Bigler R D, Bushkin Y, Chiorazzi N
Department of Neoplastic Diseases, Hahnemann University, Philadelphia, PA 19102.
J Immunol. 1988 Jul 1;141(1):21-8.
A large subset of normal resting peripheral blood T cells express a protein at low density defined by the murine mAb S152. Reactive T cells are present in both the CD4+ and CD8+ subpopulations. This determinant, however, is not expressed on growth factor-independent T cell lines. After activation of mononuclear cells by either Con A or PHA, greater than 80% of the cells stained at a mean fluorescence intensity that was more than six times that seen on resting cells. When PWM- or mixed lymphocyte reaction-activated cultures were studied, 7 to 22% of S152+ cells stained at high intensity whereas most cells stained at the baseline low intensity. The increased fraction of S152+ cells staining at high intensity after activation paralleled both the increased percentage of anti-Tac+ and 5E9+ cells and cellular proliferation measured by thymidine incorporation. Modulation of the S152 Ag was induced when either Con A- or PHA-activated mononuclear cells were placed into secondary cultures containing S152 mAb. Expression of the S152 Ag began to decrease after 2 h and reached a minimum after 6 h. Resting T cells, however, did not appear to modulate when cultured with S152 mAb. Immunoprecipitation and gel electrophoresis analysis revealed the S152 molecule to have a mobility of 120 kDa before reduction. After reduction the molecule was shown to be composed of two 55-kDa molecules with an isoelectric point of 5 to 6 indicating that the S152 Ag is a disulfide-linked homodimer. These studies confirm that the S152 mAb reacts with the newly defined CD27 molecule. The presence of the S152 Ag on resting and activated cells, its parallel increase with the Tac and 5E9 Ag, and its ability to modulate on activated cells suggest that this molecule may play a functional role during T cell activation.
一大组正常静息外周血T细胞以低密度表达一种由鼠单克隆抗体S152界定的蛋白。反应性T细胞存在于CD4+和CD8+亚群中。然而，该决定簇在不依赖生长因子的T细胞系上不表达。用刀豆蛋白A（Con A）或植物血凝素（PHA）激活单核细胞后，超过80%的细胞以平均荧光强度染色，该强度是静息细胞的六倍多。当研究经美洲商陆有丝分裂原（PWM）或混合淋巴细胞反应激活的培养物时，7%至22%的S152+细胞以高强度染色，而大多数细胞以基线低强度染色。激活后以高强度染色的S152+细胞比例增加，与抗Tac+和5E9+细胞百分比的增加以及通过胸腺嘧啶核苷掺入测量的细胞增殖平行。当将Con A或PHA激活的单核细胞置于含有S152单克隆抗体的二次培养物中时，可诱导S152抗原的调节。S152抗原的表达在2小时后开始下降，并在6小时后降至最低。然而，静息T细胞与S152单克隆抗体一起培养时似乎不会发生调节。免疫沉淀和凝胶电泳分析显示，还原前S152分子的迁移率为120 kDa。还原后，该分子显示由两个55 kDa的分子组成，等电点为5至6，表明S152抗原是一种二硫键连接的同型二聚体。这些研究证实S152单克隆抗体与新定义的CD27分子反应。S152抗原在静息和激活细胞上的存在、其与Tac和5E9抗原的平行增加以及其在激活细胞上的调节能力表明，该分子可能在T细胞激活过程中发挥功能作用。
