Hall B M, Jelbart M E, Dorsch S E
Transplantation. 1984 Jun;37(6):595-600. doi: 10.1097/00007890-198406000-00014.
DA rats treated with cyclosporine for 2 weeks after being grafted with an RT1-incompatible PVG heart graft did not reject the graft and developed a state of specific unresponsiveness to graft antigens. The cellular mechanisms maintaining this state of unresponsiveness were studied by testing the capacity of lymphocytes from these animals to effect or inhibit graft rejection in irradiated grafted hosts. Whole lymph node and spleen cell populations, and the T cell subpopulation separated from the latter, failed to restore the rejection of PVG hearts in irradiated DA recipients but restored third-party Wistar-Furth (W/F) rejection. Both whole spleen cells and the splenic T cell subpopulation had the capacity to suppress the ability of normal DA lymphocytes to cause graft rejection. Suppression was not dependent upon a state of chimerism in grafted cyclosporine -treated animals, and was not associated with any measurable alterations in the proportion of cytotoxic/suppressor T cells in lymphoid tissues. These studies show that the state of specific unresponsiveness that follows the treatment of heart grafted rats with cyclosporine is dependent, in part, upon active suppression that is induced or mediated by T lymphocytes. Many features of the immune reactivity of cyclosporine -treated grafted rats support the hypothesis that the mechanism of specific suppression in these animals is akin to that of enhancement, rather than to that of transplantation tolerance induced in neonatal rats.
用环孢素处理移植了RT1不相容的PVG心脏移植物2周后的DA大鼠，未排斥该移植物，并对移植物抗原产生了特异性无反应状态。通过检测这些动物的淋巴细胞在受辐照的移植宿主中影响或抑制移植物排斥的能力，研究了维持这种无反应状态的细胞机制。整个淋巴结和脾细胞群体，以及从后者分离出的T细胞亚群，未能恢复受辐照的DA受体中PVG心脏的排斥反应，但恢复了第三方Wistar-Furth（W/F）的排斥反应。全脾细胞和脾T细胞亚群均有抑制正常DA淋巴细胞引起移植物排斥的能力。抑制作用不依赖于移植环孢素处理动物中的嵌合状态，也与淋巴组织中细胞毒性/抑制性T细胞比例的任何可测量变化无关。这些研究表明，用环孢素处理心脏移植大鼠后出现的特异性无反应状态部分依赖于由T淋巴细胞诱导或介导的主动抑制。环孢素处理的移植大鼠免疫反应的许多特征支持这样的假设，即这些动物中特异性抑制的机制类似于增强机制，而不是新生大鼠诱导的移植耐受机制。
