       Document 0112
 DOCN  M9630112
 TI    Generation and role of defective proviruses in cytopathic feline
       leukemia virus (FeLV-FAIDS) infections.
 DT    9603
 AU    de Noronha CM; Reinhart TA; Mullins JI; Department of Cancer Biology,
       Harvard School of Public Health,; Boston, Massachusetts 02115, USA.
 SO    J Virol. 1996 Jan;70(1):359-67. Unique Identifier : AIDSLINE
       MED/96099451
 AB    Cytopathic feline leukemia virus (FeLV) infections of feline T-cell line
       (FeT-cell) cultures led to the accumulation and maintenance of threefold
       more proviruses with deletions within the polymerase gene (pol) than
       minimally cytopathic FeLV infections. Over 60% of the viral DNA from
       cytopathic infections bore deletions in pol. Characterization of DNA
       sequences adjoining the deletions revealed that the junctions were most
       often flanked by RNA splice donor and acceptor consensus motifs. A
       thymidine-to-cytidine mutation introduced at the +2 position of one RNA
       splice donor-like motif inhibited formation of the two most prevalent
       viral DNA species with deletions, confirming the origin of many
       proviruses with deletions from reverse transcription of aberrantly
       spliced viral RNA species. An example of deletion by misalignment was
       also characterized. Viral inocula obtained from cells recovered after
       cytopathic infections were attenuated in their ability to cause
       cytopathic effects (CPE) and were able to confer superinfection
       resistance to naive FeT-cells, despite maintaining envelope gene (env)
       sequences with full cytopathic potential. This suggested that viral
       genomes with deletions, rather than being required for cytopathicity,
       play a role in protecting cells from CPE. Indeed, expression of a
       molecularly cloned provirus bearing one of the characterized deletions
       attenuated CPE in FeT-cells caused by superinfecting cytopathic virus.
 DE    Animal  Base Sequence  Cats  Cell Line  Defective
       Viruses/GENETICS/ISOLATION & PURIF/*PHYSIOLOGY  DNA, Viral  Genes, pol
       Genes, Viral  Leukemia Virus, Feline/GENETICS/ISOLATION &
       PURIF/*PHYSIOLOGY  Molecular Sequence Data  Proviruses/ISOLATION &
       PURIF/*PHYSIOLOGY  Sequence Deletion  Support, U.S. Gov't, P.H.S.  Virus
       Replication  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

