大鼠卡氏肺孢子虫肺炎的免疫应答

IMMUNE RESPONSE IN PNEUMOCYSTIS CARINII PNEUMONIA IN RATS

[目的 ]探讨应用糖皮质激素 (GC)诱发大鼠卡氏肺孢子虫肺炎 (Pneumocystiscariniipneumonia ,PCP)的免疫应答。 [方法 ]SD大鼠皮下注射GC建立免疫抑制PCP模型 ,测定外周血淋巴细胞比例、CD4+ T细胞 /CD8+ T细胞比例 ,肺泡灌洗液 (bronchoalveolarlavagefluid ,BALF)中淋巴细胞比例、sIL 2R和TNF α值。 [结果 ]①免疫抑制后外周血淋巴细胞比例、CD4+ T细胞 /CD8+ T细胞比例降低 ,BALF中淋巴细胞比例、TNF α、sIL 2R均降低 ;②BALF中TNF α、外周血CD4+ T细胞 /CD8+ T细胞比值在PCP组中最低 ;③PCP组的BALF中淋巴细胞比例比PC阴性对照组明显升高。 [结论 ]使用GC造成大鼠免疫抑制 ,诱发PC感染后 ,CD4+ 减少及TNF α分泌降低。

Objective] To study the inflammatory immune response to Pneumocystis canii pneumonia(PCP) in rats induced by glucocorticoid(GC).[Methods] The model of PCP was set up by injecting GC subcutanously to SD rats. Lymphocyte proportion in peripheral blood, CD4 +/CD8 + T cell ratio of PBL and lymphocyte proportion in the BALF were measured. The levels of sIL 2R and TNF α in the BALF were detected.[Results]① After the rats were immunospressed, the lymphocyte proportion in the peripheral blood and CD4 +/CD8 + ratio of PBL, and the lymphocyte proportion in the BALF were decreased, and the levels of sIL 2R, TNF α in BALF were reduced. ② The lowest levels of TNF α in BALF and CD4 +/CD8 + T cells of PBL were observed in PCP group; ③ The lymphocyte proportion in the BALF was significantly higher in PCP group than in PC negative group.[Conclusion]The reduction in the level of TNF α and CD4 + /CD8 + T cell ratio in rats treated with GC might result in PCP infection under immunosuppressive condition.