Reth M, Wienands J, Schamel W W
Department of Molecular Immunology, Biology III, University of Freiburg and Max-Planck-Institute for Immunobiology, Germany.
Immunol Rev. 2000 Aug;176:10-8. doi: 10.1034/j.1600-065x.2000.00610.x.
The B cell antigen receptor (BCR) plays a central role in the development, survival and activation of B lymphocytes. As the pre-BCR, it controls allelic exclusion of heavy chains and the expansion of pre-B cells. As the BCR, it controls the positive and negative selection of immature B cells as well as the survival and activation of mature B cells. Recent studies of receptors have shown that it is the ligand that brings them into the conformation necessary for signaling. How the multiple and structurally diverse antigens could fulfill this task for the BCR is unknown, and we regard this as an unsolved problem of Burnet's clonal selection theory This question and our recent biochemical studies lead us to propose a new model for the BCR, according to which the BCR exists as a precise oligomeric complex on the B cell surface. In this form, it can signal positive selection and survival of B cells. Binding to self- or foreign antigen results in a distortion of the oligomeric complex that gives the signal for negative selection of immature and activation of mature B cells.
B细胞抗原受体（BCR）在B淋巴细胞的发育、存活和激活过程中起着核心作用。作为前B细胞受体，它控制重链的等位基因排斥以及前B细胞的扩增。作为BCR，它控制未成熟B细胞的阳性和阴性选择以及成熟B细胞的存活和激活。最近对受体的研究表明，是配体使其进入信号传导所需的构象。多种结构各异的抗原如何为BCR完成这项任务尚不清楚，我们认为这是伯内特克隆选择理论中一个未解决的问题。这个问题以及我们最近的生化研究促使我们提出一个关于BCR的新模型，根据该模型，BCR以精确的寡聚复合物形式存在于B细胞表面。以这种形式，它可以发出B细胞阳性选择和存活的信号。与自身或外来抗原结合会导致寡聚复合物的扭曲，从而发出未成熟B细胞阴性选择和成熟B细胞激活的信号。
