title: Incomplete neutralization of hepatitis A virus in vitro due to lipid-associated virions.
abstract: Hepatitis A virus (HAV) released from infected BS-C-1 cells was incompletely neutralized when incubated with a variety of convalescent sera (non-neutralizable fraction of 17 to 32%). Chloroform extraction of virus resulted in a substantial reduction of the non-neutralizable fraction (to less than 1%), suggesting that non-neutralizable virions might be associated with lipids. Non-neutralizable HAV recovered from untreated cell culture supernatant fluids sedimented heterogeneously and less rapidly than normal virus in rate-zonal sucrose gradients and also banded at a lower density in CsCl (1.14 to 1.18 g/ml) than normal, neutralizable virus (1.32 g/ml). This bimodal distribution of HAV in CsCl gradients was confirmed by cDNA-RNA hybridization. Together, these observations suggest that a substantial proportion of HAV particles released from infected cells are lipid-associated and imply an important role for cell membranes in the assembly and release of HAV in vitro.
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D002499:Centrifugation, Density Gradient; D002522:Chlorocebus aethiops; D002725:Chloroform; D035922:Hepatitis A Antibodies; D006508:Hepatitis Antibodies / Q000276:immunology*; D006507:Hepatovirus / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D050356:Lipid Metabolism; D008055:Lipids / Q000502:physiology*; D009500:Neutralization Tests; D014771:Virion / Q000378:metabolism
chemical_list: D035922:Hepatitis A Antibodies; D006508:Hepatitis Antibodies; D007106:Immune Sera; D008055:Lipids; D002725:Chloroform