Mucosal-associated invariant T (MAIT) cells are an abundant subset of innate-like T lymphocytes. MAIT cells are activated by microbial riboflavin-derived antigens, such as 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil (5-OP-RU), when presented by the major histocompatibility complex (MHC) class I-related protein (MR1). We have synthesized all stereoisomers of 5-OP-RU to investigate the effects of its stereochemistry on the MR1-dependent MAIT cell activation and MR1 upregulation. The analysis of MAIT cell activation by these 5-OP-RU isomers revealed that the stereocenters at the 2'- and 3'-OH groups in the ribityl tail are crucial for the recognition of MAIT-TCR, whereas that of 4'-OH group does not significantly affect the regulation of MAIT cell activity. Furthermore, kinetic analysis of complex formation between the ligands and MR1 suggested that 5-OP-RU forms a covalent bond to MR1 in cells within 1 hour. These findings provide guidelines for designing ligands that regulate MAIT cell functions.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/cbic.202000466 | DOI Listing |
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating but poorly-understood disease. ME/CFS symptoms can range from mild to severe, and include immune system effects alongside incapacitating fatigue and post-exertional disease exacerbation. In this study, we examined immunological profiles of people living with ME/CFS by flow cytometry, focusing on cytotoxic cells, to determine whether people with mild/moderate (n= 43) or severe ME/CFS (n=53) expressed different immunological markers.
View Article and Find Full Text PDFJ Exp Med
February 2025
Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Australia.
Tobacco smoking is prevalent across the world and causes numerous diseases. Cigarette smoke (CS) compromises immunity, yet little is known of the components of CS that impact T cell function. MR1 is a ubiquitous molecule that presents bacterial metabolites to MAIT cells, which are highly abundant in the lungs.
View Article and Find Full Text PDFThe role of immune cells in neurodegeneration remains incompletely understood. Our recent study revealed the presence of mucosal-associated invariant T (MAIT) cells in the meninges, where they express antioxidant molecules to maintain meningeal barrier integrity. Accumulation of misfolded tau proteins are a hallmark of neurodegenerative diseases.
View Article and Find Full Text PDFCancer Drug Resist
December 2024
Department of Oncology I, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China.
Primary and secondary resistance to immune checkpoint blockade (ICB) reduces its efficacy. The mechanisms underlying immunotherapy resistance are highly complex. In non-small cell lung cancer (NSCLC), these mechanisms are primarily associated with the loss of programmed cell death-ligand 1 (PD-L1) expression, genetic mutations, circular RNA axis and transcription factor regulation, antigen presentation disorders, and dysregulation of signaling pathways.
View Article and Find Full Text PDFTransplantation
January 2025
Medical School, University of Western Australia, Perth, WA, Australia.
Tissue-resident lymphocytes (TRLs) provide a front-line immunological defense mechanism uniquely placed to detect perturbations in tissue homeostasis. The heterogeneous TRL population spans the innate to adaptive immune continuum, with roles during normal physiology in homeostatic maintenance, tissue repair, pathogen detection, and rapid mounting of immune responses. TRLs are especially enriched in the liver, with every TRL subset represented, including liver-resident natural killer cells; tissue-resident memory B cells; conventional tissue-resident memory CD8, CD4, and regulatory T cells; and unconventional gamma-delta, natural killer, and mucosal-associated invariant T cells.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!