yersinia enterocolitica serum resistance proteins yada and ail bind the complement regulator c4b-binding protein鼠疫enterocolitica抗血清蛋白质雅达和病痛绑定补充监管机构c4b-binding蛋白质.pdfVIP

Yersinia enterocolitica Serum Resistance Proteins YadA and Ail Bind the Complement Regulator C4b-Binding Protein 1. 1,2. 1. 3 1,2 Vesa Kirjavainen , Hanna Jarva , Marta Biedzka-Sarek , Anna M. Blom , Mikael Skurnik , Seppo Meri1,2* 1 Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland, 2 Helsinki University Central Hospital Laboratory Diagnostics, ¨ ¨ Helsinki, Finland, 3 Department of Laboratory Medicine, Malmo University Hospital, University of Lund, Malmo, Sweden Abstract Many pathogens are equipped with factors providing resistance against the bactericidal action of complement. Yersinia enterocolitica, a Gram-negative enteric pathogen with invasive properties, efficiently resists the deleterious action of human complement. The major Y. enterocolitica serum resistance determinants include outer membrane proteins YadA and Ail. Lipopolysaccharide (LPS) O-antigen (O-ag) and outer core (OC) do not contribute directly to complement resistance. The aim of this study was to analyze a possible mechanism whereby Y. enterocolitica could inhibit the antibody-mediated classical pathway of complement activation. We show that Y. enterocolitica serotypes O:3, O:8, and O:9 bind C4b-binding protein (C4bp), an inhibitor of both the classical and lectin pathways of complement. To identify the C4bp receptors on Y. enterocolitica serotype O:3 surface, a set of mutants expressing YadA, Ail, O-ag, and OC in different combinations was tested for the ability to bind C4bp. The studies showed that both YadA and