Project description:Background: Checkpoint blockade immunotherapy represented by PD-1/PD-L1 or CTLA4 antibody treatment, has been of tremendous success for multiple cancers. Most patients with prostate cancer (PCa) either do not respond to CTLA4 immune checkpoint blockade or develop resistance to it, often because of low CTLA4 antigen presentation in cancer cells.
Project description:DNA mismatch repair deficient (MMR-d) cancers present an abundance of neoantigens that likely underlies their exceptional responsiveness to immune checkpoint blockade (ICB). However, MMR-d colon cancers that evade CD8+ T cells through loss of Human Leukocyte Antigen (HLA) class I-mediated antigen presentation frequently remain responsive to ICB, suggesting the involvement of other immune effector cells.
Project description:Tumor mutational burden (TMB), usually representing high immunogenicity, could not always predict treatment response of immune checkpoint blockade (ICB). Here, we showed that defective antigen cross-presentation in type 1 conventional dendritic cells (cDC1) was responsible for lacking tumor-specific cytotoxic T lymphocytes (CTLs) in triple-negative breast cancer (TNBC) patients. Mechanistically, tumor cytosolic CDC37, shuttled via extracellular vesicles (EVs) into the endosomes of intratumor DCs, inhibited antigen cross-presentation by locking antigen binding to HSP90 and precluding their translocation from endosomes to cytoplasm. CDC37 knockdown in tumor cells or inhibiting CDC37/HSP90 interaction in DCs efficiently promoted antigen translocation and enhanced their cross-presentation, which improved ICB therapeutic responses. Clinically, high tumor CDC37 expression was associated with low infiltration of antigen-specific CTLs and poor ICB efficacy in TNBC patients. Therefore, tumor EV-shuttled CDC37 locks antigen/chaperone interaction and impairs antigen cross-presentation in DCs. Moreover, targeting CDC37 is promising to enhance anti-tumor immunity and reverse ICB resistance.
Project description:Immune checkpoint blockade (ICB), notably Programmed Death-1/Programmed Death-Ligand 1 (PD-1/PD-L1) inhibition, has revolutionized the treatment of non-small cell lung cancer (NSCLC). However, durable responses are only observed in a subpopulation of patients. Defective antigen presentation and an immunosuppressive tumor microenvironment can lead to deficient T-cell recruitment and ICB resistance. We evaluated in situ vaccination with CXCL9 and CXCL10-engineered dendritic cells (CXCL9/10-DC) as a novel strategy to overcome resistance to ICB using Lkb1-null murine NSCLC model. We utilized single-cell RNA-seq to evaluate alterations of immune infiltration associated with the new therapy, which combines intratumoral CXCL9/10-DC administration and PD-1 inhibition.
Project description:The anti-tumor effects of IFNγ are well-known as IFNγ binding to tumor cells increases antigen presentation and can cause cytostatic growth defects. Indeed, the inability of tumors to respond to IFNγ often renders tumors resistant to checkpoint blockade and other immunotherapies reliant on direct T cell cytotoxicity. We performed single-cell RNA-sequencing during virus therapy to get insight into the immune microenvironment of the tumor during treatment.
Project description:Immune checkpoint blockade (ICB) therapy revolutionized cancer treatment, but many patients with impaired MHC-I expression remain refractory. Histone methylation was involved in anti-tumor immunity of ICB. However, the link between histone methylation and MHC-I regulation and the related mechanisms are poorly understood. Here we show that KDM5A, an H3K4 demethylase that is critical for MHC-I expression and associated antigen presentation capacity, induces robust immune response and enhances ICB efficacy. Mechanistically, KDM5A upregulates IFN-gamma/STAT1-mediated MHC-I expression via directly binding and suppressing Scos1 in tumor cells. The genes encoding the lysosomal cathepsins are recognized and up-regulated by KDM5A, resulting in enhanced antigen-presentation abilities of both tumor cells and dendritic cells. Furthermore, pharmacological enhancing KDM5A improves response to anti-PD-1 therapy. These investigations demonstrate that enhancing KDM5A triggers MHC-associated antigen presentation of both tumor cells and DCs simultaneously to boost antitumor immunity, thus represents a candidate ICB sensitizer.
Project description:Immune checkpoint blockade (ICB) therapy revolutionized cancer treatment, but many patients with impaired MHC-I expression remain refractory. Histone methylation was involved in anti-tumor immunity of ICB. However, the link between histone methylation and MHC-I regulation and the related mechanisms are poorly understood. Here we show that KDM5A, an H3K4 demethylase that is critical for MHC-I expression and associated antigen presentation capacity, induces robust immune response and enhances ICB efficacy. Mechanistically, KDM5A upregulates IFN-gamma/STAT1-mediated MHC-I expression via directly binding and suppressing Scos1 in tumor cells. The genes encoding the lysosomal cathepsins are recognized and up-regulated by KDM5A, resulting in enhanced antigen-presentation abilities of both tumor cells and dendritic cells. Furthermore, pharmacological enhancing KDM5A improves response to anti-PD-1 therapy. These investigations demonstrate that enhancing KDM5A triggers MHC-associated antigen presentation of both tumor cells and DCs simultaneously to boost antitumor immunity, thus represents a candidate ICB sensitizer.
Project description:Immune checkpoint blockade (ICB) therapy revolutionized cancer treatment, but many patients with impaired MHC-I expression remain refractory. Histone methylation was involved in anti-tumor immunity of ICB. However, the link between histone methylation and MHC-I regulation and the related mechanisms are poorly understood. Here we show that KDM5A, an H3K4 demethylase that is critical for MHC-I expression and associated antigen presentation capacity, induces robust immune response and enhances ICB efficacy. Mechanistically, KDM5A upregulates IFN-gamma/STAT1-mediated MHC-I expression via directly binding and suppressing Scos1 in tumor cells. The genes encoding the lysosomal cathepsins are recognized and up-regulated by KDM5A, resulting in enhanced antigen-presentation abilities of both tumor cells and dendritic cells. Furthermore, pharmacological enhancing KDM5A improves response to anti-PD-1 therapy. These investigations demonstrate that enhancing KDM5A triggers MHC-associated antigen presentation of both tumor cells and DCs simultaneously to boost antitumor immunity, thus represents a candidate ICB sensitizer.
