呼吸道合胞病毒感染的大鼠气道上皮细胞对树突状细胞的影响

目的探索呼吸道合胞病毒(RSV)感染的气道上皮细胞对大鼠髓系树突状细胞(mDCs)激活和功能的影响,为研究RSV诱发哮喘的机制提供依据。方法大鼠气道上皮细胞株进行培养。在对RSV进行扩增和滴度测定后,以不同作用时间、不同滴度的RSV感染大鼠气道上皮细胞。同时分离、培养扩增大鼠mDCs,采用transwell细胞共培养系统将大鼠气道上皮细胞和大鼠mDCs共培养。其mDCs通过RT-PCR和流式细胞术检测成熟标志物和Th2细胞因子的表达、同种异体混合淋巴细胞反应(MLR)。结果大鼠mDCs与RSV感染的大鼠气道上皮细胞共培养后出现功能性成熟,包括大鼠mDCs表面共刺激分子MHCⅡ和CD86的表达增多,OX40L和TARC的mRNAs表达增高,大鼠mDCs刺激T细胞增殖的能力增强。结论 RSV感染大鼠气道上皮细胞能够促使大鼠mDCs进一步成熟并且可能具有支持Th2细胞分化和局部聚集的能力,可能是RSV诱发哮喘的一种机制。

RSV-Stimulated Rat Airway Epithelial Cells Activate Myeloid Dendritic Cells

Objective Respiratory syncytial virus（RSV） is a primary cause of lower respiratory tract infections in children,and is also the cause for the development of asthma primarily in infants.However,the immunological mechanisms by which RSV enhances allergic sensitization and asthma remain unclear.The aim of this study was to examine the influence of RSV-infected airway epithelial cells on the activation and functions of rat myeloid dendritic cells（mDCs）.Methods Rat airway epithelial cells（RAECs） were infected by RSV.Then RSV-infected RAECs were co-cultured with rat mDCs,and the expression of cytokine and maturation markers on mDCs were examined by real time PCR and flow cytometry.To confirm this functional mDC maturation,allergenic mixed lymphocyte reaction（MLR） were performed.Results We found that functional maturation of mDCs was induced by RSV-treated RAECs,as shown by their enhanced levels of OX40L and thymus-and activation-regulated chemokine（TARC） mRNAs,which increased the expressions of major histocompatibility complex II（MHCII） and CD86 costimulatory molecules and promoted T-cell proliferation in mixed lymphocyte reactions.Conclusion Our results suggest that RSV-infected epithelial cells promote the maturation of mDCs that might support Th2 cell polarization and contribute to the pathogenesis of asthma.