Asano Y, Hodes R J
J Exp Med. 1983 Jun 1;157(6):1867-84. doi: 10.1084/jem.157.6.1867.
The present studies were carried out to characterize the cellular interactions involved in the activation and function of the antigen-specific and antigen-nonspecific T suppressor (Ts) cells that regulate the IgG responses of Lyb-5-B cells. The in vitro activation of both Lyt-1+2- antigen-nonspecific Ts cells and Lyt-1-2+ antigen-specific Ts cells was shown to require the interaction of accessory cells and antigen-primed T cells. It was further demonstrated that this interaction was major histocompatibility complex (MHC)-restricted in that T cell recognition of I-A-encoded determinants on accessory cells was required for Ts cell activation. The activation of antigen-primed (A X B)F1 T cells with antigen in the presence of parentA or parentB accessory cells resulted, respectively, in the generation of parentA-restricted or parentB-restricted Ts cells. ParentA-restricted F1 Ts cells suppressed the responses generated by (A X B)F1 T helper (Th) cells cooperating with parentA (B + accessory) cells but did not suppress responses by the same (A X B)F1 Th cell population cooperating with parentB (B + accessory) cells. Neither parentA-restricted Ts cells alone nor parentB-restricted Ts cells alone suppressed the responses of (A X B)F1 (B + accessory) cells, whereas a mixture of these two Ts cell populations was able to significantly suppress the responses of F1 (B + accessory) cells. In contrast, responses of (A X B)F1 leads to parentA Th cells (restricted to recognizing parentA but not parentB MHC determinants on F1 cells) and (A X B)F1 (B + accessory) cells was suppressed by parentA-restricted Ts cells but not by parentB-restricted Ts cells. Collectively these findings suggest that the Ts cell populations characterized here do not function by directly inhibiting the activity of Th cells, B cells or accessory cells of a given MHC genotype, but rather that they appear to function through a unique mechanism involving highly specific inhibition of the interaction between MHC-restricted Th cells and the (B + accessory) cells required for these responses.
开展本研究以表征参与调节Lyb-5-B细胞IgG反应的抗原特异性和抗原非特异性T抑制（Ts）细胞激活及功能的细胞间相互作用。结果表明，Lyt-1 + 2 - 抗原非特异性Ts细胞和Lyt-1 - 2 + 抗原特异性Ts细胞的体外激活均需要辅助细胞与抗原致敏T细胞的相互作用。进一步证明，这种相互作用受主要组织相容性复合体（MHC）限制，即Ts细胞激活需要T细胞识别辅助细胞上I-A编码的决定簇。在亲本A或亲本B辅助细胞存在的情况下，用抗原激活抗原致敏的（A×B）F1 T细胞，分别产生亲本A限制或亲本B限制的Ts细胞。亲本A限制的F1 Ts细胞抑制（A×B）F1辅助性T（Th）细胞与亲本A（B + 辅助）细胞协作产生的反应，但不抑制同一（A×B）F1 Th细胞群体与亲本B（B + 辅助）细胞协作产生的反应。单独的亲本A限制的Ts细胞或单独的亲本B限制的Ts细胞均不抑制（A×B）F1（B + 辅助）细胞的反应，而这两种Ts细胞群体的混合物能够显著抑制F1（B + 辅助）细胞的反应。相比之下，亲本A限制的Ts细胞抑制（A×B）F1导致亲本A Th细胞（限于识别F1细胞上的亲本A而非亲本B MHC决定簇）和（A×B）F1（B + 辅助）细胞的反应，但亲本B限制的Ts细胞则不能。总体而言，这些发现表明，此处表征的Ts细胞群体并非通过直接抑制给定MHC基因型的Th细胞、B细胞或辅助细胞的活性来发挥作用，而是似乎通过一种独特机制发挥作用，该机制涉及高度特异性抑制MHC限制的Th细胞与这些反应所需的（B + 辅助）细胞之间的相互作用。
