title: Studies of the binding of ficolin-2 and ficolin-3 from the complement lectin pathway to Leptospira biflexa, Pasteurella pneumotropica and Diarrheagenic Escherichia coli.
abstract: Ficolins recognize pathogen associated molecular patterns and activate the lectin pathway of complement system. However, our knowledge regarding pathogen recognition of human ficolins is still limited. We therefore set out to explore and investigate the possible interactions of the two main serum ficolins, ficolin-2 and ficolin-3 with different Gram-negative bacteria. We used recombinant ficolin molecules and normal human serum, which were detected with anti-ficolin monoclonal antibodies. In addition we investigated the capacity of these pathogens to activate the lectin pathway of complement system. We show for the first time that human ficolin-2 recognizes the nonpathogenic spirochete Leptospira biflexa serovar Patoc, but not the pathogenic Leptospira interrogans serovar Kennewicki strain Fromm. Additionally, human ficolin-2 and ficolin-3 recognize pathogenic Pasteurella pneumotropica, enteropathogenic Escherichia coli (EPEC) serotype O111ab:H2 and enteroaggregative E. coli (EAEC) serogroup O71 but not four enterohemorrhagic E. coli, three EPEC, three EAEC and two nonpathogenic E. coli strains (DH5α and HB101). The lectin pathway was activated by Pasteurella pneumotropica, EPEC O111ab:H2 and EAEC O71 after incubation with C1q depleted human serum. In conclusion, this study provide novel insight in the binding and complement activating capacity of the lectin pathway initiation molecules ficolin-2 and ficolin-3 towards relevant Gram-negative pathogens of pathophysiological relevance.
authors.affiliation: Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Mexico.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Sahagún-Ruiz
authors.affiliation: Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Brazil.
authors.forename: Leandro Carvalho Dantas
authors.initials: LC
authors.lastname: Breda
authors.affiliation: Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Brazil.
authors.forename: Mónica Marcela Castiblanco
authors.initials: MM
authors.lastname: Valencia
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, Brazil.
authors.forename: Waldir P
authors.initials: WP
authors.lastname: Elias
authors.affiliation: Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Lea
authors.initials: L
authors.lastname: Munthe-Fog
authors.affiliation: Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Garred
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, Brazil.
authors.forename: Angela Silva
authors.initials: AS
authors.lastname: Barbosa
authors.affiliation: Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Brazil. Electronic address: louisaac@icb.usp.br.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Isaac
mesh_terms: D037582:Complement Pathway, Mannose-Binding Lectin / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D037102:Lectins / Q000276:immunology*; D007919:Leptospira / Q000276:immunology*; D044142:Pasteurella pneumotropica / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D000097604:Ficolins
chemical_list: D006023:Glycoproteins; D037102:Lectins; D011994:Recombinant Proteins; D000097604:Ficolins; C109662:FCN3 protein, human
keywords: Bacteria; Complement system; Ficolin; Innate immunity; Lectin pathway