IgG1/IgG2 antibody dichotomy in sera of vaccinated or naturally infected dogs with visceral leishmaniosis.
Canine antibody IgG, IgG1 and IgG2 anti-FML responses were investigated in dogs vaccinated with the fucose-mannose ligand (FML)-vaccine of Leishmania donovani and in dogs with naturally acquired visceral leishmaniosis. While similar levels of total IgG antibodies were seen in the seropositive naturally infected dogs and in vaccinees, significant differences between the groups were found regarding their IgG1/IgG2 anti-FML antibody composition (P<0.005). Higher IgG1 absorbencies were seen in infected dogs, while the IgG2 subtype was predominant in pre-immune sera, and in vaccinated animals, both after the first and the third dose (P<0.005). The average ratio between IgG1/IgG2 was then 1.124 for infected animals and 0.733 for FML-vaccinees. Also, a significant increase in IgG2 antibodies was observed from the first to the third vaccine injection (P<0.005). In the infected dogs, a high correlation between their IgG absorbance (Abs) values and the number of symptoms (P=0.017) was disclosed. Thus, the analysis of IgG subclasses disclosed a dichotomous response to visceral leishmaniosis: IgG1 associated to natural infection and IgG2 associated to a humoral response subsequent to the FML-vaccine treatment. An IgG1/IgG2>or=1 would characterize the sera of visceral leishmaniasis infected animals evoluting towards the overt disease while ratios <or=1 would characterize the sera response of vaccinated protected dogs.
Instituto de Microbiologia, "Prof Paulo de Góes", Universidade Federal do Rio de Janeiro (UFRJ), CCS, Cidade Universitária, Ilha do Fundão, CP 68040, CEP 21941-590, Rio de Janeiro, RJ, Brazil.
Carolina
C
de Oliveira Mendes
Edilma
E
Paraguai de Souza
Gulnara Patrícia
GP
Borja-Cabrera
Leopoldina
L
Maria Melo Batista
Miriam
M
Aparecida dos Santos
Luciana
L
Ellner Parra
Ingrid
I
Menz
Marcos
M
Palatnik
Clarisa Beatriz
CB
Palatnik de Sousa
D000818:Animals; D000917:Antibody Formation; D004195:Disease Models, Animal; D004283:Dog Diseases / Q000276:immunology*; D004285:Dogs; D007074:Immunoglobulin G / Q000097:blood* / Q000145:classification; D007132:Immunoglobulin Isotypes / Q000097:blood*; D007898:Leishmaniasis, Visceral / Q000276:immunology / Q000662:veterinary*; D016052:Protozoan Vaccines / Q000276:immunology / Q000627:therapeutic use
D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D016052:Protozoan Vaccines