Hepatitis D virus ribonucleoprotein complex (HDV RNP) (HDV RNP)

The Hepatitis D virus (HDV) RNA–hepatitis D antigen complex, commonly referred to as the HDV ribonucleoprotein (RNP), is the central structural and functional unit of the Hepatitis D virus. It consists of a circular, single-stranded RNA genome of approximately 1.7 kilobases associated with multiple copies of the hepatitis D antigen (HDAg), which exists in two isoforms: small (S-HDAg) and large (L-HDAg) (PubMed: 31434285). The S-HDAg is essential for the replication of the viral RNA genome within the host cell nucleus, while the L-HDAg acts as a dominant negative inhibitor of replication and is strictly required for viral assembly (UniProt: P0C6S7). Because HDV is a satellite virus, the RNP complex must be packaged into an envelope composed of Hepatitis B virus surface antigens (HBsAg) to form infectious virions (PubMed: 23966395). This complex is a primary target for therapeutic intervention; for example, lonafarnib inhibits the farnesylation of L-HDAg, preventing the RNP from interacting with HBsAg and thereby blocking the production of new virus particles (PubMed: 29111105). Additionally, novel therapies such as nucleic acid polymers and RNA interference are being developed to disrupt the stability of the RNA component or the secretion of the RNP complex to treat chronic HDV infection (PubMed: 32165595).

Other names

HDV RNA–hepatitis D antigen complexHepatitis D virus RNA-antigen complexHDV ribonucleoproteinHepatitis delta virus ribonucleoprotein

Farnesyltransferase inhibition to prevent L-HDAg prenylation and subsequent RNP-envelope assembly; RNA interference to degrade the HDV RNA component; Nucleic acid polymers to inhibit the release of the RNP complex from hepatocytes.