• Interferon α;
  • and γ;
  • polyclonal and monoclonal antibodies;
  • embryonic cell proliferation and differentiation

ABSTRACT: Interferon (IFN)α, β, and γ have been localized in normal and pathological human pregnancy using both polyclonal and monoclonal antibodies in immunohistochemical techniques. IFNα was localized to fetal chorionic villous syncytiotrophoblast throughout normal pregnancy, as well as to extravillous trophoblast in the placental bed and chorion lave. Maternal decidual leukocytes, as well as fetal Hofbauer cells in the villous mesenchyme, also contained IFNα. IFNγ was detected in villous syncytiotrophoblast, while anti-IFNβ showed only patchy weak reactivity with syncytiotrophoblast. Reaction patterns on ectopic pregnancy tissues were similar to those in early intrauterine pregnancy. In molar pregnancy, reactivity for IFNα, β, and γ was observed in syncytiotrophoblast. Along with their potential anti-viral effects, placental interferons could play a role in local immunomodulation or in regulation of embryonic cell proliferation and differentiation.