TGF‐β induces the differentiation of human CXCL13‐producing CD4+ T cells

S Kobayashi, T Watanabe, R Suzuki… - European journal of …, 2016 - Wiley Online Library
S Kobayashi, T Watanabe, R Suzuki, M Furu, H Ito, J Ito, S Matsuda, H Yoshitomi
European journal of immunology, 2016Wiley Online Library
In the ectopic lymphoid‐like structures present in chronic inflammatory conditions such as
rheumatoid arthritis, a subset of human effector memory CD4+ T cells that lacks features of
follicular helper T (Tfh) cells produces CXCL13. Here, we report that TGF‐β induces the
differentiation of human CXCL13‐producing CD4+ T cells from naïve CD4+ T cells. The TGF‐
β‐induced CXCL13‐producing CD4+ T cells do not express CXCR5, B‐cell lymphoma 6
(BCL6), and other Tfh‐cell markers. Furthermore, expression levels of CD25 (IL‐2Rα) in …
In the ectopic lymphoid‐like structures present in chronic inflammatory conditions such as rheumatoid arthritis, a subset of human effector memory CD4+ T cells that lacks features of follicular helper T (Tfh) cells produces CXCL13. Here, we report that TGF‐β induces the differentiation of human CXCL13‐producing CD4+ T cells from naïve CD4+ T cells. The TGF‐β‐induced CXCL13‐producing CD4+ T cells do not express CXCR5, B‐cell lymphoma 6 (BCL6), and other Tfh‐cell markers. Furthermore, expression levels of CD25 (IL‐2Rα) in CXCL13‐producing CD4+ T cells are significantly lower than those in FoxP3+ in vitro induced Treg cells. Consistent with this, neutralization of IL‐2 and knockdown of STAT5 clearly upregulate CXCL13 production by CD4+ T cells, while downregulating the expression of FoxP3. Furthermore, overexpression of FoxP3 in naïve CD4+ T cells downregulates CXCL13 production, and knockdown of FoxP3 fails to inhibit the differentiation of CXCL13‐producing CD4+ T cells. As reported in rheumatoid arthritis, proinflammatory cytokines enhance secondary CXCL13 production from reactivated CXCL13‐producing CD4+ T cells. Our findings demonstrate that CXCL13‐producing CD4+ T cells lacking Tfh‐cell features differentiate via TGF‐β signaling but not via FoxP3, and exert their function in IL‐2‐limited but TGF‐β‐rich and proinflammatory cytokine‐rich inflammatory conditions.
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