Han Xiaobing, Fan Yijun, Wang Shuhe, Yang Jie, Bilenki Laura, Qiu Hongyu, Jiao Lei, Yang Xi
Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
Eur J Immunol. 2004 Apr;34(4):981-9. doi: 10.1002/eji.200324387.
Our previous study has shown that Chlamydia lung infection can inhibit local eosinophilic inflammation induced by allergen sensitization and challenge, which is correlated with altered cytokine production. In the present study, we examined the role played by dendritic cells (DC) in chlamydial infection-mediated modulation of allergic responses. The results showed that DC freshly isolated from Chlamydia-infected mice (iIDC), unlike those from naive control mice (iNDC), could efficiently modulate immune responses to ovalbumin in vitro and in vivo. Co-culture of freshly isolated DC with naive CD4 cells from T cell receptor transgenic mice (DO11.10) showed that iIDC directed Th1-dominant, while iNDC directed Th2-dominant, allergen-specific CD4 T cell responses. Moreover, adoptive transfer of iIDC, but not iNDC, could inhibit systemic and local eosinophilia induced by allergen exposure. The reduction of eosinophilia was associated with a decrease in IL-5 receptor expression on bone marrow cells and the production of IL-5 and IL-13 by T lymphocytes. Analysis of the DC showed that iIDC expressed significantly higher levels of mRNA for Toll-like receptor 9 and produced more IL-12 compared to iNDC. The data demonstrate a critical role played by DC in infection-mediated inhibition of allergic responses.
我们之前的研究表明，衣原体肺部感染可抑制变应原致敏和激发所诱导的局部嗜酸性粒细胞炎症，这与细胞因子产生的改变相关。在本研究中，我们检测了树突状细胞（DC）在衣原体感染介导的变应性反应调节中所起的作用。结果显示，与来自未感染对照小鼠的DC（iNDC）不同，从衣原体感染小鼠新鲜分离的DC（iIDC）在体外和体内均能有效调节对卵清蛋白的免疫反应。将新鲜分离的DC与来自T细胞受体转基因小鼠（DO11.10）的未致敏CD4细胞共培养显示，iIDC引导Th1主导的变应原特异性CD4 T细胞反应，而iNDC引导Th2主导的反应。此外，iIDC而非iNDC的过继转移可抑制变应原暴露所诱导的全身和局部嗜酸性粒细胞增多。嗜酸性粒细胞增多的减少与骨髓细胞上IL-5受体表达的降低以及T淋巴细胞产生IL-5和IL-13的减少相关。对DC的分析显示，与iNDC相比，iIDC Toll样受体9的mRNA表达水平显著更高且产生更多的IL-12。这些数据证明了DC在感染介导的变应性反应抑制中起关键作用。
