title: Immunological characterization of the complement regulator factor H-binding CRASP and Erp proteins of Borrelia burgdorferi.
abstract: Complement activation plays an important role in the elimination of invading microorganisms. Borrelia (B.) burgdorferi sensu lato the etiological agent of Lyme borreliosis, can resist complement-mediated killing. The mechanism of complement resistance of B. burgdorferi sensu stricto apparently depends on the expression of several outer surface proteins described as CRASPs (complement regulator-acquiring surface proteins). These borrelial surface proteins are able to bind components of the complement regulatory system, factor H and/or factor H-like protein 1 (FHL-1), two crucial fluid-phase negative regulators of the alternative pathway of complement. It was previously demonstrated that one CRASP is encoded by a member of the erp gene family. The purpose of the study was to use a set of monoclonal antibodies (mAb) and polyclonal antisera to characterize the relatedness of factor H-binding CRASP and Erp proteins among several B. burgdorferi sensu stricto and B. afzelii strains. Based on the observed cross-reactivities between B. burgdorferi sensu stricto strains LW2 and PKa-1, it is concluded that BbCRASP-3 is similar to ErpP, BbCRASP-4 is structurally related to ErpC, and BbCRASP-5 is similar to ErpA. The BaCRASP-2 and BaCRASP-4 proteins of B. afzelii strain EB1 reacted with both anti-ErpA and anti-ErpP antibodies whereas BaCRASP-5 of B. afzelii strain FEM1-D15 exclusively reacted with BbCRASP-3/ErpP specific antibodies. Together, these data indicate that most of the factor H-binding CRASPs are members of the Erp protein family, which represents a polymorphic class of proteins with similar or identical immunological reactivities.
authors.affiliation: Institute of Medical Microbiology, University Hospital of Frankfurt, Frankfurt, Germany. Kraiczy@em.uni-frankfurt.de
authors.forename: Peter
authors.initials: P
authors.lastname: Kraiczy
authors.forename: Kristina
authors.initials: K
authors.lastname: Hartmann
authors.forename: Jens
authors.initials: J
authors.lastname: Hellwage
authors.forename: Christine
authors.initials: C
authors.lastname: Skerka
authors.forename: Michael
authors.initials: M
authors.lastname: Kirschfink
authors.forename: Volker
authors.initials: V
authors.lastname: Brade
authors.forename: Peter F
authors.initials: PF
authors.lastname: Zipfel
authors.forename: Reinhard
authors.initials: R
authors.lastname: Wallich
authors.forename: Brian
authors.initials: B
authors.lastname: Stevenson
mesh_terms: D000942:Antigens, Bacterial / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D025065:Borrelia burgdorferi / Q000276:immunology*; D015748:Borrelia burgdorferi Group / Q000276:immunology*; D017242:Complement Factor H / Q000276:immunology*; D003429:Cross Reactions; D006801:Humans; D015151:Immunoblotting; D008074:Lipoproteins / Q000276:immunology*; D008193:Lyme Disease / Q000276:immunology*; D008565:Membrane Proteins / Q000276:immunology*; D011994:Recombinant Proteins
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C493495:CFH protein, human; D008074:Lipoproteins; D008565:Membrane Proteins; C084998:OspE protein, Borrelia burgdorferi; D011994:Recombinant Proteins; C440651:complement regulator-acquiring surface proteins, Borrelia burgdorferi; D017242:Complement Factor H