Culty M, Miyake K, Kincade P W, Sikorski E, Butcher E C, Underhill C
Department of Anatomy and Cell Biology, Georgetown Medical Center, Washington, D.C. 20007.
J Cell Biol. 1990 Dec;111(6 Pt 1):2765-74. doi: 10.1083/jcb.111.6.2765.
The present study was undertaken to determine the relationship between the hyaluronate receptor and CD44 (H-CAM), cell-surface glycoproteins of similar molecular weights that have been implicated in cell adhesion. In initial experiments, a panel of monoclonal antibodies directed against CD44 were tested for their ability to cross react with the hyaluronate receptor. These antibodies immunoprecipitated [3H]hyaluronate binding activity from detergent extracts of both mouse and human cells, indicating that the hyaluronate receptor is identical to CD44. In addition, one of these antibodies (KM-201 to mouse CD44) directly blocked the binding of labeled hyaluronate to the receptor and inhibited hyaluronate dependent aggregation of SV-3T3 cells. CD44 has also been implicated in lymphocyte binding to high endothelial venules during lymphocyte homing. Interestingly, the monoclonal antibody Hermes-3, which blocks lymphocyte binding to the high endothelial venules of mucosal lymphoid tissue, had no effect on the binding of labeled hyaluronate. Furthermore, the binding of lymphocytes to high endothelial cells of lymph nodes and mucosal lymphoid tissue was not significantly affected by treatment with agents that block the binding of hyaluronate (hyaluronidase, excess hyaluronate and specific antibodies). Thus, CD44 appears to have at least two distinct functional domains, one for binding hyaluronate and another involved in interactions with mucosal high endothelial venules.
本研究旨在确定透明质酸受体与CD44（H-CAM）之间的关系，CD44是分子量相似的细胞表面糖蛋白，与细胞黏附有关。在最初的实验中，检测了一组针对CD44的单克隆抗体与透明质酸受体交叉反应的能力。这些抗体从小鼠和人类细胞的去污剂提取物中免疫沉淀出[3H]透明质酸结合活性，表明透明质酸受体与CD44相同。此外，其中一种抗体（针对小鼠CD44的KM-201）直接阻断了标记透明质酸与受体的结合，并抑制了SV-3T3细胞的透明质酸依赖性聚集。CD44在淋巴细胞归巢过程中也与淋巴细胞与高内皮微静脉的结合有关。有趣的是，阻断淋巴细胞与黏膜淋巴组织高内皮微静脉结合的单克隆抗体Hermes-3对标记透明质酸的结合没有影响。此外，用阻断透明质酸结合的试剂（透明质酸酶、过量透明质酸和特异性抗体）处理后，淋巴细胞与淋巴结和黏膜淋巴组织高内皮细胞的结合没有受到显著影响。因此，CD44似乎至少有两个不同的功能结构域，一个用于结合透明质酸，另一个参与与黏膜高内皮微静脉的相互作用。
