Characterization Of CD14^highCD16⁺ Monocytes And Their Significance In Chronic Hepatitis B Patients

Objective:To investigate the expression characteristics of CD16+monocytes from patients with chronic HBV infection by observing the frequency, phenotypes and function of circulating CD14highCD16+monocytes and the frequency and phenotypes intrahepatic CD 14highCD16+monocytes in different populations and in different disease phases of CHB. Furthermore, we investigate the relationship between CD 14highCD16+monocytes and the disease progression.Methods:CD14highCD16+monocytes in peripheral blood from 18 health controls and 86 chronic hepatitis B patients, including 22 patients in immune tolerant phase and 64 patients in immune active phase, were quantitatively measured, and the expressions of HLA-DR, TLR2 and PD-L1 on CD14highCD16+ monocytes were analyzed by flow cytometry. We have studied cytokine production in CD14highCD16+monocytes on whole peripheral blood samples stimulated with LPS in active CHB group. We also observed the frequency of CD14highCD16+monocytes infiltrating in the liver of the CHB patients. Furthermore, clinical variables, including serum ALT, HBV markers, HBV-DNA levels and etc, were surveyed for each subjects.Results:1.In immune active patients, the frequency of CD14highCD16+ monocytes in peripheral blood was significantly higher as compared to health controls and patients in immune tolerant phase(P<0.01); 2.In CHB patients, elevated proportions of circulating CD 14highCD16+monocytes were correlated with increased serum ALT levels(r=-0.283, P=0.008) and decreased HBV DNA loads(r=-0.283,P=0.008);3.Liver-infiltrating CD 14highCD 16+monocytes frequency has a positive correlation with increased inflammation activity in liver tissue in patients with chronic hepatitis B infection (r=0.890, P＜0.001); 4.A significant positive correlation was found between PD-L1 expression on monocytes (r=0.358, P=0.035) and serum AST levels, and the highest levels of PD-L1 were consistently found on CD14highCD16+monocytes(MFI:16.75±9.36) from patients in immune active phase; 5. In CHB patients, liver-infiltrating CD14highCD16+monocytes frequency and the expression of HLA-DR on liver-infiltrating CD14highCD16+monocytes were significantly increased as compared to peripheral blood(P<0.01); 6.In CHB patients, the high levels of TLR2 were consistently found on CD14highCD16+monocytes, significantly less on other subsets(P<0.05); 7.After the LPS stimulation, CD14highCD16+ subpopulation produced significantly more TNF-a and IL-6 than CD14highCD16-(P<0.05) and CD 14lowCD 16+monocytes (P<0.01).Conclusion:Our findings suggest CD14highCD16+monocytes play an active role not only in circulating but also in liver in situ modulating effectors of immune response to HBV infection. The findings about the correlation between CD14highCD16+monocytes profile and HBV replication or liver inflammation in chronic HBV infection will provide new insight into the characterization of CD14highCD16+monocytes and their significance in chronic hepatitis B patients.