大鼠卡氏肺孢子虫肺炎的免疫应答

[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。

IMMUNE RESPONSE IN PNEUMOCYSTIS CARINII PNEUMONIA IN RATS

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-alpha 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-alpha in BALF were reduced. 2. The lowest levels of TNF-alpha 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-alpha and CD4+/CD8+ T cell ratio in rats treated with GC might result in PCP infection under immunosuppressive condition.