Although several PFam54 members play an important role in the pathogenesis of Lyme disease, the exact function has been determined only for CspA, which binds complement regulator factor H (CFH) and factor H-like protein 1 (FHL-1); thus, CspA is essential to resist the vertebrate host's immune response.
The aim of this study was to select genes related to the alternative pathway of the complement system [including complement factor H (CFH)], differentiating the type of infection in the system model, that is, a culture of normal human diploid fibroblasts infected with three different spirochaete genospecies: Borrelia afzelii, Borrelia garinii and Borrelia burgdorferii sensu stricto, by comparing the infected fibroblast culture with the control fibroblast one.
Identification and characterization of the factor H and FHL-1 binding complement regulator-acquiring surface protein 1 of the Lyme disease spirochete Borrelia spielmanii sp. nov.
The goals of this study were to assess the ligand binding capability of CspZ orthologs derived from an extensive panel of human Lyme disease isolates and to further define the molecular basis of the interaction between FH and CspZ.
Dual binding specificity of a Borrelia hermsii-associated complement regulator-acquiring surface protein for factor H and plasminogen discloses a putative virulence factor of relapsing fever spirochetes.
Functional characterization of BbCRASP-2, a distinct outer membrane protein of Borrelia burgdorferi that binds host complement regulators factor H and FHL-1.
Immunological and molecular analyses of the Borrelia hermsii factor H and factor H-like protein 1 binding protein, FhbA: demonstration of its utility as a diagnostic marker and epidemiological tool for tick-borne relapsing fever.
Evidence that the BBA68 protein (BbCRASP-1) of the Lyme disease spirochetes does not contribute to factor H-mediated immune evasion in humans and other animals.
In the present study we have elucidated the putative potential of other members of the gbb54 paralogous family, including orthologs ZSA66, ZSA69, ZSA70, ZSA71, ZSA72 and ZSA73 of the European B. burgdorferi s.s. strain ZS7, to bind human FHL-1 and factor H. In spite of their overall similarity in protein sequence, between 47% and 67%, and the fact that the C-terminal region of ZSA69 shows 70% similarity with BbCRASP-1, none of the orthologous proteins was able to bind human FHL-1 and/or factor H. BbCRASP-1 is the only member of the paralogous gene family gbb54 that binds to human complement regulators, supporting the notion that BbCRASP-1 plays a critical role in evasion of complement by B. burgdorferi s.s. and thus may be helpful in the development of novel therapeutic strategies against Lyme borreliosis.
Complement resistance of Borrelia burgdorferi correlates with the expression of BbCRASP-1, a novel linear plasmid-encoded surface protein that interacts with human factor H and FHL-1 and is unrelated to Erp proteins.
Complement inhibitor factor H binding to Lyme disease spirochetes is mediated by inducible expression of multiple plasmid-encoded outer surface protein E paralogs.