Identification of a novel surface protein on activated CD4+ T cells that induces contact-dependent B cell differentiation (help).
Identification of a novel surface protein on activated CD4+ T cells that induces contact-dependent B cell differentiation (help).
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DOI：
10.1084/jem.175.4.1091
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发表时间：
1992-04-01
期刊：
影响因子：
--
通讯作者：
Chess L
中科院分区：
文献类型：
--
作者：
Lederman S;Yellin MJ;Krichevsky A;Belko J;Lee JJ;Chess L
CD4 + T淋巴细胞为B细胞提供接触依赖性刺激，这对于在称为T辅助功能的过程中产生特异性抗体应答至关重要。介导这种功能的活化的CD4 + T细胞的表面结构尚不完全清楚。我们以前报道的分离功能独特的亚克隆的Jurkat白血病T细胞系（D1.1），组成型表达接触依赖性辅助效应功能。为了鉴定介导接触依赖性辅助性T细胞功能的T细胞表面分子，产生了一种单克隆抗体（mAb），命名为5c8，其抑制D1.1介导的B细胞活化，并从表面碘化的D1.1细胞中免疫沉淀一种新的30 kD蛋白结构。正常CD4 + T细胞在被佛波醇肉豆蔻酸酯乙酸酯和植物血凝素激活后5 - 6小时瞬时表达5c8抗原（Ag），在激活后5 - 6小时表达最大，并且在24小时不表达。相反，静息和活化的CD8 + T细胞都不表达5c8 Ag。在功能研究中，mAb 5c8抑制固定的、活化的CD 4 + T细胞诱导B细胞表面CD 23表达的能力。此外，mAb 5c8抑制由美洲商陆有丝分裂原驱动的CD4 + T细胞指导末端B细胞分化的能力。总之，这些数据表明，5c8 Ag是一种新的，活化诱导的表面T细胞蛋白，参与介导的接触依赖性元件的辅助效应功能的CD4 + T淋巴细胞。
CD4+ T lymphocytes provide contact-dependent stimuli to B cells that are critical for the generation of specific antibody responses in a process termed T helper function. The surface structures on activated CD4+ T cells that mediate this function are not fully known. We previously reported the isolation of a functionally unique subclone of the Jurkat leukemic T cell line (D1.1) that constitutively expressed contact-dependent helper effector function. To identify T cell surface molecules that mediate contact-dependent T helper function, a monoclonal antibody (mAb), designated 5c8, was generated that inhibits D1.1-mediated B cell activation and immunoprecipitates a novel 30-kD protein structure from surface-iodinated D1.1 cells. Normal CD4+ T cells express 5c8 antigen (Ag) transiently 5-6 h after activation by phorbol myristate acetate and phytohemagglutinin with maximal expression 5-6 h after activation and absence of expression by 24 h. In contrast, neither resting nor activated CD8+ T cells express 5c8 Ag. In functional studies, mAb 5c8 inhibits the ability of fixed, activated CD4+ T cells to induce B cell surface CD23 expression. In addition, mAb 5c8 inhibits the ability of CD4+ T cells to direct terminal B cell differentiation driven by pokeweed mitogen. Taken together, these data suggest that 5c8 Ag is a novel, activation-induced surface T cell protein that is involved in mediating a contact-dependent element of the helper effector function of CD4+ T lymphocytes.