Schäfer H, Scheper R J, Healey D G, Schenkel J, Burger R
Department of Immunology, Robert Koch-Institute, Bundesgesundheitsamt, Berlin, FRG.
Eur J Immunol. 1991 Mar;21(3):701-5. doi: 10.1002/eji.1830210324.
Monoclonal antibodies (mAb) to differentiation antigens frequently influence the in vitro function of antigen-bearing cells. We characterized a 32-36-kDa membrane protein expressed on guinea pig lymphocytes and Langerhans cells. A series of independently derived mAb to this protein, now called guinea pig T cell activation antigen (gpTAA), induced strong proliferation of T cells in vitro. Cross-linking of the mAb by a secondary antibody (rabbit anti-mouse Ig) and costimulation with phorbol 12-myristate 13-acetate were required for activation. Treatment of the cells with phosphatidylinositol-specific phospholipase C greatly reduced the amount of antigen expressed on the cell surface as measured by flow cytometry analysis. This finding indicates that the antigen is anchored to the cell membrane via phosphatidylinositol linkage as shown similarly for other membrane proteins with T cell activating properties, e.g. Thy-1 and Ly-6. The guinea pig protein differs, however, in its molecular weight and tissue distribution from similar proteins identified in the mouse or in the rat system. Unlike Thy-1, gpTAA is also expressed on B Lymphocytes and Langerhans cells. Considering the previously described involvement in cellular adhesion, and the functional characteristics reported here, gpTAA might represent a new species of differentiation antigen with T cell-activating capacity.
针对分化抗原的单克隆抗体（mAb）常常会影响带有抗原的细胞的体外功能。我们鉴定了一种在豚鼠淋巴细胞和朗格汉斯细胞上表达的32 - 36 kDa膜蛋白。一系列针对该蛋白（现称为豚鼠T细胞活化抗原（gpTAA））的独立衍生单克隆抗体在体外诱导T细胞强烈增殖。需要用二抗（兔抗小鼠Ig）使单克隆抗体交联并与佛波醇12 - 肉豆蔻酸酯13 - 乙酸酯共同刺激才能激活。用磷脂酰肌醇特异性磷脂酶C处理细胞后，通过流式细胞术分析测量发现细胞表面表达的抗原量大大减少。这一发现表明该抗原通过磷脂酰肌醇连接锚定在细胞膜上，其他具有T细胞激活特性的膜蛋白（如Thy - 1和Ly - 6）也有类似情况。然而，豚鼠蛋白在分子量和组织分布上与在小鼠或大鼠系统中鉴定出的类似蛋白不同。与Thy - 1不同，gpTAA也在B淋巴细胞和朗格汉斯细胞上表达。考虑到先前描述的其在细胞黏附中的作用以及此处报道的功能特性，gpTAA可能代表一种具有T细胞激活能力的新的分化抗原种类。
