Impact of adjuvant formulation in cancer immunotherapy

GUSTAVO CARRIZO, ENRIQUE CORAPI, DANIEL COMPAGNO & DIEGO LADERACH

Mar del Plata

Congreso; Reunión Anual Sociedad Argentina de Inmunología 2016; 2016

IMPACT OF ADJUVANT FORMULATION IN CANCER IMMUNOTHERAPYGustavo Carrizo, Enrique Corapi, Daniel Compagno & Diego LaderachLaboratorio de Glico-Oncología Molecular y Funcional, IQUIBICEN-CONICET, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires.Worldwide, cancer is a major cause of human suffering and death. The lack of effective treatments has led to exploring new options; cancer immunotherapy has been proposed as a breakthrough. However, our knowledge about the fine conditions to induce an immune response within a tumor microenvironment is still in its infancy. In this respect, much of our current proposals have been inspired from responses against pathogens. In particular, it is well known that the type and the concentrations of adjuvants used in infection-protective immunization protocols induce immune effector functions, but, concomitantly, a burst of regulatory T cells that could be counterproductive for the proposal. The main goal of this study was to evaluate different adjuvant formulations comparing their potential to induce anti-tumor immunity vs Treg expansion. Results from our laboratory propose Galectin-1 as a tumor associated antigen since it is highly expressed on tumor cells. The relevance of the adjuvants was demonstrated by immunization against a Gal-1-derived peptide which causes a delayed tumor (B16-F10) emergence only when the combinatorial 25uM CpG and 900mM Poly-U-PEI was used. To evaluate the impact of adjuvant on effector vs Tregs, we quantify total lymph node cells, total CD4+ and CD8+T cells and Tregs obtained at different doses of combinatorial adjuvants. Our results show a clear burst of effector and Treg populations at higher adjuvant doses, while at lower doses we obtained a moderate lymphocyte expansion but no burst of Tregs (p