Bcl-2 expression on germinal center lymphocytes modulated by the emperipolesis of follicular dendritic cells

Germinal Center （GC） B细胞具有极高的可信赖性。“细胞机制调节了这种敏感性，但它并没有完全被削弱。”To investigate whether follicular dendritic cells （FDC）能够调节GC B cells的susceptibility，我们在体外构建了GC模型：FDC的tonsillar B cells的emperipolesis。然后，我们分析了细胞在三色流动细胞中的表现（Bcl-2和Fas）。B细胞非中心的B细胞在最少18小时被挽救，并显示了Gfas和Bcl-2的微型规则。GC Founder Cell（CD38イイD1+イエD1， IgDイD1+イエD1 ; GCFC） and GC B cells（CD38イイD1+イエD1， IgDイD1-イエD1） showed approximately a twofold increased expression of Fas ; in contrast， mantle zone B cells （CD38-D1， IgD-D1+-D1） and memory B cells （CD38-D1， IgD-D1） showed no changes。地幔区和存储器B细胞中的Bcl-2表达被大约减少了一半;继续使用GCFC和GC b细胞来表达小Bcl-2，但这一点没有改变。我们的发现强烈建议FDC在GC内扮演一个部分的调节中的潜在缺陷在B细胞中的凋亡。

Germinal center (GC) B cells are highly susceptible to apoptosis. The cellular mechanism regulating this sensitivity, however has not yet been fully delineated. To investigate whether follicular dendritic cells (FDC) are capable of regulating the susceptibility to apoptosis of GC B cells, we constructed a GC model in vitro : emperipolesis of tonsillar B cells by FDC. We then analyzed the expression of apoptosis-related proteins (Bcl-2 and Fas) on the cells by three-color flow cytometry. B cells nonentrapped B cells were rescued for at least 18h and showed peculiar regulation of Gfas and Bcl-2. GC founder cells (CD38ィイD1+ィエD1, IgDィイD1+ィエD1 ; GCFC) and GC B cells (CD38ィイD1+ィエD1, IgDィイD1-ィエD1) showed approximately a twofold increased expression of Fas ; in contrast, mantle zone B cells (CD38ィイD1-ィエD1, IgDィイD1+ィエD1) and memory B cells (CD38ィイD1-ィエD1, IgDィイD1-ィエD1) showed no changes. Bcl-2 expression in mantle zone and memory B cells was reduced by approximately one-half ; however, GCFC and GC b cells continued to express little Bcl-2 and this did not change. Our findings strongly suggested that FDC play a part in the modulation of the susceptibility to apoptosis on B cells within GC.