调节性T细胞在大鼠小肠移植急性排斥反应中的作用

The role of regulatory T cells in acute allograft rejection in rat heterotopic small intestine transplantation

目的 分析调节性T细胞在大鼠急性排斥反应中的作用。方法 采用免疫组化SABC染色法 ,测定BN→LEW大鼠小肠移植急性排斥反应时 ,外周血及移植肠浸润淋巴细胞中调节性T细胞 :CD4 + 、CD8+ 、CD2 5 + T淋巴细胞及相关细胞因子IL - 4和IFN -γ的表达 ,并与同基因大鼠间小肠移植 (BN→BN)作比较。结果 外周血淋巴细胞分析显示 ,大鼠小肠移植急性排斥反应时 ,以CD4 + CD2 5 + T细胞为主 ,CD8+ 淋巴细胞只占少部分 ;分泌IL - 4的细胞在术后 4、7、14d分别只占 14 .3% ,16 .2 %和 16 .9%。移植肠基底浸润的淋巴细胞以CD4 + 、CD2 5 + 和分泌IFN -γ的淋巴细胞为主。结论 在大鼠同种小肠移植中 ,急性排斥反应与CD2 5 + CD4 + T细胞及Th1相关细胞因子IFN -γ的表达增加相关。而CD8+ T淋巴细胞和Th2相关细胞因子IL-

Aim To explore the role of regulatory T cells in acute allograft rejection in rat heterotopic small intestine transplantation. Methods The immunohistochemical SABC staining was used to analyze the percentage of CD4 +, CD8 +, CD25 + T lymphocyte and IL-4 and IFN-γ expressions in peripheral blood lymphocytes and infiltrating lymphocytes in engrafted small intestine. Rats of syrgenic graft (BN→BN group) were used as control. Results The IHC analysis showed that the CD4 + and CD25 + T lymphocytes predominanced in peripheral blood during acute rejection. The percentage of lymphocytes secreting IL-4 accounted for only 14.3%, 16.2% and 16.9% respectively on the 4th, 7th and 14th days after transplantation. The infiltrating lymphocytes in allograft were mainly CD4 +CD25 + T lymphocytes and the lymphocytes secreting IFN-γ. Conclusion Acute allograft rejection in rat small intestine transplantation was correlated with increase of the CD4 +CD25 + T lymphocytes and Th1 cytokine IFN γ expression, while CD8 +T lympocytes and Th2 cytokine IL 4 may protect the allograft from rejection.