Torres Alfredo G, Li Yongguo, Tutt Christopher B, Xin Lijun, Eaves-Pyles Tonyia, Soong Lynn
Department of Microbiology and Immunology, 301 University Blvd., University of Texas Medical Branch, Galveston, Texas 77555-1070, USA.
Infect Immun. 2006 May;74(5):2676-85. doi: 10.1128/IAI.74.5.2676-2685.2006.
Outer membrane protein A (OmpA) is located in the membrane of Escherichia coli and other gram-negative bacteria and plays a multifunctional role in bacterial physiology and pathogenesis. In enterohemorrhagic E. coli (EHEC), especially serotype O157:H7, OmpA interacts with cultured human intestinal cells and likely acts as an important component to stimulate the immune response during infection. To test this hypothesis, we analyzed the effect of EHEC OmpA on cytokine production by dendritic cells (DCs) and on DC migration across polarized intestinal epithelial cells. OmpA induced murine DCs to secrete interleukin-1 (IL-1), IL-10, and IL-12 in a dose-dependent manner, and this effect was independent of Toll-like receptor 4. Although DCs displayed differential responses to EHEC OmpA and OmpA-specific antibodies enhanced DC cytokine secretion, we cannot discard that other EHEC surface elements were likely to be involved. While OmpA was required for bacterial binding to polarized Caco-2 cells, it was not needed for the induction of cytokine production by Caco-2 cells or for human DC migration across polarized cells.
外膜蛋白A（OmpA）位于大肠杆菌和其他革兰氏阴性菌的细胞膜中，在细菌生理学和发病机制中发挥着多功能作用。在肠出血性大肠杆菌（EHEC）中，尤其是血清型O157:H7，OmpA与培养的人肠道细胞相互作用，并且可能在感染期间作为刺激免疫反应的重要成分。为了验证这一假设，我们分析了EHEC OmpA对树突状细胞（DCs）细胞因子产生的影响以及对DCs跨极化肠上皮细胞迁移的影响。OmpA以剂量依赖性方式诱导小鼠DCs分泌白细胞介素-1（IL-1）、IL-10和IL-12，并且这种效应不依赖于Toll样受体4。尽管DCs对EHEC OmpA表现出不同的反应，且OmpA特异性抗体增强了DC细胞因子的分泌，但我们不能排除其他EHEC表面元件可能也参与其中。虽然OmpA是细菌与极化的Caco-2细胞结合所必需的，但它对于Caco-2细胞诱导细胞因子产生或人DCs跨极化细胞迁移并非必需。
