Expression of CD94/NKG2A, LIR-1, and p49 receptors in lymphoid cells freshly isolated from maternal decidua in early pregnancy. The lymphoid population analyzed was derived from maternal decidua tissue obtained from elective (10th week) termination of pregnancy. Cells were purified on Ficoll–Hypaque gradients and were analyzed for surface expression of informative markers including CD56, CD16, CD94, NKG2A, LIR-1 (by using the specific mAbs indicated in Materials and Methods followed by an anti-mouse IgG1), and p49 (by using the TOP-2 antiserum); a PE-conjugated anti-mouse IgG1 was used as second reagent.