title: Granulocytic myeloid derived suppressor cells expand in human pregnancy and modulate T-cell responses.
abstract: 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.
authors.affiliation: Department of Neonatology, Tuebingen University Children's Hospital, Tuebingen, Germany.
authors.forename: Natascha
authors.initials: N
authors.lastname: Köstlin
authors.forename: Hellen
authors.initials: H
authors.lastname: Kugel
authors.forename: Bärbel
authors.initials: B
authors.lastname: Spring
authors.forename: Anja
authors.initials: A
authors.lastname: Leiber
authors.forename: Alexander
authors.initials: A
authors.lastname: Marmé
authors.forename: Melanie
authors.initials: M
authors.lastname: Henes
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Rieber
authors.forename: Dominik
authors.initials: D
authors.lastname: Hartl
authors.forename: Christian F
authors.initials: CF
authors.lastname: Poets
authors.forename: Christian
authors.initials: C
authors.lastname: Gille
mesh_terms: D000293:Adolescent; D000328:Adult; D001119:Arginase / Q000276:immunology*; D005260:Female; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D007108:Immune Tolerance / Q000502:physiology; D008875:Middle Aged; D022423:Myeloid Cells / Q000166:cytology / Q000276:immunology*; D052247:Nitric Oxide Synthase Type II / Q000276:immunology*; D011247:Pregnancy / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
chemical_list: C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; C574619:ARG1 protein, human; D001119:Arginase
keywords: Myeloid-derived suppressor cells (MDSCs); Reproductive immunology; T cells; Tolerance