title: Altered antibody responses in mannose-binding lectin-A deficient mice do not affect Trichuris muris or Schistosoma mansoni infections.
abstract: Parasitic helminths possess surface glycoconjugates that are recognized by the serum collectin molecule, mannose-binding lectin (MBL). Once bound, MBL triggers the lectin pathway of complement. Mice have two MBL, MBL-A and MBL-C. We previously showed that MBL-A deficient (MBL-A(-/-)) mice have enhanced survival of Brugia malayi microfilariae and abrogated microfilariae-specific IgM responses. In this study we show that MBL-A deficiency does not alter immunity to either Trichuris muris or Schistosoma mansoni. However, anti-nematode IgM levels were significantly lower in T. muris infected MBL-A(-/-) than wild-type mice. Interestingly nematode-specific IgG1 and IgG2a levels were higher in MBL-A(-/-) mice. Although, larval schistosomes are surrounded by a complement-sensitive membranous tegument, neither adult worm development, egg output, egg granuloma size nor cellular composition was affected in MBL-A(-/-) mice. In contrast to anti-nematode IgM responses, anti-schistosome IgM (and also IgG1 and IgG2b) responses were unaltered from wild-type mice. Anti-schistosome IgG2a was elevated, while IgG3 was significantly lowered, in MBL-A(-/-) mice. These results suggest that MBL-A is not a necessary component for immunity to either T. muris or S. mansoni helminths, however, MBL-A appears to be necessary for the development of specific IgM responses to nematode antigens.
authors.affiliation: Royal Veterinary College, London, UK. rlawrence@rvc.ac.uk
authors.forename: R A
authors.initials: RA
authors.lastname: Lawrence
authors.forename: T
authors.initials: T
authors.lastname: Carter
authors.forename: L V
authors.initials: LV
authors.lastname: Bell
authors.forename: K J
authors.initials: KJ
authors.lastname: Else
authors.forename: J
authors.initials: J
authors.lastname: Summerfield
authors.forename: Q
authors.initials: Q
authors.lastname: Bickle
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood / Q000276:immunology*; D000918:Antibody Specificity; D004198:Disease Susceptibility; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D008297:Male; D037601:Mannose-Binding Lectin / Q000172:deficiency* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D012555:Schistosomiasis mansoni / Q000097:blood / Q000276:immunology*; D014257:Trichuriasis / Q000097:blood / Q000276:immunology*
chemical_list: D000909:Antibodies, Helminth; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D037601:Mannose-Binding Lectin; C069858:mannose binding protein A