The immunological function of extracellular vesicles in hepatitis B virus-infected hepatocytes

Hepatitis B virus (HBV) generates large amounts of complete and incomplete viral particles. Except for the virion, which acts as infectious particles, the function of those particles remains elusive. Extracellular vesicles (EVs) have been revealed to have biological functions. The EVs which size are less than 100 nm in diameter, were collected from HBV infected-patients. These vesicles contain, complete and incomplete virions, and exosomes, which have been recently shown to be critical as intercellular communicators. Here, the effects of the exosome, the complete, and the incomplete particles on the target cells were investigated. These particles are endocytosed by monocyte/macrophages and function primarily to upregulate PD-L1. The functions and composition of the EVs were affected by nucleotide reverse transcriptase inhibitors (NRTIs), suggesting that the EVs are involved in the pathogenesis of HBV hepatitis and clinical course of those patients treated by NRTIs.