The antigen recognition mechanism by dual receptors of cytotoxic T lymphocytes

我们研究了体外混合淋巴细胞培养(MLC)诱导的细胞毒性T淋巴细胞(CTL)的特异性。我们采用独特的培养系统，将应答小鼠的骨髓(BM)细胞作为辅助细胞加入到含有应答淋巴结细胞和同种异体刺激脾细胞的培养中。本文从脾细胞制备了两种不同的刺激性树突状细胞(DC)，DEC-205细胞去除(Mac-1细胞富集型；MDC)或Mac-1细胞去除(DEC-205细胞富集型；LDC)。在allo-MLC中，MDC诱导的CTL对刺激细胞的同种主要组织相容性抗原复合体(MHC)和异基因X染色体连锁产物(XLGP)具有双重特异性。在刀豆蛋白A诱导的多克隆CTL中，以自体的、非同种异体的脾细胞作为刺激细胞。MDC刺激诱导的CTL具有双重特异性，如多克隆的allo-MHC和刺激物自身的XLGP。相反，当使用LDC刺激时，具有双重特异性的CTL被特异性抑制。综上所述，我们认为不仅MHC而且XLGP具有免疫调节功能，如在外周诱导CTL，并且在两个DC亚群中，MDC可以激活免疫反应，而LDC可以抑制免疫反应。

We studied the specificity of cytotoxic T lymphocytes(CTLs) which were induced in mixed lymphocyte cultures(MLC) in vitro. We used the unique culture system that bone marrow(BM) cells from responder mice as accessory cells were added to the cultures, which contained both responder lymph node cells and allogeneic stimulator spleen cells. In this report, two different stimulatory dendritic cell(DC) populations were prepared from spleen cells, such as DEC-205+ cell depleted(Mac-1+ cell enriched;MDC) or Mac-1+ cell depleted(DEC-205+ cell enriched;LDC) spleen cells.In allo-MLC, the CTL induced by the stimulation of MDC had the dual specificity for both allo major histocompatibility antigen complex(MHC) and allo X-chromosome linked gene products(XLGP) of stimulator cells. On the other hand, the CTL induced by the stimulation of LDC had the specificity for allo MHC alone.In polyclonal CTL induction by concanayalin A, autologous, not allogeneic, spleen cells were used as stimulator cells. The CTL induced by MDC-stimuli had the dual specificity, such as polyclonal allo-MHC and stimulator-self-XLGP. On the contrary, when LDC-stimuli was used, the CTL having the dual specificity were specifically suppressed.In conclusion, we suggested that not only MHC but also XLGP had the regulatory function of immune response, such as CTL induction in periphery, and among two DC subpopulations MDC could activate the immune response, the other hand, LDC could suppress that.