A study of the relationship of virus-like particles and Australia Antigen in liver

The ultrastructural and antigenic characteristics of the HB Ag-associated liver particles and the relationship of the liver particles to serum HB Ag were studied by three correlative and comparative observations. (1) Ultrastructural tissue study in 29 patients defined the morphologic characteristics of the unique noncoated virus-like particles that were found in liver cell nuclei and sometimes in the cytoplasm. Their presence in liver tissue may be of diagnostic significance for active disease. The coated particles were shown to be morphologically identical to the Dane particles in serum, and were found in the cisternae of proliferative endoplasmic reticulum. In addition, the cisternae of the endoplasmic reticulum contained peculiar filaments and their probable cross sections with an owl eye appearance. The outer covering of the coated particles was shown to be continuous with the filaments, suggesting that the latter were probably the crystalloid coat material. (2) Phosphotungstic acid negative stain of liver tissue homogenates and ultrastructural sections of the pellets from the homogenates provided a convenient linkage for comparative morphologic interpretation of the tissue and smear findings. Evidence indicated the hepatic origin of the HB Ag particles. (3) Immunoagglutination electron microscopy indicated that the HB Ag particles in tissue homogenates and sera were antigenically identical, whereas the noncoated particles, although morphologically similar to the core component of the Dane particles, were most likely antigenically different from the coat material of HB Ag. The observations support the concept that the Dane particles have dual antigenic specificities. Possible explanations are given for the absence of pure core particles in the serum.