Lower FOXP3 mRNA Expression in First-Trimester Decidual Tissue from Uncomplicated Term Pregnancies with a Male Fetus

Differences in Immune phenotype in decidual tissue from multigravid women compared to primigravid women

PROBLEM

Women with a previous uncomplicated pregnancy have lower risks of immune-associated pregnancy disorders in a subsequent pregnancy. This could indicate a different maternal immune response in multigravid women compared to primigravid women. In a previous study, we showed persistent higher memory T cell proportions with higher CD69 expression after uncomplicated pregnancies. To our knowledge no studies have reported on immune cells in general, and immune memory cells and macrophages specifically in multigravid and primigravid women.

METHOD OF STUDY

T cells and macrophages were isolated from term decidua parietalis and decidua basalis tissue from healthy primigravid women (n = 12) and multigravid women (n = 12). Using flow cytometry, different T cell populations including memory T cells and macrophages were analyzed. To analyze whether a different immune phenotype is already present in early pregnancy, decidual tissue from uncomplicated ongoing pregnancies between 9 and 12 weeks of gestation from multigravida and primigravid women was investigated using qRT-PCR.

RESULTS

Nearly all T cell subsets analyzed in the decidua parietalis had significantly higher CD69⁺ proportions in multigravid women compared to primigravid women. A higher proportion of decidual (CD50^- ) M2-like macrophages was found in the decidua parietalis in multigravid women compared to primigravid women. In first trimester decidual tissue higher FOXP3 mRNA expression was found in multigravid women compared to primigravid women.

CONCLUSIONS

This study shows that decidual tissue from multigravid women has a more activated and immunoregulatory phenotype compared to decidual tissue from primigravid women in early pregnancy and at term which could suggest a more balanced immune adaptation towards pregnancy after earlier uncomplicated pregnancies.

MicroRNAs in amniotic fluid and maternal blood plasma associated with sex determination and early gonad differentiation in cattle†

We hypothesized that sexually dimorphic differences exist in the expression of miRNAs in amniotic fluid (AF) and maternal blood plasma (MP) in association with the process of sex determination and gonad differentiation in cattle. Amniotic fluid and MP were collected from six pregnant heifers (three carrying a single male and three a single female embryo) following slaughter on Day 39 postinsemination, coinciding with the peak of SRY expression. Samples (six AF and six MP) were profiled using an miRNA Serum/Plasma Focus PCR Panel. Differentially expressed (DE) miRNAs were identified in AF (n = 5) and associated MP (n = 56) of male vs. female embryos (P < 0.05). Functional analysis showed that inflammatory and immune response were among the 13 biological processes enriched by miRNAs DE in MP in the male group (FDR < 0.05), suggesting that these sex-dependent DE miRNAs may be implicated in modulating the receptivity of the dam to a male embryo. Further, we compared the downstream targets of the sex-dependent DE miRNAs detected in MP with genes previously identified as DE in male vs. female genital ridges. The analyses revealed potential targets that might be important during this developmental stage such as SHROOM2, DDX3Y, SOX9, SRY, PPP1CB, JARID2, USP9X, KDM6A, and EIF2S3. Results from this study highlight novel aspects of sex determination and embryo–maternal communication in cattle such as the potential role of miRNAs in gonad development as well as in the modulation of the receptivity of the dam to a male embryo.

Review of the immune mechanisms of preeclampsia and the potential of immune modulating therapy

Successful pregnancy relies on maternal immunologic tolerance mechanisms limit maladaptive immune responses against the semi-allogeneic fetus and placenta and support fetal growth. Preeclampsia is a common disorder of pregnancy that affects 4-10% of pregnancies and is a leading cause of maternal and neonatal morbidity and mortality. Preeclampsia clinically manifests as maternal hypertension, proteinuria, and progressive multi-organ injury likely triggered by hypoxic injury to the placenta, resulting in local and systemic anti-angiogenic and inflammatory factor production. Despite the steady rising rates of preeclampsia in the United States, effective treatment options are limited to delivery, which improves maternal status often at the cost of prematurity in the newborn. Preeclampsia also increases the lifelong risk of cardiovascular disease for both mother and infant. Thus, identifying new therapeutic targets is a high priority area to improve maternal, fetal, and infant health outcomes. Immune abnormalities in the placenta and in the maternal circulation have been reported to precede the clinical onset of disease. In particular, excessive systemic and placental complement activation and impaired adaptive T cell tolerance with Th1/Th2/Th17/Treg imbalance has been reported in humans and in animal models of preeclampsia. In this review, we focus on the evidence for the immune origins of preeclampsia, discuss the promise of immune modulating therapy for prevention or treatment, and highlight key areas for future research.

Immune checkpoint molecules on T cell subsets of pregnancies with preeclampsia and gestational diabetes mellitus

Immune checkpoint molecules may play a crucial role in safeguarding pregnancy by regulating immune responses at the maternal-fetal interface. In this study, we aim to investigate the expression of PD-1, GITR, HLA-G, and CTLA-4 on T cell subsets in peripheral blood (PB), retroplacental blood (RPB), and cord blood (CB) in normal pregnancy (NP), preeclampsia (PE) and gestational diabetes mellitus (GDM). PB, RPB, and CB were collected immediately after delivery, and the expression of PD-1, GITR, HLA-G, and CTLA-4 on T cell subsets were measured by flow cytometric analysis. The proportions of Tregs in PB, RPB, and CB from NP were significantly higher than those of PE and GDM (P < 0.01, respectively). PD-1⁺ and GITR⁺ T cell subsets (CD3⁺, CD4⁺, and CD8⁺ T cells, and Tregs) in PB, as well as PD-1⁺ T cell subsets in RPB from NP, were significantly higher than those of PE and GDM (P < 0.01, respectively). In NP, PE, and GDM, the proportion of PD-1⁺ Tregs was significantly decreased in CB as compared to those of PB and RPB (P < 0.05, respectively) and the proportion of GITR⁺ Tregs was significantly higher in PB as compared to those of CB and RPB (P < 0.01, respectively). The proportion of HLA-G⁺ Tregs in PB was significantly lower than those of CB and RPB (P < 0.01, respectively). In conclusion, decreased PD-1⁺ and GITR⁺ T cell subsets and decreased proportion of Tregs in PB and RPB may play a role in chronic inflammatory immune activation of effector T cells in PE and GDM.

Association between fetal sex and maternal plasma microRNA responses to prenatal alcohol exposure: evidence from a birth outcome-stratified cohort

Most persons with fetal alcohol spectrum disorders (FASDs) remain undiagnosed or are diagnosed in later life. To address the need for earlier diagnosis, we previously assessed miRNAs in the blood plasma of pregnant women who were classified as unexposed to alcohol (UE), heavily exposed with affected infants (HEa), or heavily exposed with apparently unaffected infants (HEua). We reported that maternal miRNAs predicted FASD-related growth and psychomotor deficits in infants. Here, we assessed whether fetal sex influenced alterations in maternal circulating miRNAs following prenatal alcohol exposure (PAE). To overcome the loss of statistical power due to disaggregating maternal samples by fetal sex, we adapted a strategy of iterative bootstrap resampling with replacement to assess the stability of statistical parameter estimates. Bootstrap estimates of parametric and effect size tests identified male and female fetal sex-associated maternal miRNA responses to PAE that were not observed in the aggregated sample. Additionally, we observed, in HEa mothers of female, but not male fetuses, a network of co-secreted miRNAs whose expression was linked to miRNAs encoded on the X-chromosome. Interestingly, the number of significant miRNA correlations for the HEua group mothers with female fetuses was intermediate between HEa and UE mothers at mid-pregnancy, but more similar to UE mothers by the end of pregnancy. Collectively, these data show that fetal sex predicts maternal circulating miRNA adaptations, a critical consideration when adopting maternal miRNAs as diagnostic biomarkers. Moreover, a maternal co-secretion network, predominantly in pregnancies with female fetuses, emerged as an index of risk for adverse birth outcomes due to PAE.

Toll-Like Receptor-4 Antagonist (+)-Naloxone Confers Sexually Dimorphic Protection From Inflammation-Induced Fetal Programming in Mice

Inflammation elicited by infection or noninfectious insults during gestation induces proinflammatory cytokines that can shift the trajectory of development to alter offspring phenotype, promote adiposity, and increase susceptibility to metabolic disease in later life. In this study, we use mice to investigate the utility of a small molecule Toll-like receptor (TLR)4 antagonist (+)-naloxone, the nonopioid isomer of the opioid receptor antagonist (-)-naloxone, for mitigating altered fetal metabolic programming induced by a modest systemic inflammatory challenge in late gestation. In adult progeny exposed to lipopolysaccharide (LPS) challenge in utero, male but not female offspring exhibited elevated adipose tissue, reduced muscle mass, and elevated plasma leptin at 20 weeks of age. Effects were largely reversed by coadministration of (+)-naloxone following LPS. When given alone without LPS, (+)-naloxone elicited accelerated postweaning growth and elevated muscle and fat mass in adult male but not female offspring. LPS induced expression of inflammatory cytokines Il1a, Il1b, Il6, Tnf, and Il10 in fetal brain, placental, and uterine tissues, and (+)-naloxone suppressed LPS-induced cytokine expression. Fetal sex-specific regulation of cytokine expression was evident, with higher Il1a, Il1b, Il6, and Il10 induced by LPS in tissues associated with male fetuses, and greater suppression by (+)-naloxone of Il6 in females. These data demonstrate that modulating TLR4 signaling with (+)-naloxone provides protection from inflammatory diversion of fetal developmental programming in utero, associated with attenuation of gestational tissue cytokine expression in a fetal sex-specific manner. The results suggest that pharmacologic interventions targeting TLR4 warrant evaluation for attenuating developmental programming effects of fetal exposure to maternal inflammatory mediators.