for advanced cancers, is only beneficial for a minority of treated patients. There is evidence that a lack of efficient T cell activation may be responsible for the failure. Here, we demonstrate that IL-21 can be targeted to tumor-reactive T cells by fusion of IL-21 to anti-PD-1 antibody. To our surprise, the fusion protein PD-1Ab21 promoted the generation of TSCM-like CD8+ T cells with enhanced cell proliferation. A transcriptome analysis of isolated TN, activated and PD-1Ab-cultured CD44highCD62Lhigh T cells, IL-2-generated TE/TEM, IL-15-generated TCM as well as PD-1Ab21 and IL-21-generated CD44lowCD62Lhigh T cells provides corroborating evidence that PD-1Ab21 induces conversion of activated CD8+ T cells back to a memory subset that is distinct from TCM cells, but similar to TSCM. PD-1Ab21 treatment showed potent antitumor effects in established tumor-bearing mice accompanied with an increased frequency of TSCM and robust expansion of tumor-specific CD8+ T cells with a memory phenotype, and was superior to a combination of PD-1 blockade and IL-21 infusion. Therefore, we have developed a potential strategy to improve the therapeutic effects of immune checkpoint blockade by simultaneously targeting cytokines to tumor-reactive T cells.
Project description:Immune checkpoint blockade (ICB) has revolutionized cancer treatment, but most patients do not respond. PD-1 blockade “unleashes” CD8 T cells, including those specific for mutation-associated neoantigens (MANA), but factors in the tumor microenvironment can inhibit responses by dampening MANA-specific T cell function. Recent advances in single cell transcriptomics are revealing global T cell dysfunction programs in tumor-infiltrating lymphocytes (TIL). However, the vast majority of TIL do not recognize tumor antigens and little is known about transcriptional programs of true MANA-specific TIL. Here, we use an integrated approach to identify MANA-specific T cell clones using the MANA functional expansion of specific T cells (MANAFEST) assay in neoadjuvant anti-PD-1-treated lung cancers and use their TCR CDR3 as barcodes to track them and analyze their transcriptional programs and function in the tumor microenvironment using single cell RNA sequencing. We find both MANA-and virus-specific clones in TIL and adjacent normal lung, regardless of response status. MANA-specific, influenza (flu)-specific and EBV-specific TIL each have unique transcriptional programs. Most MANA-specific clones are tissue resident memory (TRM) cells, an incompletely activated cytolytic program, including EOMES deficiency, and higher levels of genes encoding T cell inhibitory molecules and Tox2. Notably, MANA-specific T cells express low levels of IL-7R and are functionally less responsive to IL-7 compared with tissue-resident flu-specific clones. MANA-specific clones from anti-PD-1 non-responding tumors express TCR with markedly lower ligand-dependent signaling capability, are largely confined to HOBIThi TRM subsets and coordinately up-regulate genes encoding specific checkpoints, killer inhibitory receptors, and intracellular inhibitors of T cell activation and cytotoxicity. These findings provide mechanistic and potential therapeutic insights into overcoming resistance to PD-1 blockade.
Project description:Immune checkpoint blockade (ICB) has revolutionized cancer treatment, but most patients do not respond. PD-1 blockade “unleashes” CD8 T cells, including those specific for mutation-associated neoantigens (MANA), but factors in the tumor microenvironment can inhibit responses by dampening MANA-specific T cell function. Recent advances in single cell transcriptomics are revealing global T cell dysfunction programs in tumor-infiltrating lymphocytes (TIL). However, the vast majority of TIL do not recognize tumor antigens and little is known about transcriptional programs of true MANA-specific TIL. Here, we use an integrated approach to identify MANA-specific T cell clones using the MANA functional expansion of specific T cells (MANAFEST) assay in neoadjuvant anti-PD-1-treated lung cancers and use their TCR CDR3 as barcodes to track them and analyze their transcriptional programs and function in the tumor microenvironment using single cell RNA sequencing. We find both MANA-and virus-specific clones in TIL and adjacent normal lung, regardless of response status. MANA-specific, influenza (flu)-specific and EBV-specific TIL each have unique transcriptional programs. Most MANA-specific clones are tissue resident memory (TRM) cells, an incompletely activated cytolytic program, including EOMES deficiency, and higher levels of genes encoding T cell inhibitory molecules and Tox2. Notably, MANA-specific T cells express low levels of IL-7R and are functionally less responsive to IL-7 compared with tissue-resident flu-specific clones. MANA-specific clones from anti-PD-1 non-responding tumors express TCR with markedly lower ligand-dependent signaling capability, are largely confined to HOBIThi TRM subsets and coordinately up-regulate genes encoding specific checkpoints, killer inhibitory receptors, and intracellular inhibitors of T cell activation and cytotoxicity. These findings provide mechanistic and potential therapeutic insights into overcoming resistance to PD-1 blockade.
Project description:CD8+ T cells in chronic viral infections like HIV develop functional defects such as loss of IL-2 secretion and decreased proliferative potential that are collectively termed exhaustion1. Exhausted T cells express increased levels of multiple inhibitory receptors, such as Programmed Death 1 (PD-1). PD-1 inhibition contributes to impaired virus-specific T cell function in chronic infection because antibody-mediated blockade of its ligand, Programmed Death Ligand 1 (PD-L1) is sufficient to improve T cell function and reduce viral replication in animal models. Reversing PD-1 inhibition is therefore an attractive therapeutic target, but the cellular mechanisms by which PD-1 ligation results in T cell inhibition are not fully understood. PD-1 is thought to limit T cell activation by attenuating T cell receptor (TCR) signaling. It is not known whether PD-1 ligation also acts by upregulating genes in exhausted T cells that impair their function. Here, we analyzed gene-expression profiles from HIV-specific CD8+ T cells in patients with HIV and show that PD-1 coordinately upregulates a program of genes in exhausted CD8+ T cells from humans and mice. This program includes upregulation of basic leucine transcription factor, ATF-like (BATF), a transcription factor in the AP-1 family. Enforced expression of BATF was sufficient to impair T cell proliferation and cytokine secretion, while BATF knockdown reduced PD-1 inhibition. Silencing BATF in CD4+ and CD8+ T cells from chronic viremic patients rescued HIV-specific T cell function. Thus inhibitory receptors can cause T cell exhaustion by upregulating genes â such as BATF â that inhibit T cell function. PD-1 expressing Jurkat cells were cultured for 18 hours with beads coated with antibodies to CD3 and CD28, with our without an antibody to PD-1.