FUNCTIONAL-CHARACTERISTICS OF HUMAN TROPHOBLAST INTERFERONS

Human trophoblast populations from first- and third-trimester placenta s produce interferons (IFNs) in the presence of growth factors (CSF an d PDGF) or when infected with virus. The highly invasive extravillous trophoblast population produced a higher level of IFNs (three- to eigh tfold, P < 0.05) than the noninvasive villous trophoblast population w hen stimulated with growth factors and/or virus. The level of IFN prod uced was dependent on the type of trophoblast population, the type of inducer and the stage of differentiation of the trophoblasts. Tandem i mmunoaffinity chromatography of the virus-induced trophoblast IFNs res ulted in the isolation of trophoblast IFN-alpha and -beta types. The p urified trophoblast IFNs have antiviral, antiproliferative and immunor egulatory properties. Furthermore, the trophoblast IFNs inhibited the expression of proto-oncogenes such as EGF-R, c-erbB2 and c-fms reporte d to be involved in normal trophoblast growth and differentiation. The se data suggest essential roles of interferons in normal human develop ment during pregnancy.