Binding of the major and large HBsAg to human hepatocytes and liver plasma membranes: Putative external and internal receptors for infection and secretion of hepatitis B virus
✍ Scribed by William P. J. Leenders; Harrie L. Glansbeek; Wieke C. C. De Bruin; Dr. Sing-Hiem Yap
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 715 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0270-9139
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✦ Synopsis
A likely mechanism of the strong hepatotrophism of the hepatitis B virus is the presence of specific receptors for the surface antigen of hepatitis B virus on hepatocyte membranes. To examine this hypothesis, we have performed binding studies using recombinant large (preS1 + preS2 + S ) and mqjor ( S ) proteins with adult human hepatocytes, rat hepatocytes, human fibroblasts, human peripheral blood mononuclear cells and plasma membranes derived from these cell types. We found that mqjor HBsAg was able to bind specifically to human hepatocytes, human fibroblasts and human blood mononuclear cells. This binding could be inhibited by recombinant middle (preS2 + S ) protein but not by the recombinant large protein. No binding could be demonstrated between large HBaAg and human hepatocytes. However, large protein bound specifically to plasma membranes derived from human liver tiesue, human fibroblasts and HepG2A16 cells. This binding could be partially inhibited by the mqjor protein and by a synthetic preSl peptide but not by a synthetic preS2 peptide. These results support the assumption that hepatitis B virus absorption and penetration into human hepatocytes is mediated by specific receptors recognizing an amino acid sequence in the S-region. This recognition site is not displayed by the recombinant large protein. However, the large protein is recognized by its preSl region and by a second binding site in the S-region by a receptor molecule, located on the inner surface of the plasma membranes or intracellular membranes of human hepatocytes and of some other cell types derived from human tissue. (HEPATOLOGY 1990;12:141-147.) HBV infection is a major health problem. It has been estimated that more than 200 million people worldwide