Document 0080
 DOCN  M9580080
 TI    CD4 expression on dendritic cells and their infection by human
       immunodeficiency virus.
 DT    9506
 AU    Patterson S; Gross J; English N; Stackpoole A; Bedford P; Knight SC;
       Antigen Presentation Research Group, Clinical Research Centre,; Harrow,
       Middlesex, UK.
 SO    J Gen Virol. 1995 May;76 ( Pt 5):1155-63. Unique Identifier : AIDSLINE
       MED/95248283
 AB    Infection of dendritic cells (DC) by human immunodeficiency virus (HIV)
       has been disputed. Employing a fluorescence-activated cell sorter, DC,
       identified by the absence of membrane markers for T, B, natural killer
       (NK) and monocytic cells and by high levels of MHC class II DR antigen,
       were shown to express low levels of CD4. Immunomagnetic beads were used
       to separate blood low density cells, which are enriched for DC, into
       CD4-positive and -negative populations. Examination of these cells by
       electron microscopy showed an increase in the percentage of cells with
       DC morphology in the CD4-positive fraction and a reduction in the
       CD4-negative fraction. Electron microscopy of semi-purified DC
       preparations infected in vitro for 5 days with HIV-1 revealed
       morphologically distinct veiled DC with mature virions on the cell
       surface and virus budding through the cell membrane. Further evidence
       for the growth of HIV in DC was provided by experiments in which DC were
       extensively depleted of contaminating lymphocytes and monocytes prior to
       infection. Estimation of provirus load by a nested PCR indicated that
       after 5 days an infection level of one provirus copy per five cells
       could be achieved. After 7 days the provirus copy number could exceed
       the cellular genome copy number, suggesting that some cells had more
       than one provirus. Infectious virus could not be demonstrated in these
       cultures after 24 h but was detected after 5 or 7 days. Infection of DC
       in the presence of antibodies against CD4 was inhibited and suggests
       infection occurs via a CD4-dependent pathway. These results confirm that
       DC are susceptible to HIV infection in vitro. The immunological
       consequences of DC infection in vivo may be significant in the
       pathogenesis of AIDS.
 DE    Antigens, CD4/*ANALYSIS  Base Sequence  Dendritic
       Cells/IMMUNOLOGY/*VIROLOGY  DNA, Viral/ANALYSIS  Human  HIV/*GROWTH &
       DEVELOPMENT  Molecular Sequence Data  Polymerase Chain Reaction  JOURNAL
       ARTICLE

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