van Kemenade F J, Tellegen E, Maurice M M, Lankester A C, Kuijpers T W, Brouwer M, de Jong R, Miedema F, van Lier R A
Department of Clinical Viro-Immunology, University of Amsterdam, The Netherlands.
J Immunol. 1994 May 1;152(9):4425-32.
Accessory molecules on T cells can support adhesion and transduce agonistic signals that facilitate Ag receptor-induced T cell activation. The T cell differentiation Ag CD2 may exert both functions, as has been amply demonstrated in studies with CD2 mAbs. In addition, experiments in which either purified ligand (CD58) or transfected CD2 and CD58 molecules were used have confirmed this notion. However, controversy exists as to whether CD2 alters its affinity for CD58 in the course of T cell stimulation, and whether this putative affinity change affects CD2-mediated activation signals. We now describe a CD2 mAb (HIK27) that recognizes an epitope constitutively expressed on resting T cells and induces increased adhesiveness of CD2 toward CD58. Addition of HIK27 to a stimulatory but nonmitogenic pair of CD2 mAbs induces a strong proliferative response. Finally, HIK27 was found to be co-mitogenic with CD58 expressed on sheep erythrocytes, B cell lines, and CD58-transfected L cells. The simultaneous modulation of CD2 adhesion and signaling on HIK27 binding suggests that both functions of the molecule may be enhanced in the course of T cell stimulation.
T细胞上的辅助分子可支持黏附作用并转导激动信号，从而促进抗原受体诱导的T细胞活化。T细胞分化抗原CD2可能兼具这两种功能，这在针对CD2单克隆抗体的研究中已得到充分证明。此外，使用纯化配体（CD58）或转染的CD2和CD58分子进行的实验也证实了这一观点。然而，关于CD2在T细胞刺激过程中是否改变其对CD58的亲和力，以及这种假定的亲和力变化是否影响CD2介导的活化信号，仍存在争议。我们现在描述一种CD2单克隆抗体（HIK27），它识别静息T细胞上组成性表达的一个表位，并诱导CD2对CD58的黏附性增加。将HIK27添加到一对具有刺激作用但无促有丝分裂作用的CD2单克隆抗体中，可诱导强烈的增殖反应。最后，发现HIK27与绵羊红细胞、B细胞系以及CD58转染的L细胞上表达的CD58具有协同促有丝分裂作用。HIK27结合时对CD2黏附作用和信号传导的同时调节表明，该分子的两种功能在T细胞刺激过程中可能都会增强。
