The feline immunodeficiency virus ORF-A gene facilitates efficient viral replication in established T-cell lines and peripheral blood lymphocytes.
Frameshift mutants corresponding to all of the identified open reading frames of feline immunodeficiency virus, including the ORF-A gene, which has an unknown function, were constructed in vitro. Upon transfection into cells, no significant difference between the phenotypes of ORF-A mutant clones and those of wild-type clones was demonstrated. Although only ORF-A mutant virus among all mutant viruses from transfected cells showed infectivity in established T-cell lines, the replication and propagation of the ORF-A mutant virus were efficiently reduced compared with those of the wild-type virus. Moreover, the loss of the function of the ORF-A gene resulted in a severe defect in productive infection in primary peripheral blood lymphocytes both in the amount of reverse transcriptase activity produced and in core protein expression. These findings demonstrate that the ORF-A gene of feline immunodeficiency virus is required for efficient viral replication and suggest that the ORF-A gene is likely to be important for natural infection.
Tomonaga
K
K
Department of Veterinary Microbiology, Faculty of Agriculture, University of Tokyo, Japan.
Miyazawa
T
T
Sakuragi
J
J
Mori
T
T
Adachi
A
A
Mikami
T
T
D000818:Animals; D001483:Base Sequence; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D002415:Cats; D002460:Cell Line; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D005814:Genes, Viral; D016089:Immunodeficiency Virus, Feline / Q000201:enzymology / Q000235:genetics* / Q000502:physiology*; D008214:Lymphocytes / Q000382:microbiology*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D016133:Polymerase Chain Reaction; D012194:RNA-Directed DNA Polymerase / Q000032:analysis; D016176:T-Lymphocyte Subsets / Q000382:microbiology*; D013601:T-Lymphocytes / Q000382:microbiology*; D014162:Transfection; D014771:Virion / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D014779:Virus Replication
D015704:CD4 Antigens; D016827:CD8 Antigens; D004279:DNA, Viral; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D012194:RNA-Directed DNA Polymerase