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:Background: Chaperon-mediated autophagy (CMA) has taken on a new emphasis in cancer biology. However, the roles of CMA in hypoxic tumours are poorly understood. We investigated the anti-tumour effects of the natural product ManA through the activation of CMA in tumour progression under hypoxia. Methods: The effect of ManA on CMA activation was assessed in mouse xenograft models and cells. The gene expressions of HIF-1α, HSP90AA1, and transcription factor EB (TFEB) were analysed using The Cancer Genome Atlas (TCGA) datasets to assess the clinical relevance of CMA. Results: ManA activates photoswitchable CMA reporter activity and inhibits Hsp90 chaperone function by disrupting the Hsp90/F1F0-ATP synthase complex. Hsp90 inhibition enhances the interaction between CMA substrates and LAMP-2A and TFEB nuclear localisation, suggesting CMA activation by ManA. ManA-activated CMA retards tumour growth and displays cooperative anti-tumour activity with anti-PD-1 antibody. TCGA datasets show that a combined expression of HSP90AA1High/HIF1AHigh or TFEBLow/HIF1AHigh is strongly correlated with poor prognosis in patients with lung cancer. Conclusions: ManA-induced CMA activation by modulating Hsp90 under hypoxia induces HIF-1α degradation and reduces tumour growth. Thus, inducing CMA activity by targeting Hsp90 may be a promising therapeutic strategy against hypoxic tumours.
Project description:We used single-cell RNA sequencing (scRNAseq) to compare cells from the lungs of Mycobacterium tuberculosis infected mice between C57BL/6J mice and a cohort of wild-derived mouse lines MANA, MANB and MANC (Jackson Laboratories: ManA/NachJ #035354; ManB/NachJ #035355).