Fig. 1
From: L-kynurenine induces NK cell loss in gastric cancer microenvironment via promoting ferroptosis
IDO produced L-KYN from GC cells impairs NK viability in vitro. A The concentration of L-KYN in the culture supernatant of SGC-7901, MGC-803 or GES-1 cells measured by ELISA. B The ratio of the remaining NK-92 cell number relative to the originally seeded cell number in the non-contract co-culture system with GES-1, MGC-803 or SGC-7901 cells. The control group referred to that the NK-92 cells were seeded into the co-culture wells alone. C The flow cytometric analysis for the proportion of FVD+ NK-92 cells in the co-culture system. The pictures above showed the representative results. D The flow cytometric results that showed the proportion of FVD+ NK-92 cells when stimulated with the culture supernatant of GES-1, MGC-803 or SGC-7901 cells. The control group referred to the medium without culturing with cells. E The proportion of FVD+ NK-92 cells when treated with gradient concentrations of L-KYN for 24 or 48 h. F and G The proportion of FVD+ NK-92 cells when co-cultured with GES-1, SGC-7901Con, SGC-7901IDO-KO (F), or treated with the culture supernatant of SGC-7901Con or SGC-7901IDO-KO (G) for 48 h. The control group in (F) indicated the NK-92 cells were only treated with medium. H and I The proportion of FVD+ primary human NK (hNK) cells when treated with gradient concentrations of L-KYN for 48 h (H) or the culture supernatant from GES-1, SGC-7901Con and SGC-7901IDO-KO cells (I). All the results were replicated in 3 (H and I) or 4 (A - G) independent experiments. * refers to the p-value of group SGC-7901 vs GES-1 and # refers to the group SGC-7901 vs MGC-803 (A - D). * p < 0.05, ** p < 0.01, *** p < 0.001, # p < 0.05, ## p < 0.01, ### p < 0.001