T follicular helper (Tfh) cells are crucial for regulating autoimmune inflammation and protective immunity against viral infection. However, the molecular mechanism controlling Tfh cell differentiation is poorly understood. Here, through two mixed bone marrow chimeric experiments, we identified Peli1, a T cell-enriched E3 ubiquitin ligase, as an intrinsic regulator that inhibits Tfh cell differentiation. Peli1 deficiency significantly promoted c-Rel-mediated inducible T-cell costimulator (ICOS) expression, and PELI1 mRNA expression was negatively associated with ICOS expression on human CD4 T cells. Mechanistically, increased ICOS expression on Peli1-KO CD4 T cells enhanced the activation of PI3K-AKT signaling and thus suppressed the expression of Klf2, a transcription factor that inhibits Tfh differentiation. Therefore, reconstitution of Klf2 abolished the differences in Tfh differentiation and germinal center reaction between WT and Peli1-KO cells. As a consequence, Peli1-deficient CD4 T cells promoted lupus-like autoimmunity but protected against H1N1 influenza virus infection in mouse models. Collectively, our findings established Peli1 as a critical negative regulator of Tfh differentiation and indicated that targeting Peli1 may have beneficial therapeutic effects in Tfh-related autoimmunity or infectious diseases.
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http://dx.doi.org/10.1038/s41423-021-00660-5 | DOI Listing |
Int J Mol Sci
January 2025
Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28220 Madrid, Spain.
Class IA PI3K p110δ and p110α subunits participate in TCR and costimulatory receptor signals involved in T cell-mediated immunity, but the role of p110α is not completely understood. Here, we analyzed a mouse model of the Cre-dependent functional inactivation of p110α (kinase dead) in T lymphocytes (p110αKD-T, KD). KD mice showed increased cellularity in thymus and spleen and altered T cell differentiation with increased number of CD4CD8 DP thymocytes, enhanced proportion of CD4 SP lymphocytes linked to altered apoptosis, lower Treg cells, and increased AKT and ERK phosphorylation in activated thymocytes.
View Article and Find Full Text PDFClin Rheumatol
January 2025
Jiangsu Institute of Clinical Immunology, the First Affiliated Hospital of Soochow University, Suzhou, 215021, China.
Objectives: The research aimed to assess the proportions of Gamma delta (γδ) T cells and the expression levels of CD226, ICOS, CD40L, OX40, TIGIT, LAG-3, Tim-3, and PD-1 on γδ T cells in the peripheral blood of patients diagnosed with primary Sjögren's syndrome (pSS), and to evaluate the clinical significance of these findings.
Methods: Utilizing flow cytometry, we investigated the proportion of γδ T cells and the expression of CD226, ICOS, CD40L, OX40, TIGIT, LAG-3, PD-1, and Tim-3 on γδ T cells in 37 patients diagnosed with pSS and 28 healthy controls (HC). Moreover, we explored the potential associations between the proportion of γδ T cells, TIGIT + γδ T cells, PD-1 + γδ T cells, and TIGIT + PD-1 + γδ T cells with clinical symptoms and laboratory parameters.
Inflamm Res
January 2025
Department of Otolaryngology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, China.
Background: Allergic rhinitis (AR) represents a persistent inflammatory condition affecting the upper respiratory tract, characterized by abnormal initiation of the immunoglobulin E (IgE)-mediated cascade. Follicular helper T (Tfh) cells and regulatory T (Tfr) cells are pivotal in orchestrating the development of IgE production in AR patients. IL-35, an anti-inflammatory cytokine, secreted by various cellular subpopulations.
View Article and Find Full Text PDFCardiooncology
January 2025
Dept of Oncology Tier 2 Canada Research Chair, University of Alberta, Alberta, Canada.
Background: With early detection and improvements in systemic and local therapies, millions of people are surviving cancer, but for some at a high cost. In some cancer types, cardiovascular disease now competes with recurrent cancer as the cause of death. Traditional care models, in which the cardiologist or oncologist assess patients individually, do not address complex cancer and cardiovascular needs.
View Article and Find Full Text PDFPediatr Allergy Immunol
January 2025
Department of Microbiology, Immunology and Transplantation, Allergy and Immunology Research Group, KU Leuven, Leuven, Belgium.
Background: Type 1 regulatory T (Tr1) cells are critical players in maintaining peripheral tolerance, by producing high IL-10 levels in association with inducible T-cell co-stimulator (ICOS) expression. Whether these cells play a role in naturally acquired baked egg tolerance is unknown.
Objectives: Evaluate frequencies of egg-responsive Tr1 and Th2 cells in egg-allergic children that naturally acquired baked egg tolerance (BET) versus non-egg-allergic (NEA) children.
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