Regulatory T cells (Tregs) are thought to play a major role in pregnancy by inhibiting the maternal immune system and preventing fetal rejection. In decidual tissues, NK cells (dNK) reside in close contact with particular myelomonocytic CD14(+) (dCD14(+)) cells. Here we show that the interaction between dNK and dCD14(+) cells results in induction of Tregs. The interaction is mediated by soluble factors as shown by transwell experiments, and the prominent role of IFN-gamma is revealed by the effect of a neutralizing monoclonal antibody. Following interaction with dNK cells, dCD14(+) cells express indoleamine 2,3-dioxygenase (IDO), which, in turn, induces Tregs. Notably, unlike peripheral blood NK (pNK) cells, dNK cells are resistant to inhibition by the IDO metabolite L-kynurenine. "Conditioned" dCD14(+) cells also may induce Tregs through transforming growth factor-beta (TGF-beta) production or CTLA-4-mediated interactions, as indicated by the effect of specific neutralizing Abs. Remarkably, only the interaction between dNK and dCD14(+) cells results in Treg induction, whereas other coculture combinations involving either NK or CD14(+) cells isolated from peripheral blood are ineffective. Our study provides interesting clues to understanding how the crosstalk between decidual NK and CD14(+) cells may initiate a process that leads to Treg induction and immunosuppression. Along this line, it is conceivable that an impaired function of these cells may result in pregnancy failure.
Crosstalk between decidual NK and CD14+ myelomonocytic cells results in induction of Tregs and immunosuppression
VACCA, PAOLA;CANTONI, CLAUDIA;FENOGLIO, DANIELA;MORETTA, LORENZO;MINGARI, MARIA CRISTINA
2010-01-01
Abstract
Regulatory T cells (Tregs) are thought to play a major role in pregnancy by inhibiting the maternal immune system and preventing fetal rejection. In decidual tissues, NK cells (dNK) reside in close contact with particular myelomonocytic CD14(+) (dCD14(+)) cells. Here we show that the interaction between dNK and dCD14(+) cells results in induction of Tregs. The interaction is mediated by soluble factors as shown by transwell experiments, and the prominent role of IFN-gamma is revealed by the effect of a neutralizing monoclonal antibody. Following interaction with dNK cells, dCD14(+) cells express indoleamine 2,3-dioxygenase (IDO), which, in turn, induces Tregs. Notably, unlike peripheral blood NK (pNK) cells, dNK cells are resistant to inhibition by the IDO metabolite L-kynurenine. "Conditioned" dCD14(+) cells also may induce Tregs through transforming growth factor-beta (TGF-beta) production or CTLA-4-mediated interactions, as indicated by the effect of specific neutralizing Abs. Remarkably, only the interaction between dNK and dCD14(+) cells results in Treg induction, whereas other coculture combinations involving either NK or CD14(+) cells isolated from peripheral blood are ineffective. Our study provides interesting clues to understanding how the crosstalk between decidual NK and CD14(+) cells may initiate a process that leads to Treg induction and immunosuppression. Along this line, it is conceivable that an impaired function of these cells may result in pregnancy failure.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.