title: Contribution of the outer membrane protein OmpW in Escherichia coli to complement resistance from binding to factor H.
abstract: The serum complement system is essential for innate immune defense against invading pathogenic bacteria. Some of the 8-stranded β-barrel outer membrane proteins confer bacterial resistance to the innate host immunity. We have previously demonstrated that OmpW, also an 8-stranded β-barrel protein that was identified a decade ago, protects bacteria against host phagocytosis. In this study, we investigated the complement resistance of OmpW. Our results indicate that the upregulation of OmpW is associated with increased survival when bacteria are exposed to normal human sera (NHS). Mutant bacteria lacking OmpW in NHS exhibited significantly lower survival rates in comparison to wild-type and ompW complemented bacteria. Furthermore, the bacterial survival significantly decreased in NHS that was supplemented with EGTA-Mg(2+) compared to that in NHS supplemented with EDTA. These results suggest that OmpW confer resistance to alternative complement pathway-mediated killing. Moreover, the binding of OmpW to factor H, a major inhibitor of alternative pathway, was found, indicating that OmpW recruitment of factor H is a mechanism for bacterial evasion of complement attack.
authors.affiliation: School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China.
authors.forename: Weiyan
authors.initials: W
authors.lastname: Li
authors.affiliation: School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China.
authors.forename: Liangyou
authors.initials: L
authors.lastname: Wen
authors.affiliation: School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China.
authors.forename: Chuchu
authors.initials: C
authors.lastname: Li
authors.affiliation: School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Chen
authors.affiliation: School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China.
authors.forename: Zhicang
authors.initials: Z
authors.lastname: Ye
authors.affiliation: School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.affiliation: School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China. Electronic address: jianyi.pan@zstu.edu.cn.
authors.forename: Jianyi
authors.initials: J
authors.lastname: Pan
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D001770:Blood Bactericidal Activity; D017242:Complement Factor H / Q000378:metabolism*; D051056:Complement Inactivating Agents; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D055786:Gene Knockout Techniques; D005816:Genetic Complementation Test; D006801:Humans; D057131:Immune Evasion; D007155:Immunologic Factors / Q000378:metabolism*; D050296:Microbial Viability; D011485:Protein Binding
chemical_list: D001425:Bacterial Outer Membrane Proteins; D051056:Complement Inactivating Agents; D029968:Escherichia coli Proteins; D007155:Immunologic Factors; C064035:ompW protein, E coli; D017242:Complement Factor H
keywords: Alternative pathway; Complement; Factor H; Outer membrane protein OmpW; β-barrel