Granulocytic myeloid derived suppressor cells expand in human pregnancy and modulate T‐cell responses

N Köstlin, H Kugel, B Spring, A Leiber… - European journal of …, 2014 - Wiley Online Library
N Köstlin, H Kugel, B Spring, A Leiber, A Marmé, M Henes, N Rieber, D Hartl, CF Poets…
European journal of immunology, 2014Wiley Online Library
Immune tolerance toward the semiallogeneic fetus plays a crucial role in the maintenance of
pregnancy. Myeloid‐derived suppressor cells (MDSC s) are innate immune cells
characterized by their ability to modulate T‐cell responses. Recently, we showed that MDSC
s accumulate in cord blood of healthy newborns, yet their role in materno–fetal tolerance
remained elusive. In the present study, we demonstrate that MDSCs with a granulocytic
phenotype (GR‐MDSC s) are highly increased in the peripheral blood of healthy pregnant …
Immune tolerance toward the semiallogeneic fetus plays a crucial role in the maintenance of pregnancy. Myeloid‐derived suppressor cells (MDSCs) are innate immune cells characterized by their ability to modulate T‐cell responses. Recently, we showed that MDSCs accumulate in cord blood of healthy newborns, yet their role in materno–fetal tolerance remained elusive. In the present study, we demonstrate that MDSCs with a granulocytic phenotype (GR‐MDSCs) are highly increased in the peripheral blood of healthy pregnant women during all stages of pregnancy compared with nonpregnant controls, whereas numbers of monocytic MDSCs were unchanged. GR‐MDSCs expressed the effector enzymes arginase‐I and iNOS, produced high amounts of ROS and efficiently suppressed T‐cell proliferation. After parturition, GR‐MDSCs decreased within a few days. In combination, our results show that GR‐MDSCs expand in normal human pregnancy and may indicate a role for MDSCs in materno–fetal tolerance.
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