AN ORAL-SALMONELLA CANCER IMMUNOTHERAPY INDUCES A TUMOR-SPECIFIC IMMUNE RESPONSE IN LIVER AND LIVER DRAINING LYMPH NODES

ALEJANDRINA VENDRELL; MARÍA J. GRAVISACO; JUAN C. GOIN; ANDREA CANELLADA; CLAUDIA MONGINI; CLAUDIA I. WALDNER

Medellín

Congreso; 11th Congress of the Latin American Association of Immunology - 10o. Congreso de la Asociación Colombiana de Alergia, Asma e Inmunología,; 2015

Asociación Latino Americana de Inmunología (ALAI)

Previously, we showed that oral administration of the Salmonella Typhi vaccine strain CVD 915 before tumor challenge decreases the development of liver metastasis in a mouse model of breast cancer (LM3 mammary adenocarcinoma). The aim of the present work was to elucidate the immune mechanisms involved in the therapeutic effect of CVD 915 and characterize the antitumor immune response in the liver and liver draining lymph nodes (LDLN). For this purpose, one group of BALB/c mice was inoculated with 1e9 UFC of CVD 915 via o.g. while another received PBS as a control. After 24 h, mice were injected with 1e5 LM3 cells into the spleen to mimic hematogenous spread of tumor cells into the liver, and subjected to splenectomy. To further characterize antitumor mechanisms, livers and its main draining nodes were sampled 20 days after tumor challenge and phenotypical and functional analyses on these organs were performed. As we demonstrated previously for the intrahepatic immune cells (IHIC), LDLN cells from treated mice produced large amount of Th1 cytokines, such as IFN-γ, TNF-α and IL-2 ex vivo, while control mice produced low amounts of TNF-α and no detectable levels of IFN-γ and IL-2. IFN-γ and TNF-α levels generated by LDLN cells from treated animals increased in the presence of tumor cell antigens (p