ALPER TUNGA OZDEMİR, CENGİZ KİRMAZ, RABİA BİLGE OZGUL OZDEMİR, MUSTAFA OZTATLİCİ, MEHMET IBRAHİM TUGLU, PİNAR KİLİCARSLAN SONMEZ, KAMİL VURAL, AFİG BERDELİ
Eurasian Journal of Medical Investigation - 2021;5(3):334-340
Objectives: In this study, it was aimed to investigate how the effects of Mesenchymal stem cells (MSCs) on the anti tumor properties of NK-92 cells change with programmed death-ligand-1 (PD-L1) blocking antibodies. Methods: NK-92 cells were co-cultured with MDA-MB-231 breast tumor cells and MSCs. To evaluate the effect of anti PD-L1 antibodies, cells were cultured for 48 hours with and without the addition of 1, 5, and 10 µg/ml anti PD-L1 antibody. IFN-?, TNF-?, IL-10 and IDO levels of medium supernatants were determined by ELISA. CCK-8 kit was used to evaluate cytotoxic activity. Results: IFN-? and TNF-? expressions of NK-92 cells co-cultured with MDA-MB-231 increased significantly, but this increase was significantly decreased in culture groups with MSCs. IDO expressions increased significantly in co-culture groups with MSCs only. Cytotoxic effects of NK-92 cells were significantly reduced in culture groups with MSCs. How ever, the suppression effects caused by MSCs improved in the presence of anti-PD-L1 antibodies and in a dose depen dent manner. Conclusion: In our findings, we found that MSCs are a highly effective inhibitors, and the IDO enzyme they secrete may play a major role in this. However, the suppressive effects caused by MSCs may be significantly improved by blocking the PD-1/PD-L1 axis.
