抗T细胞受体αβ单克隆抗体促进异基因小鼠皮肤移植耐受及其机制的研究

Study on the improved effect of anti-TCR α β monoclonal antibody on the induction of transplantation tolerance to the allogeneic skin graft in mice and its mechanisms

目的 探讨静脉注射异基因脾细胞 (SC)和抗T细胞受体 (TCR)αβ单克隆抗体加腹腔注射环磷酰胺 (CP)诱导的成年小鼠异基因皮肤移植耐受及其形成的机制。方法 对C5 7BL/ 6 (H 2 b,B6 )小鼠经尾静脉注射BALB/c小鼠 (H 2 d)脾细胞 ,2d后腹腔注射CP ,之后第 2、4天分别经尾静脉注射抗小鼠 TCRαβ的单克隆抗体 ,然后进行皮肤移植。分组 :(1)未处理B6小鼠 ,皮肤供者为BALB/c小鼠 ;(2 )未处理B6小鼠 ,皮肤供者为KM小鼠 ;(3)SC +CP +抗TCRαβ单抗处理的B6小鼠 ,皮肤供者为BALB/c小鼠 ;(4)SC +CP +抗TCRαβ单抗处理的B6小鼠 ,皮肤供者为KM小鼠。每组各 5只B6小鼠通过嵌合体检查、过继转移实验及外源白细胞介素 2 (IL 2 )对耐受小鼠供体特异性混合淋巴细胞反应 (MLR)的影响 ,探讨耐受形成的机制。采用成组t检验进行统计学分析。结果 BALB/c小鼠的皮肤移植物在耐受B6小鼠中存活 6 6 3d ,与各对照组比较 ,差异有显著意义 (P <0 0 0 1) ,流式细胞分析仪分析结果表明 ,耐受小鼠胸腺和脾脏内均形成了微量混合嵌合体 ,耐受诱导后第 15天、35天和第70天胸腺内供体来源细胞嵌合水平依次为 2 6 7% ,1 6 1% ,0 47% ,脾脏中依次为 7 6 6 % ,5 99% ,3 87% ;体、内外细胞转移实验均未显示耐受小鼠脾细胞中存在抑制细?

Objective To study skin allograft tolerance induced by intravenous injection of allogeneic spleen cells and intraperitoneal injection of cyclophosphamide (CP), followed by anti TCR monoclonal antibody injections in adult recipient mice and its mechanisms. Methods Injecting the spleen cells of BALB/c mice (H 2 d) were injected to C57BL/6 mice (H 2 b, B6) via the tail vein. Two days later an intraperioneal injection of cyclophosphamide was given to the B6 mice, and followed by anti TCRαβ monoclonal antibody injection via the tail vein, after which skin of BALB/c mice were grafted to the tolerance induced B6 mice. The control groups were: (1) normal B6 mice grafted with BABL/c skin; (2) normal B6 mice grafted with KM skin; (3) B6 mice treated with SC+CP+anti TCR α β monoclonal antibody administration and grafted with BALB/c skin allograft; (4) B6 mice treated as group 3, and grafted with KM skin instead of BALB/c skin. Detection of chimerism, adoptive transfer assay and the effect of exogenous IL 2 on MLR were performed to explore tolerance mechenisms. Group data in each experiment were compared with Group′s t test. Results The survival of BALB/c skin allograft in recipient B6 mice was 66.3 days, P <0.001 compared with the other three groups. The results of FACS analysis showed that a mixed microchimerism was developed in the thymus and spleen of tolerant mice. The percentage of cells of BALB/c origin in the thymus on day 15, 35, and 70 after induction of tolerance was 2.67%, 1.61%, and 0.47%, and in the spleen is 7.66%, 5.99%, and 3.87%, respectively. No suppressive activity in the spleen cells of tolerant mice was observed by in vivo and in vitro cell transfer experiments. MLR of spleen cells in the tolerant B6 mice to spleen cells of BALB/c origin was specifically suppressed, which was 4 725±406 cpm by 3?H TdR incorporation. However, the specific inhibition of MLR of tolerant B6 mice could be partially reversed ( P <0 01), the 3?H TdR incorporation reached 18 175±3 642 cpm by adding exogenous IL 2. Conclusion Chimerism and clonal anergy are the main mechanisms of the tolerance.