Differences in Circulating Dendritic Cell Subtypes in Pregnant Women, Cord Blood and Healthy Adult Women

Abstract

Different subtypes of dendritic cells (DC) influence the differentiation of naíve T lymphocytes into T helper type 1 (Th1) and Th2 effector cells. We evaluated the percentages of DC subtypes in peripheral blood from pregnant women (maternal blood) and their cord blood compared to the peripheral blood of healthy non pregnant women (control). Circulating DC were identified by flow cytometry as lineage (CD3, CD14, CD16, CD19, CD20, and CD56)-negative and HLA-DR-positive cells. Subtypes of DC were further characterized as myeloid DC (CD11c+/CD123±), lymphoid DC (CD11c-/CD123+++) and less differentiated DC (CD11c-/CD123±). The frequency of DC out of all nucleated cells was significantly lower in maternal blood than in control (P<0.001). The ratio of myeloid DC/lymphoid DC was significantly higher in maternal blood than in control (P<0.01). HLA-DR expressions of myeloid DC as mean fluorescence intensity (MFI) were significantly less in maternal blood and in cord blood than in control (P<0.001, respectively). The DC differentiation factors, TNF-α and GM-CSF, released from mononuclear cells after lipopolysaccharide stimulation were significantly lower in maternal blood than in control (P<0.01). The distribution of DC subtypes was different in maternal and cord blood from those of non-pregnant women. Their role during pregnancy remains to be determined.

Maternal Circulating Dendritic Cell Subtypes at Delivery and During the 1‐Year Postpartum Period

“…In the present study, the DC percentage and absolute numbers among leukocytes were low in maternal blood at the time of delivery, despite the physiological increase in total leukocyte numbers at this time. These results are consistent with those of previous studies . Therefore, it is believed that decreased levels of DCs play important roles in immune tolerance that is necessary for maintaining pregnancy.…”

The role of inflammation in the pathology of preeclampsia

“…Cells involved in innate immunity, such as monocytes and granulocytes, are increased in the circulation and show an increase in cell activation during pregnancy (31, 32). Other inflammatory cells, such as DCs and NK cells, are decreased in the periphery during normal pregnancy (33, 34). The function of DCs has recently been studied and it was noted that co-stimulatory molecules responsible for DC tolerance are increased during normal pregnancy (35, 36).…”

The Placenta in Toxicology. Part II

“…Also, granulocyte function is changed during pregnancy: granulocytes show increased production of oxygen radicals (Sacks et al 1998) and increased phagocytic activity (Barriga, Rodriquez, and Ortega 1994). The number of dendritic cells (DCs), which are antigen presenting cells, on the other hand, were found to be decreased during pregnancy (Cordeau et al 2012;Darmochwal-Kolarz et al 2003;Shin et al 2009;Ueda et al 2003). However, it has been shown that these cells show increased tolerogenic properties (Darmochwal-Kolarz et al 2012): upon stimulation, interferon (IFN)-a production and costimulatory molecules such as CD54 and CD86 are decreased (Cordeau et al 2012), while the expression of tolerance-associated molecules, for example, CD200 and CD200R, is increased during pregnancy (Darmochwal-Kolarz et al 2012).…”