CD4 AND CD8 T-CELL RESPONSES TO NEOSPORA CANINUM ANTIGENS FORMULATED WITH IMMUNE STIMULATING COMPLEXES IN PREGNANT HEIFERS

HECKER YP; QUATTROCCHI V; ZAMORANO P; CÓCERES V; ÁNGEL S; ODEÓN A; CAMPERO CM; MOORE DP

Lima

Congreso; Congress of the Latin American Association of Inmunology ALAI 2012; 2012

Latin American Association of Inmunology

The aim of this study was to compare the immune responses to live Neospora-tachyzoites, native antigens and recombinant proteins formulated with ISCOMs in pregnant heifers. To prepare the either the live tachyzoites or the native antigens, the Nc6 strain was used. Eighteen seronegative pregnant heifers were involved: 4 were inoculated intravenously with live tachyzoites (Group A); 4 were inoculated with native antigens formulated with ISCOMs (Group B); 4 were inoculated with a mixture of 4 recombinant proteins plus ISCOMs (Group C); 3 received ISCOMs alone (Group D) and 3 were controls receiving PBS (Group E). The animals were bled weekly to assess total IgG and periodically (days 0, 14, 21, 35, 65, 92, 111 and 121st) to characterize T cells. After vaccination and mating, the animals were challenged using Nc1 strain at day 70th of gestation. Specific antibody titers were similar after the first dose in both Groups A and B but they were higher in Group B after receiving the second dose. There was an interaction through the time for animals in Groups B and C, which showed an increased percentage of CD8+ T cells when comparing days 0 and 14th. A higher proportion of animals from Group C showed an increased CD8+ T cell response at day 21st when comparing animals from Groups D and E. Surprisingly; there was a decrease in both CD4+ and CD8+ T cells when inoculating live parasites.