Aversa G, Punnonen J, Carballido J M, Cocks B G, de Vries J E
DNAX Research Institute, Human Immunology Department, Palo Alto, CA 94303-1104.
Semin Immunol. 1994 Oct;6(5):295-301. doi: 10.1006/smim.1994.1038.
The CD40 ligand (CD40L) is a member of the TNF family, and has emerged as a key molecule in the contact-mediated signal required for B cell activation and differentiation. The cloned CD40L expressed on heterologous cells, or in the form of soluble multimeric molecules, can directly activate B cells and, in conjunction with cytokines, can induce Ig isotype switching in naive B cells. Patients with hyper-IgM syndrome, which results from defective CD40L expression, generally have no circulating Ig, except for IgM, indicating that the CD40L is also important for Ig isotype switching, in vivo. CD40L does not play a role in B cell development and appears not to be required for human activation and differentiation. The presence of CD40L on cells other than T cells, the relatively broad distribution of its ligand CD40, and the ability of T cells to be co-stimulated via CD40L, indicates a broader role for CD40L-CD40 mediated intercellular communication.
CD40配体（CD40L）是肿瘤坏死因子（TNF）家族的成员，已成为B细胞激活和分化所需的接触介导信号中的关键分子。在异源细胞上表达的或可溶性多聚体分子形式的克隆CD40L可直接激活B细胞，并与细胞因子一起诱导未成熟B细胞发生Ig同种型转换。由于CD40L表达缺陷导致的高IgM综合征患者，除IgM外通常无循环Ig，这表明CD40L在体内对Ig同种型转换也很重要。CD40L在B细胞发育中不起作用，似乎对人类B细胞的激活和分化也不是必需的。T细胞以外的细胞上存在CD40L及其配体CD40相对广泛的分布，以及T细胞通过CD40L被共刺激的能力，表明CD40L-CD40介导的细胞间通讯具有更广泛的作用。
