Phenotypic characterization of human decidual macrophages

Abstract

SUMMARYPregnancy is a challenge to the immune system, which not only has to protect the mother and the fetus from invading pathogens but to also maintain immunological tolerance against the fetus. However, the mechanisms inhibiting local immune responses in the maternal decidual tissue are poorly understood. We have studied decidual CD14 + macrophages, which may be important in the maintenance of a tolerance against the developing fetus. Decidual macrophages expressed HLA-DR, but lower levels of costimulatory molecule CD86 than peripheral blood CD14+ monocytes from pregnant and nonpregnant women. Decidual macrophages produced spontaneously high levels of interleukin-10. Our findings suggest that decidual macrophages could represent an inhibitory type of APCs. Supporting this conclusion indoleamine 2,3-dioxygenase (IDO), suggested to have an immunosuppressive role in pregnancy, was expressed in decidual macrophages. Furthermore, decidual macrophages were not able to differentiate into dendritic cells under the influence of IL-4 + GM-CSF. These results suggest an immunoinhibitory function of decidual macrophages at the maternal-fetal interface.

The activating effect of IFN-γ on monocytes/macrophages is regulated by the LIF–trophoblast–IL-10 axis via Stat1 inhibition and Stat3 activation

“…9-11 IL-10-producing decidual Mws expressed CD14 and HLA-DR, but these cells exhibited lower levels of the costimulatory molecules CD40 and CD86 than peripheral blood monocytes from pregnant and non-pregnant women. 11 Furthermore, decidual Mws fail to differentiate into dendritic cells under the influence of IL-4 and GM-CSF. 11 Sayama et al 63 recently demonstrated that decidual Mws are able to suppress T-cell IFN-c production.…”

“…11 Furthermore, decidual Mws fail to differentiate into dendritic cells under the influence of IL-4 and GM-CSF. 11 Sayama et al 63 recently demonstrated that decidual Mws are able to suppress T-cell IFN-c production. This suppression occurs via B7-H1, which is a costimulatory ligand in the B7 family that negatively modulates T-cell activity by binding to the corresponding receptor PD-1.…”

Immunological properties of human decidual macrophages – a possible role in intrauterine immunity

“…The DMs present in human early decidual tissue have a capacity for allo-antigen presentation, a higher suppressive activity, and a lower capacity to produce IL-1 following LPS stimulation than peripheral blood monocytes (Mizuno et al 1994). DMs may represent an inhibitory type of antigen presenting cells and are thought to have an immunosuppressive role in early pregnancy due to their high levels of interleukin 10 and inodoleamine 2,3-dioxygenase (Heikkinen et al 2003, Kudo et al 2004. , were titrated against a constant concentration of decidual cells (10 6 ).…”

“…DMs may also produce cytokines such as IL-1, TNF-a and IL-6 in response to an infection and therefore cause an intrauterine inflammatory reaction that could provoke preterm parturition (McGregor et al 1988). Moreover, during implantation DMs have an important role in the regulation of apoptosis which is critical for the invasion of the developing embryo (Abrahams et al 2004) and have several biochemical functions that favour local immunological tolerance against fetal tissues (Heikkinen et al 2003).…”

Immune cells in the placental bed

“…A role in immunosuppression has also been proposed due to their suppression of one-way mixed lymphocyte reaction (Mizuno et al, 1994). In addition, Heikkinen et al (2003) reported that decidual macrophages from term pregnancy have low level expression of the T lymphocyte co-stimula- Decidua basalis (db) and decidua parietalis (dp) from second trimester and term. Flow cytometry…”