Wang Claire Q F, Cheng C Yan
Center for Biomedical Research, Population Council, New York, NY 10065, USA.
J Cell Biol. 2007 Aug 13;178(4):549-56. doi: 10.1083/jcb.200704061.
During spermatogenesis, preleptotene spermatocytes traverse the blood-testis barrier (BTB) in the seminiferous epithelium, which is reminiscent of viral pathogens breaking through the tight junctions of host epithelial cells. The process also closely resembles the migration of leukocytes across endothelial tight junctions to reach inflammation sites. Cell adhesion molecules of the immunoglobulin superfamily (e.g., JAM/CAR/nectin) participate in germ cell migration by conferring transient adhesion between Sertoli and germ cells through homophilic and heterophilic interactions. The same molecules also comprise the junctional complexes at the BTB. Interestingly, JAM/CAR/nectin molecules mediate virus uptake and leukocyte transmigration in strikingly similar manners. It is likely that the strategy used by viruses and leukocytes to break through junctional barriers is used by germ cells to open up the inter-Sertoli cell junctions. In associating these diverse cellular events, we highlight the "guiding" role of JAM/CAR/nectin molecules for germ cell passage. Knowledge on viral invasion and leukocyte transmigration has also shed insights into germ cell movement during spermatogenesis.
在精子发生过程中，细线前期精母细胞穿过生精上皮中的血睾屏障（BTB），这让人联想到病毒病原体突破宿主上皮细胞的紧密连接。这个过程也与白细胞穿过内皮紧密连接到达炎症部位的迁移过程极为相似。免疫球蛋白超家族的细胞黏附分子（如JAM/CAR/nectin）通过同源和异源相互作用在支持细胞和生殖细胞之间形成瞬时黏附，从而参与生殖细胞的迁移。同样的分子也构成了血睾屏障处的连接复合体。有趣的是，JAM/CAR/nectin分子介导病毒摄取和白细胞迁移的方式惊人地相似。生殖细胞很可能利用了病毒和白细胞突破连接屏障的策略来打开支持细胞间的连接。在关联这些不同的细胞事件时，我们强调了JAM/CAR/nectin分子对生殖细胞通过的“引导”作用。关于病毒入侵和白细胞迁移的知识也为精子发生过程中生殖细胞的运动提供了见解。
