       Document 0517
 DOCN  M9630517
 TI    Role of CD4 endocytosis in human immunodeficiency virus infection.
 DT    9603
 AU    Pelchen-Matthews A; Clapham P; Marsh M; Medical Research Council
       Laboratory for Molecular Cell Biology,; University College London,
       United Kingdom.
 SO    J Virol. 1995 Dec;69(12):8164-8. Unique Identifier : AIDSLINE
       MED/96079080
 AB    We have analyzed the role of CD4 endocytosis in human immunodeficiency
       virus (HIV) entry by measuring the infection of HeLa cells expressing
       various CD4 constructs with endocytosis rates of between 0.2 and 30%/min
       in a quantitative infectious focus assay. For a number of
       laboratory-adapted HIV-1 and HIV-2 strains, the highest levels of
       infection were found on cells with very limited CD4 endocytosis, while
       cells with efficient CD4 uptake were only poorly infectable, suggesting
       that CD4 internalization is not required for HIV entry. This was
       confirmed in a modified assay involving prebinding of HIV-1LAI to
       HeLa-CD4 cells at 4 degrees C, synchronized virus entry during warming
       to 37 degrees C, and neutralization of virions remaining at the cell
       surface with anti-V3 loop antibodies. Warming cells in hypertonic medium
       inhibited CD4 endocytosis but did not affect the rate or the extent of
       infection. These studies confirm that HIV infection does not require
       endocytosis and that laboratory-adapted virus strains can enter HeLa-CD4
       cells by fusion at the plasma membrane.
 DE    Alanine  Amino Acid Sequence  Antigens, CD4/BIOSYNTHESIS/*PHYSIOLOGY
       Comparative Study  *Endocytosis  Hela Cells  Human  Hypertonic Solutions
       HIV-1/*PHYSIOLOGY  HIV-2/*PHYSIOLOGY  Mutagenesis, Site-Directed  Point
       Mutation  Recombinant Proteins/BIOSYNTHESIS/METABOLISM  Serine  Support,
       Non-U.S. Gov't  Transfection  JOURNAL ARTICLE

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

