Borrelia burgdorferi inhibits human neutrophil functions.
Outer surface proteins OspA and OspB are among the most prominent Borrelia burgdorferi surface molecules. We constructed OspAB and OspA complementation mutants of B. burgdorferi Osp-less strain B313 and investigated the role of these surface proteins in the interactions of B. burgdorferi, human neutrophils and the complement system. We found that (1) OspB inhibits the phagocytosis and oxidative burst of human neutrophils at low serum concentrations, whereas OspA induces the oxidative burst in neutrophils; (2) OspB may have an inhibiting role in serum sensitivity and complement activation; (3) all studied strains inhibit the chemotaxis of human neutrophils specifically towards fMLP but not towards C5a, regardless of their Osp expression. These results suggest that although OspA and OspB are co-ordinately transcribed, they differ in their effects on human neutrophil functions. Our findings suggest that B. burgdorferi exploits a wide variety of immune evasion mechanisms, besides previously documented complement resistance, to survive in the vertebrate host.
Hartiala
Pauliina
P
Department of Medical Microbiology, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland. pauliina.hartiala@utu.fi
Hytönen
Jukka
J
Suhonen
Juha
J
Leppäranta
Outi
O
Tuominen-Gustafsson
Helena
H
Viljanen
Matti K
MK
D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology; D000954:Antigens, Surface / Q000235:genetics / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology; D025065:Borrelia burgdorferi / Q000235:genetics / Q000276:immunology*; D002464:Cell Migration Inhibition / Q000276:immunology; D003165:Complement System Proteins / Q000276:immunology; D017353:Gene Deletion; D006801:Humans; D008074:Lipoproteins / Q000235:genetics / Q000276:immunology; D009504:Neutrophils / Q000276:immunology* / Q000382:microbiology*; D010587:Phagocytosis / Q000276:immunology; D016897:Respiratory Burst / Q000276:immunology
D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D008074:Lipoproteins; C072045:OspA protein; C077030:OspB protein, Borrelia burgdorferi; D003165:Complement System Proteins