The response to TLR ligation of human CD16+CD14− monocytes is weakly modulated as a consequence of persistent infection with the hepatitis C virus

Abstract: Little is known about the frequency and function of CD16+CD14− monocytes from chronic HCV patients. We observed that the absolute numbers and ratio of CD16+CD14− to CD14+CD16− monocytes were similar between chronic HCV patients and healthy individuals. Functionally, we found that CD16+CD14− monocytes are more responsive to TLR8-ligation and only weakly responsive to LPS stimulation in producing TNF as compared to CD14+CD16− monocytes. We found no overt impairment of the function of CD16+CD14− monocytes from patients, except for an augmented induction of MIP-1β-producing CD16+CD14− monocytes upon TLR4-ligation. However, the increased frequency of MIP-1β-producing CD16+CD14− monocytes was not associated with viral load, ALT or fibrosis level. Our findings indicate that, different from other infectious diseases, the frequency and function of CD16+CD14− monocytes are only minimally altered as a consequence of the persistent state of HCV infections, and our findings therefore do not suggest a role for CD16+CD14− monocytes in HCV pathogenesis. [Copyright &y& Elsevier]