Induction of cell-mediated immunity to HBsAg polypeptides

Adult male guinea pigs were immunized with hepatitis B virus polypeptides prepared by Triton X-100 solubilization of purified 22-nm hepatitis B surface antigen (HBsAg) particles. A virus-specific subunit containing both the 28,000 molecular weight glycoprotein and the 23,000 molecular weight protein stimulated both cell-mediated and humoral immunity. A whole-blood-cell transformation assay additionally showed that the 64,000 molecular weight component of HBsAg, previously shown to contain host-specific antigens, also stimulated a cellular response to purified intact HBsAg particles, suggesting the additional presence of virus-specific material in this fraction. Immunization of animals with the 28,000--23,000 molecular weight polypeptides subsequently prepared in micelle form enhanced the demonstration of a cell-mediated reaction after only a single dose of immunogen. The results provide further evidence as to the suitability of HBsAg polypeptides prepared by Triton X-100 solubilization for hepatitis B prophylaxis.