EXPRESSION OF IA ANTIGENS ON FUNCTIONAL CELL SUBPOPULATIONS

一系列识别相同抗原的T细胞克隆 与给定的E α E β II类相关的分子 分子的敏感性进行了研究，以抑制由 一组15种不同的抗I-E单克隆抗体， 同一个I-E分子上的决定簇 结果表明 不同的T细胞克隆似乎识别抗原， 与不同的决定簇或构象的关联 相同的I-E分子 T细胞克隆对丝裂原的反应 还分析了关节炎支原体上清液（MAS）。 它 确定大约15%的测试克隆 当在I-E轴承的背景下提出时， 抗原提呈细胞，这种反应性是独立的， 这些克隆的主要特异性或MHC限制， 常规抗原。 当不同Ia表达群体的表达能力 对克隆T细胞进行了评估，所有测试的克隆都能够 对含有粘附细胞的辐射刺激细胞作出反应 或丝裂霉素处理的纯化的静息B细胞群。 在 相反，只有克隆T细胞的亚群对 LPS激活B细胞母细胞，尽管Ia表达增强 这些B细胞母细胞，表明T细胞所需的信号， 细胞活化在T细胞克隆中可能不同，不同的Ia 携带抗原呈递细胞可以胜任 不同的T细胞。

A series of T cell clones which recognized the same antigenic molecule in association with a given E alpha E beta class II molecule were studied for their susceptibility to inhibition by a panel of 15 different anti I-E monoclonal antibodies specific for determinants on the same I-E molecule. The results demonstrated that different T cell clones appear to recognize antigen in association with distinct determinants or conformations on the same I-E molecule. The responses of T cell clones to the mitogen Mycoplasma arthritidis supernatant (MAS) were also analyzed. It was determined that approximately 15% of the clones tested responded to MAS when presented in the context of I-E bearing antigen presenting cells, and that this reactivity was independent of the primary specificity or MHC restriction of those clones to conventional antigens. When the ability of different Ia expressing populations to present to cloned T cells was evaluated, all of the clones tested were able to respond to adherent cell-containing irradiated stimulating cells or to mitomycin treated purified resting B cell populations. In contrast, only a subpopulation of cloned T cells was responsive to LPS activated B cell blasts, in spite of the enhanced Ia expression by these B cell blasts, indicating that the signals required for T cell activation may vary among T cell clones, and that distinct Ia bearing antigen presenting cells may be competent for presentation of different T cells.