Ig is a Y‐shaped protein produced by plasma cells and exerts multiple functions in humoral immunity. There are five groups of Igs including IgA, IgD, IgE, IgG, and IgM, which differ in their heavy chain class. The primary function of Igs includes the neutralization of extrinsic pathogens, agglutination of foreign cells for phagocytosis, precipitation of soluble antigens in serum, and complement fixation. The B cells activated by antigen(s) can differentiate into antibody‐producing cells that are called plasma cells and usually matured in the germinal center (GC). Follicular T helper (Tfh) cells crosstalk with antigen‐presenting cells and play a crucial role in the development of the GC. Moreover, Tfh cells regulate trafficking through the GC to allow formative interaction with GC B cells that ultimately results in affinity maturation, B‐cell memory, and Ig class switching. The B7 family is a series of number of structurally related membrane proteins that bind with a specific receptor to deliver costimulatory or co‐inhibitory signals that regulate the activation of T cells in GC. Here, we review and summarize the recent advance of the effects of B7 family members on Ig production and relative diseases.

中文翻译：

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B7家族成员在免疫球蛋白生成中的作用

Ig是浆细胞产生的Y型蛋白质，在体液免疫中发挥多种功能。有五类Ig，包括IgA，IgD，IgE，IgG和IgM，它们的重链类别不同。Igs的主要功能包括中和外源性病原体，为吞噬作用凝集外源细胞，在血清中沉淀可溶性抗原以及补体固定。被抗原激活的B细胞可以分化成抗体的细胞，称为浆细胞，通常在生发中心（GC）中成熟。滤泡性T辅助（Tfh）细胞与抗原呈递细胞发生串扰，并在GC的发展中起关键作用。此外，Tfh细胞通过GC调节运输，从而与GC B细胞形成相互作用，最终导致亲和力成熟，B细胞存储器和Ig类切换。B7家族是一系列与结构相关的膜蛋白，它们与特定的受体结合，以提供共刺激或共抑制信号，从而调节GC中T细胞的活化。在这里，我们回顾和总结B7家族成员对Ig产生和相关疾病的影响的最新进展。