Denépoux S, Razanajaona D, Blanchard D, Meffre G, Capra J D, Banchereau J, Lebecque S
Schering-Plough Laboratory for Immunological Research, Dardilly, France.
Immunity. 1997 Jan;6(1):35-46. doi: 10.1016/s1074-7613(00)80240-x.
Both the B cell-surface trigger(s) and the intracellular molecular mechanism(s) of somatic hypermutation in immunoglobulin (Ig) variable region genes remain unknown, partly because of the lack of a simple and reproducible in vitro model. Here, we show that upon surface immunoglobulin cross-linking followed by co-culture with activated cloned T cells, the Burkitt's lymphoma cell line BL2 is induced to mutate its IgV(H) gene. Repeated activation of BL2 cells increased the frequency of mutation. The in vitro-induced mutations, which do not affect the IgM constant region, are point mutations distributed over the entire V(H)DJ(H) gene segment and do not show evidence of antigen-driven selection.
B细胞表面触发因素以及免疫球蛋白（Ig）可变区基因中体细胞高频突变的细胞内分子机制仍然未知，部分原因是缺乏简单且可重复的体外模型。在此，我们表明，在表面免疫球蛋白交联后与活化的克隆T细胞共培养时，伯基特淋巴瘤细胞系BL2被诱导使其IgV(H)基因突变。BL2细胞的反复活化增加了突变频率。体外诱导的突变不影响IgM恒定区，是分布在整个V(H)DJ(H)基因片段上的点突变，且未显示出抗原驱动选择的证据。
