摘要
Circulating monocyte subsets with distinct functions play important roles in hepatitis C virus （HCV） infection. However, the mechanisms have not been well studied. In this study, we analyzed the distributions and phenotypic characteristics of three circulating monocyte subsets--CD14^＋＋CD16^-, CD14^＋＋CD16^＋ and CD14^＋＋mCD16^——in chronic HCV-infected patients, HCV spontaneous resolvers and healthy controls, and we evaluated the possible link between HCV viremia and disease progression. Our results indicated that the frequency of the CD 14^＋＋CD 16^＋ monocyte subset was decreased, and negatively correlated with HCV RNA and core antigen levels during chronic HCV infection. PD-L1 expression and the PD-L1/CD86 ratio in CD14^＋＋CD16^＋ monocytes were higher during chronic HCV infection than in spontaneous HCV resolvers and healthy controls. The PD-L1/CD86 ratio positively correlated with HCV viral load and core antigen levels. Finally, PD-L1 was significantly increased, while cytokine secretions were dramatically decreased upon Toll-like receptor （TLR） ligand binding and HCV JFH-lstimulation. These findings indicates the compromised immune status of the CD14^＋＋CD16^＋ monocytes during chronic HCV infection and provides new insights into the specific role of the CD14^＋＋CD16^＋ monocytes and their significance in chronic HCV infection.
Circulating monocyte subsets with distinct functions play important roles in hepatitis C virus （HCV） infection. However, the mechanisms have not been well studied. In this study, we analyzed the distributions and phenotypic characteristics of three circulating monocyte subsets--CD14^＋＋CD16^-, CD14^＋＋CD16^＋ and CD14^＋＋mCD16^——in chronic HCV-infected patients, HCV spontaneous resolvers and healthy controls, and we evaluated the possible link between HCV viremia and disease progression. Our results indicated that the frequency of the CD 14^＋＋CD 16^＋ monocyte subset was decreased, and negatively correlated with HCV RNA and core antigen levels during chronic HCV infection. PD-L1 expression and the PD-L1/CD86 ratio in CD14^＋＋CD16^＋ monocytes were higher during chronic HCV infection than in spontaneous HCV resolvers and healthy controls. The PD-L1/CD86 ratio positively correlated with HCV viral load and core antigen levels. Finally, PD-L1 was significantly increased, while cytokine secretions were dramatically decreased upon Toll-like receptor （TLR） ligand binding and HCV JFH-lstimulation. These findings indicates the compromised immune status of the CD14^＋＋CD16^＋ monocytes during chronic HCV infection and provides new insights into the specific role of the CD14^＋＋CD16^＋ monocytes and their significance in chronic HCV infection.
