ATTENUATED SALMONELLA AS ADJUVANT IN CANCER VACCINES

VENDRELL A, DI SCIULLO P, GRAVISACO M.J, COLMAN E, RIZZO N, MONGINI C, WALDNER C.

UNIVERSIDADA DE CIENCIAS VETERINARIAS DE TANDIL

Congreso; IV REUNION anual DE SAFE; 2008

SOCIEDAD ARGENTINA DE FARMACOLOFIA

ATTENUATED SALMONELLA AS ADJUVANT IN CANCER VACCINES Vendrell A, Di Sciullo P, Gravisaco M.J, Colman E, Rizzo N, Mongini C, Waldner C. CEFYBO, CONICET-UBA. Paraguay 2155, P16 (CP 1121). Buenos Aires. E- mail: avendrell@fvet.uba.ar. The role of innate immunity in stimulating adaptive immune responses is the basis of the action of adjuvants which are useful in clinical vaccines by promoting a nonspecific pro-inflammatory response to elicit specific host defense. Based on previous studies that demonstrated the ability of Salmonella to elicit an inflammatory Th1 response when it is inoculated by mucosal route, we propose to study the use of an attenuated Salmonella strain as an adjuvant in cancer vaccines to stimulate the innate and modulate the adaptive immune response against tumors. Two times at seven days intervals BALB/c mice were immunized via the orogastric route with 2x109 UFC of CVD915 or PBS (control) using a gavage needle, and simultaneously, 1x106 irradiated LBC tumor cells (LBCi) or PBS were inoculated by intraperitoneal (i.p) injection. Seven days after the second immunization, all groups of animals were challenged i.p with wild-type LBC cells. Mice immunized with bacteria simultaneously with LBCi display a significant increase in the medium survival time respect to PBS-treated mice (p < 0.05, Log rank test). Our findings suggest that immunization with Salmonella in combination with irradiated tumor cells could be a useful strategy for prophylactic vaccination that merits further studies to prove its potential in cancer vaccines.