Characterization and localization of the Gova/b alloantigens to the glycosylphosphatidylinositol-anchored protein CDw109 on human platelets.
Characterization and localization of the Gova/b alloantigens to the glycosylphosphatidylinositol-anchored protein CDw109 on human platelets.
复制标题
人血小板上糖基磷脂酰肌醇锚定蛋白 CDw109 的 Gova/b 同种异体抗原的表征和定位。
DOI：
10.1182/blood.v86.7.2807.2807
复制
发表时间：
1995
期刊：
影响因子：
20.3
通讯作者：
J. Kelton
中科院分区：
文献类型：
--
作者：
J. Smith;C. Hayward;P. Horsewood;T. Warkentin;G. Denomme;J. Kelton
Gova/b同种异体抗原表达于人血小板上一个175kD的蛋白(GP175)上。抗GOV同种异体抗体与输血后紫癜和同种免疫性新生儿血小板减少症有关。在这份报告中，我们描述了同种异体抗原的免疫化学特征，并鉴定了表达Gov表位的血小板蛋白。经磷脂酰肌醇特异性磷脂酶C处理的血小板释放了大约50%的含有Gov表位的GP175，这表明至少有一部分这种蛋白以糖基化磷脂酰肌醇(GPI)连接的亚型存在。放射免疫沉淀和免疫耗竭研究表明，Gova/b同种异体抗原表达于GPI锚定的CDw109蛋白上。GOVA/b表位在CDw109胞外120 kD的可溶性片段(P120)上表达，该片段由钙依赖的蛋白酶裂解而成。P120胰凝乳酶消化的抗GOV免疫沉淀物含有CDw109的70-和52-kD片段。天然CDw109的脱糖基化对GOV同种异体抗血清的识别没有影响；然而，暴露于十二烷基硫酸钠后，表位被破坏。GOVA/b同种异体抗原表达于血小板和PHA激活的T细胞、培养的人脐静脉内皮细胞以及多种肿瘤细胞系，与CDw109的组织分布一致。
The Gova/b alloantigens are expressed on a 175-kD protein (GP175) on human platelets. Anti-Gov alloantibodies have been implicated in posttransfusion purpura and alloimmune neonatal thrombocytopenia. In this report we characterize the immunochemistry of the alloantigens and identify the platelet protein that expresses the Gov epitopes. Approximately 50% of GP175 containing the Gov epitope was released from platelets treated with phosphatidylinositol-specific phospholipase C, indicating that at least some of this protein exists as a glycosylphosphatidylinositol (GPI)-linked isoform. Radioimmunoprecipitation and immunodepletion studies indicated that the Gova/b alloantigens are expressed on the GPI-anchored CDw109 protein. The Gova/b epitopes were expressed on an extracellular, 120-kD soluble fragment (p120) of CDw109 produced by calcium-dependent protease cleavage. Anti-Gov immunoprecipitates of chymotryptic digests of p120 contained 70- and 52-kD fragments of CDw109. Deglycosylation of native CDw109 had no effect on recognition by Gov alloantisera; however, the epitopes were destroyed after exposure to sodium dodecyl sulfate. Gova/b alloantigens were expressed on platelets and PHA-activated T-cells, cultured human umbilical vein endothelial cells, and by many different tumor cell lines, consistent with the tissue distribution of CDw109.