Xi Jin, Pan Zhi-qiang, Jie Ying, Liu Li-min, Wang Li
Beijing Tongren Eye Center, Capital University of Medical Sciences, Beijing 100730, China.
Zhonghua Yan Ke Za Zhi. 2007 Dec;43(12):1114-8.
To explore the expression of CD4+CD25+ regulatory T cells in corneal graft, in the iris and peripheral blood in the high risk rat corneal transplant tolerance induced by superantigen staphylococcal enterotoxin B (SEB).
A high risk rat penetrating corneal transplantation model was established, whereas SD rat donor corneas were implanted into Wistar rat recipients. The recipient rats were divided into two groups. Group control and group SEB had intraperitoneal injection of normal saline solution or SEB (75 microg/kg), respectively. Orthotopic corneal transplantation was performed 1 day after the injection. The corneal graft survival time was evaluated. The expression of CD4+CD25+ T cells in corneal grafts and the iris was evaluated by immunohistochemical staining. The percentage of CD4+CD25+ regulatory T cells in peripheral blood was determined by flow cytometry.
Corneal graft mean survival time was (11.63+/-2.83) d in group control and (14.13+/-0.99) d in group SEB. The difference of survival time between these two groups was statistically significant (P<0.05). Histopathology showed remarkable inflammatory cells infiltration in the rejected grafts. The intensity of the infiltration was compatible with the severity of rejection reaction. Immunohistochemical staining of grafts showed that the CD4+CD25+ regulatory T cells were expressed in rejected grafts in both groups 20 days after the surgery, but not before the surgery. The iris whole mount staining showed that before the surgery, no expression of CD4+CD25+ regulatory T cells was observed in group control but relatively remarkable expression was observed in group SEB. Twenty days after the transplantation, CD4+CD25+ regulatory T cells were observed in both groups while group SEB had more pronounced expression. Peripheral blood flow cytometry analysis revealed that the mean percentages of CD4+CD25+ regulatory T cells were stable before and after surgery in group control. However, in group SEB, an increase shift appeared and followed by a decrease to normal level 20 d after the surgery.
CD4+CD25+ regulatory T cells take part in immune tolerance in rat immune tolerance induced by superantigen SEB in high risk rat corneal transplantation.
探讨超抗原金黄色葡萄球菌肠毒素B（SEB）诱导高风险大鼠角膜移植免疫耐受过程中，角膜植片、虹膜及外周血中CD4+CD25+调节性T细胞的表达情况。
建立高风险大鼠穿透性角膜移植模型，将SD大鼠供体角膜植入Wistar大鼠受体。受体大鼠分为两组，对照组和SEB组分别腹腔注射生理盐水或SEB（75μg/kg）。注射1天后行原位角膜移植，评估角膜植片存活时间。采用免疫组织化学染色法评估角膜植片和虹膜中CD4+CD25+T细胞的表达。通过流式细胞术检测外周血中CD4+CD25+调节性T细胞的百分比。
对照组角膜植片平均存活时间为（11.63±2.83）天，SEB组为（14.13±0.99）天。两组存活时间差异有统计学意义（P<0.05）。组织病理学显示，排斥反应的植片中可见明显的炎性细胞浸润，浸润强度与排斥反应的严重程度相符。植片免疫组织化学染色显示，术后20天两组排斥反应的植片中均有CD4+CD25+调节性T细胞表达，而术前无表达。虹膜全层染色显示，术前对照组未观察到CD4+CD25+调节性T细胞表达，而SEB组表达相对明显。移植后20天，两组均观察到CD4+CD25+调节性T细胞，SEB组表达更显著。外周血流式细胞术分析显示，对照组术后CD4+CD25+调节性T细胞平均百分比术前术后稳定。然而，SEB组术后出现升高，术后20天降至正常水平。
在高风险大鼠角膜移植中，超抗原SEB诱导的大鼠免疫耐受过程中，CD4+CD25+调节性T细胞参与免疫耐受。
