Submitted September 8, 2008
Accepted March 6, 2009
Endogenous IL-17 contributes to reduced tumor growth and metastasis
Ilona Kryczek, Shuang Wei, Wojciech Szeliga, Linhua Vatan, and Weiping Zou*
Department of Surgery, University of Michigan, Ann Arbor, MI, United States
* Corresponding author; email: wzou{at}med.umich.edu.
It has been reported that ectopically expressed IL-17 in tumor cells suppress tumor progression through enhanced anti-tumor immunity in immune competent mice, or promote tumor progression through an increase in inflammatory angiogenesis in immune deficient mice. The role of endogenous IL-17 in tumor immunity remains undefined. Here we showed that tumor growth and lung metastasis were enhanced in IL-17-deficient mice, associated with decreased IFN
+ NK cells and tumor specific IFN+ T cells in the tumor draining lymph nodes and tumors. Together with the published data showing that in vitro TGF
and IL-6-polarized Th17 cells induce tumor regression, our work supports the notion that endogenous IL-17 or/and Th17 cells may play a protective role in tumor immunity.
