Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA398304 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Resistance to Checkpoint Blockade Therapy Through Inactivation of Antigen Presentation
| PRJNA398303 | ENA
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.
2025-04-02 | GSE234387 | GEO
Project description:Atractylenolide I enhances responsiveness to immune checkpoint blockade therapy by activating tumor antigen presentation
| PRJNA718568 | ENA
Project description:To address RAS pathway hyperactivation and targeted therapy resistance in KRASG12C-mutant NSCLC, we evaluated the potential of the RAS(ON) G12C-selective covalent inhibitor elironrasib and the RAS(ON) multi-selective inhibitor daraxonrasib combination to maximize RAS pathway suppression and forestall pathway reactivation in a series of preclinical models. We demonstrate that the RAS(ON) inhibitor doublet induces profound and sustained tumor regressions and overcomes the increased RAS pathway oncogenic flux that underlies resistance to inactive state–selective KRASG12C inhibitors in NSCLC. Additionally, in immune-competent preclinical models, the RAS(ON) inhibitor doublet enhances tumor immune recognition by boosting antigen presentation and remodeling the suppressive tumor microenvironment, thus promoting immune-dependent complete regressions and sensitization of an immuno-refractory model to checkpoint blockade. Collectively these findings provide a preclinical rationale for the evaluation of a targeted RAS(ON) inhibitor doublet therapy regimen in combination with immune checkpoint blockade in patients with KRASG12C-mutant NSCLC.
2025-12-29 | GSE315010 | GEO
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.
2025-10-17 | PXD069576 |
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.
2022-11-01 | GSE216534 | GEO
Project description:Macrophage-directed immunotherapy has emerged as a promising strategy to eliminate tumors by unleashing phagocytosis, exemplified by blockade of the CD47-SIRPα “don’t eat me” axis. However, despite robust enhancement of phagocytosis, such approaches often fail to generate durable antitumor immunity in solid tumors, highlighting a critical disconnect between innate immune activation and effective T cell responses. Here, we identify PCSK9 as an adaptive resistance factor induced by macrophage immune checkpoint blockade. Tumor-derived PCSK9 promotes lysosomal degradation of MHC-I in macrophages, thereby impairing antigen cross-presentation and limiting CD8⁺ T cell priming. This previously unrecognized mechanism reveals how phagocytosis-targeted therapies can paradoxically suppress adaptive immunity. To overcome this resistance, we engineered bispecific fusion proteins that concurrently target the CD47-SIRPα phagocytosis checkpoint and the PCSK9–MHC-I antigen presentation axis, among which SIRPαD1-αPCSK9 emerged as the optimal format. Dual targeting synergistically enhances macrophage phagocytosis, preserves antigen cross-presentation capacity, and reprograms the tumor microenvironment toward an immunostimulatory state. Consequently, SIRPαD1-αPCSK9 elicits robust activation of both innate and adaptive antitumor immunity, leading to potent tumor control with improved safety. These findings uncover a novel mechanism of resistance to macrophage-centered immunotherapy and establish a rational dual-targeting strategy that bridges phagocytosis and T cell activation, offering a new paradigm for macrophage-driven cancer immunotherapy.
2026-06-17 | GSE335282 | GEO
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.
2023-05-22 | GSE232730 | GEO
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.
2023-02-03 | GSE222795 | GEO
Project description:<p>Although immune checkpoint blockade (CPB) leads to prolonged responses in 15-40% of patients with metastatic melanoma, treatment refractory disease and progression after initial response remain major causes of mortality. While predictors of response have been reported, the common mechanisms of both primary and acquired resistance are poorly understood. To identify mechanisms of resistance and examine the evolving landscape in response to CPB, we performed whole exome sequencing (WES), immunohistochemistry (IHC), and RNA-sequencing (RNAseq) of longitudinal tumor biopsies from 17 metastatic melanoma patients treated with various CPB therapies. We found no significant changes in both mutational and neoantigen loads over time between responders and nonresponders. However, we identified abnormalities in one gene, beta-2-microglobulin (<i>B2M</i>), an essential component of MHC Class I antigen presentation, that were present in samples during disease progression but not regression. In total, we identified <i>B2M</i> aberrations in 29.4% of patients, including multiple early frameshift mutations, loss of heterozygosity (LOH) overlapping <i>B2M</i>, and absence of tumor-specific <i>B2M</i> protein expression. Additional defects in the antigen presentation and IFNγ pathways were identified but were not restricted to progressing lesions in our cohort. In two independent cohorts of 105 and 38 melanoma patients treated with ipilimumab (anti-CTLA4) and pembrolizumab (anti-PD1) respectively, we found that <i>B2M</i> LOH was enriched 3-fold in nonresponders (~30%) vs. responders (~10%) and associated with poorer overall survival (log-rank p=0.01, p=0.006). Loss of both copies of <i>B2M</i> was found only in nonresponders. We also found evidence for association of LOH overlapping <i>IFNGR1</i> with poorer overall survival exclusively in the anti-PD1 cohort. Thus, <i>B2M</i> loss is likely a common mechanism of primary and acquired resistance to therapies targeting CTLA4 or PD-1.</p>
| phs001427 | dbGaP