Dane Particle “Specific” Antigenic Determinants

Abstract

It is generally recognized that the determinants of HBsAg are shared among small spherical HBsAg, variably long filamentous forms, and Dane particles (19). However, there is accumulating evidence indicating that Dane particles and, to some extent, filamentous forms also possess distinct antigenic determinants not found on small spherical surface antigen. For example, the serum from some patients with acute hepatitis B contained antibodies which specifically precipitated radiolabeled Dane particles (389). A high frequency of individuals having self-limited acute HBV infection (71% of 31 patients) possessed this type of antibody specificity, which usually disappeared in those cases progressing to chronicity. Further, 42% of asymptomatic carriers with normal liver histology and 13% of those having chronic hepatitis demonstrated this type of specificity (390). Aggregates composed almost entirely of Dane particles have been observed by electron microscopy in HBsAg positive sera in the absence of anti-HBs (391–394). Treatment of Dane particles with 0.01% mucasol, chloroform, or 0.25% deoxycholate resulted in greatly increased aggregation, suggesting that most if not all of these specific antigenic sites are cryptic in nature and that they become exposed following partial denaturation of the envelope components (391).