Influenza virus infection results in strong, mainly T-dependent, extrafollicular and germinal center B cell responses, which provide lifelong humoral immunity against the homotypic virus strain. Follicular T helper cells (T(FH)) are key regulators of humoral immunity. Questions remain regarding the presence, identity, and function of T(FH) subsets regulating early extrafollicular and later germinal center B cell responses. This study demonstrates that ICOS but not CXCR5 marks T cells with B helper activity induced by influenza virus infection and identifies germinal center T cells (T(GC)) as lymph node-resident CD4(+) ICOS(+) CXCR4(+) CXCR5(+) PSGL-1(lo) PD-1(hi) cells. The CXCR4 expression intensity further distinguished their germinal center light and dark zone locations. This population emerged strongly in regional lymph nodes and with kinetics similar to those of germinal center B cells and were the only T(FH) subsets missing in influenza virus-infected, germinal center-deficient SAP(-/-) mice, mice which were shown previously to lack protective memory responses after a secondary influenza virus challenge, thus indicting the nonredundant functions of CXCR4- and CXCR5-coexpressing CD4 helper cells in antiviral B cell immunity. CXCR4-single-positive T cells, present in B cell-mediated autoimmunity and regarded as "extrafollicular" helper T cells, were rare throughout the response, despite prominent extrafollicular B cell responses, revealing fundamental differences in autoimmune- and infection-induced T-dependent B cell responses. While all ICOS(+) subsets induced similar antibody levels in vitro, CXCR5-single-positive T cells were superior in inducing B cell proliferation. The regulation of T cell localization, marked by the single and coexpression of CXCR4 and CXCR5, might be an important determinant of T(FH) function.
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http://dx.doi.org/10.1128/JVI.06904-11 | DOI Listing |
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MOE Key Laboratory of Biosystems Homeostasis and Protection, College of Life Sciences, Zhejiang University, No.866 Yuhangtang Road, 310058, Hangzhou, China.
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Department of Cancer Biology, Maria Sklodowska-Curie National Research Institute of Oncology, Roentgena 5, 02-781 Warszawa, Poland.
High-grade B-cell lymphoma with 11q aberration (HGBCL-11q) is a rare germi-nal centre lymphoma characterised by a typical gain/loss pattern on chromo-some 11q but without MYC translocation. It shares some features with Burkitt lymphoma (BL), HGBCLs and germinal centre-derived diffuse large B-cell lym-phoma, not otherwise specified (GCB-DLBCL-NOS). Since microRNA expression in HGBCL-11q remains unknown, we aimed to identify and compare the mi-croRNA expression profiles in HGBCL-11q, BL and in GCB-DLBCL-NOS.
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Laboratory of Oncology, Medical Research Center, The Second People's Hospital of Changzhou, The Third Affiliated Hospital of Nanjing Medical University, Changzhou, China.
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January 2025
Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA; Gerstner Sloan Kettering Graduate School of Biomedical Sciences, New York, NY 10065, USA. Electronic address:
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