Zhang Q W, Mayumi H, Umesue M, Tomita Y, Nomoto K, Yasui H
Research Institute of Angiocardiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Transplantation. 1997 Jun 15;63(11):1667-73. doi: 10.1097/00007890-199706150-00022.
Injection of allo-spleen cells (SC) followed by a single dose of cyclophosphamide (CP) can induce tolerance of tumor and/or skin allografts in mice. To minimize the damage caused by CP, fractionation of CP that can establish long-lasting skin graft survival, stable mixed chimerism, and intrathymic clonal deletion in the host was investigated in the present study.
Allo-SC (10(8)) were given intravenously on day 0. CP at 200 mg/kg was given intraperitoneally on day 2 in a single dose (CP 200x1 group). CP at 100, 66, 50, 40, and 33 mg/kg was given daily from day 1 through days 2, 3, 4, 5 and 6, respectively, in the fractionated doses (CP 100x2, 66x3, 50x4, 40x5, and 33x6 groups; total dose=200 mg/kg). Allografting was performed on day 14.
In a fully allogeneic combination of C57BL/6 (H2b)-->AKR (H2k, Mls-1a), an EL-4 tumor (H2b) was specifically accepted to kill the AKR mice in all of the SC+CP 200x1, 100x2, 66x3, 50x4, 40x5, and 33x6 groups (n=6), but C57BL/6 skin graft survival was not prolonged in any of the tumor-tolerant groups. In an H2-identical combination of AKR-->C3H (H2k, Mls-1b), AKR skin graft survival was prolonged remarkably (80-90 days) in the SC+CP 200x1, 100x2, and 66x3 groups (n=5-11), but was prolonged moderately (20-60 days) in the SC+CP 50x4 and 40x5 groups. In both of the SC+CP 200x1 and 66x3 groups in the AKR-->C3H combination, mixed chimerism was maintained for as long as 100 days after tolerance induction in both the spleen and thymus, associated with intrathymic clonal deletion of Vbeta6+ T cells. The decreases in leukocyte count, hemoglobin level, spleen weight, SC count, and body weight were significantly smaller in the SC+CP 66x3 group than in the SC+CP 200x1 group.
Fractionated CP is effective in ameliorating the compromised state induced by a single dose of CP. To induce a long-lasting skin allograft survival associated with stable mixed chimerism and intrathymic clonal deletion in an H2-identical combination, 200 mg/kg of CP can be divided into three or fewer fractions.
注射同种异体脾细胞（SC）后给予单剂量环磷酰胺（CP）可诱导小鼠对肿瘤和/或皮肤同种异体移植物产生耐受。为了尽量减少CP造成的损伤，本研究探讨了能使宿主建立长期皮肤移植物存活、稳定混合嵌合状态及胸腺内克隆清除的CP分次给药方案。
第0天静脉注射同种异体SC（10⁸个）。第2天腹腔注射单剂量200mg/kg的CP（CP 200x1组）。分别从第1天至第2、3、4、5和6天，每天给予100、66、50、40和33mg/kg的CP，为分次给药方案（CP 100x2、66x3、50x4、40x5和33x6组；总剂量=200mg/kg）。第14天进行同种异体移植。
在C57BL/6（H2b）→AKR（H2k，Mls-1a）的完全同种异体组合中，EL-4肿瘤（H2b）在所有SC+CP 200x1、100x2、66x3、50x4、40x5和33x6组（n=6）中均能特异性地被接受以杀死AKR小鼠，但在任何肿瘤耐受组中C57BL/6皮肤移植物的存活时间均未延长。在AKR→C3H（H2k，Mls-1b）的H2相同组合中，SC+CP 200x1、100x2和66x3组（n=5-11）中AKR皮肤移植物的存活时间显著延长（80-90天），而SC+CP 50x4和40x5组中存活时间适度延长（20-60天）。在AKR→C3H组合的SC+CP 200x1和66x3组中，耐受诱导后脾脏和胸腺中的混合嵌合状态维持长达100天，伴有胸腺内Vβ6⁺T细胞的克隆清除。SC+CP 66x3组白细胞计数、血红蛋白水平、脾脏重量、SC计数和体重的下降明显小于SC+CP
