超抗原SEB诱导大鼠高危角膜移植免疫耐受淋巴细胞差异表达基因的研究

Gene disparity of lymphocytes in immune tolerance rats with high-risk corneal transplantation induced by Staphylococcal Enterotoxin B

目的应用基因芯片研究高危角膜移植中产生免疫耐受和发生排斥反应的受体大鼠淋巴细胞的差异基因。方法供体和受体分别为Fisher344和Lewis大鼠。受体大鼠随机分为2组,治疗组术前腹腔注射0·2ml SEB(75μg/kg),每次间隔4d,共3次。对照组注射生理盐水。缝线法建立高危角膜移植动物模型。术后研究受体植片存活时间、免疫状态和淋巴细胞差异基因。结果对照组植片平均存活时间为(7·30±0·67)d,治疗组为(12·50±1·41)d,(P<0·05)。治疗组淋巴细胞对ConA和供体淋巴细胞抗原的增生反应明显降低,DTH反应强度也明显降低。基因芯片显示两组淋巴细胞存在23个差异基因,与神经系统、肿瘤生长以及编码酶类有关。结论SEB可诱导高危角膜移植免疫耐受,相关淋巴细胞差异基因的作用需进一步研究。

Objective Staphylococcal enterotoxin B （SEB） is a superantigen derived from bacterium and could induce tolerance in corneal transplantation,but the mechanism was still not clear. The study was to examine the gene disparity in the recipient＇ s lymphocytes in rats with high-risk corneal transplantation immune tolerance induced by SEB. Methods Twelve Fisher 344 rats were used as donors and 24 Lewis rats were used as recipients. Corneal neovaseularization was induced by sutures. All the rats were divided randomly into two groups. 0. 2 ml SEB （75μg/kg） was injected intraperitoneally at a 4-day interval for 3 times in SEB-treated rats before keratoplasty ,and the control rats received saline buffer in the similar fashion. All the allografts were observed and scored for 30 days. The proliferation ability of the lymphocytes and delayed-type hypersensitivity （DTH） reaction of recipients were measured. Different gene expressions in the spleen lymphocytes between control group and SEB-treated group were identified with the Oligo gene chip. Results The mean survival time of corneal grafts in control rats was （7.30 ± 0. 67）days,while that in the SEB-treated rats was （12. 50 ± 1.41 ） days,showing a marked difference between these two groups（ P 〈 0. 05）. The proliferation ability of lymphocytes was weakened and the DTH reaction was also significantly reduced in SEB-treated rats in comparison with control rats,indicating the forming of immune tolerance in SEB-treated rats. Gene chip showed that there were about 23 different genes between the SEB-treated rats and the control rats. These genes had an extensive distribution, including some relevant genes to the nervous system, tumor growth, and enzymes coding. Conclusion SEB could induce immune tolerance in rats and prolong the survival time of allografts in rats with high-risk corneal transplantation. SEB had significant regulatory function on a wide variety of genes of the lymphocytes, but their function in treating high-risk corneal transplantation needs to be further elucidated.