Abstract 1455: IL-4 derived from T follicular helper cells in tumor draining lymph nodes regulate myeloid cell properties and anti-tumor immunity

Recent findings show that immune cells constitute a large fraction of the tumor microenvironment and modulate tumor progression. Clinical data indicate that chronic inflammation is present at tumor sites and that IL-4 in particular is up-regulated. Current results demonstrate that T follicular helper (Tfh) cells arise in tumor draining lymph nodes where they produce an abundance of IL-4. Deletion of IL-4 expressing Tfh cells improves anti-tumor immunity, delays tumor growth and reduces the immunosuppressive activity of myeloid-derived suppressor cells (MDSC) and M2 macrophages. These findings suggest that IL-4 from Tfh cells impact anti-tumor immunity and constitute an attractive therapeutic target to reduce immune suppression in the tumor microenvironment and thus enhance the efficacy of cancer immunotherapy. Citation Format: Hidekazu Shirota, Dennis M. Klinman, Shuku-ei A. Ito, Chikashi Ishioka. IL-4 derived from T follicular helper cells in tumor draining lymph nodes regulate myeloid cell properties and anti-tumor immunity. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1455.