Hepatitis B virus preS2 protein (preS2)

The Hepatitis B virus preS2 protein is a vital structural component of the viral envelope, located within the Middle (M) and Large (L) surface proteins. It plays a significant role in the viral life cycle, particularly in mediating the attachment of the virus to host hepatocytes and assisting in the assembly and secretion of viral particles (UniProt: P03142). In addition to its structural functions, the preS2 domain is known to possess transcriptional transactivation properties, which have been linked to the progression of liver disease and the development of hepatocellular carcinoma (PubMed: 12633301). As a therapeutic target, preS2 is utilized in advanced third-generation Hepatitis B vaccines, such as PreHevbrio, to elicit a more robust and comprehensive immune response than standard vaccines containing only the S-antigen (FDA: PreHevbrio Label). These vaccines induce neutralizing antibodies that specifically target the preS2 region, thereby preventing viral entry and infection. Furthermore, the presence of anti-preS2 antibodies is often used as a biomarker to assess the efficacy of immunization and the level of protective immunity in patients (PubMed: 34935145).

Other names

Middle surface proteinM proteinHBV preS2 domainHepatitis B virus middle envelope proteinHBsAg preS2

Induction of neutralizing antibodies that block viral attachment and entry into hepatocytes; stimulation of T-cell responses to enhance viral clearance.