CYTOKINES LEVELS IN CARUNCLES OF PREGNANT HEIFERS IMMUNIZED WITH EXPERIMENTAL VACCINES AGAINST NEOSPORA CANINUM AND CHALLENGED

HECKER Y.P.; REGIDOR-CERRILLO J; VERNA A.; MORRELL E.; ORTEGA-MORA LM; ODEÓN A.; CAMPERO C.M.; MOORE D.P.

Mar del Plata

Congreso; X Congreso Argentino de Protozoología y Enfermedades Parasitarias; 2014

Sociedad Argentina de Protozoología

The aim of the present study was to evaluate the immune response in maternal-fetal interface of pregnant cattle immunized with a live and two inactivated experimental vaccines against Neospora caninum and then challenged.Twenty pregnant heifers were divided in 5 groups of 4 animals, each receiving different inoculation before mating: group A animals were intravenously (iv) inoculated with 6.25×107 live tachyzoites of the NC-6 strain, group B heifers were inoculated twice subcutaneously (sc) with N. caninum native antigen extract formulated with ISCOMs; group C heifers were sc inoculated twice with three recombinant proteins (rNcSAG1, rNcHSP20, rNcGRA7) formulated with ISCOMs; group D were sc injected with sterile phosphate-buffered saline (PBS) and group E heifers received sc ISCOM-matrix (without antigen). All groups were iv challenged with the NC-1 strain at 70 days of gestation and were slaughtered at day 104 of gestation. Cytokine levels (IFN-γ, IL-4, IL-10, IL-12 and TNF-α) were measured using real-time reverse transcription-PCR. In the present study was found significantly low levels of IFN-γ, IL-4, IL-10, IL-12 and TNF-α mRNA levels in group A in relation to group B, C, D and E (P<0.05). In contrast, cytokine mRNA levels showed a high levels of IFN-γ, IL-12p40 and TNF-α, which are representatives of Th1 response, and increased mRNA levels of Th2 (IL-4) and regulatory cytokines (IL-10), confirming a mixed Th1 and Th2 pattern in N. caninum-infected caruncles in group B, C, D and E. There were not differences among these last four groups (P>0.05). These findings indicated that in group A there was not active immune response in caruncles. Possibly the solid immune response developed in dams that received live tachyzoites (group A) avoided the arrival of N. caninum to materno-fetal interface. On the other hand, in group B and C were observed similar levels of cytokines to group D and E indicating the failed to induce memory response against experimental challenge.