An infectious clone of woolly monkey hepatitis B virus.

Members of the Hepadnaviridae family have been isolated from birds, rodents, and primates. A new hepadnavirus isolated from the woolly monkey, a New World primate, is phylogenetically distinct from other primate isolates. An animal model has been established for woolly monkey hepatitis B virus (WMHBV) by using spider monkeys, since woolly monkeys are endangered. In this study, a greater-than-genome length construct was prepared without amplification by using covalently closed circular DNA extracted from the liver of an infected woolly monkey. Transfection of the human liver cell line Huh7 with WMHBV DNA resulted in the production of viral transcripts, DNA replicative intermediates, and secreted virions at levels similar to those obtained with an infectious human HBV clone, demonstrating that the host range restriction of WMHBV is not at the level of genome replication. WMHBV particles from the medium of transfected cultures initiated an infection in a spider monkey similar to that obtained with virions derived from woolly monkey serum. In an attempt to adapt the virus for higher levels of replication in spider monkeys, immunosuppressed and newborn animals were inoculated. Neither procedure produced persistent infections, and the level of viral replication remained several logs lower than that observed in persistently infected woolly monkeys. These data demonstrate the production of an infectious clone for WMHBV and extend the characterization of the spider monkey animal model.