Galectin-1 as a target for prostate cancer immunotherapy.

GERALDINE CONTRUFO, FELIPE MARTÍN JAWORSKI, LUCAS DANIEL GENTILINI, IGNACIO GONZÁLEZ PÉREZ, DANIEL GEORGES COMPAGNO AND DIEGO LADERACH

Mar del Plata

Congreso; Reunión Anual Sociedad Argentina de Inmunología (SAI) 2014; 2014

SAI

Worldwide, Prostate Cancer (PCa) is one of the most frequent cancers in adult men. The lack of effective treatments has led the scientific community to explore new alternatives such as immunotherapy. It is believed that immunization with 8-to-10-mer peptides containing subdominant epitopes may activate CD8+ T lymphocyte clones capable of recognizing tumor-associated antigens, induce tumor-specific cytotoxicity and bypass tolerance mechanisms. Galectin-1 (Gal-1), a β-galactoside-binding protein, is highly overexpressed in tumor cells. Our group has demonstrated its expression increases throughout human PCa progression, playing key roles in this process. We hypothesized that immunization with Gal-1-derived peptides may induce an immune response capable of modulating prostate tumor growth. Adult male C57BL/6 mice were immunized s.c. as follows: 3 injections of an immunomodulatory oligonucleotide (CpG-1826) followed by 2 injections of the Gal-1-derived peptide together with the Pan DR T helper epitope (PADRE). Immunized mice were challenged s.c. with syngenic TRAMP-C1 prostate tumor cells and tumor growth was subsequently assessed. We found that immunization with two of the essayed peptides were capable to reduce tumorigenicity (p