Xue W, Zhang S, Minocha H C
Kansas State University, Manhattan 66506, USA.
Vet Microbiol. 1997 Sep;57(2-3):105-18. doi: 10.1016/s0378-1135(97)00117-x.
In a previous communication, we reported a 50-kDa cell surface protein from Madin-Darby bovine kidney (MDBK) cells as a putative receptor for bovine viral diarrhea virus (BVDV). The present study delineates further characterization of the receptor protein. Protease treatment of cultured MDBK cells adversely affected the receptor, thus abolishing the binding of anti-D89 (BVDV anti-idiotypes) to the cells. However, pretreatment of the cells with either phospholipases or glycosidases did not significantly change the anti-D89 binding to the cells. Additionally, pretreatment of cell monolayers with proteases decreased BVDV attachment and replication in the cells. These results suggested that the receptor for BVDV is a protein in nature, and glycosylation and phosphorylation may not play a direct role in BVDV attachment to cells. The BVDV receptor gradually regenerated on the cell surface after the protease-treated cells were cultured in normal growth medium. Regeneration of the BVDV receptor to a normal level took about 4 h as indicated by flow cytometric analysis and this process was inhibited in the presence of cycloheximide, a protein synthesis inhibitor. The 50-kDa receptor protein purified by electro-elution inhibited BVDV infection in a plaque reduction assay. It also inhibited anti-D89 binding to cells as analyzed by flow cytometry. These data demonstrated the nature of the 50-kDa protein as a specific receptor for BVDV.
在之前的一篇通讯中，我们报道了从马-达二氏牛肾（MDBK）细胞中分离出的一种50 kDa细胞表面蛋白，它被认为是牛病毒性腹泻病毒（BVDV）的受体。本研究进一步阐述了该受体蛋白的特性。用蛋白酶处理培养的MDBK细胞会对受体产生不利影响，从而消除抗D89（BVDV抗独特型）与细胞的结合。然而，用磷脂酶或糖苷酶对细胞进行预处理并不会显著改变抗D89与细胞的结合。此外，用蛋白酶对细胞单层进行预处理会降低BVDV在细胞中的附着和复制。这些结果表明，BVDV的受体本质上是一种蛋白质，糖基化和磷酸化可能在BVDV与细胞的附着过程中不发挥直接作用。在蛋白酶处理过的细胞于正常生长培养基中培养后，BVDV受体在细胞表面逐渐再生。流式细胞术分析表明，BVDV受体再生至正常水平大约需要4小时，并且在蛋白质合成抑制剂环己酰亚胺存在的情况下，这一过程受到抑制。通过电洗脱纯化的50 kDa受体蛋白在蚀斑减少试验中抑制了BVDV感染。流式细胞术分析还表明，它抑制了抗D89与细胞的结合。这些数据证明了50 kDa蛋白作为BVDV特异性受体的性质。
