Prenatal blood metals, per- and polyfluoroalkyl substances and antigen- or mitogen-stimulated cord blood lymphocyte proliferation and cytokine secretion.

BACKGROUND: Evidence suggests that prenatal per- and polyfluoroalkyl substances (PFAS) and metals, two classes of chemicals found ubiquitously in human populations, influence immune system development and response. OBJECTIVE: We evaluated whether first trimester blood PFAS and metals were associated with antigen- or mitogen-stimulated cord blood lymphocyte proliferation and cytokine secretion. METHODS: We measured six PFAS, as well as six nonessential and four essential metals, in first trimester blood from participants in the longitudinal pre-birth Project Viva cohort, recruited between 1999-2000 in eastern Massachusetts. We measured antigen- or mitogen-stimulated cord blood mononuclear cell proliferation responses (n=269-314) and cytokine secretion (n=217-302). We used covariate-adjusted least absolute shrinkage and selection operator (LASSO) for variable selection and multivariable regression to estimate associations with the immune markers. RESULTS: Each ng/mL of MeFOSAA was associated with a 3.6% (1.4, 5.8) higher lymphocyte proliferation response after stimulation with egg antigen, as well as 0.8 (0.7, 1.0) reduced odds of having IFN-γ detected in response to dust mite. Each ng/g increment of cesium was associated with 27.8% (-45.1, -4.9) lower IL-10 levels in response to dust mite. Each ng/g increment of mercury was associated with 12.0% (1.3, 23.8) higher IL-13 levels in response to mitogen PHA. Each ng/g increment of selenium and zinc was associated with 0.2% (0.01, 0.4) and 0.01% (0.002, 0.02) higher TNF-α in response to mitogen PHA, respectively. CONCLUSIONS: Prenatal metals and PFAS influence cord blood lymphocyte proliferation and cytokine secretion in ways that may increase risk for atopic disease in childhood.

Oral administration of the commensal Alistipes onderdonkii prolongs allograft survival.

Intestinal commensals can exert immunomodulatory effects on the host, with beneficial or detrimental consequences depending on underlying diseases. We have previously correlated longer survival of minor mismatched skin grafts in mice with the presence of an intestinal commensal bacterium, Alistipes onderdonkii. In this study, we investigated its sufficiency and mechanism of action. Oral administration of A onderdonkii strain DSM19147 but not DSM108265 was sufficient to prolong minor mismatched skin graft survival through inhibition of tumor necrosis factor production. Through metabolomic and metagenomic comparisons between DSM19147 and DSM108265, we identified candidate gene products associated with the anti-inflammatory effect of DSM19147. A onderdonkii DSM19147 can lower inflammation both at a steady state and after transplantation and may serve as an anti-inflammatory probiotic beneficial for transplant recipients.

BORN TO WHEEZE OR LEARNED WHEN WE WERE YOUNG: MATERNAL AND ENVIRONMENTAL FACTORS INFLUENCE ATOPIC RISK.

The prevalence of atopic diseases is increasing globally, particularly in children. Heritable genetics can partially explain risk of disease. Evidence also points to acquired genetic material, in the form of the microbiome, as an important factor in disease pathogenesis. The acquisition of the microbiome dynamically changes in response to differences in lifestyle and environmental factors. Also, in utero, maternal and environmental factors influence atopic risk for allergic rhinitis, eczema, asthma, and food allergy. Combining the analytical power of omics, we focus on how the microbiota mediates effects between mother, environment, immunity, and risk of atopic disease. In parallel, we stress that health care disparities impact asthma morbidity and mortality. Efforts to improve asthma outcomes must include multidisciplinary strategies.

Transmission Dynamics of Large Coronavirus Disease Outbreak in Homeless Shelter, Chicago, Illinois, USA, 2020.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has the potential for rapid transmission in congregate settings. We describe the multidisciplinary response to an outbreak of coronavirus disease (COVID-19) in a large homeless shelter in Chicago, Illinois, USA. The response to the outbreak included 4 rounds of mass PCR testing of all staff and residents and subsequent isolation of persons who tested positive for SARS-CoV-2. We further describe the dynamics of the shelter outbreak by fitting a modified susceptible-exposed-infectious-recovered compartmental model incorporating the widespread SARS-CoV-2 testing and isolation measures implemented in this shelter. Our model demonstrates that rapid transmission of COVID-19 in the shelter occurred before the outbreak was detected; rates of transmission declined after widespread testing and isolation measures were put in place. Overall, we demonstrate the feasibility of mass PCR testing and isolation in congregate settings and suggest the necessity of prompt response to suspected COVID-19 outbreaks in homeless shelters.

The olfactory G protein-coupled receptor (Olfr-78/OR51E2) modulates the intestinal response to colitis.

Olfactory receptor-78 (Olfr-78) is a recently identified G protein-coupled receptor activated by short-chain fatty acids acetate and propionate. A suggested role for this receptor exists in the prostate where it may influence chronic inflammatory response leading to intraepithelial neoplasia. Olfr-78 has also been shown to be expressed in mouse colon. Short-chain fatty acids and their receptors are well known to modulate inflammation in the gut. Considering this possibility, we first explored if colitis regulated Olfr-78 expression in the gut, where we observed a significant reduction in the expression of Olfr-78 transcript in mouse models of dextran sodium sulfate (DSS)- and 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. To more directly test this, mice deficient in Olfr-78 were administered with DSS in water for 7 days and were found to have increased expression of IL-1ß and inflammatory signs in colon compared with control mice. Next, we explored the expression of its human counterpart olfactory receptor family 51, subfamily E, member 2 (OR51E2) in human intestinal samples and observed that it was in fact also expressed in human colon samples. RNA sequence analysis revealed significant changes in the genes involved in infection, immunity, inflammation, and colorectal cancer between wild-type and Olfr-78 knockout mice. Collectively, our findings show that Olfr-78 is highly expressed in colon and downregulated in DSS- and TNBS-induced colitis, and DSS-treated Olfr-78 null mice had increased colonic expression of cytokine RNA levels, suggesting a potential role for this receptor in intestinal inflammation. Future investigations are needed to understand how Olfr-78/OR51E2 in both mouse and human intestine modulates gastrointestinal pathophysiology.

Utilizing longitudinal microbiome taxonomic profiles to predict food allergy via Long Short-Term Memory networks.

Food allergy is usually difficult to diagnose in early life, and the inability to diagnose patients with atopic diseases at an early age may lead to severe complications. Numerous studies have suggested an association between the infant gut microbiome and development of allergy. In this work, we investigated the capacity of Long Short-Term Memory (LSTM) networks to predict food allergies in early life (0-3 years) from subjects' longitudinal gut microbiome profiles. Using the DIABIMMUNE dataset, we show an increase in predictive power using our model compared to Hidden Markov Model, Multi-Layer Perceptron Neural Network, Support Vector Machine, Random Forest, and LASSO regression. We further evaluated whether the training of LSTM networks benefits from reduced representations of microbial features. We considered sparse autoencoder for extraction of potential latent representations in addition to standard feature selection procedures based on Minimum Redundancy Maximum Relevance (mRMR) and variance prior to the training of LSTM networks. The comprehensive evaluation reveals that LSTM networks with the mRMR selected features achieve significantly better performance compared to the other tested machine learning models.

Intestinal TGR5 agonism improves hepatic steatosis and insulin sensitivity in Western diet-fed mice.

Takeda G protein-coupled receptor 5 (TGR5) agonists induce systemic release of glucagon-like peptides (GLPs) from intestinal L cells, a potentially therapeutic action against metabolic diseases such as nonalcoholic steatohepatitis (NASH), nonalcoholic fatty liver disease (NAFLD), and Type 2 diabetes. Historically, TGR5 agonist use has been hindered by side effects, including inhibition of gallbladder emptying. Here, we characterize RDX8940, a novel, orally administered TGR5 agonist designed to have minimal systemic effects and investigate its activity in mice fed a Western diet, a model of NAFLD and mild insulin resistance. Agonist activity, binding selectivity, toxicity, solubility, and permeability of RDX8940 were characterized in standard in vitro models. RDX8940 pharmacokinetics and effects on GLP secretion, insulin sensitivity, and liver steatosis were assessed in C57BL/6 mice fed normal or Western diet chow and given single or repeated doses of RDX8940 or vehicle, with or without dipeptidyl peptidase-4 (DPP4) inhibitors. Gallbladder effects were assessed in CD-1 mice fed normal chow and given RDX8940 or a systemic TGR5 agonist or vehicle. Our results showed that RDX8940 is minimally systemic, potent, and selective, and induces incretin (GLP-1, GLP-2, and peptide YY) secretion. RDX8940-induced increases in plasma active GLP-1 (aGLP-1) levels were enhanced by repeated dosing and by coadministration of DPP4 inhibitors. RDX8940 increased hepatic exposure to aGLP-1 without requiring coadministration of a DPP4 inhibitor. In mice fed a Western diet, RDX8940 improved liver steatosis and insulin sensitivity. Unlike systemic TGR5 agonists, RDX8940 did not inhibit gallbladder emptying. These results indicate that RDX8940 may have therapeutic potential in patients with NAFLD/NASH. NEW & NOTEWORTHY Takeda G protein-coupled receptor 5 (TGR5) agonists have potential as a treatment for nonalcoholic steatohepatitis and nonalcoholic fatty liver disease (NAFLD) but have until now been associated with undesirable side effects associated with systemic TGR5 agonism, including blockade of gallbladder emptying. We demonstrate that RDX8940, a potent, selective, minimally systemic oral TGR5 agonist, improves liver steatosis and insulin sensitivity in a mouse model of NAFLD and does not inhibit gallbladder emptying in mice.

Prenatal Maternal Depression and Neonatal Immune Responses.

OBJECTIVE: The aim of the study was to examine the association of lifetime maternal depression with regulation of immune responses in the infant, measured by cytokine levels and lymphocyte proliferation (LP) in cord blood mononuclear cells collected at delivery. METHODS: We studied women recruited in early pregnancy into the Project Viva longitudinal cohort who had cord blood assayed after delivery (N = 463). Women reported about depressive symptoms in midpregnancy (Edinburgh Postnatal Depression Scale) and depression history by questionnaire. Immune responses were assayed by an index of LP, and concentrations of five cytokines (interleukin [IL]-6, IL-10, IL-13, tumor necrosis tumor necrosis factor factor α, and interferon γ) after incubation of cord blood mononuclear cells either in medium alone or stimulated with phytohemagglutinin (PHA), cockroach extract, or house dust mite extract. We examined associations of maternal depression with these sets of cytokine measures using multivariable linear or tobit regression analyses. RESULTS: After adjustment for confounders (mother's age, race/ethnicity, education, household income, season of birth, and child sex), levels of IL-10 after stimulation with cockroach or dust mite allergen were lower in cord blood from ever versus never depressed women, and a similar trend was evident in IL-10 stimulated with PHA (percentage difference: cockroach extract = -41.4, p = .027; house dust mite extract = 1-36.0, p = .071; PHA = -24.2, p = .333). No significant differences were seen in levels of other cytokines or LP. CONCLUSIONS: Maternal depression is associated with offspring immune responses at birth, which may have implications for later life atopic risk or immune function.

Associations of urban greenness with asthma and respiratory symptoms in Mexican American children.

BACKGROUND: Evidence on the association between residential surrounding greenness (RSG) in urban areas with asthma and asthma symptoms is inconsistent. OBJECTIVE: To examine the association of RSG with respiratory outcomes in a sample of Mexican American children living in inner-city Chicago, Illinois. METHODS: This study is based on parent-reported data on 1915 Mexican American children. We calculated RSG using the normalized difference vegetation index based on satellite imagery within buffers of 100, 250, and 500 m of each child's residence. Multivariable multilevel mixed-effect logistic regression was used to estimate adjusted odds ratios (aORs) for the effect of a 1-interquartile range increase in greenness. RESULTS: In adjusted analyses, a protective effect of greenness within 100 m was observed for lifetime wheezing (aOR, 0.82; 95% CI, 0.69-0.96). Environmental tobacco smoke (ETS) exposure modified the association of RSG with lifetime asthma and current dry cough at night. For all buffer distances, increased greenness was associated with lower odds of lifetime asthma among children with current ETS exposure (100 m: aOR, 0.43; 95% CI, 0.22-0.87; 250 m: aOR, 0.39; 95% CI, 0.18-0.84; 500 m: aOR, 0.48; 95% CI, 0.26-0.90) and lower odds of current dry cough at night among children with perinatal ETS exposure (100 m: aOR, 0.53; 95% CI, 0.31-0.92; 250 m: aOR, 0.55; 95% CI, 0.31-0.98; 500 m: aOR, 0.55; 95% CI, 0.35-0.87). CONCLUSION: Our results suggest inverse associations of urban greenness with respiratory outcomes, especially in children exposed to ETS. Further research is needed to examine the mechanisms through which RSG may be associated with the risk of asthma and contribute to health.

In vitro antioxidant activities of Rhodobacter sphaeroides and protective effect on Caco-2 cell line model.

The present study aimed to evaluate the in vitro antioxidant activities and the protective effect of Rhodobacter sphaeroides on H2O2-induced oxidative stress in Caco-2 cells. The results showed that the antioxidant action of R. sphaeroides varied with different cell concentrations and treatments. Also, the intact cells and intracellular cell-free extracts showed better antioxidant activities. Caco-2 cell-based oxidative stress model was developed by optimizing H2O2 concentration and culture time with the half lethal dose and methyl thiazolyl tetrazolium. By increasing the activity of endogenous antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, upregulating the antioxidant ability of the anti-superoxide anion and anti-hydroxyl radical, R. sphaeroides, especially the mutant strain R. sphaeroides (CGMCC No. 8513), exhibited significant protective activity against H2O2-induced oxidative stress in Caco-2 cells. Taken together, R. sphaeroides (CGMCC No. 8513) exhibits strong antioxidant activities and is a candidate to be investigated as a potential probiotic in the future.

A Circulating MicroRNA Signature Serves as a Diagnostic and Prognostic Indicator in Sarcoidosis.

MicroRNAs (miRNAs) act as post-transcriptional regulators of gene expression. In sarcoidosis, aberrant miRNA expression may enhance immune responses mounted against an unknown antigenic agent. We tested whether a distinct miRNA signature functions as a diagnostic biomarker and explored its role as an immune modulator in sarcoidosis. The expression of miRNAs in peripheral blood mononuclear cells from subjects who met clinical and histopathologic criteria for sarcoidosis was compared with that observed in matched controls in the ACCESS (A Case Controlled Etiologic Study of Sarcoidosis) study. Signature miRNAs were determined by miRNA microarray analysis and validated by quantitative RT-PCR. Microarray analysis identified 54 mature, human feature miRNAs that were differentially expressed between the groups. Significant feature miRNAs that distinguished subjects with sarcoidosis from controls were selected by means of probabilistic models adjusted for clinical variables. Eight signature miRNAs were chosen to verify the diagnosis of sarcoidosis in a validation cohort, and distinguished subjects with sarcoidosis from controls with a positive predictive value of 88%. We identified both novel and previously described genes and molecular pathways associated with sarcoidosis as targets of these signature miRNAs. Additionally, we demonstrate that signature miRNAs (hsa-miR-150-3p and hsa-miR-342-5p) are significantly associated with reduced lymphocytes and airflow limitations, both of which are known markers of a poor prognosis. Together, these findings suggest that a circulating miRNA signature serves as a noninvasive biomarker that supports the diagnosis of sarcoidosis. Future studies will test the miRNA signature as a prognostication tool to identify unfavorable changes associated with poor clinical outcomes in sarcoidosis.

Perinatal Bacterial Exposure Contributes to IL-13 Aeroallergen Response.

There is a high prevalence of aeroallergen sensitivity in asthmatic populations, and seroreactivity to aeroallergens early in infancy is associated with increased risk of developing asthma later in life. In addition to allergen sensitivity, asthma development has been associated with differential microbial exposure and infection in early life. We have previously shown that cord blood mononuclear cells respond to common aeroallergens (i.e., house dust mite [Der f1] and cockroach [Bla g2]) as assayed by lymphoproliferation and cytokine (IL-13 and IFN-γ) production. We hypothesized that there is a relationship between perinatal microbial exposure and response to specific aeroallergens. To test this hypothesis, we isolated DNA from cord blood serum samples with known lymphoproliferative and cytokine responses to Bla g2 and Der f1. Bacterial 16S ribosomal DNA amplicon libraries were generated and analyzed using high throughput sequencing of cord blood serum samples. In our analysis, we identified major compositional differences, including diversity and abundance of specific taxa, between groups whose IL-13 response to Der f1 and Bla g2 differed. We demonstrate a strong association between the ratio of Acinetobacter to Proteobacteria and IL-13 production and the probability of IL-13 production after allergen exposure. IL-13 concentrations in serum were also significantly correlated with the diversity of bacterial DNA. Together, these results underscore the relationship between immune responses to allergens and bacterial exposure during perinatal development.

Differential impact of obesity on the pathogenesis of RA or preclinical models is contingent on the disease status.

OBJECTIVE: Studies were performed to uncover the significance of obesity in rheumatoid arthritis (RA) and preclinical models. METHODS: Preclinical arthritis models were used to examine the impact of obesity on disease onset and remission. Conditioned media from RA adipose tissues were used to investigate the mechanism contributing to joint neutrophil influx and M1 macrophage differentiation observed in early and remission phases of arthritis. RESULTS: We report that mice fed with high fat diet (HFD) have an earlier onset of collagen-induced arthritis (CIA) compared with mice on regular diet. However, the differences in CIA joint swelling between the two diet groups are lost once disease is established. We found that early arthritis triggered by obesity is due to elevated joint MIP2/interleukin-8 levels detected in CIA as well as in the RA and mouse adipose tissues and the effect of this chemokine on neutrophil recruitment. Although active disease progression is similarly affected in both diet groups, arthritis resolution is accelerated in lean mice while joint inflammation is sustained in obese mice. We document that HFD can prolong toll-like receptor (TLR)4-induced arthritis by increasing joint monocyte migration and further remodelling the recruited cells into M1 macrophages. Consistently, we show that adipose condition media can transform RA and wild-type naïve myeloid cells into M1 macrophages; however, this function is impaired by TLR4 blockade or deficiency. CONCLUSIONS: We conclude that despite established disease being unaffected by obesity, the early and the resolution phases of RA are impacted by obesity through different mechanisms.

The Potential for Emerging Microbiome-Mediated Therapeutics in Asthma.

PURPOSE OF REVIEW: In terms of immune regulating functions, analysis of the microbiome has led the development of therapeutic strategies that may be applicable to asthma management. This review summarizes the current literature on the gut and lung microbiota in asthma pathogenesis with a focus on the roles of innate molecules and new microbiome-mediated therapeutics. RECENT FINDINGS: Recent clinical and basic studies to date have identified several possible therapeutics that can target innate immunity and the microbiota in asthma. Some of these drugs have shown beneficial effects in the treatment of certain asthma phenotypes and for protection against asthma during early life. Current clinical evidence does not support the use of these therapies for effective treatment of asthma. The integration of the data regarding microbiota with technologic advances, such as next generation sequencing and omics offers promise. Combining comprehensive bioinformatics, new molecules and approaches may shape future asthma treatment.

T cells and lung injury. Impact of rapamycin.

Acute lung injury (ALI) is characterized by pulmonary inflammation and edema. Innate immune cells (e.g., neutrophils and macrophages) are major contributors to inflammation in ALI. Less is known regarding the role of T cells. We examined the effects of rapamycin on inflammation in a LPS-induced murine model of ALI. Rapamycin was administered before and after initiation of injury. Inflammatory parameters, including bronchoalveolar lavage cell counts, T cell surface markers (i.e., cytotoxic T lymphocyte antigen 4 [CTLA4] and fork head-winged helix transcription factor [Foxp3]), T cell activation (CD69), IL-6, and IL-10 were analyzed. Rapamycin significantly decreased inflammatory parameters and decreased Foxp3, CTLA4, and CD69 in CD4(+) T cells. Rapamycin administration before or after the onset of lung injury, as well as systemically or by pulmonary routes, ameliorates inflammation in ALI.

Impact of single immunosuppressive drug withdrawal on lymphocyte immunoreactivity.

BACKGROUND: Chronic rejection is a major cause of graft loss in kidney transplant recipients. Nonadherence to drug therapy is a well-recognized cause of chronic rejection leading to long-term graft dysfunction and failure for transplant recipients. Immunosuppressive medications with short half-lives that require frequent dosing, such as tacrolimus, complicate transplant regimens and may increase noncompliance. Regimens could be simplified using drugs with long half-lives requiring once-daily administration, such as sirolimus. The impact of missing doses of single agents has not been studied extensively. Erratic compliance or temporary discontinuation of immunosuppressive drugs may have significant implications for chronic rejection. METHODS: Our study evaluated the impact of single drug withdrawal of commonly used immunosuppressive agents (sirolimus and tacrolimus) on lymphocyte responses. We analyzed lymphocyte proliferation, cytokine secretion, and adenosine triphosphate generation using a crossover study design with normal healthy patients. Lymphocyte proliferation was assessed using 5-bromo-2-deoxyuridine incorporation, and T cell function was analyzed by examining adenosine triphosphate generation. RESULTS: Our results indicate that sirolimus exerts prolonged suppression of lymphocyte proliferation and decreased interleukin 17A that lasts up to 48 h after drug withdrawal. In comparison, tacrolimus did not have a similar effect on lymphocyte proliferation or interleukin 17A secretion. CONCLUSION: Future analysis of sirolimus in diverse transplantation populations merits investigation.

An official American Thoracic Society/European Respiratory Society policy statement: disparities in respiratory health.

BACKGROUND: Health disparities, defined as a significant difference in health between populations, are more common for diseases of the respiratory system than for those of other organ systems, because of the environmental influence on breathing and the variation of the environment among different segments of the population. The lowest social groups are up to 14 times more likely to have respiratory diseases than are the highest. Tobacco smoke, air pollution, environmental exposures, and occupational hazards affect the lungs more than other organs, and occur disproportionately in ethnic minorities and those with lower socioeconomic status. Lack of access to quality health care contributes to disparities. METHODS: The executive committees of the American Thoracic Society (ATS) and European Respiratory Society (ERS) established a writing committee to develop a policy on health disparities. The document was reviewed, edited, and approved by the full executive committees and boards of directors of the societies. RESULTS: This document expresses a policy to address health disparities by promoting scientific inquiry and training, disseminating medical information and best practices, and monitoring and advocating for public respiratory health. ERS and ATS have strong international commitments, and work with leaders from governments, academia, and organizations to address and reduce avoidable health inequalities. Their training initiatives improve the function of health care systems and health equality. Both the ATS and ERS support all aspects of this document, confer regularly, and act together when possible, but the activities to bring about change may vary because of the differences in the continents where the two organizations carry out most of their activities. CONCLUSIONS: The ATS and ERS pledge to frame their actions to reduce respiratory health disparities. The vision of the ATS and ERS is that all persons attain better and sustained respiratory health. They call on all their members and other societies to join in this commitment.