Document 0864
 DOCN  M9540864
 TI    Epitope exposure on functional, oligomeric HIV-1 gp41 molecules.
 DT    9504
 AU    Sattentau QJ; Zolla-Pazner S; Poignard P; Centre d'Immunologie de
       Marseille-Luminy, France.
 SO    Virology. 1995 Jan 10;206(1):713-7. Unique Identifier : AIDSLINE
       MED/95133216
 AB    We have used cells infected with the HIV-1 molecular clone HX10 to study
       the binding of monoclonal antibodies (mAbs) to different epitopes within
       the extracellular domain of the HIV-1 transmembrane glycoprotein gp41.
       Gp41 mAb binding to the infected cells at 4 degrees was variable but
       weaker than the binding of an anti-gp120/V3 loop mAb and increased
       substantially for three of the gp41 antibodies at 37 degrees. Treatment
       of the cells with soluble CD4 (sCD4) at 37 degrees increased gp41 mAb
       binding to epitopes spanning residues 521-663, implying that these
       regions had probably been masked by gp120, which following interaction
       with sCD4 had subsequently dissociated from gp41. By contrast, the
       binding of a mAb to residues 662-667 which form a neutralization epitope
       was reduced by sCD4 binding. Another region which has been described as
       containing a neutralization epitope spans residues 725-750. MAbs to this
       region bound equally well to noninfected and HIV-infected cells, and
       binding was not increased in the presence of sCD4. These data strongly
       imply that this epitope is not exposed on the external surface of the
       membrane, a finding in accord with the proposed cytoplasmic localization
       of this region.
 DE    Antibodies, Monoclonal/IMMUNOLOGY  Antigenic Determinants/*IMMUNOLOGY
       Antigens, CD4/IMMUNOLOGY  Binding Sites, Antibody  Cell Line  Human  HIV
       Envelope Protein gp41/*IMMUNOLOGY  HIV-1/*IMMUNOLOGY  Neutralization
       Tests  Recombinant Proteins/IMMUNOLOGY  Support, U.S. Gov't, Non-P.H.S.
       Support, U.S. Gov't, P.H.S.  JOURNAL ARTICLE

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