Document 0624
 DOCN  M94A0624
 TI    HIV-1 grown in CD4-bearing cells may be coated with CD4.
 DT    9412
 AU    Hartley C; Gilbert M; Elbeik T; Crowe S; Mills J; Macfarlane Burnet
       Centre for Medical Research, Fairfield,; Victoria.
 SO    Annu Conf Australas Soc HIV Med. 1993 Oct 28-30;5:72 (abstract no. SB4).
       Unique Identifier : AIDSLINE ASHM5/94349031
 AB    Using a CD4-capture enzyme-immunoassay, HIV-1 (SF33) grown in
       CD4-expressing T-lymphoblastoid cells (SF33-VB) were found to contain
       100-10,000 fold less reactive gp 120 than HIV-1 (SF33) grown in
       CD4-negative human neuroblastoma cell (SF33-NB), despite similar virus
       titres. Virus strains grown in CD4-expressing cells also bound minimally
       to Sepharose immobilised CD4; in contrast, 99.9% of virus grown in
       CD4-negative cells and 95% of viral gp120 were removed by solid phase
       CD4. Detection of CD4 in sucrose density gradient purified SF33-VB in
       immunoblot assay raised the possibility that free HIV virions may be
       coated with CD4 when grown in CD4-expressing cells, thereby inhibiting
       efficient binding of virus to immobilised CD4 in these assays.
       Co-sedimentation of 125I-labelled anti-CD4 monoclonal antibody OKT4 with
       purified SF33-VB following centrifugation over a 20-60% sucrose gradient
       provides further indication that virus propagated in CD4-expressing
       cells is coated with CD4. Coating of HIV with CD4 may limit the rate of
       infection via the CD4 receptor and may contribute to the lack of
       efficacy of recombinant soluble CD4 in vivo.
 DE    Antigens, CD4/*ANALYSIS  Cell Line  Human  HIV Envelope Protein
       gp120/IMMUNOLOGY  HIV-1/*GROWTH & DEVELOPMENT/IMMUNOLOGY  Immunoenzyme
       Techniques  T4 Lymphocytes/IMMUNOLOGY/*MICROBIOLOGY  *Virus Cultivation
       MEETING ABSTRACT

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