Expression of PD -L1 and CD86 in the peripheral blood mononuclear cells of septic mice

doi:10.3969/j.issn.1002-1949.2015.10.020

Abstract：Objective To observe the expression trend of negative costimulatory molecule programmed death ligand 1 ( PD -L1 ) and positive costimulatory molecule CD 86 in peripheral blood mononuclear cells of septic mice , to investigate the immune status of sepsis in mice .Methods Sixty C57 mice were randomly divided into 6 h, 24 h, 48 h sepsis model group and the sham group , 10 mice in each group .Sepsis model was reproduced by cecal ligation and puncture .6 h, 24 h, 48 h after successful modeling peripheral blood mononuclear cells were taken for detection of PD -L1 and CD86 by flow cytometry, while HE staining was used to observe the morphological changes of intestine .Results Under the 100 × light microscope , the 24 h and 48 h sepsis group showed serious intestinal epithelial mucosal villous damage , but the sham group and 6 h sepsis group showed normal small intestinal villi . CD86 and PD-L1 expression in sepsis model group in 6 h, 24 h, 48 h was all increased compared with that in sham group (P<0.05).And elevated levels of PD-L1 in 24 h, 48 h is more significant (P<0.01).CD86 and PD-L1 were increased at the beginning of 6 h, 24 h reached the peak, and 48 h began to decline .Conclusion Peripheral blood mononuclear cells in sepsis mice showed increased expression of CD86 and PD -L1, and the rise of PD -L1 level was even more significant , which suggests that negative regulation of specific immunity is dominant during the early stage of sepsis .