Document 0602
 DOCN  M9550602
 TI    Encapsidation of poliovirus replicons encoding the complete human
       immunodeficiency virus type 1 gag gene by using a complementation system
       which provides the P1 capsid protein in trans.
 DT    9505
 AU    Porter DC; Ansardi DC; Morrow CD; Department of Microbiology, University
       of Alabama at Birmingham; 35294.
 SO    J Virol. 1995 Mar;69(3):1548-55. Unique Identifier : AIDSLINE
       MED/95156580
 AB    Poliovirus genomes which contain small regions of the human
       immunodeficiency virus type 1 (HIV-1) gag, pol, and env genes
       substituted in frame for the P1 capsid region replicate and express
       HIV-1 proteins as fusion proteins with the P1 capsid precursor protein
       upon transfection into cells (W. S. Choi, R. Pal-Ghosh, and C. D.
       Morrow, J. Virol. 65:2875-2883, 1991). Since these genomes, referred to
       as replicons, do not express capsid proteins, a complementation system
       was developed to encapsidate the genomes by providing P1 capsid proteins
       in trans from a recombinant vaccinia virus, VV-P1. Virus stocks of
       encapsidated replicons were generated after serial passage of the
       replicon genomes into cells previously infected with VV-P1 (D. C.
       Porter, D. C. Ansardi, W. S. Choi, and C. D. Morrow, J. Virol.
       67:3712-3719, 1993). Using this system, we have further defined the role
       of the P1 region in viral protein expression and RNA encapsidation. In
       the present study, we constructed poliovirus replicons which contain the
       complete 1,492-bp gag gene of HIV-1 substituted for the entire P1 region
       of poliovirus. To investigate whether the VP4 coding region was required
       for the replication and encapsidation of poliovirus RNA, a second
       replicon in which the complete gag gene was substituted for the VP2,
       VP3, and VP1 capsid sequences was constructed. Transfection of replicon
       RNA with and without the VP4 coding region into cells resulted in
       similar levels of expression of the HIV-1 Gag protein and poliovirus 3CD
       protein, as indicated by immunoprecipitation using specific antibodies.
       Northern (RNA) blot analysis of RNA from transfected cells demonstrated
       comparable levels of RNA replication for each replicon. Transfection of
       the replicon genomes into cells infected with VV-P1 resulted in the
       encapsidation of the genomes; serial passage in the presence of VV-P1
       resulted in the generation of virus stocks of encapsidated replicons.
       Analysis of the levels of protein expression and encapsidated replicon
       RNA from virus stocks after 21 serial passages of the replicon genomes
       with VV-P1 indicated that the replicon which contained the VP4 coding
       region was present at a higher level than the replicon which contained a
       complete substitution of the P1 capsid sequences. These differences in
       encapsidation, though, were not detected after only two serial passages
       of the replicons with VV-P1 or upon coinfection and serial passage with
       type 1 Sabin poliovirus.(ABSTRACT TRUNCATED AT 400 WORDS)
 DE    Amino Acid Sequence  Animal  Base Sequence  Capsid/GENETICS/*METABOLISM
       Cercopithecus aethiops  DNA Primers/CHEMISTRY  Gene Expression
       Regulation, Viral  Genes, gag  Genetic Complementation Test  Hela Cells
       Human  HIV-1/*GENETICS  In Vitro  Molecular Sequence Data  Morphogenesis
       Polioviruses/GROWTH & DEVELOPMENT/*GENETICS  Protein Processing,
       Post-Translational  Proteins/METABOLISM  Replicon  RNA,
       Messenger/GENETICS  Support, Non-U.S. Gov't  Support, U.S. Gov't, P.H.S.
       Viral Proteins/METABOLISM  JOURNAL ARTICLE

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