Van Kooten C, Galibert L, Seon B K, Garrone P, Liu Y J, Banchereau J
Laboratory for Immunological Research, Schering-Plough, Dardilly, France.
Clin Exp Immunol. 1997 Dec;110(3):509-15. doi: 10.1046/j.1365-2249.1997.4201436.x.
Antigen-dependent activation of B lymphocytes is mediated through surface immunoglobulins and their associated molecules Ig-alpha (CD79a, Mb1) and Ig-beta (CD79b, B29). Here we show that an antibody directed against the extracellular part of human Ig-beta can, when cross-linked by CD32-transfected L cells, induce an IL-2-dependent proliferation of tonsil B cells. With the use of L cells stably transfected with both CD32 and CD40L, anti-Ig-beta activation of B cells was combined with CD40 triggering, an important component of the T cell-dependent B cell activation. This dual cellular activation resulted in two different phases, with initially synergistic proliferative effects, both without and with IL-2 or IL-10. Then, after 5-6 days of culture, cells stimulated with both anti-Ig-beta and CD40L underwent massive cell death, in contrast to B cells activated with CD40L alone. Cell death was not prevented by the addition of IL-2 or IL-10, but was prevented by the addition of IL-4. These results are discussed in the context of positive and negative selection of mature B cells.
B淋巴细胞的抗原依赖性激活是通过表面免疫球蛋白及其相关分子Ig-α（CD79a，Mb1）和Ig-β（CD79b，B29）介导的。在此我们表明，一种针对人Ig-β细胞外部分的抗体，当被转染了CD32的L细胞交联时，可诱导扁桃体B细胞的IL-2依赖性增殖。通过使用稳定转染了CD32和CD40L的L细胞，B细胞的抗Ig-β激活与CD40触发相结合，CD40触发是T细胞依赖性B细胞激活的一个重要组成部分。这种双重细胞激活导致两个不同阶段，最初具有协同增殖效应，无论有无IL-2或IL-10。然后，在培养5至6天后，与单独用CD40L激活的B细胞相比，用抗Ig-β和CD40L刺激的细胞发生大量细胞死亡。添加IL-2或IL-10不能阻止细胞死亡，但添加IL-4可以阻止。这些结果在成熟B细胞的阳性和阴性选择背景下进行了讨论。
