journal contribution
posted on 2023-03-31, 18:15 authored by Irina V. Tiper, Sarah M. Temkin, Sarah Spiegel, Simeon E. Goldblum, Robert L. Giuntoli, Mathias Oelke, Jonathan P. Schneck, Tonya J. Webb The source of GD3 impacts CD1d-mediated antigen presentation.(A) LCD1d cells were treated with GD3 from different sources for 4 hours, then washed extensively and cocultured with NKT cell hybridomas. IL-2 was measured, as an indication of NKT cell activation, by standard cytokine ELISA. (B) Pretreatment of a-GalCer loaded aAPC with GD3. a-GalCer loaded aAPC were incubated for 4hr with either medium, GD3, GD2, or ovarian cancer-associated ascites. The aAPC were washed extensively and then cocultured with a Va14+ NKT cell hybridoma, N38-3C3. NKT cell recognition of CD1d was assessed by measuring IL-2 production in the supernatants by ELISA.
Funding
NIH
NCI
Gynecologic Cancer Foundation/Ann Schreiber Ovarian Cancer Research
History
ARTICLE ABSTRACT
Purpose: Natural killer T (NKT) cells are important mediators of antitumor immune responses. We have previously shown that ovarian cancers shed the ganglioside GD3, which inhibits NKT-cell activation. Ovarian cancers also secrete high levels of VEGF. In this study, we sought to test the hypothesis that VEGF production by ovarian cancers suppresses NKT-cell–mediated antitumor responses.Experimental Design: To investigate the effects of VEGF on CD1d-mediated NKT-cell activation, a conditioned media model was established, wherein the supernatants from ovarian cancer cell lines (OV-CAR-3 and SK-OV-3) were used to treat CD1d-expressing antigen-presenting cells (APC) and cocultured with NKT hybridomas. Ovarian cancer–associated VEGF was inhibited by treatment with bevacizumab and genistein; conditioned medium was collected, and CD1d-mediated NKT-cell responses were assayed by ELISA.Results: Ovarian cancer tissue and ascites contain lymphocytic infiltrates, suggesting that immune cells traffic to tumors, but are then inhibited by immunosuppressive molecules within the tumor microenvironment. OV-CAR-3 and SK-OV-3 cell lines produce high levels of VEGF and GD3. Pretreatment of APCs with ascites or conditioned medium from OV-CAR-3 and SK-OV-3 blocked CD1d-mediated NKT-cell activation. Inhibition of VEGF resulted in a concomitant reduction in GD3 levels and restoration of NKT-cell responses.Conclusions: We found that VEGF inhibition restores NKT-cell function in an in vitro ovarian cancer model. These studies suggest that the combination of immune modulation with antiangiogenic treatment has therapeutic potential in ovarian cancer. Clin Cancer Res; 22(16); 4249–58. ©2016 AACR.
