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Updated: Jul 18, 2026
Isolation of Primary Mouse Trophoblast Cells and Trophoblast Invasion Assay
Published on: January 8, 2012
Uptake of human immunodeficiency virus envelope protein gp120 by human trophoblast in culture
A L Esterman1, T H Finlay, J D Lee
1Department of Pediatrics, New York University Medical Center, NY 10016, USA.
Objective:
Our purpose was to determine whether human trophoblast has a cell surface CD4 antigen that will bind to gp120, the envelope protein of human immunodeficiency virus.
Study Design:
Uptake of iodine 125-labeled gp120 by trophoblast in culture was measured. Particular attention was paid to technical details that may have caused the contradictory results reported by previous investigators: the source of the recombinant gp120, the method of radioiodination, and the isolation procedure of trophoblast to ensure elimination of contaminating cells, particularly macrophages.
Results:
Uptake of transferrin-free iodine 125-labeled gp120 to trophoblast was unaffected by adding a 200 molar excess of gp120, by preincubating gp120 with soluble CD4 to block the CD4 binding sites on gp120 and by preincubation of trophoblast with a blocking antibody to CD4 (OKT4a). In contrast, uptake of gp120 by CD4-positive H9 human lymphocytes was reduced 79% by a 200 molar excess of gp120 and > 50% by a CD4-blocking antibody.
Conclusions:
Uptake of gp120 to trophoblast is by a high capacity, CD4-independent mechanism that is probably nonspecific and may be related to the mechanism for binding other circulating glycoproteins in maternal blood.
