TY - JOUR
T1 - In hepatocytes infected with duck hepatitis B virus, the template for viral RNA synthesis is amplified by an intracellular pathway
AU - Wu, Tsung Teh
AU - Coates, Laura
AU - Aldrics, Carol E.
AU - Summers, Jesse
AU - Mason, William S.
N1 - Funding Information:
We are grateful to Drs. L. Condreay, R. Katz, and J. Taylor for helpful suggestions, to A. O’Connell and W. T. London for DHBV-positive ducklings, and to C. House for assistance in the laboratory. We acknowledge A. Capriotti and M. Piatek for assistance in the prepara-tlon of this manuscript. This research was supported by Public Health Services Grants Al-l 8641, CA-06927, and RR-05539 from the National Institutes of Health and by an appropriation from the Commonwealth of Pennsylvania. T.-T. Wu is a graduate student of the Department of Pathology, University of Pennsylvania.
PY - 1990/3
Y1 - 1990/3
N2 - During the productive phase of chronic hepadnaviral infections, virion DNA synthesis occurs in the cytoplasm of the infected hepatocyte, but viral RNA is synthesized in the nucleus, apparently from a covalently closed, circular (CCC) viral DNA. J. Tuttleman, C. Pourcel, and 1. Summers (1986a, Cell 47, 451-460) have shown that the intracellular levels of CCC DNA can increase during initiation of infection of duck hepatocytes in vitro with duck hepatitis B virus and during long term culture of infected duck hepatocytes in vitro. This amplification of CCC DNA occurs through the reverse transcription pathway. To distinguish between an entirely intracellular process of amplification and amplification due to multiple infections by extracellular virus in the virus producing cultures, suramin was added to the infected cultures to block superinfection. We found that CCC DNA amplification occurred at least as efficiently in the presence of suramin as in its absence. First, there was a net increase in the total amount of CCC DNA in the cultures both in the presence and in the absence of suramin. Second, synthesis of CCC DNA in the presence and absence of suramin was observed by density labeling of this viral DNA by growth of the cultures in medium containing BUdR. Amplification was also demonstrable in the presence of neutralizing duck antibodies. These results support the hypothesis of Tuttleman et al. (1986a) that CCC DNA amplification in chronically infected cultures and, by inference, the mechanism of persistent infection involves primarily intracellular regulatory mechanisms.
AB - During the productive phase of chronic hepadnaviral infections, virion DNA synthesis occurs in the cytoplasm of the infected hepatocyte, but viral RNA is synthesized in the nucleus, apparently from a covalently closed, circular (CCC) viral DNA. J. Tuttleman, C. Pourcel, and 1. Summers (1986a, Cell 47, 451-460) have shown that the intracellular levels of CCC DNA can increase during initiation of infection of duck hepatocytes in vitro with duck hepatitis B virus and during long term culture of infected duck hepatocytes in vitro. This amplification of CCC DNA occurs through the reverse transcription pathway. To distinguish between an entirely intracellular process of amplification and amplification due to multiple infections by extracellular virus in the virus producing cultures, suramin was added to the infected cultures to block superinfection. We found that CCC DNA amplification occurred at least as efficiently in the presence of suramin as in its absence. First, there was a net increase in the total amount of CCC DNA in the cultures both in the presence and in the absence of suramin. Second, synthesis of CCC DNA in the presence and absence of suramin was observed by density labeling of this viral DNA by growth of the cultures in medium containing BUdR. Amplification was also demonstrable in the presence of neutralizing duck antibodies. These results support the hypothesis of Tuttleman et al. (1986a) that CCC DNA amplification in chronically infected cultures and, by inference, the mechanism of persistent infection involves primarily intracellular regulatory mechanisms.
UR - http://www.scopus.com/inward/record.url?scp=0025329760&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025329760&partnerID=8YFLogxK
U2 - 10.1016/0042-6822(90)90206-7
DO - 10.1016/0042-6822(90)90206-7
M3 - Article
C2 - 2155510
AN - SCOPUS:0025329760
SN - 0042-6822
VL - 175
SP - 255
EP - 261
JO - Virology
JF - Virology
IS - 1
ER -