Direct evidence for cytotoxicity associated with expression of hepatitis delta virus antigen.
It has been postulated that hepatocyte injury resulting from infection with hepatitis D virus may be caused by a direct virus cytotoxicity in contrast to immune-mediated injury associated with hepatitis B virus. We have transfected HeLa and HepG2 continuous cell lines with a recombinant plasmid containing the hepatitis D antigen gene under the inducible control of the human metallothionein promoter. The addition of zinc to the cell culture medium then led to the expression of hepatitis D antigen associated with, in the short term, a significant reduction in the rate of RNA but not DNA synthesis and, in the longer term, cell death. The necrotic cells had pyknotic nuclei and shrunken eosinophilic cytoplasm; these necrotic cells resembled the apoptotic bodies seen in hepatitis D virus-related hepatitis. The level of hepatitis D antigen in individual cells that produced these changes was similar to the level of hepatitis D antigen in hepatocytes from a chimpanzee with acute hepatitis D virus infection. We conclude that the expression of hepatitis D antigen resulted in significant cytotoxic changes in these cells, providing strong support for the view that hepatitis D antigen may be specifically cytotoxic to infected hepatocytes in vivo.
Cole
S M
SM
Division of Medical Virology, Institute of Medical and Veterinary Science, Adelaide, Australia.
Gowans
E J
EJ
Macnaughton
T B
TB
Hall
P D
PD
Burrell
C J
CJ
D000818:Animals; D000956:Antigens, Viral / Q000096:biosynthesis* / Q000235:genetics; D002460:Cell Line; D002470:Cell Survival; D002999:Clone Cells; D004247:DNA / Q000096:biosynthesis; D005455:Fluorescent Antibody Technique; D015967:Gene Expression Regulation, Viral; D006367:HeLa Cells; D003698:Hepatitis Delta Virus / Q000235:genetics / Q000276:immunology*; D035923:Hepatitis delta Antigens; D006801:Humans; D015151:Immunoblotting; D008099:Liver / Q000166:cytology / Q000382:microbiology; D008668:Metallothionein / Q000235:genetics; D002679:Pan troglodytes; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012313:RNA / Q000096:biosynthesis; D014162:Transfection; D015032:Zinc / Q000494:pharmacology
D000956:Antigens, Viral; D035923:Hepatitis delta Antigens; C442244:hepatitis delta virus large antigen; D012313:RNA; D004247:DNA; D008668:Metallothionein; D015032:Zinc