Document 1235
 DOCN  M9591235
 TI    Emergence of antigenic variants of simian immunodeficiency virus
       (SIVmac) in a seronegative macaque after SIVmac239 infection.
 DT    9509
 AU    Chuang LF; Blackbourn DJ; Chuang AJ; Killam KF Jr; Liu X; Li Y; Kung HF;
       Chuang RY; Department of Medical Pharmacology and Toxicology, University
       of; California, Davis 95616, USA.
 SO    Cell Mol Biol Res. 1994;40(7-8):661-9. Unique Identifier : AIDSLINE
       MED/95307605
 AB    Infection with the macaque strain of the simian immunodeficiency virus
       (SIVmac) induces simian immunodeficiency syndrome in rhesus macaques.
       This report describes the isolation and identification of antigenic
       variants of SIVmac in one of the infected monkeys (macaque #22803).
       Eight naive rhesus monkeys were inoculated with a titered viral stock of
       the molecularly cloned SIVmac239. Standard serological analysis revealed
       that all but two were seroconverted. Western blot analysis confirmed the
       seronegativity of macaque #22803. In addition, sera recovered from this
       monkey were not able to neutralize the parent SIVmac239. However, virus
       could be isolated from all of the infected animals, including macaque
       #22803. Sera recovered were reactive to the autologous virus. The
       results suggest that the virus from macaque #22803 may have undergone
       extensive antigenic shift in vivo. To test this hypothesis, a portion of
       the gag gene was amplified by the polymerase chain reaction (PCR),
       cloned, and sequenced. Sequence analysis revealed amino acid changes
       that were clustered between amino acids 200-245. Evaluation of the
       possible selective pressures contributing to the observed viral mutation
       revealed that in comparison with the other SIVmac239-infected monkeys,
       macaque #22803 produced an unusually high T cell proliferative response
       toward mitogen stimulation before infection, and continued to display a
       persistently high plasma viremia titer after infection.
 DE    Amino Acid Sequence  Animal  Antibodies, Viral/BLOOD  *Antigenic
       Variation  Antigens, Viral/*BIOSYNTHESIS/ISOLATION & PURIF  Base
       Sequence  Blotting, Western  Cloning, Molecular  DNA Primers
       Enzyme-Linked Immunosorbent Assay  Gene Products,
       gag/*BIOSYNTHESIS/ISOLATION & PURIF  Genes, gag  Lymphocyte
       Transformation  Lymphocytes/IMMUNOLOGY/VIROLOGY  Macaca mulatta
       Molecular Sequence Data  Neutralization Tests  Polymerase Chain Reaction
       RNA, Viral/ANALYSIS  Simian Acquired Immunodeficiency
       Syndrome/BLOOD/*IMMUNOLOGY  Support, U.S. Gov't, P.H.S.
       SIV/GENETICS/*IMMUNOLOGY/ISOLATION & PURIF  T-Lymphocytes/IMMUNOLOGY
       Time Factors  JOURNAL ARTICLE

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