Immunological responses of naturally infected dogs to Type I and II recombinant cysteine proteinases of Leishmania infantum

Evaluation of humoral and cellular immune responses of naturally infected dogs against type I (rCPB) (Recombinant cycsteine proteinase B), and II (rCPA) (Recombinant cycsteine proteinase A) recombinant cysteine proteinases and C-terminal extension (CTE) of Leishmania infantum (L. infantum). In this study, fourteen infected dogs (7 with symptoms, 7 asymptomatics) from an endemic area and three uninfected dogs from a nonendemic region were selected and their humoral and cellular responses against type I and II recombinant cysteine proteinases, C-terminal extension (CTE) and F/T of Leishmania infantum were evaluated using the ELISA and lymphocyte proliferation assay, respectively. The level of specific IgG isotypes (IgG1 and IgG2) and lymphocyte proliferative response against rCPA, rCPB, CTE and Freezed/Thawed lysate (F/T) of L. infantum were examined. The results showed that in both of the symptomatic and asymptomatic dogs there is a high lymphoproliferative response to F/T antigens and moderate responses were observed when rCPs (Recombinant cycsteine proteinase) (rCPA and rCPB) and CTE were used. The level of antibody (total IgG, IgG1 and IgG2) recognition toward rCPA was low in the both groups of the dogs. In contrast, the CTE stimulates similarly as the CPB both of the humoral and cellular responses of all the infected animals and the level.