Bosseloir A, Bouzahzah F, Defrance T H, Heinen E, Simar L J
Institute of Human Histology, University of Liège, Belgium.
Scand J Immunol. 1996 Jan;43(1):23-30. doi: 10.1046/j.1365-3083.1996.d01-7.x.
Follicular dendritic cells (FDC) are unique non-lymphoid cells found only in lymph follicles. They play a part in the survival, proliferation and differentiation of B cells. To analyse the influence of FDC on B-lymphocyte proliferation, we isolated them from human tonsils on albumin gradients and treated them with mitomycin C to prevent the multiplication of lymphoid cells harboured in their cytoplasmic evaginations. FDC cultured for 12-16 h remained attached to the substrate; non-adherent cells were carefully eliminated by washing. Purified B cells cultured alone or with contaminant-cleared FDC were maintained for 2 days in the presence or absence of various stimulants, after which tritiated thymidine uptake by these cells was measured. In the absence of activators, FDC did not induce B-cell multiplication. B cells cultured in the presence of FDC exhibited increased 3H-TdR uptake when activated with anti-CD40 MoAb, anti-immunoglobulin MoAb or transferrin, but not when stimulated with Staphylococcus aureus strain Cowan I (SAC) at a given concentration. In the latter case, B-cell proliferation clearly decreased. In control cocultures where mitomycin-C-treated non-adherent cells were used instead of FDC in the presence of the different stimulants, no increase in B-cell proliferation was observed. The results suggest that, inside the germinal centres, FDC modulation of B-cell proliferation depends on the activation state of the B cells and on the stimulant encountered.
滤泡树突状细胞（FDC）是仅存在于淋巴滤泡中的独特非淋巴细胞。它们在B细胞的存活、增殖和分化中发挥作用。为了分析FDC对B淋巴细胞增殖的影响，我们在白蛋白梯度上从人扁桃体中分离出FDC，并用丝裂霉素C处理以防止其细胞质突起中所含淋巴细胞的增殖。培养12 - 16小时的FDC仍附着于底物上；通过洗涤小心地去除未附着的细胞。单独培养或与清除了污染物的FDC一起培养的纯化B细胞在有或没有各种刺激物的情况下维持2天，之后测量这些细胞对氚标记胸腺嘧啶核苷的摄取。在没有激活剂的情况下，FDC不会诱导B细胞增殖。当用抗CD40单克隆抗体、抗免疫球蛋白单克隆抗体或转铁蛋白激活时，在FDC存在下培养的B细胞表现出3H - TdR摄取增加，但在给定浓度的金黄色葡萄球菌Cowan I株（SAC）刺激时则没有增加。在后一种情况下，B细胞增殖明显减少。在对照共培养中，在不同刺激物存在下使用经丝裂霉素C处理的未附着细胞代替FDC，未观察到B细胞增殖增加。结果表明，在生发中心内，FDC对B细胞增殖的调节取决于B细胞的激活状态和所遇到的刺激物。
