Effect of cytotoxic T lymphocytic associated antigen 4 on acute rejection and CD4 + , CD8 + T cells after liver allotransplantation in rats

Objective To observe the effects of cytotoxic T lymphocytic associated antigen 4 (CTLA4Ig) on CD4 + and CD8 + T cells after orthotopic liver transplantation in rats (ROLT).Methods The ROLT was established.All rats were divided into 2 groups randomly (group A:control group,and group B:study group).CTLA41g was administrated by intraperitoneal injection at a dose of 80 μg.B7 expression was detected.CD4 +/CD8 + T cells were measured.RAI was identified.Results The expression of B7-1 and B7-2 mRNA was decreased significantly on the 2nd,3rd,and 7th day in group B as compared with group A (B7-1:0.166 ± 0.012 vs.0.353 ± 0.043 ; 0.375 ± 0.022 vs.0.503 ± 0.058 ; 0.475 ± 0.023 vs.0.799±0.135;P＜0.01; B7-2:0.170±0.022 vs.0.341 ±0.040; 0.357 ±0.031 vs.0.475±0.041 ; 0.512 ± 0.103 vs.0.829 ± 0.124 ; P ＜ 0.01).The infiltration of CD4 +/CD8 + T cells was decreased significantly on the 2nd,3rd,and 7th day in group B as compared with group A (CD4 +:12.7 ±3.7 vs.21.0±4.4; 15.5 ±3.8 vs.28.2 ±5.2; 18.6 ±4.0 vs.35.0±7.0;P＜0.01; CD8+:9.3±1.5 vs.16.9±2.9; 12.1±2.2 vs.19.9 ±5.3; 17.1±3.7 vs.29.0±5.4;P＜0.01).The RAI was decreased significantly on the 2nd,3rd,and 7th day in group B as compared with group A (1.3 ±0.2 vs.1.9±0.3,P＜0.05; 2.0±0.4 vs.2.6±0.5,P＜0.05; 2.5 ±0.7 vs.4.6±1.1,P＜0.01).Survival period was significantly longer in group B than in group A [(40.9 ± 9.3) d vs.(9.2 ± 2.1) d,P ＜0.01].Conclusion Rat liver allograft immune tolerance can be induced by CTLA4Ig. Key words: Liver transplantation;  Cytotoxic T lymphocytic associated antigen 4 ;  CD4 + /CD8+ T cells;  Acute rejection