Viroids and viral hepatitis in marmosets

Abstract

DIENER¹ and Zuckerman² have recently speculated that hepatitis A and B, respectively, may be caused by infective naked nucleic acids or viroids. In response to their hypotheses, we felt it would be of interest to investigate the nature of an agent known to cause hepatitis in marmoset monkeys. We reasoned that if the aetiologic agent of hepatitis found in serum is a free, or naked, nucleic acid in this system, then its infectivity should be destroyed by the action of a specific endonuclease. For example, a free viral DNA would be rendered uninfective after treatment with pancreatic DNase. The virus used in our study was the ‘Barker’ agent, originally recovered by Deinhardt et al. from acute phase sera of marmosets inoculated with serum from a human case of viral hepatitis³. This virus consistently induces hepatitis in such animals, although its pedigree as a human hepatitis agent has been a subject of controversy⁴.