Cabrero J G, Freeman G J, Lane W S, Reiser H
Department of Pathology, Harvard Medical School, Boston, MA 02115.
Proc Natl Acad Sci U S A. 1993 Apr 15;90(8):3418-22. doi: 10.1073/pnas.90.8.3418.
We have recently described a murine lymphocyte protein, provisionally termed sgp-60, which is expressed on virtually all lymphocytes of both T- and B-cell origin. A hamster monoclonal antibody to sgp-60 can inhibit interleukin-2 (IL-2) production, IL-2-receptor expression, and T-cell proliferation, events normally observed after stimulation of T cells with an antibody to the T-cell receptor/CD3 complex or with the lectin concanavalin A. Our previous studies did not reveal the molecular nature of the sgp-60 antigen. Purification of sgp-60 and protein sequencing demonstrate that sgp-60 is identical to the CD48 antigen, a ligand for the CD2 antigen, which is also called Blast-1 in humans, BCM1 in mice, and OX-45 in rats. The identity of sgp-60 and CD48 was independently confirmed in gene transfection experiments. The anti-sgp-60 monoclonal antibody was selectively reactive with COS-7 cells transfected with a BCM1 cDNA clone but not with Kb-transfected controls. The results of the present report, together with our previous functional studies, may have implications for the role of CD2 and CD48 in murine T-cell activation.
我们最近描述了一种小鼠淋巴细胞蛋白，暂称为sgp-60，它在几乎所有T细胞和B细胞来源的淋巴细胞上均有表达。一种针对sgp-60的仓鼠单克隆抗体能够抑制白细胞介素-2（IL-2）的产生、IL-2受体的表达以及T细胞增殖，这些都是在用抗T细胞受体/CD3复合物抗体或凝集素伴刀豆球蛋白A刺激T细胞后通常会观察到的事件。我们之前的研究并未揭示sgp-60抗原的分子性质。sgp-60的纯化和蛋白质测序表明，sgp-60与CD48抗原相同，CD48抗原是CD2抗原的配体，在人类中也称为Blast-1，在小鼠中称为BCM1，在大鼠中称为OX-45。在基因转染实验中独立证实了sgp-60和CD48的一致性。抗sgp-60单克隆抗体与用BCM1 cDNA克隆转染的COS-7细胞有选择性反应，但与转染Kb的对照细胞无反应。本报告的结果，连同我们之前的功能研究，可能对CD2和CD48在小鼠T细胞活化中的作用有影响。
