Human GITR Ligand Is Expressed on Tumor Cells and Reduces Cytokine Production and Cellular Cytotoxicity of NK Cells Identified to Express GITR.

Abstract Members of the tumor necrosis factor (TNF) superfamily mediate multiple cellular functions including cellular proliferation, differentiation, and cell death. Human Glucocorticoid-induced TNF Receptor (GITR) has been shown to be expressed on T cells, is upregulated following activation and mediates costimulatory signals. The human GITR ligand (GITRL) has been reported to be expressed on antigen presenting cells and various healthy nonlymphoid tissues including small intestine, ovary, testis, kidney and endothelial cells. We analyzed multiple tumor cell lines of hematopoietic and epithelial origin as well as of germ cell lineage and various gliomas by RT-PCR and FACS analysis. Both G…