Levy Shoshana
Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA,
Immunol Res. 2014 May;58(2-3):179-85. doi: 10.1007/s12026-014-8490-7.
A case of a young girl diagnosed with an antibody deficiency syndrome serves to highlight the role of CD81 in B cell biology. Moreover, this case illustrates a fundamental function of the tetraspanin family, namely their association with partner proteins. Characterization of the patient's B cells revealed lack of surface CD19 although both of her CD19 alleles were normal. Further analysis determined that her antibody deficiency syndrome was due to a mutation in the CD81 gene, which did not enable expression of CD19 on the surface of the patient's B cells. Actually, the partnership of CD81 with CD19 and the dependency of CD19 for its trafficking to the cell surface expression were first documented in CD81-deficient mice. CD81 is a widely expressed protein, yet the mutation in the antibody-deficient patient impaired mostly her B cell function. CD81 is required for multiple normal physiological functions, which have been subverted by major human pathogens, such as hepatitis C virus. However, this review will focus on the function of CD81 in cells of the adaptive immune system. Specifically, it will highlight studies focusing on the different roles of CD81 in B and T cells and on its function in B-T cell interactions.
一名被诊断患有抗体缺陷综合征的年轻女孩的病例，凸显了CD81在B细胞生物学中的作用。此外，该病例说明了四跨膜蛋白家族的一项基本功能，即它们与伴侣蛋白的关联。对该患者B细胞的特征分析显示，尽管她的两个CD19等位基因均正常，但缺乏表面CD19。进一步分析确定，她的抗体缺陷综合征是由于CD81基因发生突变，导致患者B细胞表面无法表达CD19。实际上，CD81与CD19的伙伴关系以及CD19向细胞表面表达转运的依赖性，最早是在CD81缺陷小鼠中记录的。CD81是一种广泛表达的蛋白质，但抗体缺陷患者的突变主要损害了她的B细胞功能。CD81是多种正常生理功能所必需的，而这些功能已被主要人类病原体（如丙型肝炎病毒）破坏。然而，本综述将聚焦于CD81在适应性免疫系统细胞中的功能。具体而言，将重点介绍关注CD81在B细胞和T细胞中的不同作用及其在B-T细胞相互作用中的功能的研究。
