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Characterization and classification of virus particles associated with hepatitis A. I. Size, density, and
Abstract:
Virus-like particles were purified from stools of patients in an epidemic of hepatitis A in Germany. When reference MS-1 chimpanzee pre-inoculation and convalescent sera were used, the close serological relationship of the purified particles to well-known isolates of hepatitis A could be established. On the other hand, the physicochemical characteristics of the particles were determined in parallel to the characteristics of a marker parvovirus (LuIII) and a marker picornavirus (poliovirus type 2). It could be shown that the majority of the hepatitis A-associated particles band at 1.34 g/ml in CsCl and, like poliovirus, sediment at about 160S. In addition, a distinct hepatitis A antigen was observed, which banded at 1.305 g/ml and sedimented between 50 and 90S. A further component accumulated in the density range of between 1.38 and 1.44 g/ml. However, it seemed to be rather labile. Upon reisolation from CsCl and sedimentation in sucrose, it resolved into a 160S, a 90 to 100S, and a 50S form. The size of the 160S particles (27 to 29 nm) could be readily distinguished from that of the parvovirus (22 to 24 nm). It is concluded, therefore, that hepatitis A-associated virus particles are more likely to be classified with the picornaviruses than with the parvoviruses.
Insights
Hepatitis A virus particles purified from patient stools were serologically linked to known hepatitis A isolates. Physicochemical analysis suggests these particles are more akin to picornaviruses than parvoviruses.
Area of Science:
- Virology
- Hepatology
Background:
- Hepatitis A virus (HAV) causes infectious hepatitis.
- Previous classifications of HAV were uncertain.
Purpose of the Study:
- To characterize the physicochemical properties of hepatitis A virus particles.
- To determine the classification of hepatitis A virus particles.
Main Methods:
- Purification of virus-like particles from patient stools.
- Serological testing using reference antisera.
- Physicochemical analysis including CsCl density gradient centrifugation and sucrose gradient sedimentation.
- Comparison with marker parvovirus (LuIII) and picornavirus (poliovirus type 2).
Main Results:
- Hepatitis A virus particles banded at 1.34 g/ml in CsCl and sedimented at approximately 160S, similar to poliovirus.
- Distinct hepatitis A antigen components were observed at different densities and sedimentation rates.
- Particle size (27-29 nm) differed from parvovirus (22-24 nm).
Conclusions:
- Hepatitis A virus particles share physicochemical characteristics with picornaviruses.
- Hepatitis A virus is likely classifiable as a picornavirus, not a parvovirus.