HBcAg

File:Hepatitis B virus v2.svg

A simplified drawing of the HBV particle and surface antigen. Purple = Lipid Envelope, Red = Nucleocapsid Core (Note: This drawing is slightly misleading in that the nucleocapsid core is a single entity even though it is depicted as a light blue icosahedral line shape and a red ring of circles).

The genome organisation of HBV. The genes overlap. (ORF Core, at bottom left, encodes HBcAg.

HBcAg (core antigen) is a hepatitis B viral protein. It is an indicator of active viral replication; this means the person infected with Hepatitis B can likely transmit the virus on to another person (i.e. the person is infectious).

Structure and Function

HBcAg is an antigen can be found on the surface of the nucleocapsid core (the inner most layer of the hepatitis b virus). While both HBcAg and HBeAg are made from the same reading frame, HBcAg is not secreted. HBcAg is considered "particulate" and it does not circulate in the blood. However, it is readily detected in hepatocytes after biopsy. The presence of both HBcAg and HBeAg proteins together act as a marker of viral replication, and antibodies to these antigens are a marker of declining replication.

Interactions

Tapasin can interact with HBcAg18-27 and enhance cytotoxic T lymphocyte response against HBV.

See Also

Hepatitis B Extracellular Antigen