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CD21 age-associated or atypical memory B cells are autoantibody enriched and poised for plasma cell differentiation. These cells overaccumulate in chronic infections, autoimmune disease, and immunodeficiency, posing the question of what checkpoints normally oppose their accumulation. Here, we reveal a critical role for paralogous calcium-NFAT-regulated transcription factors EGR2 and EGR3 that are induced in self-reactive B cells. CD21 and B1 B cells lacking EGR2 and EGR3 accumulate and circulate in young mice in numbers 10- to 20-fold greater than normal and overexpress a large set of EGR2 ChIP-seq target genes, including known drivers of plasma cell differentiation. Most follicular B cells constitutively express Egr2 proportionally to surface IgM downregulation by self-antigens, and EGR2/3 deficiency abolishes this cardinal feature of B cell anergy. These results explain the cardinal features of B cell anergy, define a key transcriptional checkpoint repressing CD21 B cell formation, and inform how NFATC1 or EGR2 mutations promote B1 cell-derived chronic lymphocytic leukemias.
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http://dx.doi.org/10.1016/j.celrep.2021.110259 | DOI Listing |
JMA J
January 2025
Department of Otolaryngology-Head and Neck Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan.
CD4 T cells, the so-called T helper cells, are one of the main players in the human immune system, which can regulate acquired immunity. Dysfunction of the acquired immune system induces various chronic inflammatory diseases such as malignancies and autoimmune diseases. IgG4-related disease (IgG4-RD) is also a chronic inflammatory disease that is characterized by elevated serum IgG4 concentration and infiltration of IgG4-positive plasma cells in affected tissues.
View Article and Find Full Text PDFClin Exp Immunol
January 2025
4th Department of Internal Medicine, Hippokration General Hospital, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Objective: To investigate whether T-bet+ B cells, as well as age-associated B cells/ABCs (CD19 + CD21-CD11c + T-bet+) and double-negative B cells/DN (CD19 + IgD-CD27- CXCR5-T-bet+), serve as prognostic and/or therapeutic tools for systemic lupus erythematosus (SLE) in humans.
Methods: Flow cytometry was used for enumerating T-bet+ B cells and ABCs/DN subsets, found in the peripheral blood of 10 healthy donors and 22 active SLE patients. Whole blood assay cultures, combined with in vitro pharmacological treatments, were performed to evaluate the effects of hydroxychloroquine, anifrolumab, and fasudil (a ROCK kinase inhibitor) on T-bet+ B cells' percentage.
J Cell Physiol
January 2025
Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China.
The aging process often leads to immune-related diseases, including infections, tumors, and autoimmune disorders. Recently, researchers identified a special subpopulation of B cells in elderly female mice that increases with age and accumulates prematurely in mouse models of autoimmune diseases or viral infections; these B cells are known as age-related B cells (ABCs). These cells possess distinctive cell surface phenotypes and transcriptional characteristics, and the cell population is widely recognized as CD11cCD11bT-betCD21CD23 cells.
View Article and Find Full Text PDFClin Exp Immunol
July 2024
4th Department of Internal Medicine, Hippokration General Hospital, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Apart from serving as a Th1 lineage commitment regulator, transcription factor T-bet is also expressed in other immune cell types and thus orchestrates their functions. In case of B cells, more specifically, T-bet is responsible for their isotype switching to specific IgG sub-classes (IgG2a/c in mice and IgG1/3 in humans). In various autoimmune disorders, such as systemic lupus erythematosus and/or rheumatoid arthritis, subsets of T-bet expressing B cells, known as age-associated B cells (CD19+CD11c+CD21-T-bet+) and/or double-negative B cells (CD19+IgD-CD27-T-bet+), display an expansion and seem to drive disease pathogenesis.
View Article and Find Full Text PDFClin Exp Rheumatol
January 2024
Department of Rheumatology, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, National Clinical Research Center for Dermatologic and Immunologic Diseases, State Key Laboratory of Complex Severe and Rare Diseases, Beijing, China. zhangwen91@sina
Objectives: To assess the expression of age-associated B cells (ABCs), and characterise the surface markers of ABCs in patients with IgG4-related disease (IgG4-RD).
Methods: Fifty-one newly diagnosed patients with IgG4-RD, 18 IgG4-RD patients with disease remission, 34 patients with other autoimmune diseases, and 61 age- and sex-matched healthy controls (HCs) were included. Circulating ABCs, as well as surface markers were detected by flow cytometry, and tissue infiltration of ABCs were assessed by immunofluorescence (IF).