Immunological characterization of the complement regulator factor H-binding CRASP and Erp proteins of Borrelia burgdorferi

Int J Med Microbiol. 2004 Apr;293 Suppl 37:152-7. doi: 10.1016/s1433-1128(04)80029-9.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antigens, Bacterial / immunology*
  • Bacterial Outer Membrane Proteins / immunology*
  • Bacterial Proteins / immunology*
  • Borrelia burgdorferi / immunology*
  • Borrelia burgdorferi Group / immunology*
  • Complement Factor H / immunology*
  • Cross Reactions
  • Humans
  • Immunoblotting
  • Lipoproteins / immunology*
  • Lyme Disease / immunology*
  • Membrane Proteins / immunology*
  • Recombinant Proteins


  • Antigens, Bacterial
  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • Lipoproteins
  • Membrane Proteins
  • OspE protein, Borrelia burgdorferi
  • Recombinant Proteins
  • complement factor H, human
  • complement regulator-acquiring surface proteins, Borrelia burgdorferi
  • Complement Factor H