Dominant IL-10 and TGF-β mRNA expression in γδT cells of human early pregnancy decidua suggests immunoregulatory potential

PROBLEM: To examine the cytokine gene expression in gammadeltaT-cells from human early pregnancy decidua. METHOD OF STUDY: The cytokine messenger RNA (mRNA) expression in isolated decidual T-cell receptor (TCR)gammadelta(+)/CD56(+) and TCRgammadelta single positive cells was investigated with a panel of cytokine primers and probes selected to distinguish between T helper (Th)1, Th2, Th3 and regulatory T-cells (Tr1) type of immune response using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: TCRgammadelta(+)/CD56(+) cells express almost exclusively the immunosuppressive cytokines interleukin-10 (IL-10) and transforming growth factor (TGF)-beta. The TCRgammadelta single positive cells enhance their transcription of IL-10 and TGF-beta, compared with the TCRgammadelta(+)/CD56(+) cells and additionally express mRNA for IL-1beta and IL-6. CONCLUSIONS: The present findings suggest that gammadeltaT cells in normal pregnancy create a cytokine milieu promoting immunotolerance to the fetus. We hypothesize that through the production of the immunosuppressive cytokines IL-10 and/or TGF-beta the gammadeltaT cells could function directly as regulatory T cells or induce the differentiation of Th0 TCRalphabeta(+) cells into regulatory/suppresser cells.