The IL17RA/IL17 pathway sustain the induction of effector and memory cytotoxic T cell responses against tumors

C RODRIGUEZ; F CANALE; S BOCCARDO; EV ACOSTA RODRIGUEZ; J TOSELLO BOARI; CG BECCARIA; A GRUPPI; C ARAUJO FURLAN; S BOSSIO; C MONTES

Cancún, Quintana Roo

Congreso; XII Congress of the Latin American Association of Immunology and XXIII Congress of the Mexican Society of Immunology; 2019

17 cytokines play important roles in protecting the host against extracellular pathogens and promoting inflammatory pathology in autoimmune diseases (1). In cancer, several reports have shown that IL-17 can have both anti- and pro-tumoral effects (2). However, the particular mechanism that determines its tumor promoting or suppressive functions in a given tumor are not known yet. Previously, our team and others demonstrated that IL-17 family plays a central role in the induction of CD8+ T cell (CTL) and NK responses (3). As these subsets are critical for tumor resistance, we evaluated the role of IL-17 signaling in the induction of the anti-tumoral CTL immunity and tumor progression. To this end, B6 (WT), IL-17RA KO (RKO) and IL-17A/F double KO (DKO) mice were injected with tumor cell lines exhibiting progressor (B16-SIY and MCA101-OVA) and regressor (MC57-SIY) growth patterns (4, 5). We determined that volumes of B16 and MC57, but not MCA101, tumors were increased in RKO and DKO mice compared to WT mice at several days post injection (dpi). To further understand these differences in tumor progression, we evaluated the primary CTL response against B16 and MC57 tumors. We determined that 20 days upon B16 injection, RKO and DKO mice showed reduced numbers of total and tumor-specific CD8+ T cells (p