不同Th1/Th2细胞免疫应答支气管肺泡灌洗液中细胞学的变化

Changes of cell composition in bronchoalveolar lavage fluid in different Th1/Th2 cell immune response

目的 探讨不同Th细胞优势应答下支气管肺泡灌洗液 (BALF)中的细胞学变化 ,了解Th1/Th2细胞免疫应答的细胞和分子机制。方法 用鸡卵清蛋白 (OVA)致敏Wistar大鼠 (每组 10只 ) ,制作致敏大鼠哮喘模型 ;用”冻干BCG”皮内注射制作BCG免疫大鼠模型。收集BALF并做HE染色 ,进行细胞分类计数。采用流式细胞术 ,测定BALF中 ,CD2 + 、CD2 8+ 及γδTCR+ T细胞占总淋巴细胞的百分率及平均荧光密度 (MIF)。用原位杂交法 ,检测肺组织中IL 4mRNA和IFN γmRNA的表达。用ELISA法检测血清IL 4和IFN γ的浓度。结果 哮喘组BALF中淋巴细胞、嗜酸性粒细胞 (EOS)、浆细胞和中性粒细胞的总数 ,均显著多于正常组 (P <0 .0 1) ;BCG免疫组BALF中 ,淋巴细胞和巨噬细胞的总数也显著高于正常组 (P <0 .0 1)。哮喘组BALF中 ,CD2 + T细胞占淋巴细胞的百分率明显少于正常组 (P <0 .0 1) ,非CD2 + 细胞明显增加。但哮喘组CD2 + T细胞的MFI显著高于正常组及BCG组 (P <0 .0 5 ) ;BCG组BALF中 ,CD2 + T细胞的百分率与正常组相比较无显著差异 (P >0 .0 5 ) ,其CD2 + T细胞的MFI显著高于正常组 (P <0 .0 5 )。哮喘组和BCG组BALF中 ,CD2 8+ 细胞占淋巴细胞的百分率显著多于正常组 (P <0 .0 1) ;BCG组CD2 8+ 细胞的MFI高于哮喘组 (P <0 .0

Aim To explore the changes of cell composition in bronchoalveolar lavage fluid(BALF) in different Th1/Th2 cell immune response. Understand the mechanism of Th1/Th2 cell immune response at cellular and molecular levels. Methods Wistar rats ( n =10, for each group) were sensitized and challenged with ovalbumin to establish an asthmatic model, immunized with BCG vaccine to establish a immunized rat model. Cell composition in the BALF was detected by HE staining. The percentage and mean fluorescence intensity (MFI) of CD2 +, CD28 + and γδTCR + T cells were detected by flow cytometry. The levels of IL 4 and IFN γ were determined by ELISA. The expressions of IL 4 mRNA and IFN γmRNA were determined by in situ hybridization. Results As compared to the control group , the sum of all lymphocytes, eosinophils (EOS), plasmacyte and neutrophils in BALF of asthmatic group significantly increased( P <0.01); the total lymphocytes and macrophages in BALF of the BCG immunized group also increased notably ( P <0.01). The percentage of CD2 + T cells decreased distinctly ( P <0.01), but the number of non CD2 + T cells increased in BALF of asthmatic group. The MFI of CD2 + T cells in BALF of asthmatic group was obviously more than those of control group and BCG immunized group. The percentage of CD2 + T cells had no significant difference ( P >0.05) but the MFI of CD2 + T cells was significantly higher ( P <0.01), compared between BCG immunized group and control group. As compared with control group, the percentage and MFI of CD28 + T cells in BALF of asthmatic group and BCG immunized group significantly increased ( P <0.01), while MFI of BCG immunized group was higher than that of the asthma group. Additionally, in BALF of the asthmatic group and BCG immunized group , the percentage of γδT cells were markedly higher than that in control group ( P <0.01). Conclusion The predominant response of Th2 cells are well related to the increased B lymphocytes, EOS, plasmacytes and neutrophils(they are all antigen presenting cell) as well as the high expression of CD2 + T cells in asthma. The predominant response of Th1 cells has relation to the increased T lymphocytes and macrophages as well as the high expression of CD28 + on T cells in BCG immunized group. γδT cells may also have a pattern of Th1/Th2 cell. They participate in both immunoregulation of BCG vaccine and pathogenesis of asthma, may being a initiatic cell which regulates Th0 cells to differentiate towards Th1/Th2 cells.