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 γδT‐cells from human early pregnancy decidua. METHOD OF STUDY: The cytokine messenger RNA (mRNA) expression in isolated decidual T‐cell receptor (TCR)γδ + /CD56 + and TCRγδ 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: TCRγδ + /CD56 + cells express almost exclusively the immunosuppressive cytokines interleukin‐10 (IL‐10) and transforming growth factor (TGF)‐β. The TCRγδ single positive cells enhance their transcription of IL‐10 and TGF‐β, compared with the TCRγδ + /CD56 + cells and additionally express mRNA for IL‐1β and IL‐6. CONCLUSIONS: The present findings suggest that γδT 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‐β the γδT cells could function directly as regulatory T cells or induce the differentiation of Th0 TCRαβ + cells into regulatory/suppresser cells.