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Unlabelled: Small extracellular vesicle (sEV, or exosome) communication among cells in the tumor microenvironment has been modeled mainly in cell culture, whereas their relevance in cancer pathogenesis and progression in vivo is less characterized. Here we investigated cancer-microenvironment interactions in vivo using mouse models of chronic lymphocytic leukemia (CLL). sEVs isolated directly from CLL tissue were enriched in specific miRNA and immune-checkpoint ligands. Distinct molecular components of tumor-derived sEVs altered CD8+ T-cell transcriptome, proteome, and metabolome, leading to decreased functions and cell exhaustion ex vivo and in vivo. Using antagomiRs and blocking antibodies, we defined specific cargo-mediated alterations on CD8+ T cells. Abrogating sEV biogenesis by Rab27a/b knockout dramatically delayed CLL pathogenesis. This phenotype was rescued by exogenous leukemic sEV or CD8+ T-cell depletion. Finally, high expression of sEV-related genes correlated with poor outcomes in CLL patients, suggesting sEV profiling as a prognostic tool. In conclusion, sEVs shape the immune microenvironment during CLL progression.
Significance: sEVs produced in the leukemia microenvironment impair CD8+ T-cell mediated antitumor immune response and are indispensable for leukemia progression in vivo in murine preclinical models. In addition, high expression of sEV-related genes correlated with poor survival and unfavorable clinical parameters in CLL patients. See related commentary by Zhong and Guo, p. 5. This article is highlighted in the In This Issue feature, p. 1.
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http://dx.doi.org/10.1158/2643-3230.BCD-22-0029 | DOI Listing |
Nat Cell Biol
September 2025
NHC Key Laboratory of Molecular Probes and Targeted Diagnosis and Therapy, Harbin Medical University, Harbin, China.
The colon exhibits higher propensity for tumour development than ileum. However, the role of immune microenvironment differences in driving this disparity remains unclear. Here, by comparing paired ileum and colon samples from patients with colorectal cancer (CRC) and healthy donors, we identified ileum-enriched CD160CD8 T cells with previously unrecognized characteristics, including resistance to terminal exhaustion and strong clonal expansion.
View Article and Find Full Text PDFJ Control Release
September 2025
Department of Ultrasound, China-Japan Friendship Hospital, Beijing 100029, China; National Center for Respiratory Medicine; State Key Laboratory of Respiratory Health and Multimorbidity; National Clinical Research Center for Respiratory Diseases; Institute of Respiratory Medicine, Chinese Academy of
Anaplastic thyroid cancer (ATC) is the most aggressive form of thyroid malignancy and currently lacks effective treatment options. While anti-PD1 therapy has shown remarkable clinical results in some cases, only a subset of ATC patients responds to it. Eganelisib (IPI549), a highly selective PI3Kγ inhibitor, can alleviate the tumor immunosuppressive state by reducing the proportion of M2-like tumor associated macrophages, partially overcoming patient resistance to anti-PD1 therapy and synergizing with its efficacy.
View Article and Find Full Text PDFCell Rep Med
September 2025
Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada. Electronic address:
The success of immune checkpoint inhibitors is limited by multiple factors, including poor T cell infiltration and function within tumors, partly due to a dense extracellular matrix (ECM). Here, we investigate modulating the ECM by targeting integrin α5β1, a major fibronectin-binding and organizing integrin, to improve immunotherapy outcomes. Use of a function-blocking murinized α5β1 antibody reduces fibronectin fibril formation, enhances CD8 T cell transendothelial migration, increases vascular permeability, and decreases vessel-associated collagen.
View Article and Find Full Text PDFBiochem Biophys Res Commun
September 2025
State Key Laboratory of Medicinal Chemical Biology and College of Life Science, Nankai University, Tianjin, China. Electronic address:
Oncolytic viruses (OVs) represent a promising approach for cancer immunotherapy by inducing direct tumor lysis and stimulating antitumor immunity. However, tumor-intrinsic resistance remains a major barrier to their efficacy. In this study, we established an OV-resistant MC38 colon cancer model (MC38) and identified interferon regulatory factor 7 (IRF7), a key regulator of type I interferon signaling, as significantly upregulated in resistant cells.
View Article and Find Full Text PDFBiomaterials
September 2025
Key Laboratory of Biopharmaceutical Preparation and Delivery, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China. Electronic address:
The stimulator of interferon genes (STING) pathway represents a promising target in cancer immunotherapy. However, the clinical translation of cyclic dinucleotide (CDN)-based STING agonists remains hindered by insufficient formation of functional CDN-STING complexes. This critical bottleneck arises from two interdependent barriers: inefficient cytosolic CDN delivery and tumor-specific STING silencing via DNA methyltransferase-mediated promoter hypermethylation.
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