Biology subjects

Coatnoan, N.

Publications and source records attributed to Coatnoan, N..

4 recordsLinked to original sources

bioRxiv2025

Thymic selection of the T cell receptor repertoire is biased toward autoimmunity in females

Women represent about 80% of patients with autoimmune diseases. This may partly result from sex-based differences in T cell receptor (TCR) selection during thymocyte development, potentially influenced by hormones and the lower expression of the Autoimmune Regulator (AIRE) transcription factor in females. To investigate this, we analyzed sex-specific differences in TCR generation and selection. We examined TCR repertoires in double-positive thymocytes and single-positive thymic cells, including CD8 and CD4 effector T cells and regulatory T cells (Tregs), derived from male and female organ donors. Minimal sex-based differences were observed in V and J gene usage, and there were no notable differences in TCR repertoire diversity, complementarity-determining region 3 (CDR3) length, amino acid composition, or network structure. No TCR sequences were exclusive to either sex. However, female effector T cells exhibited a significantly higher prevalence of TCRs specific to self-antigens implicated in autoimmunity compared to males, while female Tregs showed a reduced frequency of such TCRs. These differences were not observed for TCRs targeting self-antigens unrelated to autoimmunity or antigens associated with cancer or viruses. Our findings identify a sex-specific imbalance in thymic selection of TCRs with autoimmunity-associated specificities, providing mechanistic insight into the increased susceptibility of women to autoimmune diseases.

systems biology↗

bioRxiv2025

Maternal immune activation imprints a regulatory T cell deficiency in offspring that drives an autism-like phenotype

Maternal immune activation (MIA) triggers an IL-17-driven autism spectrum disorder (ASD) in mouse and human offspring. While regulatory T cells (Tregs) regulate Th17 cells, their involvement in MIA and ASD pathogenesis is unknown. At the maternal level, we show that Treg stimulation suppresses interleukin-17 (IL-17) production and prevents ASD-like behaviors in offspring. At the offspring level, we show that MIA imprints a systemic and brain Treg deficiency, as evidenced by alterations in the methylome, transcriptome, and functional assays. This deficiency promotes brain inflammation, characterized by infiltration of IL-17-producing cells and neutrophils into the meninges and alterations in cortical brain structure. Stimulation of offspring Tregs with interleukin-2 reversed brain inflammation and cured established ASD-like behaviors. Thus, MIA-induced ASD is a neuroimmune disorder that can be reversed by immunomodulation. One sentence abstractMaternal immune activation during pregnancy imprints a Treg deficiency in offspring that perpetuates brain inflammation and an autism-like phenotype, which can be reversed by Treg stimulation.

immunology↗

bioRxiv2024

Immunological Profiling in Knee Osteoarthritis: Treg Dysfunction as Key Driver of Pain

Pain is the hallmark symptom of osteoarthritis (OA) and its biological drivers remain poorly understood. While the role of innate immunity in OA has been extensively studied, the involvement of adaptive immunity, in particular regulatory T cells (Tregs), is not well understood. Using a comprehensive multi-omic approach on the peripheral blood from 46 knee OA patients with similar radiographic stage, including deep immunophenotyping, cytokine profiling, transcriptomic and T-cell receptor analysis on sorted CD4 Tregs and effector T cells (Teff), we identified an immunological signature associated with OA-related pain. Cytokines promoting Treg expansion and activation (with increases of sIL2-RA, sTNFR1, sTNFR2) were correlated with the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain subscore, suggesting a potential Treg dysfunction. Nineteen T cell subsets were correlated with WOMAC pain. Notably, we found a negative correlation of cell subsets associated with Treg expansion and activation (FoxP3+CTLA4+, CD4+CD57+, Treg CD95+, CD4 Treg CD45RA-). Differential gene expression analysis between patients with low and high WOMAC pain intensity (threshold [≥] 40/100) revealed an upregulation of inflammasome-related genes such as IL1RL1, IL31RA, IFITM3, NLRP3, IFNG in Tregs. Functional enrichment analysis highlighted an overrepresentation of innate immune response, IL-8, and interferon activation pathways suggesting a pro-inflammatory state in Tregs of patients with high pain intensity. Collectively, our systems immunology approach highlights multiple associations between Treg dysfunctionality and OA-related pain, providing new insights into the adaptive immune systems contribution to OA-related pain.

immunology↗

bioRxiv2024

IL-1β Signaling Modulates T Follicular Helper and Regulatory Cells in Human Lymphoid Tissues

BackgroundDysregulation of the T follicular helper (Tfh) and T follicular regulatory (Tfr) homeostasis in the germinal center (GC) can result in antibody-mediated autoimmunity. While interleukin-1{beta} (IL-1{beta}) has been shown to be an important modulator of the GC response in animal models via the expression of IL-1 agonist (IL-1R1) and antagonist (IL-1R2) receptors on follicular T cells, such regulation has not yet been studied in humans. MethodsWe investigated Tfh and Tfr phenotypes in human secondary lymphoid organs -- namely tonsils, spleens, and mesenteric lymph nodes -- using flow cytometry, single-cell transcriptomics, and in vitro cell culture. We also benchmarked our findings with a cohort of patients with autoimmune and inflammatory diseases. ResultsWe found that Tfh and Tfr cells exhibit organ-specific phenotypes related to their activation status and IL-1 receptor expression. An excess of IL-1R1 over IL-1R2 was linked to the emergence of a unique activated Tfr subset that combines features of both Treg and GC-Tfh cells. Single-cell transcriptomics and in vitro studies showed that IL-1{beta} signaling through IL-1R1 promotes follicular T-cell activation. Inhibiting IL-1{beta} resulted in upregulation of IL-1R1 expression, showing a fine-tuned regulation. In autoimmune patients, high IL-1{beta} and circulating Tfr levels correlated with higher autoantibody levels, linking inflammation, IL-1{beta} signaling, and the Tfr/Tfh balance. ConclusionsOur study underscores the pivotal role of IL-1{beta} in follicular T-cell activation, contributing to pathological antibody production in humans. Targeting IL-1{beta} signaling in Tfh and Tfr cells could offer new treatment strategies for antibody-mediated autoimmune diseases.

immunology↗