Wabl M, Steinberg C
Department of Microbiology and Immunology, University of California, San Francisco 94143-0670, USA.
Curr Opin Immunol. 1996 Feb;8(1):89-92. doi: 10.1016/s0952-7915(96)80110-5.
Affinity maturation and class switching of antibodies are temporally, but not mechanistically, related processes. The basis of affinity maturation is the selection, in the germinal centers, of antibodies that bind the antigen better. Early in an immune response, the selection is from the primary repertoire; later, it is from mutants generated by hypermutation at the immunoglobulin loci. Recently, the door has been opened for the study of the molecular mechanism of hypermutation, which is expected to make a major contribution to general biology. Class switching has been studied in the past for its obvious clinical importance, but also at the basic level of DNA recombination. Progress in understanding class switching has been trailing the progress made in V(D)J recombination, but new in vitro systems and gene-targeted mice are closing the gap.
抗体的亲和力成熟和类别转换是在时间上相关但机制上无关的过程。亲和力成熟的基础是在生发中心选择能更好结合抗原的抗体。在免疫反应早期，选择来自初级抗体库；后期，则来自免疫球蛋白基因座处通过高突变产生的突变体。最近，高突变分子机制的研究之门已经打开，预计这将对普通生物学做出重大贡献。过去，类别转换因其明显的临床重要性而受到研究，同时也在DNA重组的基础层面进行了研究。在理解类别转换方面取得的进展一直落后于V(D)J重组方面取得的进展，但新的体外系统和基因靶向小鼠正在缩小这一差距。
