HCV immune evasion and regulatory T cell activation: cause or consequence?

Hepatitis C virus(HCV)infection remains a major public health problem given that an estimated 71 million people are currently infected and 1.75 million are newly infected every year.Up to 85%of HCV infections become persistent and may eventually lead to chronic liver diseases,including cirrhosis and hepatocellular carcinoma.1 Immune responses play a crucial role in virus control and liver injury;however,the underlying mechanism is not completely understood.Patients chronically infected with HCV generally exhibit a weak peripheral blood T cell response against HCV,which could explain viral persistence.As cells that play a key role in dominant immune tolerance,regulatory T(T-reg)cells suppress inflammatory responses and prevent the development of autoimmune diseases.