Browsing by Author "Garcia-Flores, Valeria"

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    Fetal and maternal NLRP3 signaling is required for preterm labor and birth
    (AMER SOC CLINICAL INVESTIGATION INC, 2022) Motomura, Kenichiro; Romero, Roberto; Galaz, Jose; Tao, Li; Garcia-Flores, Valeria; Xu, Yi; Done, Bogdan; Arenas-Hernandez, Marcia; Miller, Derek; Gutierrez-Contreras, Pedro; Farias-Jofre, Marcelo; Aras, Siddhesh; Grossman, Lawrence, I; Tarca, Adi L.; Gomez-Lopez, Nardhy
    Preterm birth is the leading cause of neonatal morbidity and mortality worldwide. One of every 4 preterm neonates is born to a mother with intra-amniotic inflammation driven by invading bacteria. However, the molecular mechanisms underlying this hostile immune response remain unclear. Here, we used a translationally relevant model of preterm birth in Nlrp3-deficient and-sufficient pregnant mice to identify what we believe is a previously unknown dual role for the NLRP3 pathway in the fetal and maternal signaling required for the premature onset of the labor cascade leading to fetal injury and neonatal death. Specifically, the NLRP3 sensor molecule and/or inflammasome is essential for triggering intra-amniotic and decidual inflammation, fetal membrane activation, uterine contractility, and cervical dilation. NLRP3 also regulates the functional status of neutrophils and macrophages in the uterus and decidua, without altering their influx, as well as maternal systemic inflammation. Finally, both embryo transfer experimentation and heterozygous mating systems provided mechanistic evidence showing that NLRP3 signaling in both the fetus and the mother is required for the premature activation of the labor cascade. These data provide insights into the mechanisms of fetal-maternal dialog in the syndrome of preterm labor and indicate that targeting the NLRP3 pathway could prevent adverse perinatal outcomes.
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    Pregnancy imparts distinct systemic adaptive immune function
    (WILEY, 2022) Demery-Poulos, Catherine; Romero, Roberto; Xu, Yi; Arenas-Hernandez, Marcia; Miller, Derek; Tao, Li; Galaz, Jose; Farias-Jofre, Marcelo; Bhatti, Gaurav; Garcia-Flores, Valeria; Seyerle, Megan; Tarca, Adi L.; Gomez-Lopez, Nardhy
    Problem Pregnancy represents a state of systemic immune activation that is primarily driven by alterations in circulating innate immune cells. Recent studies have suggested that cellular adaptive immune components, T cells and B cells, also undergo changes throughout gestation. However, the phenotypes and functions of such adaptive immune cells are poorly understood. Herein, we utilized high-dimensional flow cytometry and functional assays to characterize T-cell and B-cell responses in pregnant and non-pregnant women. Methods Peripheral blood mononuclear cells from pregnant (n = 20) and non-pregnant (n = 25) women were used for phenotyping of T-cell and B-cell subsets. T-cell proliferation and B-cell activation were assessed by flow cytometry after in vitro stimulation, and lymphocyte cytotoxicity was evaluated by using a cell-based assay. Statistical comparisons were performed with linear mixed-effects models. Results Pregnancy was associated with modestly enhanced basal activation of peripheral CD4(+) T cells. Both CD4(+) and CD8(+) T cells from pregnant women showed increased activation-induced proliferation; yet, a reduced proportion of these cells expressed activation markers compared to non-pregnant women. There were no differences in peripheral lymphocyte cytotoxicity between study groups. A greater proportion of B cells from pregnant women displayed memory-like and activated phenotypes, and such cells exhibited higher activation following stimulation. Conclusion Maternal circulating T cells and B cells display distinct responses during pregnancy. The former may reflect the unique capacity of T cells to respond to potential threats without undergoing aberrant activation, thereby preventing systemic inflammatory responses that can lead to adverse perinatal consequences.