Abstract
Exosomes seem to play an important role in hepatits C virus (HCV) and hepatitis E virus (HEV) infection by shielding their cargo from the host immune responses, with microRNAs being key exosomal components. Little is known about their involvement in a mixed HCV/HEV infection or at the early stages of infection, such as in asymptomatic blood donors (BDs). To obtain preliminary data, we have compared the exosomal microRNA expression profiles in four each of HCV RNA-positive, HEV RNA-positive and negative blood donors and four patients, one of whom was a rare patient with HCV/HEV co-infection. Exosomes were purified from sera by a combination of a precipitation and density gradient centrifugation and exosomal microRNA was analysed using Taqman array cards. Out of 33 deregulated miRNAs, miR-885-5p and miR-365 were upregulated in HCV BDs, miR-627-5p was downregulated in HCV BD and miR-221 was downregulated in HCV patients and BDs. In HEV infection, miR-526b appeared specifically downregulated. Six miRNAs (miR-628-3p, miR-194, miR-151-3p, miR-512-3p, miR-335 and miR-590) indicated a potential involvement in both infections. First time preliminary data on pre- and post-antiviral treatment exosomal microRNA profiles of the HEV/HCV co-infected patient revealed a pool of 77 upregulated and 43 downregulated miRNAs to be further investigated for their potential roles in these viral infections.