Document 3292
 DOCN  M94A3292
 TI    A novel in vitro HIV property in pediatric isolates.
 DT    9412
 AU    St. Clair M; Vavro CL; Pennington KN; Valentine M; McKinney RE;
       Burroughs Wellcome Co., RTP NC 27709.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):11 (abstract no. 019A). Unique
       Identifier : AIDSLINE ICA10/94369283
 AB    A novel in vitro virus property has been identified in virus isolated
       from 5 of 28 pediatric patients with HIV disease. This new property
       differs from the previously defined Syncytia Inducing(SI) and
       Non-Syncytia Inducing (NSI) phenotypes in that the virus is able to
       replicate in MT-2 cells without the cytopathogenic effects observed with
       the SI phenotype. We have designated this property as NSI+. The 5
       patients (10 months to 9 years old) had received Zidovudine (ZDV), DDI,
       or ZDV + DDI for various lengths of time and have relatively stable HIV
       disease. Three patients received virus by vertical transmission, 2 by
       transfusion soon after birth from a single donor. All patients had
       stable CD4+ lymphocyte percentages until just prior to the emergence of
       the new virus behavior when CD4+ counts abruptly decreased and then
       recovered to baseline values. Patient peripheral blood lymphocytes
       (PBL's) were cocultured with donor PBL's. Cultures were frozen at peak
       reverse transcriptase(RT) levels. Positive PBL cultures were cocultured
       with MT-2 cells to determine the virus phenotype (SI vs. NSI). These 5
       patients had cocultures which demonstrated replication in MT-2 cells
       without the formation of syncytia (were NSI+). While NSI+ virus
       replicated in MT-2 cells to a titer (as determined by RT) ten-fold lower
       than that produced by SI virus, NSI+ replicated to a level 50-fold above
       background. In contrast, the typical NSI phenotype is incapable of
       replicating to significant titers in MT-2 cells. Further passage of NSI+
       in MT-2 cells did not result in a change of phenotype from NSI+ to SI.
       Extensive mixing experiments of the 3 viral phenotypes has shown that
       NSI+ is not a small SI contamination in an NSI background. Further
       investigation of NSI+, including antibody neutralization studies and
       genetic analysis of the envelope region of HIV, may elucidate its
       significance in HIV disease.
 DE    Cells, Cultured  Child  Child, Preschool  Human
       HIV/CLASSIFICATION/GROWTH & DEVELOPMENT/*GENETICS  HIV
       Infections/*MICROBIOLOGY  Infant  Lymphocytes  Phenotype  T4 Lymphocytes
       Virus Replication  MEETING ABSTRACT

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