Cell mediated immunity and specific IgG1 and IgG2 antibody response in natural and experimental canine leishmaniosis

In the present study, we have followed up Leishmania infantum infection in dogs: (1) naturally infected; (2) experimentally infected with amastigotes; and (3) experimentally infected with culture promastigotes. The main objec tive was to evaluate the differences of the humoral and cellular immune res ponses of each group. Sera from 12 beagle dogs were analysed for total anti -leishmanial antibodies and IgG1 and IgG2 subclasses by enzyme-linked immun osorbent assay (ELISA). Lymphoproliferation to L. infantum antigen was also performed. All naturally infected animals were symptomatic with a marked h umoral response. Dogs inoculated with amastigotes were asymptomotic and pre sented lower antibody titres than naturally infected. Dogs inoculated with culture promastigotes were asymptomotic with no significant humoral respons e. Strong proliferative responses to Leishmania antigen was observed in dog s inoculated with promastigotes. In our experimental model, IgG1 antibody l evels presented a similar pattern in all infected animals, and IgG2 reactiv ity was high in naturally infected dogs. (C) 2001 Elsevier Science B.V. All rights reserved.