The HBx gene of hepatitis B virus can influence hepatic microenvironment via exosomes by transferring its mRNA and protein.
The cellular secretory vesicles known as 'exosomes' have emerged as key player in intercellular transport and communication between different eukaryotic in order to maintain body homeostasis. Many pathogenic viruses utilize exosome pathway to efficiently transfer bioactive components from infected cells to naïve cells. Here, we show that HBx can tweak the exosome biogenesis machinery both by enhancing neutral sphingomyelinase2 activity as well as by interacting with exosomal biomarkers such as neutral sphingomyelinase2, CD9 and CD81. The nano particle tracking analysis revealed enhanced secretion of exosomes by the HBx-expressing cells while confocal studies confirmed the co-localization of HBx with CD9 and CD63. Importantly, we observed the encapsulation of HBx mRNA and protein in these exosomes besides some other qualitative changes. The exosomal cargo secreted by HBx-expressing cells had a profound effect on the recipient hepatic cells including creation of a milieu conducive for cellular-transformation. Thus, the present study unfolds a novel role of HBx in intercellular communication by facilitating horizontal transfer of viral gene products and other host factors via exosomes in order to support viral spread and pathogenesis.
['Kapoor|Neetu Rohit|NR|', 'Chadha|Radhika|R|', 'Kumar|Saravanan|S|', 'Choedon|Tenzin|T|', 'Reddy|Vanga Siva|VS|', 'Kumar|Vijay|V|']
D055354:Exosomes D006509:Hepatitis B D006515:Hepatitis B virus D054884:Host-Pathogen Interactions D006801:Humans D008099:Liver D008666:Metalloendopeptidases D011485:Protein Binding D012333:RNA, Messenger D012367:RNA, Viral D060225:Tetraspanin 28 D060245:Tetraspanin 29 D015534:Trans-Activators D014764:Viral Proteins D054334:Viral Regulatory and Accessory Proteins
Hepatitis B virus Exosome Neutral sphingomyelinase2 HBx protein Hepatic stellate cells Liver disease