Gray D, Siepmann K, Wohlleben G
Department of Immunology, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
Semin Immunol. 1994 Oct;6(5):303-10. doi: 10.1006/smim.1994.1039.
Interaction of CD40 on B cells with its ligand on activated T helper cells is crucial for the generation of mature T-dependent antibody responses. Experimental observations suggest that CD40 ligation acts at several points in B cell differentiation; however, it is not clear whether the consequences of ligation are direct or indirect. While its role in B cell activation is clearly direct we discuss the several ways in which it might drive isotype switching, the influence that it has on the development of memory B cells and the possibility that certain types of T-dependent antibody response are CD40L-independent. Experiments in which the ligation of CD40 is blocked in vivo reveal that early CD40 signals are important for the development of memory B cells but this may only reflect the ability of 'memory precursors' generated by CD40 ligation to accept subsequent programming or survival signals.
B细胞上的CD40与其配体在活化的辅助性T细胞上的相互作用对于成熟的T细胞依赖性抗体反应的产生至关重要。实验观察表明，CD40连接在B细胞分化的几个阶段发挥作用；然而，尚不清楚连接的后果是直接的还是间接的。虽然其在B细胞活化中的作用显然是直接的，但我们讨论了它可能驱动同种型转换的几种方式、它对记忆B细胞发育的影响以及某些类型的T细胞依赖性抗体反应可能不依赖CD40L的可能性。在体内阻断CD40连接的实验表明，早期CD40信号对记忆B细胞的发育很重要，但这可能仅反映了由CD40连接产生的“记忆前体”接受后续编程或存活信号的能力。
