Zhang Q W, Tomita Y, Matsuzaki G, Yoshikawa M, Shimizu I, Nakashima Y, Sueishi K, Nomoto K, Yasui H
Department of Cardiovascular Surgery, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Transplantation. 2000 Sep 27;70(6):906-16. doi: 10.1097/00007890-200009270-00008.
We elucidated the possible role of chimerism in skin and heart allograft tolerance using cyclophosphamide (CP)-induced tolerance. When C3H (H-2k; Thy1.2, Mls-1b) mice were i.v. primed with 1x10(8) spleen cells (SC) from H-2 matched AKR (H-2k; Thy1.1, Mls-1a) mice and then treated i.p. with 200 mg/kg of CP, the survivals of both AKR skin grafts and heart grafts (HG) were permanently prolonged in a tolerogen-specific fashion. After this treatment, a minimal degree of mixed chimerism, the clonal destruction of Mls-1a-reactive CD4+Vbeta6+ T cells in the periphery, and the clonal deletion of Vbeta6+ thymocytes were all observed. When AKR SC and 100 mg/kg CP were used for conditioning, the AKR HG were permanently accepted, but the survival of the AKR skin grafts was only mildly prolonged. The clonal destruction of CD4+Vbeta6+ T cells in the periphery and the intrathymic clonal deletion of Vbeta6+ thymocytes were induced in both the SC and the 100 mg/kg CP-treated C3H mice. A minimal degree of mixed chimerism was detectable at 4 and 12 weeks after AKR SC and 100 mg/kg CP treatment, and still did not disappear at 40 weeks. The degree of mixed chimerism induced with SC and 100 mg/kg CP was significantly lower than that with SC and 200 mg/kg CP during the observation. No posttransplant cardiac allograft vasculopathy (CAV) was observed to develop, while both the Th1 type (interferon-gamma) and Th2 type (interleukin-4 and -10) cytokine expressions decreased in the AKR HG of the tolerant C3H mice treated with both AKR SC plus 200 mg/kg CP, and AKR SC plus 100 mg/kg CP. A second set of skin grafts from donor AKR mice survived for more than 100 days in a tolerogen-specific fashion in all C3H mice treated with AKR SC and 200 mg/kg CP and also accepted the AKR HG for over 200 days, while 80% of the C3H mice treated with AKR SC and 100 mg/kg CP and accepted the AKR HG for more than 200 days. These results strongly suggested the following conclusions: 1) the degree of chimerism can strongly influence the induction of skin and heart allograft tolerance, 2) posttransplant CAV does not develop in the donor HG maintained by chimerism-based CP-induced tolerance, 3) the mRNA expression of both Th1 and Th2 type cytokine decreased in the donor HG maintained by chimerism-based CP-induced tolerance, and 4) the induction of skin allograft tolerance is more difficult than the prevention of posttransplant CAV.
我们利用环磷酰胺（CP）诱导的耐受性，阐明了嵌合现象在皮肤和心脏同种异体移植耐受中的可能作用。当C3H（H-2k；Thy1.2，Mls-1b）小鼠经静脉注射用来自H-2匹配的AKR（H-2k；Thy1.1，Mls-1a）小鼠的1×10⁸个脾细胞（SC）进行预处理，然后腹腔注射200mg/kg的CP时，AKR皮肤移植物和心脏移植物（HG）的存活时间均以耐受原特异性方式永久性延长。经过这种处理后，观察到了最低程度的混合嵌合现象、外周血中Mls-1a反应性CD4⁺Vβ6⁺T细胞的克隆性破坏以及Vβ6⁺胸腺细胞的克隆性缺失。当使用AKR SC和100mg/kg CP进行预处理时，AKR HG被永久性接受，但AKR皮肤移植物的存活时间仅略有延长。在SC组和100mg/kg CP处理的C3H小鼠中均诱导了外周血中CD4⁺Vβ6⁺T细胞的克隆性破坏以及胸腺内Vβ6⁺胸腺细胞的克隆性缺失。在AKR SC和100mg/kg CP处理后4周和12周可检测到最低程度的混合嵌合现象，并且在40周时仍未消失。在观察期间，SC和100mg/kg CP诱导的混合嵌合程度明显低于SC和200mg/kg CP诱导的程度。未观察到移植后心脏同种异体移植血管病变（CAV）的发生，而在用AKR SC加200mg/kg CP以及AKR SC加100mg/kg CP处理的耐受C3H小鼠的AKR HG中，Th1型（干扰素-γ）和Th2型（白细胞介素-4和-10）细胞因子表达均降低。在用AKR SC和200mg/kg CP处理的所有C3H小鼠中，来自供体AKR小鼠的第二组皮肤移植物以耐受原特异性方式存活超过100天，并且也接受AKR HG超过200天，而在用AKR SC和100mg/kg CP处理并接受AKR HG超过200天的C3H小鼠中，80%的小鼠也是如此。这些结果有力地表明了以下结论：1）嵌合程度可强烈影响皮肤和心脏同种异体移植耐受诱导；2）在基于嵌合的CP诱导的耐受性维持的供体HG中不发生移植后CAV；3）在基于嵌合的CP诱导的耐受性维持的供体HG中，Th1和Th2型细胞因子的mRNA表达均降低；4）诱导皮肤同种异体移植耐受比预防移植后CAV更困难。
