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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.
2024-03-31 | GSE260912 | GEO
Project description:Dendritic cells (DCs) play a pivotal role in priming adaptive immunity. However, the involvement of DCs in controlling excessive and deleterious T cell responses remains poorly defined. Moreover, the metabolic dependence and regulation of DC function are unclear. Here we show that LKB1 signaling in DCs functions as a brake to restrain excessive tumor-promoting regulatory T cell (Treg) and Th17 cell responses, thereby promoting protective anti-tumor immunity and maintaining proper immune homeostasis. LKB1 deficiency results in dysregulated metabolism and mTOR activation of DCs. Loss of LKB1 also leads to aberrant DC maturation and production of cytokines and immunoregulatory molecules. Blocking mTOR signaling in LKB1-deficient DCs partially rectifies the abnormal phenotypes of DC activation and Treg expansion, whereas uncontrolled Th17 responses depend upon IL-6-STAT3 signaling. By coordinating metabolic and immune quiescence of DCs, LKB1 acts as a crucial signaling hub in DCs to enforce protective anti-tumor immunity and normal immune homeostasis.
| S-EPMC6796952 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2019-04-16 | GSE128475 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2015-08-11 | E-GEOD-71871 | biostudies-arrayexpress
Project description:The activation and recruitment of CD4(+) T cells are critical for the development of efficient antitumor immunity and may allow for the optimization of current cancer immunotherapy strategies. Searching for more optimal and selective targets for CD4(+) T cells, we have investigated phosphopeptides, a new category of tumor-derived epitopes linked to proteins with vital cellular functions. Although MHC I-restricted phosphopeptides have been identified, it was previously unknown whether human MHC II molecules present phosphopeptides for specific CD4(+) T cell recognition. We first demonstrated the fine specificity of human CD4(+) T cells to discriminate a phosphoresidue by using cells raised against the candidate melanoma antigen mutant B-Raf or its phosphorylated counterpart. Then, we assessed the presence and complexity of human MHC II-associated phosphopeptides by analyzing 2 autologous pairs of melanoma and EBV-transformed B lymphoblastoid lines. By using sequential affinity isolation, biochemical enrichment, mass spectrometric sequencing, and comparative analysis, a total of 175 HLA-DR-associated phosphopeptides were characterized. Many were derived from source proteins that may have roles in cancer development, growth, and metastasis. Most were expressed exclusively by either melanomas or transformed B cells, suggesting the potential to define cell type-specific phosphatome "fingerprints." We then generated HLA-DRbeta1*0101-restricted CD4(+) T cells specific for a phospho-MART-1 peptide identified in both melanoma cell lines. These T cells showed specificity for phosphopeptide-pulsed antigen-presenting cells as well as for intact melanoma cells. This previously undescribed demonstration of MHC II-restricted phosphopeptides recognizable by human CD4(+) T cells provides potential new targets for cancer immunotherapy.
| S-EPMC2715484 | biostudies-other
Project description:BackgroundTumor-associated macrophages (TAMs) promote key processes in the modulation of tumor microenvironment (TME). However, the clinical significance of heterogeneous subpopulations of TAMs in hepatocellular carcinoma (HCC) remains unknown.MethodsHCC tissues from Zhongshan Hospital and data from The Cancer Genome Atlas were obtained and analyzed. Immunohistochemistry and flow cytometry were performed to detect the characteristics of sialic acid-binding immunoglobulin-like lectin 10high (Siglec-10hi) TAMs and explore their impact on the TME of HCC. The effect of Siglec-10 blockade was evaluated in vitro based on fresh human tumor tissues.ResultsOur data revealed that Siglec-10 was abundant in a large proportion of HCC specimens and prominently distributed on macrophages. Kaplan-Meier curves and Cox regression analysis showed that intratumoral Siglec-10+ cell enrichment was associated with unfavorable prognosis in patients with HCC. Notably, multiple anti-inflammatory cytokines and inhibitory receptors were enriched in Siglec-10hi TAMs. RNA sequencing data also revealed that numerous M2-like signaling pathways were significantly upregulated in Siglec-10hi TAMs. High infiltration of Siglec-10hi TAMs was associated with impaired CD8+ T cell function in HCC. Of note, blocking Siglec-10 with the competitive binding antibody Siglec-10 Fc led to decreased expression of immunosuppressive molecules and increased the cytotoxic effects of CD8+ T cells against HCC cells. Moreover, blocking Siglec-10 promoted the anti-tumor efficacy of the programmed cell death protein 1 (PD-1) inhibitor pembrolizumab.ConclusionsSiglec-10hi TAMs are associated with immune suppression in the TME, and indicate poor prognosis in patients with HCC. Targeting Siglec-10hi TAMs may serve as a promising immunotherapy approach for HCC.
| S-EPMC8191104 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2023-02-22 | GSE197229 | GEO
Project description:Tumor-associated fibrosis is characterized by unchecked pro-fibrotic and pro-inflammatory signaling. The components of fibrosis including significant numbers of cancer-associated fibroblasts, dense collagen deposition, and extracellular matrix stiffness, are well appreciated regulators of tumor progression but may also be critical regulators of immune surveillance. While this suggests that the efficacy of immunotherapy may be limited in highly fibrotic cancers like pancreas, it also suggests a therapeutic opportunity to target fibrosis in these tumor types to reawaken anti-tumor immunity. This review discusses the mechanisms by which fibrosis might subvert tumor immunity and how to overcome these mechanisms.
| S-EPMC5603233 | biostudies-literature
Project description:Immunological checkpoint blockade therapies benefit a limited population of cancer patients. We have previously shown that vaccine immunotherapy with Toll-like receptor (TLR)3-adjuvant and tumor antigen overcomes anti-programmed death ligand-1 (PD-L1) resistance in mouse tumor models. In the present study, 4 different ovalbumin (OVA)-expressing tumor cell lines were implanted into syngeneic mice and subjected to anti-tumor immunotherapy using ARNAX and whole OVA protein. ARNAX is a TLR3-specific agonist that does not activate the mitochondrial antiviral-signaling protein (MAVS) pathway, and thus does not induce systemic inflammation. Dendritic cell priming and proliferative CTL were induced by ARNAX + OVA, but complete remission was achieved only in a PD-L1-low cell line of EG7. Addition of anti-PD-L1 antibody to the ARNAX + OVA therapy brought complete remission to another PD-L1-high subline of EG7. Tumor shrinkage but not remission was observed in MO5 in that regimen. We analyzed tumor cells and tumor-infiltrating immune cells to identify factors associated with successful ARNAX vaccine therapy. Tumors that responded to ARNAX therapy expressed high levels of MHC class I and low levels of PD-L1. The tumor-infiltrating immune cells in ARNAX-susceptible tumors contained fewer immunosuppressive myeloid cells with low PD-L1 expression. Combination with anti-PD-L1 antibody functioned not only within tumor sites but also within lymphoid tissues, augmenting the therapeutic efficacy of the ARNAX vaccine. Notably, ARNAX therapy induced memory CD8+ T cells and rejection of reimplanted tumors. Thus, ARNAX vaccine + anti-PD-L1 therapy enabled permanent remission against some tumors that stably present antigens.
| S-EPMC6029830 | biostudies-other
Project description:Synthetic biology is a powerful tool to create therapeutics which can be rationally designed to enable unique and combinatorial functionalities. Here we utilize non-pathogenic E coli Nissle as a versatile platform for the development of a living biotherapeutic for the treatment of cancer. The engineered bacterial strain, referred to as SYNB1891, targets STING-activation to phagocytic antigen-presenting cells (APCs) in the tumor and activates complementary innate immune pathways. SYNB1891 treatment results in efficacious antitumor immunity with the formation of immunological memory in murine tumor models and robust activation of human APCs. SYNB1891 is designed to meet manufacturability and regulatory requirements with built in biocontainment features which do not compromise its efficacy. This work provides a roadmap for the development of future therapeutics and demonstrates the transformative potential of synthetic biology for the treatment of human disease when drug development criteria are incorporated into the design process for a living medicine.
| S-EPMC7264239 | biostudies-literature