Immunogenicity of hybrid hepatitis B surface antigen particles.

Hepatitis B surface antigen (HBsAg) produced by recombinant DNA technology is now widely and safely used worldwide for hepatitis B vaccination. We used the HBsAg particle as a carrier molecule for presentation of selected human immunodeficiency virus type 1 (HIV-1) determinants to the immune system. Immunization studies carried out in primates showed that the particles elicit HIV specific virus neutralizing antibodies as well as T cell proliferative responses to both pathogens. As an experimental approach to active immunotherapy for hepatitis B virus (HBV) chronic carriers, we evaluated the efficiency of such hybrid antigen to overcome B cell tolerance in HBV transgenic mice.