title: The relapsing fever spirochete Borrelia miyamotoi resists complement-mediated killing by human serum.
abstract: Borrelia miyamotoi, a relapsing fever spirochete transmitted by ixodid ticks, is able to cause infections associated with systemic complaints, including malaise and fever, as well as meningoencephalitis in immunocompromised patients. In order to elucidate immune evasion of previously difficult to cultivate B. miyamotoi, we have examined the ability of this newly emerging human pathogen to escape the complement system. Growth inhibition assays revealed that B. miyamotoi is strongly resistant to complement-mediated bacteriolysis. Investigating complement activation, we found that B. miyamotoi showed reduced deposition of components C3, C5, C7, C8, C9 as well as the membrane attack complex (MAC) on the borrelial surface. In addition, no aberrations in cell morphology were observed after incubation of B. miyamotoi in active human serum, confirming the findings of the growth inhibition assay. The data presented here provide strong evidence that B. miyamotoi overcome human complement by affecting the central complement component C3, thereby inhibiting formation of the C3 convertase and downstream activation of the complement cascade.
authors.affiliation: Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Str. 40, D-60596 Frankfurt, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Teegler
authors.affiliation: Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Str. 40, D-60596 Frankfurt, Germany.
authors.forename: Pia
authors.initials: P
authors.lastname: Herzberger
authors.affiliation: German National Reference Centre for Borrelia, Oberschleissheim, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Margos
authors.affiliation: German National Reference Centre for Borrelia, Oberschleissheim, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Fingerle
authors.affiliation: Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Str. 40, D-60596 Frankfurt, Germany. Electronic address: Kraiczy@em.uni-frankfurt.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Kraiczy
mesh_terms: D000818:Animals; D001898:Borrelia / Q000254:growth & development / Q000276:immunology*; D003176:Complement C3 / Q000276:immunology*; D006801:Humans; D012061:Relapsing Fever / Q000276:immunology* / Q000821:virology
chemical_list: D003176:Complement C3
keywords: Borrelia; Borrelia miyamotoi; Complement; Immune evasion; Spirochetes