Abstract 1562: The G protein-coupled receptor mFPR2 promotes antitumor host defense

Abstract

Abstract mFPR2 is a G protein-coupled receptor interacting with chemotactic agonists produced by bacteria and the host. In vivo, mFPR2 plays a major role in innate and adaptive immune responses as shown by reduced severity of allergic airway inflammation and diminished production of Th1 and Th2 cytokines in mFPR2-deficient mice. These defects were associated with impaired trafficking of antigen presenting dendritic cells into the inflammatory sites and the draining lymph nodes. The aim of this study is to examine the role of mFPR2 in tumor progression. We found that mFPR2-deficient mice bearing subcutaneously implanted Lewis Lung Cancer cells (LLC) exhibited significantly shortened survival rate due to more rapidly growing tumors. In contrast, in mFPR2-transgenic (Tg) mice, subcutaneously implanted LLC tumors grew more slowly than those in wild type (WT) littermates. We further observed a decrease in the proportion of CD11b+ and Gr1+ myeloid cells accompanied by reduced infiltration of CD11b+Gr1low myeloid-derived suppressor cells and CD4+Foxp3+ regulatory T cells in LLC tumors in mFPR2-Tg mice. These results suggest that mFPR2 may play an important role in anti-tumor host defense by down-regulating immune suppressive cell infiltration in tumor tissues. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1562. doi:10.1158/1538-7445.AM2011-1562