Inserm E. 99-41, Centre hépato-biliaire, Hôpital Paul-Brousse, 12-14, avenue Paul-Vaillant-Couturier, 94804 Villejuif Cedex
The initial event in the life cycle of a virus is its attachment to specific receptors on host cells, which consitutes a major determinant of virus tropism. Many specific HBV envelope binding proteins have been identified. The pre-S2 and S regions possess a polymerized human serum albumine binding site. Apolipoprotein H and human annexin V (hAV) interact with the HBs domain. A 50-kd metalloproteinase binds to pre-S1 and pre-S2 domains. Various proteins, such as interleukin 6, immunoglobulin A receptor, asialoglycoprotein receptor, glyceraldehyde-3-phosphate dehydrogenase, CD1a and a 80 kd protein which interacts with the pre-S1 domain are described. Furthermore, GAPDH and annexin V determine in vitro cell infectability by HBV. The respective roles of the three protein domains of HBV envelope and of the various receptor candidates is discussed.