Fig. 5

PD-L1 expression on neutrophils is induced by the cytokines of GM-CSF and TNF-α. a Purified neutrophils from healthy controls were exposed to conditioned medium in vitro as indicated. PD-L1 expression on neutrophils was determined at 0, 6, 24 and 48 h. b The mean fluorescence intensity (MFI) of PD-L1 on neutrophils is shown. c, d Selected cytokines and chemokines were detected by liquid chip technology in conditioned medium from normal liver cells or hepatoma cells and tissue lysis supernatants from intratumoural and peritumoural tissues. e Neutrophils were exposed to the indicated cytokines for 24 h. The relative expression of PD-L1 on neutrophils was detected by qRT-PCR. f PD-L1 expression on neutrophils was significantly reduced with specific neutralizing antibodies against GM-CSF and TNF-α compared with the control (Student’s t-Test)