HLA-DM catalyzes the release of MHC class II-associated invariant chain-derived peptides (CLIP) from class II molecules. Recent evidence has suggested that HLA-DO is a negative regulator of HLA-DM in B cells, but the physiological function of HLA-DO remains unclear. Analysis of antigen presentation by B cells from mice lacking H2-O (the mouse equivalent of HLA-DO), together with biochemical analysis using purified HLA-DO and HLA-DM molecules, suggests that HLA-DO/H2-O influences the peptide loading of class II molecules by limiting the pH range in which HLA-DM is active. This effect may serve to decrease the presentation of antigens internalized by fluid-phase endocytosis, thus concentrating the B cell-mediated antigen presentation to antigens internalized by membrane immunoglobulin.
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http://dx.doi.org/10.1016/s1074-7613(00)80475-6 | DOI Listing |
J Adv Res
January 2025
Cancer Center, Department of Medical Oncology, Key Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang Province, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, China. Electronic address:
Introduction: Parkin-mediated mitophagy is essential for the clearance of damaged mitochondria, and it inhibits tumour development. The role of mitophagy in modulating tumour immunity is becoming clearer, but the underlying mechanism is still poorly understood.
Objective: This study was designed to examine the role for Parkin in the immune microenvironment of liver tumors induced by carbon tetrachloride (CCl).
EMBO J
January 2025
Department of Oncology, The University of Oxford, Oxford, OX3 7DQ, UK.
Hypoxia is a common feature of solid tumors that has previously been linked to resistance to radiotherapy and chemotherapy, and more recently to immunotherapy. In particular, hypoxic tumors exclude T cells and inhibit their activity, suggesting that tumor cells acquire a mechanism to evade T-cell recognition and killing. Our analysis of hypoxic tumors indicates that hypoxia downregulates the expression of MHC class I and its bound peptides (i.
View Article and Find Full Text PDFRetin Cases Brief Rep
December 2024
Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, USA.
Purpose: To report the clinical presentation, treatment course, and outcome of a case of bilateral frosted branch angiitis (FBA) and neuroretinitis associated with acute Epstein-Barr virus (EBV) infection in a pediatric patient with Turner Syndrome.
Methods: Case report with multimodal ocular imaging and extensive systemic workup.
Results: A 16-year-old female with Turner syndrome presented with acute bilateral vision loss, hearing loss, and ataxia.
Angew Chem Int Ed Engl
January 2025
University of Chicago Division of the Physical Sciences, chemistry, UNITED STATES OF AMERICA.
Immune checkpoint blockade (ICB) has revolutionized the treatment of many cancers by leveraging the immune system to combat malignancies. However, its efficacy is limited by the immunosuppressive tumor microenvironment and other regulatory mechanisms of the immune system. Innate immune modulators (IIMs) provide potent immune activation to complement adaptive immune responses and help overcome resistance to ICB.
View Article and Find Full Text PDFCell Rep
January 2025
Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address:
Tumor-draining lymph node dendritic cells (DCs) are poor stimulators of tumor antigen-specific CD4 T cells; however, the mechanism behind this defect is unclear. We now show that, in tumor-draining lymph node DCs, a large proportion of major histocompatibility complex class II (MHC-II) molecules retains the class II-associated invariant chain peptide (CLIP) fragment of the invariant chain bound to the MHC-II peptide binding groove due to reduced expression of the peptide editor H2-M and enhanced activity of the CLIP-generating proteinase cathepsin S. The net effect of this is that MHC-II molecules are unable to efficiently bind antigenic peptides.
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