       Document 0552
 DOCN  M9650552
 TI    Kinetics of HIV infection of human placental syncytiotrophoblast
       cultures: an ultrastructural and immunocytochemical study.
 DT    9605
 AU    Fazely F; Fry GN; Thirkill TL; Hakim H; King BF; Douglas GC; Department
       of Medical Pathology, School of Medicine, University; of California,
       Davis 95616, USA.
 SO    AIDS Res Hum Retroviruses. 1995 Sep;11(9):1023-30. Unique Identifier :
       AIDSLINE MED/96089209
 AB    We previously demonstrated that syncytiotrophoblast (ST) cells from term
       human placentas could be infected when cocultured with HIV-infected
       lymphocytic cells. Here, we have used fluorescence microscopy and
       transmission electron microscopy to examine the kinetics of this
       infection process. Molt-4 clone 8 cells infected with HIV-1Lai or
       filtered supernatant from these cultures were incubated with ST cells
       for different times. In cell-associated infection, immunofluorescence
       microscopy revealed that some ST colonies were positive for HIV core
       proteins (p24,p55) after 1 hr. The number of positive colonies and the
       intensity of the ST-associated fluorescence increased with time.
       Transmission electron microscopy showed viral particles with HIV
       morphology associated with the ST cell surface at 1 hr. Immature virions
       with budding morphology were observed at 2 hr. In cell-free infection,
       positive p24,p55 staining was first detected in a few ST colonies at 4
       hr. The number of positive colonies increased with time. At 24 hr, the
       fluorescence pattern and intensity resembled that seen with
       cell-mediated infection at 4 hr. Transmission electron microscopy
       revealed an increasing number of viral particles associated with the ST
       cell plasma membrane with respect to time, and budding virions first
       appeared at 8 hr. These results demonstrate that HIV infection of
       placental ST cells proceeds very rapidly in culture and that,
       furthermore, cell-associated infection of ST is much more efficient than
       the infection with cell-free virus.
 DE    Clone Cells  Female  Gene Products, gag/METABOLISM  Human  HIV Core
       Protein p24/METABOLISM  HIV Infections/*ETIOLOGY/METABOLISM/VIROLOGY
       HIV-1/METABOLISM/*PATHOGENICITY/ULTRASTRUCTURE  Immunohistochemistry
       Kinetics  Microscopy, Electron  Microscopy, Fluorescence  Pregnancy
       Protein Precursors/METABOLISM  Support, U.S. Gov't, P.H.S.
       Trophoblast/METABOLISM/ULTRASTRUCTURE/*VIROLOGY  JOURNAL ARTICLE

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

