GITR ligation enhances functionality of tumor‐infiltrating T cells in hepatocellular carcinoma. Issue 4 (27th February 2019)

• Record Type: Journal Article
• Authors: van Beek, Adriaan A.; Zhou, Guoying; Doukas, Michail; Boor, Patrick P.C.; Noordam, Lisanne; Mancham, Shanta; Campos Carrascosa, Lucia; van der Heide‐Mulder, Marieke; Polak, Wojciech G.; Ijzermans, Jan N.M.; Pan, Qiuwei; Heirman, Carlo; Mahne, Ashley; Bucktrout, Samantha L.; Bruno, Marco J.; Sprengers, Dave; Kwekkeboom, Jaap
• Is Part Of: International journal of cancer. Volume 145:Issue 4(2019)
• Page Start: 1111
• Page End: 1124
• Publication Date: 2019-02-27
• Subjects: GITR -- CD357 -- TNFRSF18 -- Treg -- HCC -- cancer immunotherapy -- PD1; Cancer -- Periodicals; Cancer -- Prevention -- Periodicals; 616.994
• DOI: 10.1002/ijc.32181
• Languages: English
• ISSNs: 0020-7136

Abstract

Abstract : No curative treatment options are available for advanced hepatocellular carcinoma (HCC). Anti‐PD1 antibody therapy can induce tumor regression in 20% of advanced HCC patients, demonstrating that co‐inhibitory immune checkpoint blockade has therapeutic potential for this type of cancer. However, whether agonistic targeting of co‐stimulatory receptors might be able to stimulate anti‐tumor immunity in HCC is as yet unknown. We investigated whether agonistic targeting of the co‐stimulatory receptor GITR could reinvigorate ex vivo functional responses of tumor‐infiltrating lymphocytes (TIL) freshly isolated from resected tumors of HCC patients. In addition, we compared GITR expression between TIL and paired samples of leukocytes isolated from blood and tumor‐free liver tissues, and studied the effects of combined GITR and PD1 targeting on ex vivo TIL responses. In all three tissue compartments, CD4 + FoxP3 + regulatory T cells (Treg) showed higher GITR − expression than effector T‐cell subsets. The highest expression of GITR was found on CD4 + FoxP3 hi CD45RA − activated Treg in tumors. Recombinant GITR‐ligand as well as a humanized agonistic anti‐GITR antibody enhanced ex vivo proliferative responses of CD4 + and CD8 + TIL to tumor antigens presented by mRNA‐transfected autologous B‐cell blasts, and also reinforced proliferation, IFN‐γ secretion and granzyme B production in stimulations of TIL with CD3/CD28 antibodies. Combining GITR ligation with anti‐PD1 antibody nivolumab further enhanced tumor antigen‐specific responses of TIL in some, but not all, HCC patients, compared to either single treatment. In conclusion, agonistic targeting of GITR can enhance functionality of HCC TIL, and may therefore be a promising strategy for single or combinatorial immunotherapy in HCC. Abstract : What's new? Therapeutic antibodies that block interaction of the T cell co‐inhibitory receptor PD1 can unleash pre‐existing anti‐cancer T cell responses in hepatocellular carcinoma (HCC). However, whether agonistic targeting of co‐stimulatory receptors could stimulate anti‐tumor immunity remains unknown. This study is the first to show that agonistic targeting of the co‐stimulatory receptor GITR can reinforce the functionality of tumor‐infiltrating T cells isolated from human tumors. Combined targeting of PD1 and GITR exerts additive stimulatory effects on ex vivo functionality of tumor‐infiltrating T cells from HCC patients. Targeting of GITR thus emerges as a promising strategy for single or combinatorial immunotherapy in HCC.