Functional expression of B7/BB1 on activated T lymphocytes.
Functional expression of B7/BB1 on activated T lymphocytes.
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DOI：
10.1084/jem.177.3.845
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发表时间：
1993-03-01
影响因子：
15.3
通讯作者：
Lanier, L L
中科院分区：
文献类型：
--
作者：
Azuma, M;Yssel, H;Phillips, J H;Spits, H;Lanier, L L
B7/BB1是一种膜分化抗原，表达在活化的B细胞、巨噬细胞和树突状细胞上，与T淋巴细胞和胸腺细胞上表达的对抗受体CD28结合。CD28和B7之间的相互作用导致通过CD3/T细胞受体复合物激活T细胞的有效共刺激。我们现在报道B7也在活化的人外周血T细胞、CD4 T细胞克隆、CD8 T细胞克隆和自然杀伤细胞克隆上表达。B7在T细胞活化后出现较晚，可在CD4和CD8 T细胞亚群中检测到，并且存在于抗原特异性，主要组织相容性复合体限制的CD4和CD8 T细胞克隆中。通过125i标记的活化T细胞的免疫沉淀和B7转录本的检测，证实了B7在活化T细胞上的表达。B7+ CD4+ T细胞克隆能够刺激原发性异体混合淋巴细胞反应，使用小的静息外周血T细胞作为应答者。抗b7单克隆抗体可部分抑制同种异体抗原诱导的增殖反应和细胞因子的产生。由于活化的T细胞可以共表达CD28及其拮抗剂B7，这表明活化的T细胞可能能够通过CD28激活途径进行自分泌共刺激。
B7/BB1 is a membrane differentiation antigen expressed on activated B cells, macrophages, and dendritic cells that binds to a counter- receptor, CD28, expressed on T lymphocytes and thymocytes. Interaction between CD28 and B7 results in potent costimulation of T cell activation initiated via the CD3/T cell receptor complex. We now report that B7 is also expressed on activated human peripheral blood T cells, CD4 T cell clones, CD8 T cell clones, and natural killer cell clones. B7 appears relatively late after T cell activation, can be detected on both CD4 and CD8 T cell subsets, and is present on antigen-specific, major histocompatibility complex-restricted CD4 and CD8 T cell clones. Expression of B7 on activated T cells was confirmed by immunoprecipitation from 125I-labeled activated T cells and by detection of B7 transcripts. A B7+ CD4+ T cell clone was able to stimulate a primary allogeneic mixed lymphocyte response using small, resting peripheral blood T cells as responders. The alloantigen-induced proliferative response and cytokine production was partially inhibited by anti-B7 monoclonal antibody. Since activated T cells can coexpress both CD28 and its counter-receptor, B7, this suggests that activated T cells may be capable of autocrine costimulation via the CD28 activation pathway.