Recruitment of dendritic cells to tumor microenvironment mediated by NK cell derived chemotactic factors

XIMENA LUCIA RAFFO; RAUL GERMAN SPALLANZANI; ANDREA ZIBLAT; CAROLINA INES DOMAICA; NORBERTO WALTER ZWIRNER; MERCEDES BEATRIZ FUERTES

Los Cocos

Congreso; LXI Reunion Anual de la Sociedad Argentina de Inmunologia; 2013

Sociedad Argentina de Inmunologia

Contrary to preconceptions, spontaneous T cell priming occurs frequently in response to a growing tumor. It has recently been reported that antitumor CD8+ T cell priming is dependent on dendritic cells (DC), however the innate immune mechanisms that promote their recruitment to tumors remain ill-defined. We have previously reported that Natural Killer (NK) cells constitute a critical component for the antitumor immune response since antigen-specific CD8+ T cell priming was severely reduced in NK cell-depleted mice compared to non-depleted mice. Although NK cells can produce chemokines upon cytokine stimulation, a role of NK cells in DC recruitment has not been pursued. Therefore, the aim of this work was to study if NK cells can induce the migration of DC to tumors, in vitro and in vivo. To address this, C57BL/6 mice were subcutaneously challenged with MC57 fibrosarcoma cells and the tumor infiltrating immune cells were studied at early stages by flow cytometry. We observed an early DC (CD3-B220-CD11c+) and NK cell (DX5+CD3-) infiltration followed by CD8+ T cells. NK cell-depleted mice showed a significant decrease in DC tumor infiltration compared to control mice six days after tumor challenge (p