霍乱毒素对淋巴细胞活化增殖的影响及其机制

研究探讨霍乱毒素（ＣＴＸ）对淋巴细胞活化、增殖的影响及可能的作用机制。研究结果表明，　　ＣＴＸ可显著升高静息ＰＢＭＣ和／或ＣＤ３单抗激活的琳巴细胞内ｃＡＭＰ水平，该效应与ＣＴＸ抑制淋巴细胞增殖和ＩＬ－２的作用密切相关；　　ＡＣ激活剂Ｆｏｒｓｋｏｌｉｎ通过升高细胞内ｃＡＭｐ水平，对于ＣＤ３单抗激活的淋巴细胞增殖有明显的抑制作用；ＣＴＸ不能干扰ＩＬ－２依赖株ＣＴＬＬ细胞的增殖效应，也不影响ＣＴＬＬ细胞内ｃＡＭＰ水平。实验结果提示，ＣＴＸ敏感的Ｇ蛋白亚类参与了ＣＤ３单抗对淋巴细胞活化的调节，ＣＴＸ的抑制作用与其升高细胞内ｃＡＭｐ水平有关。

Effects of CTX on activation and. proliferation of lymphocytes

The influences of cholera toxin (CTX) on T cell proliferation and IL-2 production were investigated. The results indicated that CT X could obviously inhibit proliferation and IL-2 secretion of T lymphocytes stimulated by CD3 McAb ,and the antiproliferative effect was related to the increase of intracellular cAMP by CTX. The inhibition could be mimicked by forskolin ,an activator of AC ,through elevating intracellular cAMP. It is suggested that some CTX-sensitive subgroup of G protein takes. part in the regulation. On the other side ,CTX couldn't inhibit proliferation of IL-2-dependent cell, CTLL ,and had no effect on their intracellular cAMP levels. The results indicated that functional regulation of CTLL cells was independent of CTX-sensitive G protein , and CD3 McAb and IL-2 function via different pathways in different Cells .