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生发中心是在T细胞依赖性抗体应答过程中于外周淋巴组织内形成的一个特殊的结构。在GC内,受抗原刺激而活化的B细胞进行克隆扩增、IgV区基因的体细胞高度突变、亲和力成熟以及同类型转换,最终形成记忆性B细胞或是产生Ig的浆细胞。在GC内B细胞增殖的同时,也启动了凋亡机制,以确保最终形成的记忆B细胞或浆细胞对抗原的高度特异性。FDCs是参与再次免疫应答的重要细胞,它主要是通过表面的FcR和CR将免疫复合物结合在细胞膜上,并选择性的将抗原递呈给表达高亲和力BCR的B细胞,使之激活并产生抗体或形成记忆B细胞。因此,FDCs在生发中心反应、免疫记忆的维持、B细胞的分化、成熟以及记忆B细胞的形成具有极其重要的作用。但最近的研究对FDCs及其结合的免疫复合物的重要性提出了质疑,认为FDCs在生发中心反应、B细胞的分化、成熟以及记忆B细胞的形成中的作用很可能是非特异性的,并对驻留在FDCs表面的免疫复合物的其它潜在功能进行了讨论。
Germinal centers are a special structure formed in peripheral lymphoid tissue during T cell-dependent antibody responses. Within the GC, B cells activated by antigen stimulation undergo clonal expansion, somatic hypermutation of the IgV region genes, affinity maturation, and the same type of conversion, eventually forming memory B cells or Ig-producing plasma cells. B cell proliferation within the GC also initiates an apoptosis mechanism to ensure that the resulting memory B cells or plasma cells are highly specific for the antigen. FDCs are important cells involved in the re-immune response. They mainly bind immune complexes to the cell membrane through surface FcRs and CRs, and selectively present antigens to B cells expressing high-affinity BCRs to activate and produce them Antibodies or memory B cells. Therefore, FDCs play an extremely important role in the germinal center reaction, the maintenance of immune memory, the differentiation and maturation of B cells and the formation of memory B cells. However, recent studies have questioned the importance of FDCs and their associated immune complexes, arguing that the role of FDCs in germinal center responses, B cell differentiation, maturation, and memory B cell formation is likely to be nonspecific and Other potential functions of immune complexes residing on the surface of FDCs are discussed.