| Autor: |
Yada, Yutaro, Matsumoto, Masanori, Inoue, Takeshi, Baba, Akemi, Higuchi, Ryota, Kawai, Chie, Yanagisawa, Masashi, Kitamura, Daisuke, Ohga, Shouichi, Kurosaki, Tomohiro, Baba, Yoshihiro |
| Zdroj: |
The Journal of Experimental Medicine; January 2024, Vol. 221 Issue: 1 pe20222178-e20222178, 1p |
| Abstrakt: |
Positive selection of high-affinity germinal center (GC) B cells is driven by antigen internalization through their B cell receptor (BCR) and presentation to follicular helper T cells. However, the requirements of BCR signaling in GC B cells remain poorly understood. Store-operated Ca2+ entry, mediated by stromal interacting molecule 1 (STIM1) and STIM2, is the main Ca2+ influx pathway triggered by BCR engagement. Here, we showed that STIM-deficient B cells have reduced B cell competitiveness compared with wild-type B cells during GC responses. B cell–specific deletion of STIM proteins decreased the number of high-affinity B cells in the late phase of GC formation. STIM deficiency did not affect GC B cell proliferation and antigen presentation but led to the enhancement of apoptosis due to the impaired upregulation of anti-apoptotic Bcl2a1. STIM-mediated activation of NFAT was required for the expression of Bcl2a1 after BCR stimulation. These findings suggest that STIM-mediated survival signals after antigen capture regulate the optimal selection and maintenance of GC B cells. |
| Databáze: |
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