The physiological role of T cell anergy induction as a key mechanism supporting self-tolerance remains undefined, and natural antigens that induce anergy are largely unknown. In this report, we used TCR sequencing to show that the recruitment of CD4CD44Foxp3CD73FR4 anergic (Tan) cells expands the CD4Foxp3 (Tregs) repertoire. Next, we report that blockade in peripherally-induced Tregs (pTregs) formation due to mutation in CNS1 region of Foxp3 or chronic exposure to a selecting self-peptide result in an accumulation of Tan cells. Finally, we show that microbial antigens from Akkermansia muciniphila commensal bacteria can induce anergy and drive conversion of naive CD4CD44Foxp3 T (Tn) cells to the Treg lineage. Overall, data presented here suggest that Tan induction helps the Treg repertoire to become optimally balanced to provide tolerance toward ubiquitous and microbiome-derived epitopes, improving host ability to avert systemic autoimmunity and intestinal inflammation.
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http://dx.doi.org/10.1038/s41385-020-00349-4 | DOI Listing |
Cancer Metastasis Rev
January 2025
Department of Industrial and Molecular Pharmaceutics, Purdue University, West Lafayette, IN, USA.
The role of natural killer (NK) cells as immune effectors is well established, as is their utility as immunotherapeutic agents against various cancers. However, NK cells' anti-cancer roles are suppressed in cancer patients by various immunomodulatory mechanisms which alter these cells' identity, function, and potential for immunosurveillance. This manifests in abnormal NK cell responses accompanied by changes in phenotypic or genotypic identity, giving rise to specific NK cell subsets that are either hypofunctional or, more broadly, defective in their responses.
View Article and Find Full Text PDFNat Commun
January 2025
Division of Rheumatology, Rosalind Russell and Ephraim P. Engleman Arthritis Research Center, Department of Medicine, University of California, San Francisco, CA, 94143, USA.
The Nr4a nuclear hormone receptors are transcriptionally upregulated in response to antigen recognition by the T cell receptor (TCR) in the thymus and are implicated in clonal deletion, but the mechanisms by which they operate are not clear. Moreover, their role in central tolerance is obscured by redundancy among the Nr4a family members and by their reported functions in Treg generation and maintenance. Here we take advantage of competitive bone marrow chimeras and the OT-II/RIPmOVA model to show that Nr4a1 and Nr4a3 are essential for the upregulation of Bcl2l11/BIM and thymic clonal deletion by self-antigen.
View Article and Find Full Text PDFJ Extracell Vesicles
January 2025
Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
Parasitic helminths secrete extracellular vesicles (EVs) into their host tissues to modulate immune responses, but the underlying mechanisms are poorly understood. We demonstrate that Ascaris EVs are efficiently internalised by monocytes in human peripheral blood mononuclear cells and increase the percentage of classical monocytes. Furthermore, EV treatment of monocytes induced a novel anti-inflammatory phenotype characterised by CD14, CD16, CC chemokine receptor 2 (CCR2) and programmed death-ligand 1 (PD-L1) cells.
View Article and Find Full Text PDFImmune Netw
December 2024
The Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics Rheumatology & Musculoskeletal Sciences, University of Oxford, Oxford OX3 7FY, United Kingdom.
Immunological tolerance is a fundamental arm of any functioning immune system. Not only does tolerance mitigate collateral damage from host immune responses, but in doing so permits a robust response sufficient to clear infection as necessary. Yet, despite occupying such a cornerstone, research aiming to unravel the intricacies of tolerance induction is mired by interchangeable and often misused terminologies, with markers and mechanistic pathways that beg the question of redundancy.
View Article and Find Full Text PDFCancers (Basel)
December 2024
Clinical Cooperation Unit Applied Tumor Immunity, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
Reduced expression of adhesion molecules in tumor vasculature can limit infiltration of effector T cells. To improve T cell adhesion to tumor endothelial cell (EC) antigens and enhance transendothelial migration, we developed bispecific, T-cell engaging antibodies (bsAb) that activate T cells after cross-linking with EC cell surface antigens. Recombinant T-cell stimulatory anti-VEGFR2-anti-CD3 and costimulatory anti-TIE2-anti-CD28 or anti-PD-L1-anti-CD28 bsAb were engineered and expressed.
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