Hepatitis B e-antigen (HBeAg) is a viral protein associated with HBV infections. Unlike the surface antigen, the e-antigen is found in the blood only when there are viruses also present. When the virus goes into “hiding,” the e-antigen will no longer be present in the blood. HBeAg is often used as a marker of ability to spread the virus to other people (infectivity). Measurement of e-antigen may also be used to monitor the effectiveness of HBV treatment; successful treatment will usually eliminate HBeAg from the blood and lead to development of antibodies against e-antigen (anti-HBe). There are some types (strains) of HBV that do not make e-antigen; these are especially common in the Middle East and Asia. In areas where these strains of HBV are common, testing for HBeAg is not very useful.
Function:
May regulate immune response to the intracellular capsid in acting as a T-cell tolerogen, by having an immunoregulatory effect which prevents destruction of infected cells by cytotoxic T-cells. This immune regulation may predispose to chronicity during perinatal infections and prevent severe liver injury during adult infections.
Subunit:
Homodimerizes.
Subcellular Location:
Secreted. Host nucleus.
Post-translational modifications:
Phosphorylated.
Cleaved by host furin.
Similarity:
Belongs to the orthohepadnavirus precore antigen family.
SWISS:
P0C573
Gene ID:
N/A
Database links:
Entrez Gene: 944568 Hepatitis B virus
SwissProt: Q89714 Hepatitis B virus
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