Cellular and molecular basis of antitumor response associated with parasite antigens

FARRÉ, CECILIA; CAMBRONERA, PAULA; BISCARI, LUCÍA; COCORDANO, NABILA; ALLOATTI, ANDRÉS

Congreso; LXVII Reunión Anual de la Sociedad Argentina de Inmunología; 2019

SAI

In recent years, immunotherapy has emerged as a promising line of research in the development of antitumor treatments, whose purpose is to restore and/or enhance the ability of the immune system to effectively combat neoplastic cells. It has long been known that parasitic infections may affect tumor growth. In particular, Trypanosoma cruzi (causative agent of Chagas disease) presents a series of antigens with antiangiogenic and antitumor properties.Among the possible reasons why parasitic antigens derived from T. cruzi could interfere with tumor growth, both innate and adaptive immunity might participate. However, cellular and molecular bases of this process are still unknown. Our preliminary results suggest that BALB/c mice infected with T. cruzi show delayed growth of 4T1 tumor, associated with an increase in cellular immunity.To elucidate the mechanisms involved, we immunized BALB/c mice with antigen formulations (protein concentration: 1mg/ml) derived from: T. cruzi epimastigotes; T. cruzi tripomastigotes; 4T1 tumor cells or PBS as control. Additionally, we planned two different experimental schemes, immunizing mice before (prophylactic approach) and after (therapeutic) tumor inoculation (n=7 for each group). Whereas the therapeutic approach did not show significant differences with the control group, the prophylactic scheme (in particular antigen formulations of parasite origin) significantly delayed tumor growth and increased survival. Differences were also significant when analyzing percentages of CD8+ T cells in spleen (p