Biochemical characterization of Australia antigen. Evidence for defective particles of hepatitis B virus.

Australia antigen exists in the sera of chronic carriers in several particulate forms, one of which may represent the virion of hepatitis B. This report describes the existence of subpopulations of these 43-nm particles, the Dane particles, on the basis of the staining properties of their internal cores and banding characteristics in cesium chloride (CsCl) density gradients. These data suggested that only a minor proportion of Dane particles contained an intact viral genome and represent the standard infectious virus of hepatitis B. The bulk of the Dane particles appeared to be deficient in viral nucleic acid and, as defective interfering particles, may specifically interfere with the growth of standard virus. Such defective interfering particles could thereby play a role in the persistence of HBV infection in man.