Cahalan Michael D, Parker Ian
Department of Physiology and Biophysics and Center for Immunology, University of California, Irvine, CA 92697-4561, USA.
Semin Immunol. 2005 Dec;17(6):442-51. doi: 10.1016/j.smim.2005.09.001. Epub 2005 Nov 2.
Cellular interactions in lymphoid organs initiate the immune response and determine its outcome. Using two-photon microscopy in the lymph node, several groups have begun to investigate the motility characteristics and interactions among T lymphocytes, B lymphocytes, and dendritic cells (DC) in lymphoid organs. In the first "close encounter", T cells of a particular antigen specificity interact with antigen-bearing dendritic cells and begin to activate. Activation of both CD4+ and CD8+ T cells evolves through several stages; from transient interactions to stable clusters and later to dissociation and proliferation of T cells (clonal expansion). The second "close encounter" requires that antigen-engaged B cells become accessible to T cells by directed migration to the edge of the follicle. T cells and B cells then pair up and waltz together for an extended period, while helper T cells provide signals for B cells to differentiate into plasma cells. In this topical review, we compare the activation choreography of CD4+ T cells interacting first with dendritic cells, and then with B cells, during initiation of the humoral immune response.
淋巴器官中的细胞相互作用启动免疫反应并决定其结果。通过在淋巴结中使用双光子显微镜，多个研究小组已开始研究淋巴器官中T淋巴细胞、B淋巴细胞和树突状细胞（DC）的运动特性及相互作用。在首次“亲密接触”中，具有特定抗原特异性的T细胞与携带抗原的树突状细胞相互作用并开始激活。CD4⁺和CD8⁺ T细胞的激活经历几个阶段；从短暂相互作用到稳定聚集，再到T细胞解离和增殖（克隆扩增）。第二次“亲密接触”要求已接触抗原的B细胞通过定向迁移至滤泡边缘而被T细胞接触到。然后T细胞和B细胞配对并长时间一起“共舞”，同时辅助性T细胞为B细胞分化为浆细胞提供信号。在这篇专题综述中，我们比较了在体液免疫反应启动过程中，CD4⁺ T细胞先与树突状细胞，然后与B细胞相互作用时的激活过程。
