The role of gamma/delta T-cell receptor-positive cells in pregnancy: Part II

PROBLEM: We have previously demonstrated a significantly increased ratio of gamma/delta T-cell receptor (TCR)-positive progesterone receptor(PR)-posit ive cells in the peripheral blood of healthy pregnant women compared to tha t of recurrent aborters or non-pregnant individuals. Treatment of pregnancy lymphocytes with a pan anti-gamma/delta TCR antibody inhibits progesterone -induced blocking factor (PIBF) production, increases natural killer (NK) a ctivity, and alters the cytokine profile. The present study was aimed at in vestigating the role of the different gamma/delta subpopulations in these p henomena. METHOD OF STUDY: Peripherial blood lymphocytes from healthy pregnant women were incubated with either anti-gamma 1.4 and delta 1, or anti-gamma 9 and delta 2 antibodies. The effect of these treatments on PR induction and inte rleukin (IL)-10 and IL-12 expression were tested by immunocytochemistry. NK activity of anti-gamma/delta treated lymphocytes was also determined. RESULTS: In peripheral blood of healthy pregnant women, the most frequently occurring chain combination was gamma 1.4/delta 1, whereas in recurrent ab orters, the gamma 9/delta 2 combination was predominant. Treatment of norma l pregnancy lymphocytes with a mixture of gamma 1.4 and delta 1 antibodies resulted in a significantly reduced NK activity and increased PR and IL-10 expression, whereas treatment with a mixture of gamma 9 and delta 2 antibod ies significantly reduced IL-10 production and slightly increased IL-12 pro duction and NK activity. These data suggest the presence of two functionall y distinct subpopulations in the peripheral blood of pregnant women.