Complement factor H binding by different Lyme disease and relapsing fever Borrelia in animals and human
1 Laboratorio de Espiroquetas y Patógenos Especiales, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
2 Unidad de Proteómica, Centro Nacional de Investigaciones Cardiovasculares, Instituto de Salud Carlos III, Madrid, Spain
3 Laboratory of Biomedical Microbiology and Immunology, University of Veterinary Medicine, Kosice, Slovakia
4 Neuroimmunological Institute, Slovak Academy of Sciences (SAS), Bratislava, Slovakia
BMC Research Notes 2009, 2:134 doi:10.1186/1756-0500-2-134Published: 15 July 2009
Borreliae employ multiple immune evasive strategies such as binding to complement regulatory proteins [factor H (fH) and factor H like-1 (FHL1)], differential regulation of surface membrane proteins, antigenic variation, and binding of plasminogen/plasmin and matrix metalloproteinases. As a complement regulatory subunit, fH serves as a cofactor for the factor I-mediated cleavage of C3b. fH binding by Borrelia has been correlated with pathogenesis as well as with host diversity. Here we show the differential binding of borrelial proteins to fH from human and animal sera.
Affinity ligand binding experiments, 2-D electrophoresis, and protein identification and peptide de novo sequencing based on mass spectrometry, revealed novel fH putative binding proteins of Lyme- and relapsing fever Borrelia. An OspA serotype-associated differential human and animal fH binding by B. garinii was also observed, which could be related with the ability of some strains from serotypes 4 and 7 to invade non-nervous system tissues. Also, the variable affinity of binding proteins expressed by different Borrelia to animal fH correlated with their host selectivity.
The novel animal and human putative fH binding proteins (FHBPs) in this study underscore the importance of evasion of complement in the pathogenesis of Borrelia infections.