Impact of Metabolic Stress on BeWo Syncytiotrophoblast Function.

During placental formation, cytotrophoblasts (CTBs) fuse into multinucleate, microvilli-coated syncytiotrophoblasts (STBs), which contact maternal blood, mediating nutrient, metabolite, and gas exchange between mother and fetus, and providing a barrier against fetal infection. Trophoblasts remodel the surrounding extracellular matrix through the secretion of matrix metalloproteinases (MMPs). Maternal obesity and diabetes mellitus can negatively impact fetal development and may impair trophoblast function. We sought to model the impact of metabolic stress on STB function by examining MMP and hormone secretion. The BeWo CTB cell line was syncytialized to STB-like cells with forskolin. Cell morphology was examined by electron microscopy and immunofluorescence; phenotype was further assessed by ELISA and RT-qPCR. STBs were exposed to a metabolic stress cocktail (MetaC: 30 mM glucose, 10 nM insulin, and 0.1 mM palmitic acid). BeWo syncytialization was demonstrated by increased secretion of HCGß and progesterone, elevated syncytin gene expression (ERVW-1 and ERVFRD-1), loss of tight junctions, and increased surface microvilli. MetaC strongly suppressed syncytin gene expression (ERVW-1 and ERVFRD-1), suppressed HCGß and progesterone secretion, and altered both MMP-9 and MMP-2 production. Metabolic stress modeling diabetes and obesity altered BeWo STB hormone and MMP production in vitro.

Persistent bacteremia and psoas abscess caused by a lethal toxin-deficient Paeniclostridiumsordellii.

We present a case of persistent bacteremia and psoas abscess from Paeniclostridium sordellii without severe symptoms or the classically associated toxic shock syndrome. Further laboratory evaluation demonstrated that the Paeniclostridium sordellii isolate lacked the lethal toxin gene and there was no cytotoxicity to exposed Vero cells.

Critical assessment of the current indicator for antenatal iron-containing supplementation coverage: Insights from a mixed-methods study.

Daily consumption of iron-containing supplements is recommended for all pregnant women but there is no approved global standard indicator for assessing supplementation coverage. Furthermore, the validity of commonly used coverage indicators for iron-containing supplement consumption is questionable. The WHO-UNICEF Technical Expert Advisory Group on Nutrition Monitoring, and partners, have systematically worked to identify a feasible and valid indicator of iron-containing supplement coverage for reporting by countries. In 2019, we conducted key informant interviews with respondents in eight countries, fielded an online survey (in three languages using SurveyMonkey) to which 142 nutrition professionals from 52 countries responded, and used Demographic and Health Surveys (DHS) data from four countries to assess determinants of the quality of iron-containing supplement coverage data. Less than half (45%) of online survey respondents were satisfied with the current methods for collecting iron-containing supplement coverage data in their context. Recommended changes by study respondents include recall period <5 years, adding questions about counselling, including other beneficiary groups, and assessing supply chain functionality. The DHS analysis suggested an association between time since pregnancy and data quality. Data heaping on multiples of 30 was observed in 40%-75% of data. There is a clear demand for a revised indicator and measurement guidance for coverage of iron-containing supplementation during pregnancy. Future research should continue the development and validation of a global indicator, to more precisely validate the quality of recall data, including the distinction between distribution and consumption using various question formulations.

Antibacterial and Anti-biofilm Activity of the Human Breast Milk Glycoprotein Lactoferrin against Group B Streptococcus.

Group B Streptococcus (GBS) is an encapsulated Gram-positive human pathogen that causes invasive infections in pregnant hosts and neonates, as well as immunocompromised individuals. Colonization of the human host requires the ability to adhere to mucosal surfaces and circumnavigate the nutritional challenges and antimicrobial defenses associated with the innate immune response. Biofilm formation is a critical process to facilitate GBS survival and establishment of a replicative niche in the vertebrate host. Previous work has shown that the host responds to GBS infection by producing the innate antimicrobial glycoprotein lactoferrin, which has been implicated in repressing bacterial growth and biofilm formation. Additionally, lactoferrin is highly abundant in human breast milk and could serve a protective role against invasive microbial pathogens. This study demonstrates that human breast milk lactoferrin has antimicrobial and anti-biofilm activity against GBS and inhibits its adherence to human gestational membranes. Together, these results indicate that human milk lactoferrin could be used as a prebiotic chemotherapeutic strategy to limit the impact of bacterial adherence and biofilm formation on GBS-associated disease outcomes.

A Nonhemolytic Group B Streptococcus Strain Exhibits Hypervirulence.

Group B streptococci (GBS) are Gram-positive bacteria that are a leading cause of neonatal infections. Most invasive isolates are ß-hemolytic, and hemolytic activity is critical for GBS virulence. Although nonhemolytic GBS strains are occasionally isolated, they are often thought to be virulence attenuated. In this study, we show that a nonhemolytic GBS strain (GB37) isolated from a septic neonate exhibits hypervirulence. Substitution of tryptophan to leucine (W297L) in the sensor histidine kinase CovS results in constitutive kinase signaling, leading to decreased hemolysis and increased activity of the GBS hyaluronidase, HylB. These results describe how nonpigmented and nonhemolytic GBS strains can exhibit hypervirulence.

Staphylococcus aureus Infection of Human Gestational Membranes Induces Bacterial Biofilm Formation and Host Production of Cytokines.

Staphylococcus aureus, a metabolically flexible gram-positive pathogen, causes infections in a variety of tissues. Recent evidence implicates S. aureus as an emerging cause of chorioamnionitis and premature rupture of membranes, which are associated with preterm birth and neonatal disease. We demonstrate here that S. aureus infects and forms biofilms on the choriodecidual surface of explanted human gestational membranes. Concomitantly, S. aureus elicits the production of proinflammatory cytokines, which could ultimately perturb maternal-fetal tolerance during pregnancy. Therefore, targeting the immunological response to S. aureus infection during pregnancy could attenuate disease among infected individuals, especially in the context of antibiotic resistance.

Prostaglandin E2 Regulation of Macrophage Innate Immunity.

Globally, maternal and fetal health is greatly impacted by extraplacental inflammation. Group B Streptococcus (GBS), a leading cause of chorioamnionitis, is thought to take advantage of the uterine environment during pregnancy in order to cause inflammation and infection. In this study, we demonstrate the metabolic changes of murine macrophages caused by GBS exposure. GBS alone prompted a delayed increase in lactate production, highlighting its ability to redirect macrophage metabolism from aerobic to anaerobic respiration. This production of lactate is thought to aid in the development and propagation of GBS throughout the surrounding tissue. Additionally, this study shows that PGE2 priming was able to exacerbate lactate production, shown by the rapid and substantial lactate increases seen upon GBS exposure. These data provide a novel model to study the role of GBS exposure to macrophages with and without PGE2 priming.

Lipid profiling of polarized human monocyte-derived macrophages.

The highly orchestrated transcriptional and metabolic reprogramming during activation drastically transforms the main functions and physiology of human macrophages across the polarization spectrum. Lipids, for example, can modify protein function by acting remotely as signaling molecules but also locally by altering the physical properties of cellular membranes. These changes play key roles in the functions of highly plastic immune cells due to their involvement in inflammation, immune responses, phagocytosis and wound healing processes. We report an analysis of major membrane lipids of distinct phenotypes of resting (M0), classically activated (M1), alternatively activated (M2a) and deactivated (M2c) human monocyte derived macrophages from different donors. Samples were subjected to supercritical fluid chromatography-ion mobility-mass spectrometry analysis, which allowed separations based on lipid class, facilitating the profiling of their fatty acid composition. Different levels of arachidonic acid mobilization as well as other fatty acid changes were observed for different lipid classes in the distinct polarization phenotypes, suggesting the activation of highly orchestrated and specific enzymatic processes in the biosynthesis of lipid signaling molecules and cell membrane remodeling. Thromboxane A2 production appeared to be a specific marker of M1 polarization. These alterations to the global composition of lipid bi-layer membranes in the cell provide a potential methodology for the definition and determination of cellular and tissue activation states.

Neither vaginal nor buccal administration of 800 µg misoprostol alters mucosal and systemic immune activation or the cervicovaginal microbiome: a pilot study.

OBJECTIVES: The aim of the study was to assess the extent to which misoprostol alters mucosal or systemic immune responses following either buccal or vaginal administration. METHODS: This was a prospective, crossover pilot study of 15 healthy, reproductive-age women. Women first received 800 µg misoprostol either via buccal or vaginal administration and were crossed over 1 month later to receive the drug via the other route. Cervicovaginal lavage samples, cervical Cytobrush samples, cervicovaginal swabs, urine and blood were obtained immediately prior to drug administration and the following day. Parameters assessed included urine and cervicovaginal misoprostol levels, whole blood cytokine responses (by ELISA) to immune stimulation with lipopolysaccharide, peripheral blood and cervical lymphocyte phenotyping by flow cytometry, cervicovaginal antimicrobial peptide measurement by ELISA and vaginal microbial ecology assessment by 16S rRNA sequencing. RESULTS: Neither buccal nor vaginal misoprostol significantly altered local or systemic immune and microbiological parameters. CONCLUSION: In this pilot study, we did not observe significant alteration of mucosal or systemic immunology or vaginal microbial ecology 1 day after drug administration following either the buccal or vaginal route.

Optimal serum and red blood cell folate concentrations in women of reproductive age for prevention of neural tube defects: World Health Organization guidelines.

Neural tube defects (NTDs) such as spina bifida, anencephaly, and encephalocele are serious birth defects of the brain and spine that occur during the first month of pregnancy when the neural tube fails to close completely. Randomized controlled trials and observational studies have shown that adequate daily consumption of folic acid before and during early pregnancy considerably reduces the risk for NTDs. The U.S. Public Health Service recommends that women capable of becoming pregnant consume 400 µg of folic acid daily for NTD prevention. Furthermore, fortification of staple foods (e.g., wheat flour) with folic acid has decreased folate-sensitive NTD prevalence in multiple settings and is a highly cost-effective intervention.

Leukotriene B4 enhances innate immune defense against the puerperal sepsis agent Streptococcus pyogenes.

Puerperal sepsis is a leading cause of maternal mortality worldwide. Streptococcus pyogenes [group A Streptococcus; (GAS)] is a major etiologic agent of severe postpartum sepsis, yet little is known regarding the pathogenesis of these infections. Tissue macrophages provide innate defense against GAS, and their actions are highly regulated. The intracellular second messenger cAMP can negatively regulate macrophage actions against GAS. Because leukotriene (LT) B(4) has been shown to suppress intracellular cAMP in macrophages, we hypothesized that it could enhance innate defenses against GAS. We assessed the capacity of LTB(4) to modulate antistreptococcal actions of human macrophages, including placental and decidual macrophages and used a novel intrauterine infection model of GAS in mice lacking the 5-lipoxygenase enzyme to determine the role of endogenous LTs in host defense against this pathogen. Animals lacking 5-lipoxygenase were significantly more vulnerable to intrauterine GAS infection than were wild-type mice and showed enhanced dissemination of bacteria out of the uterus and a more robust inflammatory response than did wild-type mice. In addition, LTB(4) reduced intracellular cAMP levels via the BLT1 receptor and was a potent stimulant of macrophage phagocytosis and NADPH oxidase-dependent intracellular killing of GAS. Importantly, interference was observed between the macrophage immunomodulatory actions of LTB(4) and the cAMP-inducing lipid PGE(2), suggesting that interplay between pro- and anti-inflammatory compounds may be important in vivo. This work underscores the potential for pharmacological targeting of lipid mediator signaling cascades in the treatment of invasive GAS infections.

Intrauterine group A streptococcal infections are exacerbated by prostaglandin E2.

Streptococcus pyogenes (Group A Streptococcus; GAS) is a major cause of severe postpartum sepsis, a re-emerging cause of maternal morbidity and mortality worldwide. Immunological alterations occur during pregnancy to promote maternofetal tolerance, which may increase the risk for puerperal infection. PGE2 is an immunomodulatory lipid that regulates maternofetal tolerance, parturition, and innate immunity. The extent to which PGE2 regulates host immune responses to GAS infections in the context of endometritis is unknown. To address this, both an in vivo mouse intrauterine (i.u.) GAS infection model and an in vitro human macrophage-GAS interaction model were used. In C57BL/6 mice, i.u. GAS inoculation resulted in local and systemic inflammatory responses and triggered extensive changes in the expression of eicosanoid pathway genes. The i.u. administration of PGE2 increased the mortality of infected mice, suppressed local IL-6 and IL-17A levels, enhanced neutrophilic inflammation, reduced uterine macrophage populations, and increased bacterial dissemination. A role for endogenous PGE2 in the modulation of antistreptococcal host defense was suggested, because mice lacking the genes encoding the microsomal PGE2 synthase-1 or the EP2 receptor were protected from death, as were mice treated with the EP4 receptor antagonist, GW627368X. PGE2 also regulated GAS-macrophage interactions. In GAS-infected human THP-1 (macrophage-like) cells, PGE2 inhibited the production of MCP-1 and TNF-α while augmenting IL-10 expression. PGE2 also impaired the phagocytic ability of human placental macrophages, THP-1 cells, and mouse peritoneal macrophages in vitro. Exploring the targeted disruption of PGE2 synthesis and signaling to optimize existing antimicrobial therapies against GAS may be warranted.

Five National Cancer Institute-designated cancer centers' data collection on racial/ethnic minority participation in therapeutic trials: a current view and opportunities for improvement.

BACKGROUND: To ensure that National Institutes of Health-funded research is relevant to the population's needs, specific emphasis on proportional representation of minority/sex groups into National Cancer Institute (NCI) cancer centers' clinical research programs is reported to the NCI. METHODS: EMPaCT investigators at 5 regionally diverse comprehensive cancer centers compared data reported to the NCI for their most recent Cancer Center Support Grant competitive renewal to assess and compare the centers' catchment area designations, data definitions, data elements, collection processes, reporting, and performance regarding proportional representation of race/ethnicity and sex subsets. RESULTS: Cancer centers' catchment area definitions differed widely in terms of their cancer patient versus general population specificity, levels of specificity, and geographic coverage. Racial/ethnic categories were similar, yet were defined differently, across institutions. Patients' socioeconomic status and insurance status were inconsistently captured across the 5 centers. CONCLUSIONS: Catchment area definitions and the collection of patient-level demographic factors varied widely across the 5 comprehensive cancer centers. This challenged the assessment of success by cancer centers in accruing representative populations into the cancer research enterprise. Accrual of minorities was less than desired for at least 1 racial/ethnic subcategory at 4 of the 5 centers. Institutions should clearly and consistently declare their primary catchment area and the rationale and should report how race/ethnicity and sex are defined, determined, collected, and reported. More standardized, frequent, consistent collection, reporting, and review of these data are recommended, as is a commitment to collecting socioeconomic data, given that socioeconomic status is a primary driver of cancer disparities in the United States.

HIV-1 infection of human intestinal lamina propria CD4+ T cells in vitro is enhanced by exposure to commensal Escherichia coli.

Microbial translocation has been linked to systemic immune activation in HIV-1 disease, yet mechanisms by which microbes may contribute to HIV-associated intestinal pathogenesis are poorly understood. Importantly, our understanding of the impact of translocating commensal intestinal bacteria on mucosal-associated T cell responses in the context of ongoing viral replication that occurs early in HIV-1 infection is limited. We previously identified commensal Escherichia coli-reactive Th1 and Th17 cells in normal human intestinal lamina propria (LP). In this article, we established an ex vivo assay to investigate the interactions between Th cell subsets in primary human LP mononuclear cells (LPMCs), commensal E. coli, and CCR5-tropic HIV-1(Bal). Addition of heat-killed E. coli to HIV-1-exposed LPMCs resulted in increases in HIV-1 replication, CD4 T cell activation and infection, and IL-17 and IFN-γ production. Conversely, purified LPS derived from commensal E. coli did not enhance CD4 T cell infection. E. coli exposure induced greater proliferation of LPMC Th17 than Th1 cells. Th17 cells were more permissive to infection than Th1 cells in HIV-1-exposed LPMC cultures, and Th17 cell infection frequencies significantly increased in the presence of E. coli. The E. coli-associated enhancement of infection was dependent on the presence of CD11c(+) LP dendritic cells and, in part, on MHC class II-restricted Ag presentation. These results highlight a potential role for translocating microbes in impacting mucosal HIV-1 pathogenesis during early infection by increasing HIV-1 replication and infection of intestinal Th1 and Th17 cells.

Folate Receptor Beta Signaling in the Regulation of Macrophage Antimicrobial Immune Response: A Scoping Review.

Introduction: Folate, vitamin B9, is a water-soluble vitamin that is essential to cellular proliferation and division. In addition to the reduced folate carrier, eukaryotic cells take up folate through endocytosis mediated by one of two GPI-anchored folate receptors (FRs), FRα or FRß. Two other isoforms of FR exist, FRγ and FRδ, neither of which support endocytic activities of FR signaling. FRß is expressed primarily by monocytes and macrophages and highly expressed on activated macrophages. Macrophage expression of FRß suggests a role for this receptor in modulating function of these immune sentinels, particularly as they engage in inflammatory processes. Despite several studies suggesting that folates can suppress inflammatory responses of macrophages to proinflammatory stimuli, there appears to be a lack of basic research examining the role of FRß in modulating macrophage responses to microbial sensing. We therefore conducted a scoping review to assess evidence within the published literature addressing the question, "what is known about the extent to which FRß regulates macrophage responses to sensing, and responding to, microorganisms?". Methods: As a strategy for the study selection, we queried articles indexed in the research database PubMed and the search engine Google Scholar (up until August 12, 2023), including combinations of the research words: macrophage, folate receptor beta, FOLR2. Results: We identified 2 relevant articles out of 153 that are worth discussing here, none of which directly addressed our research question. Conclusion: There is an unmet need to better define the contribution of FRß to regulating the macrophage response to microbes.

Palmitate and group B Streptococcus synergistically and differentially induce IL-1ß from human gestational membranes.

Introduction: Rupture of the gestational membranes often precedes major pregnancy complications, including preterm labor and preterm birth. One major cause of inflammation in the gestational membranes, chorioamnionitis (CAM) is often a result of bacterial infection. The commensal bacterium Streptococcus agalactiae, or Group B Streptococcus (GBS) is a leading infectious cause of CAM. Obesity is on the rise worldwide and roughly 1 in 4 pregnancy complications is related to obesity, and individuals with obesity are also more likely to be colonized by GBS. The gestational membranes are comprised of several distinct cell layers which are, from outermost to innermost: maternally-derived decidual stromal cells (DSCs), fetal cytotrophoblasts (CTBs), fetal mesenchymal cells, and fetal amnion epithelial cells (AECs). In addition, the gestational membranes have several immune cell populations; macrophages are the most common phagocyte. Here we characterize the effects of palmitate, the most common long-chain saturated fatty acid, on the inflammatory response of each layer of the gestational membranes when infected with GBS, using human cell lines and primary human tissue. Results: Palmitate itself slightly but significantly augments GBS proliferation. Palmitate and GBS co-stimulation synergized to induce many inflammatory proteins and cytokines, particularly IL-1ß and matrix metalloproteinase 9 from DSCs, CTBs, and macrophages, but not from AECs. Many of these findings are recapitulated when treating cells with palmitate and a TLR2 or TLR4 agonist, suggesting broad applicability of palmitate-pathogen synergy. Co-culture of macrophages with DSCs or CTBs, upon co-stimulation with GBS and palmitate, resulted in increased inflammatory responses, contrary to previous work in the absence of palmitate. In whole gestational membrane biopsies, the amnion layer appeared to dampen immune responses from the DSC and CTB layers (the choriodecidua) to GBS and palmitate co-stimulation. Addition of the monounsaturated fatty acid oleate, the most abundant monounsaturated fatty acid in circulation, dampened the proinflammatory effect of palmitate. Discussion: These studies reveal a complex interplay between the immunological response of the distinct layers of the gestational membrane to GBS infection and that such responses can be altered by exposure to long-chain saturated fatty acids. These data provide insight into how metabolic syndromes such as obesity might contribute to an increased risk for GBS disease during pregnancy.

Emerging Evidence and Critical Issues with the Use of Single-Drop Capillary Blood for the Measurement of Hemoglobin Concentration in Population-Level Anemia Surveys.

Accurate and precise measurement of hemoglobin concentration is critical for reliable estimations of anemia prevalence at the population level. When systematic and/or random error are introduced in hemoglobin measurement, estimates of anemia prevalence might be significantly erroneous and, hence, limit their usefulness. For decades, single-drop capillary blood has been the most common blood source used for the measurement of hemoglobin concentration in surveys, especially in low-income and middle-income countries. In this study, we highlight historical and emerging evidence that single-drop capillary blood introduces a high degree of random error (variability) to hemoglobin estimates, leading to less reliable estimates of anemia prevalence at the population level. At present, the best practice is to collect and use venous blood for measurement of hemoglobin with an automated hematology analyzer, following standard operating procedures and quality assurance measures. Where use of an automated analyzer is not possible, the analysis of venous blood in a point-of-care hemoglobinometer by trained phlebotomists or specimen collectors should be considered. A forthcoming systematic review will provide additional evidence on the accuracy and precision of single-drop capillary blood for hemoglobin assessment. In the meantime, we raise caution when using single-drop capillary blood for hemoglobin measurement as it can result in inaccurate hemoglobin estimates and less reliable anemia prevalence estimates.

Comparison of Published Estimates of the National Prevalence of Iron, Vitamin A, and Zinc Deficiency and Sources of Inconsistencies.

Micronutrient deficiencies result in a broad range of adverse health and functional consequences, but the true prevalence of specific deficiencies remains uncertain because limited information is available from nationally representative surveys using recommended biomarkers. The present review compares various reported national deficiency prevalence estimates for nutrients and years where the estimates overlap for individual countries that conducted nationally representative surveys and explores possible reasons for any discrepancies discovered. Nationally representative micronutrient status surveys that were conducted since 2000 among preschool-aged children or women of reproductive age and included assessment of iron, vitamin A, or zinc status based on recognized biomarkers were considered eligible for inclusion, along with any modeled deficiency prevalence estimates for these same countries and years. There was considerable variation across different published prevalence estimates, with larger inconsistencies when the prevalence estimate was based on proxies, such as hemoglobin for iron deficiency and dietary zinc availability for zinc deficiency. Numerous additional methodological issues affected the prevalence estimates, such as which biomarker and what cutoff was used to define deficiency, whether the biomarker was adjusted for inflammation, and what adjustment method was used. For some country-years, the various approaches resulted in fairly consistent prevalence estimates. For other country-years, however, the results differed markedly and changed the conclusions regarding the existence and severity of the micronutrient deficiency as a public health concern. In conclusion, to determine micronutrient status, we consider the assessment of one of the recommended biomarkers in a population representative survey as the best available information. If indicated, results should be adjusted for inflammation and generally acceptable cutoffs should be applied to facilitate comparisons, although individual countries may also apply nationally defined cutoffs to determine when and where to intervene. Global consensus is needed on best practices for presenting survey results and defining the prevalence of deficiency.

Review of intervention products for use in the prevention and control of anemia.

Anemia remains a major public health problem, especially in low- and middle-income countries. The World Health Organization recommends several interventions to prevent and manage anemia in vulnerable population groups, including young children, menstruating adolescent girls and women, and pregnant and postpartum women. Daily iron supplementation reduces the risk of anemia in infants, children, and pregnant women, and intermittent iron supplementation reduces anemia risk in menstruating girls and women. Micronutrient powders reduce the risk of anemia in children. Fortifying wheat flour with iron reduces the risk of anemia in the overall population, whereas the effect of fortifying maize flour and rice is still uncertain. Regarding non-nutrition-related interventions, malaria treatment and deworming have been reported to decrease anemia prevalence. Promising interventions to prevent anemia include vitamin A supplementation, multiple micronutrient supplementation for pregnant women, small-quantity lipid-based supplements, and fortification of salt with iodine and iron. Future research could address the efficacy and safety of different iron supplementation formulations, identify the most bioavailable form of iron for fortification, examine adherence to supplementation regimens and fortification standards, and investigate the effectiveness of integrating micronutrient, helminth, and malaria control programs.