SCREENING FOR CYTOKINE MESSENGER RIBONUCLEIC-ACIDS IN PURIFIED HUMAN DECIDUAL LYMPHOCYTE POPULATIONS BY THE REVERSE-TRANSCRIPTASE POLYMERASE CHAIN-REACTION

At the time of human embryo implantation, large numbers of maternal CD 56(bright)CD16(-) NK cells appear in the uterus. These unusual lymphoc ytes are believed to control the migration and differentiation of high ly invasive feta[ly derived trophoblast cells, which infiltrate into t he maternal uterus to remodel the spiral arteries during the first tri mester. One possible mechanism of control is by cytokine production. I n this study, highly purified (>99%) populations of first trimester de cidual CD56(bright)CD16(-) NK cells and CD3(+) T lymphocytes were obta ined by using a FACS. These cells were examined by reverse transcripta se PCR for their expression of mRNAs for the following cytokines: gran ulocyte-macrophage (GM)-CSF, CSF-1, TNF-alpha, IFN-gamma, TGF-beta(1), leukemia-inhibitory factor (LIF), and IL-2. Then, the expression was compared with that of resting PBL. The identity of the PCR products wa s verified by Southern blotting and hybridization with cytokine-specif ic probes. Both decidual CD56(bright)CD16(-) NK cells and CD3(+) T cel ls were found to express mRNA for CSF-1, TNF-alpha, IFN-gamma, TGF-bet a(1), and LIF, but GM-CSF mRNA was detected only in CD56(bright) NK ce lls. IL-2 mRNA was detected in only some decidual T cell samples, and then only after at least two rounds of amplification. In contrast, per ipheral blood CD56(bright)CD16(-) NK cells, CD56(dim)CD16(+) NK cells, and CD3(+) T cells expressed mRNA only for TNF-alpha and TGF-beta(1), but not for GM-CSF, CSF-1, IFN-gamma, LIF, or IL-2. These results sug gest that both decidual NK cells and decidual T cells produce a variet y of cytokines that may be involved in the control of trophoblast migr ation and differentiation during pregnancy.