Project description:Here, we performed proteomic profiling of the maternal peripheral blood and umbilical cord blood from 6 pregnant women positive for SARS-CoV-2 and 6 pregnant women negative for SARS-CoV-2, and examined viral RNA and DNA copies of SARS-CoV-2 sequences in the umbilical cord and placental tissues.
Project description:Peripheral and cord blood samples from SARS-CoV-2 positive or control pregnant women were profiled using paired-end DNBseq to evaluate transcriptomic changes associated with SARS-CoV-2 infection during pregnancy.
Project description:Pregnant women appear to be at increased risk for severe outcomes associated with COVID-19, but the pathophysiology underlying this increased morbidity and its potential impact on the developing fetus is not well understood. In this study of pregnant women with and without COVID-19, we assessed viral and immune dynamics at the placenta during maternal SARS-CoV-2 infection. Viral RNA was only rarely detected in the placentas from SARS-CoV-2-positive women in our cohort, with only 1/11 positive for infection at the maternal-fetal interface. Through bulk RNA transcriptomic analyses, we found that placentas from SARS-CoV-2-positive pregnancies exhibited inflammatory markers of immune activation, even in the majority of samples which did not show local invasion of the virus. These markers are associated with pregnancy complications such as preeclampsia and poor fetal outcomes. Overall, this study suggests that SARS-CoV-2 is associated with immune activation at the maternal-fetal interface even in the absence of detectable local viral invasion. While this likely represents a protective mechanism shielding the placenta from infection, inflammatory changes in the placenta may also contribute to poor pregnancy outcomes and thus warrant further investigation.
Project description:The discovery of fetal mRNA transcripts in maternal circulation holds great promise for noninvasive prenatal diagnosis. To identify potential fetal biomarkers, we studied whole blood and plasma transcripts common to term pregnant women and their newborns but reduced or absent in the postpartum mothers. In whole blood, 157 potentially-fetal transcripts were identified. RT-PCR confirmed the presence of specific transcripts, SNP analysis confirmed the presence of fetal transcripts in maternal circulation. Comparison of whole blood and plasma samples from the same women suggested that placental genes are more easily detected in plasma. We conclude that fetal and placental mRNA circulates in the blood of pregnant women.
Project description:During the COVID-19 pandemic, thousands of pregnant women have been infected with SARS-CoV-2 worldwide. The short- and long-term implications of maternal SARS-CoV-2 infection on fetal and childhood well-being are unknown. To characterize the fetal immune response to maternal SARS-CoV-2 infection, we performed single-cell RNA sequencing and T cell receptor sequencing on cord blood mononuclear cells from infants born to mothers infected with SARS-CoV-2 in the third trimester. We identified widespread gene expression changes in cord blood leukocytes, including upregulation of interferon-stimulated genes (ISG) and of HLA genes in CD14+ monocytes; decreased activation of CD16+ monocytes; activation of plasmacytoid dendritic cells; and activation and exhaustion of NK cells and T CD8+ cells in the cord blood of infants born to SARS-CoV-2+ mothers. Lastly, we observed fetal TCR repertoire clonal expansion in cord blood T cells from pregnancies complicated by maternal SARS-CoV-2 infection. Our results suggest that even in the absence of vertical transmission, SARS-CoV-2 maternal infection in the third trimester modulates the fetal immune system.
Project description:Pregnant women appear to be at increased risk for severe outcomes associated with COVID-19, but the pathophysiology underlying this increased morbidity and its potential impact on the developing fetus is not well understood. In this study of pregnant women with and without COVID-19, we assessed viral and immune dynamics at the placenta during maternal SARS-CoV-2 infection. Amongst uninfected women, ACE2 was detected by immunohistochemistry in syncytiotrophoblast cells of the normal placenta during early pregnancy but was rarely seen in healthy placentas at full term. Term placentas from women infected with SARS-CoV-2, however, displayed a significant increase in ACE2 levels. Using immortalized cell lines and primary isolated placental cells, we determined the vulnerability of various placental cell types to direct infection by SARS-CoV-2 in vitro. Yet, despite the susceptibility of placental cells to SARS-CoV-2 infection, viral RNA was detected in the placentas of only a subset (∼13%) of women in this cohort. Through single cell transcriptomic analyses, we found that the maternal-fetal interface of SARS-CoV-2-infected women exhibited markers associated with pregnancy complications, such as preeclampsia, and robust immune responses, including increased activation of placental NK and T cells and increased expression of interferon-related genes. Overall, this study suggests that SARS-CoV-2 is associated with immune activation at the maternal-fetal interface even in the absence of detectable local viral invasion. While this likely represents a protective mechanism shielding the placenta from infection, inflammatory changes in the placenta may also contribute to poor pregnancy outcomes and thus warrant further investigation.
Project description:The discovery of fetal mRNA transcripts in maternal circulation holds great promise for noninvasive prenatal diagnosis. To identify potential fetal biomarkers, we studied whole blood and plasma transcripts common to term pregnant women and their newborns but reduced or absent in the postpartum mothers. In whole blood, 157 potentially-fetal transcripts were identified. RT-PCR confirmed the presence of specific transcripts, SNP analysis confirmed the presence of fetal transcripts in maternal circulation. Comparison of whole blood and plasma samples from the same women suggested that placental genes are more easily detected in plasma. We conclude that fetal and placental mRNA circulates in the blood of pregnant women. [I] We profiled whole antepartum (A), postpartum (P), and umbilical cord (U) blood samples from each of 9 mothers and their 10 newborns (1 set of twins, denoted as a and b after the sample names). [II] We also profiled plasma samples (A, P, and U) from three of those mothers to allow for a direct comparison between blood and plasma.
Project description:<p>Myostatin (gene symbol: Mstn) is an autocrine and paracrine inhibitor of muscle growth. Pregnant mice with genetically reduced levels of myostatin give birth to offspring with greater adult muscle mass and bone biomechanical strength. However, maternal myostatin is not detectable in fetal circulations. Fetal growth is dependent on the maternal environment, and the provisioning of nutrients and growth factors by the placenta. Thus, this study examined the effect of reduced maternal myostatin on maternal and fetal serum metabolomes, as well as the placental metabolome. Fetal and maternal serum metabolomes were highly distinct, which is consistent with the role of the placenta in creating a specific fetal nutrient environment. There was no effect from myostatin on maternal glucose tolerance or fasting insulin. In comparisons between pregnant control and Mstn+/− mice, there were more significantly different metabolite concentrations in fetal serum, at 50, than in the mother’s serum at 33, confirming the effect of maternal myostatin reduction on the fetal metabolic milieu. Polyamines, lysophospholipids, fatty acid oxidation, and vitamin C, in fetal serum, were all affected by maternal myostatin reduction.</p>