M1/M2 macrophage polarity in normal and complicated pregnancy.

Mary B Brown,Leticia Reyes,Maria Von Chamier,Ayman B Allam

doi:10.3389/fimmu.2014.00606

Abstract

Tissue macrophages play an important role in all stages of pregnancy, including uterine stromal remodeling (decidualization) before embryo implantation, parturition, and post-partum uterine involution. The activation state and function of utero-placental macrophages are largely dependent on the local tissue microenvironment. Thus, macrophages are involved in a variety of activities such as regulation of immune cell activities, placental cell invasion, angiogenesis, and tissue remodeling. Disruption of the uterine microenvironment, particularly during the early stages of pregnancy (decidualization, implantation, and placentation) can have profound effects on macrophage activity and subsequently impact pregnancy outcome. In this review, we will provide an overview of the temporal and spatial regulation of utero-placental macrophage activation during normal pregnancy in human beings and rodents with a focus on more recent findings. We will also discuss the role of M1/M2 dysregulation within the intrauterine environment during adverse pregnancy outcomes.

Highlights

Macrophages within the maternal–fetal compartment have been a research focus for over 30 years
M2 macrophages participate in tissue remodeling, have immunosuppressive qualities, and promote TH2 or antibody mediated immune responses [6]
We provide an overview of M1/M2 dynamics relevant to the maternal–fetal interface, the temporal and spatial changes in macrophage M1/M2 within the maternal and fetal compartments during normal pregnancy, and imbalanced M1/M2 dynamics associated with complicated pregnancies

Summary

Introduction

Macrophages within the maternal–fetal compartment have been a research focus for over 30 years. These cells support a variety of processes essential for successful pregnancy such as remodeling of the uterine connective tissues and blood vessels, regulation of trophoblast (fetal cell) implantation, immune-tolerance toward fetal antigens, immunomodulation of neighboring leukocytes, and initiation of parturition [1,2,3,4,5]. Inappropriate macrophage polarization within the maternal–fetal compartments is associated with spontaneous abortion or miscarriage [12], inadequate remodeling of the uterine vessels during placentation [12,13,14], and intrauterine parasitic infections [15].

Results

Conclusion