Biology subjects

Syage, A. R.

Publications and source records attributed to Syage, A. R..

2 recordsLinked to original sources

bioRxiv2026

Molecular heterogeneity and differential metabolic signatures in thymic adipocytes

Adipocyte depots throughout the body are physiologically and molecularly distinct. With age, adipocytes increase in and around aged thymi. However, thymic adipocytes completely lack molecular characterization. We developed and optimized methods to isolate adipocyte nuclei from mouse thymi of different ages and sexes. Single-nucleus multiomic analysis of male and female mice aged 4-9 months reveals that thymic adipocytes are heterogeneous, with at least two distinct populations. One subpopulation harbors a transcription and chromatin signature consistent with beige/brown fat. A larger subpopulation more strongly resembles classic white adipose tissue and expresses genes associated with epithelial-to-mesenchymal transition (EMT) and antigen presentation. Analysis of differentially open chromatin in the white compared to beige adipose population identifies binding sites for Foxn1 and HIF-1/Arnt, consistent with a situation in which thymic white adipose cells emerge from thymic epithelial cells, possibly under hypoxic conditions. Immunofluorescence microscopy confirmed the expression of UCP1 protein in cells within the thymic parenchyma, most prominently in subcapsular cortical regions. This resource reveals a complex milieu of thymic adipocytes and identifies multiple avenues for directly probing their ontogeny, dynamics and functional significance.

immunology↗

bioRxiv2023

OCA-B promotes autoimmune demyelination through control of stem-like CD4+ T cells

Stem-like T cells selectively contribute to autoimmunity, but the activities that promote their pathogenicity are incompletely understood. Here, we identify the transcription coregulator OCA-B as a driver of the pathogenic maturation of stem-like CD4+ T cell to promote autoimmune demyelination. Using two human multiple sclerosis (MS) datasets, we show that POU2AF1, the gene encoding OCA-B, is elevated in CD4+ T cells from MS patients. We show that T cell-intrinsic OCA-B loss protects mice from experimental autoimmune encephalomyelitis (EAE) while preserving responses to viral CNS infection. In EAE models driven by antigen reencounter, OCA-B deletion nearly eliminates CNS infiltration, proinflammatory cytokine production and clinical disease. OCA-B-expressing CD4+ T cells of mice primed with autoantigen express an encephalitogenic gene program and preferentially confer disease. In a relapsing-remitting EAE model, OCA-B loss protects mice specifically at relapse. During remission, OCA-B promotes the expression of Tcf7, Slamf6, and Sell in proliferating CNS T cell populations. At relapse timepoints, OCA-B loss results in both the accumulation of an immunomodulatory CD4+ T cell population expressing Ccr9 and Bach2, and loss of pro-inflammatory gene expression from Th17 cells. These results identify OCA-B as a driver of pathogenic CD4+ T cells.

immunology↗