Kehrl John H, Hwang Il-Young, Park Chung
B-cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases/NIH, 10 Center Drive, Bethesda, MD 20892-1876, USA.
Curr Top Microbiol Immunol. 2009;334:107-27. doi: 10.1007/978-3-540-93864-4_5.
Intravital microscopy has provided extraordinary glimpses of lymphocytes crossing high endothelial venules, detailed the movements and interactions of lymphocytes within lymph organs, and recorded lymphocytes crossing the lymphatic endothelium into the efferent lymph. Helping to orchestrate these movements are signals generated by the engagement of chemoattractants with their cognate receptors. Chemokines present on high endothelial venules and within lymph organs, and the high levels of sphingosine l-phosphate in the lymph, provide signposts to help guide lymphocytes and provide intracellular signals that affect lymphocyte polarity and motility. Within lymph nodes, T and B lymphocytes migrate along networks of fibroblastic reticular cells and follicular dendritic, respectively, which provide an adhesive platform and solid phased chemokines. Illustrating the importance of chemoattractant receptors in these processes, lymphocytes that lack CXCR4, CXCR5, CCR7 or S1PR1, or which lack crucial signaling molecules activated by these receptors, exhibit defects in lymph node entrance, positioning, polarity, motility, and/or lymph node egress. This review will focus on the contributions of in vivo imaging of lymphocytes from various mouse mutants to our understanding of the roles chemoattractants play in lymphocyte entrance into and exit from lymph nodes, and in coordinating and facilitating the movements of lymphocytes within lymph nodes.
活体显微镜检查让我们得以非凡地瞥见淋巴细胞穿越高内皮微静脉的过程，详细了解淋巴细胞在淋巴器官内的运动和相互作用，并记录淋巴细胞穿越淋巴内皮进入输出淋巴管的情况。趋化因子与其同源受体结合所产生的信号有助于协调这些运动。高内皮微静脉和淋巴器官中存在的趋化因子，以及淋巴中高水平的1-磷酸鞘氨醇，提供了路标，帮助引导淋巴细胞，并提供影响淋巴细胞极性和运动性的细胞内信号。在淋巴结内，T淋巴细胞和B淋巴细胞分别沿着成纤维网状细胞网络和滤泡树突状细胞迁移，这些细胞提供了一个粘附平台和固相趋化因子。缺乏CXCR4、CXCR5、CCR7或S1PR1，或缺乏由这些受体激活的关键信号分子的淋巴细胞，在淋巴结进入、定位、极性、运动和/或淋巴结流出方面表现出缺陷，这说明了趋化因子受体在这些过程中的重要性。本综述将重点探讨对各种小鼠突变体淋巴细胞进行体内成像，对我们理解趋化因子在淋巴细胞进出淋巴结以及协调和促进淋巴细胞在淋巴结内运动中所起作用的贡献。
