Browsing by Author "Winters, Andrew D."

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    Blockade of IL-6R prevents preterm birth and adverse neonatal outcomes
    (2023) Farias-Jofre, Marcelo; Romero, Roberto; Galaz, Jose; Xu, Yi; Miller, Derek; Garcia-Flores, Valeria; Arenas-Hernandez, Marcia; Winters, Andrew D.; Berkowitz, Bruce A.; Podolsky, Robert H.; Shen, Yimin; Kanninen, Tomi; Panaitescu, Bogdan; Glazier, Catherine R.; Pique-Regi, Roger; Theis, Kevin R.; Gomez-Lopez, Nardhy
    Background Preterm birth preceded by spontaneous preterm labour often occurs in the clinical setting of sterile intra-amniotic inflammation (SIAI), a condition that currently lacks treatment.Methods Proteomic and scRNA-seq human data were analysed to evaluate the role of IL-6 and IL-1 alpha in SIAI. A C57BL/6 murine model of SIAI-induced preterm birth was developed by the ultrasound-guided intra-amniotic injection of IL-1 alpha. The blockade of IL-6R by using an aIL-6R was tested as prenatal treatment for preterm birth and adverse neonatal outcomes. QUEST-MRI evaluated brain oxidative stress in utero. Targeted transcriptomic profiling assessed maternal, foetal, and neonatal inflammation. Neonatal biometrics and neurodevelopment were tested. The neonatal gut immune-microbiome was evaluated using metagenomic sequencing and immunophenotyping.Findings IL-6 plays a critical role in the human intra-amniotic inflammatory response, which is associated with elevated concentrations of the alarmin IL-1 alpha. Intra-amniotic injection of IL-1 alpha resembles SIAI, inducing preterm birth (7% vs. 50%, p = 0.03, Fisher's exact test) and neonatal mortality (18% vs. 56%, p = 0.02, Mann-Whitney U-test). QUEST-MRI revealed no foetal brain oxidative stress upon in utero IL-1 alpha exposure (p > 0.05, mixed linear model). Prenatal treatment with aIL-6R abrogated IL-1 alpha-induced preterm birth (50% vs. 7%, p = 0.03, Fisher's exact test) by dampening inflammatory processes associated with the common pathway of labour. Importantly, aIL-6R reduces neonatal mortality (56% vs. 22%, p = 0.03, Mann-Whitney U-test) by crossing from the mother to the amniotic cavity, dampening foetal organ inflammation and improving growth. Beneficial effects of prenatal IL -6R blockade carried over to neonatal life, improving survival, growth, neurodevelopment, and gut immune homeostasis.Interpretation IL-6R blockade can serve as a strategy to treat SIAI, preventing preterm birth and adverse neonatal outcomes.
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    Is there a placental microbiota? A critical review and re-analysis of published placental microbiota datasets
    (2023) Panzer, Jonathan J.; Romero, Roberto; Greenberg, Jonathan M.; Winters, Andrew D.; Galaz, Jose; Gomez-Lopez, Nardhy; Theis, Kevin R.
    The existence of a placental microbiota is debated. The human placenta has historically been considered sterile and microbial colonization was associated with adverse pregnancy outcomes. Yet, recent DNA sequencing investigations reported a microbiota in typical human term placentas. However, this detected microbiota could represent background DNA or delivery-associated contamination. Using fifteen publicly available 16S rRNA gene datasets, existing data were uniformly re-analyzed with DADA2 to maximize comparability. While Amplicon Sequence Variants (ASVs) identified as Lactobacillus, a typical vaginal bacterium, were highly abundant and prevalent across studies, this prevalence disappeared after applying likely  DNA contaminant removal to placentas from term cesarean deliveries. A six-study sub-analysis targeting the 16S rRNA gene V4 hypervariable region demonstrated that bacterial profiles of placental samples and technical controls share principal bacterial ASVs and that placental samples clustered primarily by study origin and mode of delivery. Contemporary DNA-based evidence does not support the existence of a placental microbiota. Importance Early-gestational microbial influences on human development are unclear. By applying DNA sequencing technologies to placental tissue, bacterial DNA signals were observed, leading some to conclude that a live bacterial placental microbiome exists in typical term pregnancy. However, the low-biomass nature of the proposed microbiome and high sensitivity of current DNA sequencing technologies indicate that the signal may alternatively derive from environmental or delivery-associated bacterial DNA contamination. Here we address these alternatives with a re-analysis of 16S rRNA gene sequencing data from 15 publicly available placental datasets. After identical DADA2 pipeline processing of the raw data, subanalyses were performed to control for mode of delivery and environmental DNA contamination. Both environment and mode of delivery profoundly influenced the bacterial DNA signal from term-delivered placentas. Aside from these contamination-associated signals, consistency was lacking across studies. Thus, placentas delivered at term are unlikely to be the original source of observed bacterial DNA signals.
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    Microbial burden and inflammasome activation in amniotic fluid of patients with preterm prelabor rupture of membranes
    (2020) Theis, Kevin R.; Romero, Roberto; Motomura, Kenichiro; Galaz, Jose; Winters, Andrew D.; Pacora, Percy; Miller, Derek; Slutsky, Rebecca; Florova, Violetta; Levenson, Dustyn; Para, Robert; Varrey, Aneesha; Kacerovsky, Marian; Hsu, Chaur-Dong; Gomez-Lopez, Nardhy
    Background: Intra-amniotic inflammation, which is associated with adverse pregnancy outcomes, can occur in the presence or absence of detectable microorganisms, and involves activation of the inflammasome. lntra-amniotic inflammasome activation has been reported in clinical chorioamnionitis at term and preterm labor with intact membranes, but it has not yet been investigated in women with preterm prelabor rupture of membranes (preterm PROM) in the presence/absence of detectable microorganisms. The aim of this study was to determine whether, among women with preterm PROM, there is an association between detectable microorganisms in amniotic fluid and intra-amniotic inflammation, and whether intra-amniotic inflammasome activation correlates with microbial burden.
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    Microbiota of the Pregnant Mouse: Characterization of the Bacterial Communities in the Oral Cavity, Lung, Intestine, and Vagina through Culture and DNA Sequencing
    (2022) Greenberg, Jonathan M.; Romero, Roberto; Winters, Andrew D.; Galaz, Jose; Garcia-Flores, Valeria; Arenas-Hernandez, Marcia; Panzer, Jonathan; Shaffer, Zachary; Kracht, David J.; Gomez-Lopez, Nardhy; Theis, Kevin R.
    Mice are frequently used as animal models for mechanistic studies of infection and obstetrical disease, yet characterization of the murine microbiota during pregnancy is lacking. The objective of this study was to characterize the microbiotas of distinct body sites of the pregnant mouse-vagina, oral cavity, intestine, and lung-that harbor microorganisms that could potentially invade the murine amniotic cavity, thus leading to adverse pregnancy outcomes. The microbiotas of these body sites were characterized through anoxic, hypoxic, and oxic culture as well as through 16S rRNA gene sequencing. With the exception of the vagina, the cultured microbiotas of each body site varied by atmosphere, with the greatest diversity in the cultured microbiota appearing under anoxic conditions. Only cultures of the vagina were comprehensively representative of the microbiota observed through direct DNA sequencing of body site samples, primarily due to the predominance of two Rodentibacter strains. Identified as Rodentibacter pneumotropicus and Rodentibacter heylii, these isolates exhibited predominance patterns similar to those of Lactobacillus crispatus and Lactobacillus iners in the human vagina. Whole-genome sequencing of these Rodentibacter strains revealed shared genomic features, including the ability to degrade glycogen, an abundant polysaccharide in the vagina. In summary, we report body site-specific microbiotas in the pregnant mouse with potential ecological parallels to those of humans. Importantly, our findings indicate that the vaginal microbiotas of pregnant mice can be readily cultured, suggesting that mock vaginal microbiotas can be tractably generated and maintained for experimental manipulation in future mechanistic studies of host vaginal-microbiome interactions.
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    No Consistent Evidence for Microbiota in Murine Placental and Fetal Tissues
    (2020) Theis, Kevin R.; Romero, Roberto; Greenberg, Jonathan M.; Winters, Andrew D.; Garcia-Flores, Valeria; Motomura, Kenichiro; Ahmad, Madison M.; Galaz, Jose; Arenas-Hernandez, Marcia; Gomez-Lopez, Nardhy
    The existence of a placental microbiota and in utero colonization of the fetus have been the subjects of recent debate. The objective of this study was to determine whether the placental and fetal tissues of mice harbor bacterial communities. Bacterial profiles of the placenta and fetal brain, lung, liver, and intestine samples were characterized through culture, quantitative real-time PCR (qPCR), and 16S rRNA gene sequencing. These profiles were compared to those of the maternal mouth, lung, liver, uterus, cervix, vagina, and intestine, as well as to background technical controls. Positive bacterial cultures from placental and fetal tissue samples were rare; of the 165 total bacterial cultures of placental tissue samples from the 11 mice included in this study, only nine yielded at least a single colony, and five of those nine positive cultures came from a single mouse. Cultures of fetal intestinal tissue samples yielded just a single bacterial isolate, Staphylococcus hominis, a common skin bacterium. Bacterial loads of placental and fetal brain, lung, liver, and intestinal tissues were not higher than those of DNA contamination controls and did not yield substantive 16S rRNA gene sequencing libraries. From all placental or fetal tissue samples (n = 51), there was only a single bacterial isolate that came from a fetal brain sample having a bacterial load higher than that of contamination controls and that was identified in sequence-based surveys of at least one of its corresponding maternal samples. Therefore, using multiple modes of microbiological inquiry, there was not consistent evidence of bacterial communities in the placental and fetal tissues of mice.
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    The Vaginal Microbiota of Pregnant Women Varies with Gestational Age, Maternal Age, and Parity
    (2023) Romero, Roberto; Theis, Kevin R.; Gomez-Lopez, Nardhy; Winters, Andrew D.; Panzer, Jonathan J.; Lin, Huang; Galaz, Jose; Greenberg, Jonathan M.; Shaffer, Zachary; Kracht, David J.; Chaiworapongsa, Tinnakorn; Jung, Eunjung; Gotsch, Francesca; Ravel, Jacques; Peddada, Shyamal D.; Tarca, Adi L.
    There is debate regarding links between the vaginal microbiota and pregnancy complications, especially spontaneous preterm birth. Inconsistencies in results among studies are likely due to differences in sample sizes and cohort ethnicity.