Clement L T, Yamashita U, Shevach E M
J Immunol. 1981 Sep;127(3):1220-7.
In the course of studies investigating the effects of antisera prepared against a variety of guinea pig proteins on lymphocyte function, a goat antiserum prepared against a guinea pig gamma-globulin preparation was found to react with guinea pig T lymphocytes. This antiserum, serum 592, contained a significant titer of antibodies that were cytotoxic for a subpopulation of lymph node cells and thymocytes, and mitogenic for lymph node T cells. Immunoelectrophoretic analysis and selective absorptions of the antiserum demonstrated that the antigen recognized on thymocytes was also present on an alpha 2 globulin in guinea pig plasma, which, on the basis of physiochemical characteristics and heparin-binding affinity, appeared to be guinea pig antithrombin III (AT III). Although the antiserum was shown to contain antibodies to both protein and carbohydrate determinants on the AT III molecule, studies comparing the effects of 7 M guanidine and periodate oxidation on the antigenicity of the AT III determinant also recognized on the thymocytes indicated that this shared antigenic determinant was carbohydrate in nature. The thymocyte membrane molecule bearing this determinant was also isolated and was found to be a 210,000-dalton macromolecule that was very sensitive to proteolytic and/or autolytic degradation. These data raise the interesting possibility that guinea pig lymphoid cells may have a membrane-associated protease inhibitor related to plasma AT III.
在研究针对多种豚鼠蛋白制备的抗血清对淋巴细胞功能的影响过程中，发现一种针对豚鼠γ球蛋白制剂制备的山羊抗血清可与豚鼠T淋巴细胞发生反应。这种抗血清，即血清592，含有高滴度的抗体，这些抗体对淋巴结细胞和胸腺细胞的一个亚群具有细胞毒性，对淋巴结T细胞具有促有丝分裂作用。抗血清的免疫电泳分析和选择性吸收表明，在胸腺细胞上识别的抗原也存在于豚鼠血浆中的一种α2球蛋白上，根据其理化特性和肝素结合亲和力，该球蛋白似乎是豚鼠抗凝血酶III（AT III）。尽管抗血清显示含有针对AT III分子上蛋白质和碳水化合物决定簇的抗体，但比较7M胍和高碘酸盐氧化对胸腺细胞上也识别的AT III决定簇抗原性的影响的研究表明，这种共同的抗原决定簇本质上是碳水化合物。带有这种决定簇的胸腺细胞膜分子也被分离出来，发现是一种210,000道尔顿的大分子，对蛋白水解和/或自溶降解非常敏感。这些数据提出了一个有趣的可能性，即豚鼠淋巴细胞可能有一种与血浆AT III相关的膜相关蛋白酶抑制剂。
