THE IMMUNE ENHANCEMENT OF A NEOSPORA CANINUM VACCINE BY A NOVEL SOY LECITHIN/B -GLUCANS BASED ADJUVANT

FLORENCIA CELESTE MANSILLA; DADÍN PRANDO MOORE; OLGA LUCÍA FRANCO-MAHECHA; MARÍA ÁNGELES LAVORIA; ADRIÁN NICOLÁS GIRALDEZ; MARCELA ELVIRA IGLESIAS; MAXIMILIANO WILDA; ALEJANDRA VICTORIA CAPOZZO

Lima

Congreso; InmunoPerú 2012; 2012

Asociación Latinoamericana de Inmunología

Efficient, cost-effective and safe Th1-immunity-inducing vaccine formulations are paramount for achiev-ing protection against Neospora caninum. In this study, a new adjuvant (Providean-AVEC®) was used in the development of a N. caninum vaccine and evaluated in a mouse model. Soluble N. caninum tachy-zoite native protein extract (sNcAg) was selected as vaccine antigen based on its capacity to activate production of pro-inflammatory cytokines on dendritic cells. Vaccines containing 4 and 0.4 _g of sNcAg, and Providean-AVEC®, ISCOM-Matrix or aluminum hydroxide (Alum) were tested in BALB/c mice. While mice vaccinated with 4 _g of sNcAg + Providean-AVEC® developed specific antibodies shortly after the first dose, the rest of the high antigen payload formulations only induced seroconversion after the booster. Mice immunized with the high payload ISCOM vaccine (4 _g sNcAg) or with either low or high payload Providean-AVEC® formulations (0.4 _g and 4 _g sNcAg, respectively) elicited higher IgG2a than IgG1 serum levels, and IFN- _ anamnestic responses with a Th1-cytokine biased profile. These animals had no histological signs of cerebral lesions and parasite burden assessed by quantitative real-time PCR was not detected. Vaccine preparations including Providean-AVEC® as adjuvant limited N. canimum multiplica-tion even with only a tenth of antigen payload compared to vaccines containing other adjuvants. Using adjuvants to specifically activate dendritic cells, combined with a careful antigen selection can enhance cellular responses to inert N. caninum vaccines.