mTORC1 Signaling Regulates Proinflammatory Macrophage Function and Metabolism.

Metabolic programming is integrally linked to immune cell function. Nowhere is this clearer than in the differentiation of macrophages. Proinflammatory M1 macrophages primarily use glycolysis as a rapid energy source but also to generate antimicrobial compounds, whereas alternatively activated M2 macrophages primarily rely on oxidative phosphorylation for the longevity required for proper wound healing. mTOR signaling has been demonstrated to be a key regulator of immune cell metabolism and function. mTORC2 signaling is required for the generation of M2 macrophages, whereas the role of mTORC1 signaling, a key regulator of glycolysis, has been controversial. By using genetic deletion of mTORC1 signaling in C57BL/6 mouse macrophages, we observed enhanced M1 macrophage function in vitro and in vivo. Surprisingly, this enhancement occurred despite a significant defect in M1 macrophage glycolytic metabolism. Mechanistically, enhanced M1 function occurred because of inhibition of the class III histone deacetylases the sirtuins, resulting in enhanced histone acetylation. Our findings provide a counterpoint to the paradigm that enhanced immune cell function must occur in the presence of increased cellular metabolism and identifies a potential, pharmacologic target for the regulation of inflammatory responses.

The wash-in effect and its significance for mass casualty decontamination.

Decontamination of skin by washing may increase dermal absorption, a phenomenon known as the wash-in effect. The wash-in effect is frequently discussed in studies investigating casualty decontamination where potentially life-saving interventions may enhance the dermal penetration of toxic chemicals, leading to an increase in incidence of morbidity and rates of mortality. However, the wash-in effect is seldom investigated within the context of mass casualty decontamination and real-life consequences are therefore poorly understood. This paper reviews the existing literature on the wash-in effect to highlight the proposed mechanisms for enhanced absorption and evaluate the wash-in effect within the context of mass casualty chemical decontamination.

Airway compliance measurements in mouse models of respiratory diseases.

The quantification of airway compliance (Caw) is essential to the study of airway alterations in disease models. However, the required measurements of airway pressure and volume are difficult to acquire in mice. We hypothesized that the inflation limb of full-range pressure-volume (PV) curves could be used to quantify Caw, as it contains a segment where only the airway tree is distended. The study objective was to assess the feasibility of the approach by analysis of full-range PV curves previously collected in three mouse models: an elastase model of emphysema, a genetic model spontaneously developing emphysema (leukotriene C4 synthase knockout; LTC4S-KO), and a bleomycin model of lung fibrosis. Attempts to validate results included Caw change relative to respiratory system compliance (ΔCaw/ΔC), the minute work of breathing (mWOB), and the elastance at 20.5 Hz (Ers_20.5) from prior respiratory mechanics measurements in the same subjects. Caw was estimated at 3% of total compliance in healthy mice or 2.3 ± 1 µL/cmH2O (n = 17). The technique detected changes in models of respiratory obstructive and restrictive diseases relative to control mice as well as differences in the two emphysema models studied. The changes in Caw were consistent with those seen in ΔCaw/ΔC, mWOB, or Ers_20.5, with some variations according to the model, as well as with results reported in the literature in humans and mice. Direct Caw measurements in subjects as small as mice could prove useful to further characterize other respiratory disease models associated with airway remodeling or to assess treatment effects.

Evaluating implementation of International Health Regulations core capacities: using the Electronic States Parties Self-Assessment Annual Reporting Tool (e-SPAR) to monitor progress with Joint External Evaluation indicators.

BACKGROUND: The International Health Regulations (IHR) are a legally binding instrument designed to improve Global Health Security by limiting the cross boarder spread of health risks. All 196 signatories to the IHR (2005) are required to report progress towards IHR core capacity implementation through an annual multi-sectoral self-assessment process known as the State Parties Self-Assessment Annual Reporting (SPAR). This mandatory process sits alongside the voluntary, external, peer-reviewed Joint External Evaluations (JEE) as two core components of the IHR monitoring and evaluation framework. JEEs are intended to occur once every 4-5 years following a voluntary request from the member state. This means that interim monitoring of IHR core capacity compliance, can be challenging and additional data sources are required. The outputs of the SPAR process represent one such source. Although the JEE and SPAR tools are intended to be complimentary, there has been no publicly available mapping of JEE indicators to SPAR indicators in order to inform progress on IHR compliance. RESULTS: This paper mapped JEE indicators to SPAR indicators and found a high level of correlation suggesting the SPAR process offers a method for countries and technical assistance programmes to monitor progress on IHR compliance and identify gaps in between JEE visits. However, coverage was not complete, and several gaps were identified most notably in antimicrobial resistance (AMR) and vaccinations. CONCLUSION: Enhancing alignment between JEE and SPAR could offer a more consistent and complete way of assessing compliance with IHR.

Chemical warfare agent simulants for human volunteer trials of emergency decontamination: A systematic review.

Incidents involving the release of chemical agents can pose significant risks to public health. In such an event, emergency decontamination of affected casualties may need to be undertaken to reduce injury and possible loss of life. To ensure these methods are effective, human volunteer trials (HVTs) of decontamination protocols, using simulant contaminants, have been conducted. Simulants must be used to mimic the physicochemical properties of more harmful chemicals, while remaining non-toxic at the dose applied. This review focuses on studies that employed chemical warfare agent simulants in decontamination contexts, to identify those simulants most suitable for use in HVTs of emergency decontamination. Twenty-two simulants were identified, of which 17 were determined unsuitable for use in HVTs. The remaining simulants (n = 5) were further scrutinized for potential suitability according to toxicity, physicochemical properties and similarities to their equivalent toxic counterparts. Three suitable simulants, for use in HVTs were identified; methyl salicylate (simulant for sulphur mustard), diethyl malonate (simulant for soman) and malathion (simulant for VX or toxic industrial chemicals). All have been safely used in previous HVTs, and have a range of physicochemical properties that would allow useful inference to more toxic chemicals when employed in future studies of emergency decontamination systems.

Insidious Risk of Severe Mycobacterium chimaera Infection in Cardiac Surgery Patients.

BACKGROUND: An urgent UK investigation was launched to assess risk of invasive Mycobacterium chimaera infection in cardiothoracic surgery and a possible association with cardiopulmonary bypass heater-cooler units following alerts in Switzerland and The Netherlands. METHODS: Parallel investigations were pursued: (1) identification of cardiopulmonary bypass-associated M. chimaera infection through national laboratory and hospital admissions data linkage; (2) cohort study to assess patient risk; (3) microbiological and aerobiological investigations of heater-coolers in situ and under controlled laboratory conditions; and (4) whole-genome sequencing of clinical and environmental isolates. RESULTS: Eighteen probable cases of cardiopulmonary bypass-associated M. chimaera infection were identified; all except one occurred in adults. Patients had undergone valve replacement in 11 hospitals between 2007 and 2015, a median of 19 months prior to onset (range, 3 months to 5 years). Risk to patients increased after 2010 from <0.2 to 1.65 per 10000 person-years in 2013, a 9-fold rise for infections within 2 years of surgery (rate ratio, 9.08 [95% CI, 1.81-87.76]). Endocarditis was the most common presentation (n = 11). To date, 9 patients have died. Investigations identified aerosol release through breaches in heater-cooler tanks. Mycobacterium chimaera and other pathogens were recovered from water and air samples. Phylogenetic analysis found close clustering of strains from probable cases. CONCLUSIONS: We identified low but escalating risk of severe M. chimaera infection associated with heater-coolers with cases in a quarter of cardiothoracic centers. Our investigations strengthen etiological evidence for the role of heater-coolers in transmission and raise the possibility of an ongoing, international point-source outbreak. Active management of heater-coolers and heightened clinical awareness are imperative given the consequences of infection.

Loss of macrophage fatty acid oxidation does not potentiate systemic metabolic dysfunction.

Fatty acid oxidation in macrophages has been suggested to play a causative role in high-fat diet-induced metabolic dysfunction, particularly in the etiology of adipose-driven insulin resistance. To understand the contribution of macrophage fatty acid oxidation directly to metabolic dysfunction in high-fat diet-induced obesity, we generated mice with a myeloid-specific knockout of carnitine palmitoyltransferase II (CPT2 Mϕ-KO), an obligate step in mitochondrial long-chain fatty acid oxidation. While fatty acid oxidation was clearly induced upon IL-4 stimulation, fatty acid oxidation-deficient CPT2 Mϕ-KO bone marrow-derived macrophages displayed canonical markers of M2 polarization following IL-4 stimulation in vitro. In addition, loss of macrophage fatty acid oxidation in vivo did not alter the progression of high-fat diet-induced obesity, inflammation, macrophage polarization, oxidative stress, or glucose intolerance. These data suggest that although IL-4-stimulated alternatively activated macrophages upregulate fatty acid oxidation, fatty acid oxidation is dispensable for macrophage polarization and high-fat diet-induced metabolic dysfunction. Macrophage fatty acid oxidation likely plays a correlative, rather than causative, role in systemic metabolic dysfunction.

Cephalosporin-3'-Diazeniumdiolate NO Donor Prodrug PYRRO-C3D Enhances Azithromycin Susceptibility of Nontypeable Haemophilus influenzae Biofilms.

PYRRO-C3D is a cephalosporin-3-diazeniumdiolate nitric oxide (NO) donor prodrug designed to selectively deliver NO to bacterial infection sites. The objective of this study was to assess the activity of PYRRO-C3D against nontypeable Haemophilus influenzae (NTHi) biofilms and examine the role of NO in reducing biofilm-associated antibiotic tolerance. The activity of PYRRO-C3D on in vitro NTHi biofilms was assessed through CFU enumeration and confocal microscopy. NO release measurements were performed using an ISO-NO probe. NTHi biofilms grown on primary ciliated respiratory epithelia at an air-liquid interface were used to investigate the effects of PYRRO-C3D in the presence of host tissue. Label-free liquid chromatography-mass spectrometry (LC/MS) proteomic analyses were performed to identify differentially expressed proteins following NO treatment. PYRRO-C3D specifically released NO in the presence of NTHi, while no evidence of spontaneous NO release was observed when the compound was exposed to primary epithelial cells. NTHi lacking ß-lactamase activity failed to trigger NO release. Treatment significantly increased the susceptibility of in vitro NTHi biofilms to azithromycin, causing a log fold reduction (10-fold reduction or 1-log-unit reduction) in viability (P < 0.05) relative to azithromycin alone. The response was more pronounced for biofilms grown on primary respiratory epithelia, where a 2-log-unit reduction was observed (P < 0.01). Label-free proteomics showed that NO increased expression of 16 proteins involved in metabolic and transcriptional/translational functions. NO release from PYRRO-C3D enhances the efficacy of azithromycin against NTHi biofilms, putatively via modulation of NTHi metabolic activity. Adjunctive therapy with NO mediated through PYRRO-C3D represents a promising approach for reducing biofilm-associated antibiotic tolerance.

Primary ciliary dyskinesia ciliated airway cells show increased susceptibility to Haemophilus influenzae biofilm formation.

Non-typeable Haemophilus influenzae (NTHi) is the most common pathogen in primary ciliary dyskinesia (PCD) patients. We hypothesised that abnormal ciliary motility and low airway nitric oxide (NO) levels on airway epithelial cells from PCD patients might be permissive for NTHi colonisation and biofilm development.We used a primary epithelial cell co-culture model to investigate NTHi infection. Primary airway epithelial cells from PCD and non-PCD patients were differentiated to ciliation using an air-liquid interface culture and then co-cultured with NTHi.NTHi adherence was greater on PCD epithelial cells compared to non-PCD cells (p<0.05) and the distribution of NTHi on PCD epithelium showed more aggregated NTHi in biofilms (p<0.001). Apart from defective ciliary motility, PCD cells did not significantly differ from non-PCD epithelial cells in the degree of ciliation and epithelial integrity or in cytokine, LL-37 and NO production. Treatment of PCD epithelia using exogenous NO and antibiotic significantly reduced NTHi viability in biofilms compared with antibiotic treatment alone.Impaired ciliary function was the primary defect in PCD airway epithelium underlying susceptibility to NTHi biofilm development compared with non-PCD epithelium. Although NO responses were similar, use of targeted NO with antibiotics enhanced killing of NTHi in biofilms, suggesting a novel therapeutic approach.

European Respiratory Society guidelines for the diagnosis of primary ciliary dyskinesia.

The diagnosis of primary ciliary dyskinesia is often confirmed with standard, albeit complex and expensive, tests. In many cases, however, the diagnosis remains difficult despite the array of sophisticated diagnostic tests. There is no "gold standard" reference test. Hence, a Task Force supported by the European Respiratory Society has developed this guideline to provide evidence-based recommendations on diagnostic testing, especially in light of new developments in such tests, and the need for robust diagnoses of patients who might enter randomised controlled trials of treatments. The guideline is based on pre-defined questions relevant for clinical care, a systematic review of the literature, and assessment of the evidence using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. It focuses on clinical presentation, nasal nitric oxide, analysis of ciliary beat frequency and pattern by high-speed video-microscopy analysis, transmission electron microscopy, genotyping and immunofluorescence. It then used a modified Delphi survey to develop an algorithm for the use of diagnostic tests to definitively confirm and exclude the diagnosis of primary ciliary dyskinesia; and to provide advice when the diagnosis was not conclusive. Finally, this guideline proposes a set of quality criteria for future research on the validity of diagnostic methods for primary ciliary dyskinesia.

The dangers of widespread nitric oxide screening for primary ciliary dyskinesia.

Primary ciliary dyskinesia (PCD) is underdiagnosed and requires complex testing at specialist diagnostic centres. Measurement of nasal nitric oxide (nNO) has good sensitivity and specificity screening for PCD, but is currently usually measured at PCD centres rather than prior to referral. Proposals to include NO testing for asthma diagnoses could widen access to PCD screening if nasal mode analysers are available. Data from 282 consecutive referrals to our PCD diagnostic centre (31 PCD positive) were used to model predictive values for nNO testing with varying pretest probability and showed that predictive values were good in the referral population, but extending screening to more general populations would result in excessive false positives that may overwhelm diagnostic services. Although nNO remains a useful test, a 'normal' result with classical clinical history should still be considered for further testing.

Accuracy of diagnostic testing in primary ciliary dyskinesia.

Diagnosis of primary ciliary dyskinesia (PCD) lacks a "gold standard" test and is therefore based on combinations of tests including nasal nitric oxide (nNO), high-speed video microscopy analysis (HSVMA), genotyping and transmission electron microscopy (TEM). There are few published data on the accuracy of this approach.Using prospectively collected data from 654 consecutive patients referred for PCD diagnostics we calculated sensitivity and specificity for individual and combination testing strategies. Not all patients underwent all tests.HSVMA had excellent sensitivity and specificity (100% and 93%, respectively). TEM was 100% specific, but 21% of PCD patients had normal ultrastructure. nNO (30 nL·min(-1) cut-off) had good sensitivity and specificity (91% and 96%, respectively). Simultaneous testing using HSVMA and TEM was 100% sensitive and 92% specific.In conclusion, combination testing was found to be a highly accurate approach for diagnosing PCD. HSVMA alone has excellent accuracy, but requires significant expertise, and repeated sampling or cell culture is often needed. TEM alone is specific but misses 21% of cases. nNO (≤30 nL·min(-1)) contributes well to the diagnostic process. In isolation nNO screening at this cut-off would miss ∼10% of cases, but in combination with HSVMA could reduce unnecessary further testing. Standardisation of testing between centres is a future priority.

Study protocol, rationale and recruitment in a European multi-centre randomized controlled trial to determine the efficacy and safety of azithromycin maintenance therapy for 6 months in primary ciliary dyskinesia.

BACKGROUND: Clinical management of primary ciliary dyskinesia (PCD) respiratory disease is currently based on improving mucociliary clearance and controlling respiratory infections, through the administration of antibiotics. Treatment practices in PCD are largely extrapolated from more common chronic respiratory disorders, particularly cystic fibrosis, but no randomized controlled trials (RCT) have ever evaluated efficacy and safety of any pharmacotherapeutics used in the treatment of PCD. Maintenance therapy, with the macrolide antibiotic azithromycin, is currently widely used in chronic respiratory diseases including PCD. In addition to its antibacterial properties, azithromycin is considered to have beneficial anti-inflammatory and anti-quorum-sensing properties. The aim of this study is to determine the efficacy of azithromycin maintenance therapy for 6 months on respiratory exacerbations in PCD. The secondary objectives are to evaluate the efficacy of azithromycin on lung function, ventilation inhomogeneity, hearing impairment, and symptoms (respiratory, sinus, ears and hearing) measured on a PCD-specific health-related quality of life instrument, and to assess the safety of azithromycin maintenance therapy in PCD. METHODS: The BESTCILIA trial is a European multi-centre, double-blind, randomized, placebo-controlled, parallel group study. The intervention is tablets of azithromycin 250/500 mg according to body weight or placebo administered three times a week for 6 months. Subjects with a confirmed diagnosis of PCD, age 7-50 years, are eligible for inclusion. Chronic pulmonary infections with Gram-negative bacteria or any recent occurrence of non-tuberculous mycobacteria are exclusion criteria. The planned number of subjects to be included is 125. The trial has been approved by the Research Ethics Committees of the participating institutions. DISCUSSION: We present a study protocol of an ongoing RCT, evaluating for the first time, the efficacy and safety of a pharmacotherapeutic treatment for patients with PCD. The RCT evaluates azithromycin maintenance therapy, a drug already commonly prescribed in other chronic respiratory disorders. Furthermore, the trial will utilize the Lung clearance index and new, PCD-specific quality of life instruments as outcome measures for PCD. Recruitment is hampered by frequent occurrence of Pseudomonas aeruginosa infection, exacerbations at enrolment, and the patients' perception of disease severity and necessity of additional management and treatment during trial participation. TRIAL REGISTRATION: EudraCT 2013-004664-58 (date of registration: 2014-04-08).

An Fc domain protein-small molecule conjugate as an enhanced immunomodulator.

Proteins as well as small molecules have demonstrated success as therapeutic agents, but their pharmacologic properties sometimes fall short against particular drug targets. Although the adenosine 2a receptor (A(2A)R) has been identified as a promising target for immunotherapy, small molecule A(2A)R agonists have suffered from short pharmacokinetic half-lives and the potential for toxicity by modulating nonimmune pathways. To overcome these limitations, we have tethered the A(2A)R agonist CGS-21680 to the immunoglobulin Fc domain using expressed protein ligation with Sf9 cell secreted protein. The protein small molecule conjugate Fc-CGS retained potent Fc receptor and A(2A)R interactions and showed superior properties as a therapeutic for the treatment of a mouse model of autoimmune pneumonitis. This approach may provide a general strategy for optimizing small molecule therapeutics.

Nasal nitric oxide screening for primary ciliary dyskinesia: systematic review and meta-analysis.

Nasal nitric oxide (nNO) concentrations are low in patients with primary ciliary dyskinesia (PCD) providing a noninvasive screening test. We conducted a systematic review of the literature to examine the utility of nNO in screening for PCD, in particular 1) different respiratory manoeuvres during sampling (velum closure, tidal breathing, etc.), 2) accuracy in screening young/uncooperative children, 3) stationary versus portable analysers, and 4) nNO in "atypical" PCD. 96 papers were assessed according to modified PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria and 22 were included in this review. Meta-analysis of 11 studies comparing nNO during a velum closure breath hold gave a mean±SD nNO of 19.4±18.6 nL·min(-1) in PCD (n = 478) and 265.0±118.9 nL·min(-1) in healthy controls (n = 338). Weighted mean difference for PCD versus healthy controls was 231.1 nL·min(-1) (95% CI 193.3-268.9; n = 338) and 114.1 nL·min(-1) (95% CI 101.5-126.8; n = 415) for PCD versus cystic fibrosis. Five studies of nNO measurement during tidal breathing demonstrated that this is an acceptable manoeuvre in young children where velum closure is not possible, but the discriminatory value was reduced. Four small studies of portable NO analysers suggest these are reliable tools for screening for PCD. However, nNO must be interpreted alongside clinical suspicion. Future studies should focus on standardising sampling techniques and reporting.

Pulmonary delivery of docosahexaenoic acid mitigates bleomycin-induced pulmonary fibrosis.

BACKGROUND: Pulmonary fibrosis is an untreatable, fatal disease characterized by excess deposition of extracellular matrix and inflammation. Although the etiology of pulmonary fibrosis is unknown, recent studies have implicated dysregulated immune responses and wound healing. Since n-3 polyunsaturated fatty acids (n-3 PUFAs) may beneficially modulate immune responses in a variety of inflammatory disorders, we investigated the therapeutic role of docosahexaenoic acid (DHA), a single n-3 PUFA, in lung fibrosis. METHODS: Intratracheal DHA or PBS was administered to mouse lungs 4 days prior to intratracheal bleomycin treatment. Body weight and survival were monitored for 21 days. Bronchoalveolar fluid (BALF) and lung inflammatory cells, cytokines, eicosanoids, histology and lung function were determined on serial days (0, 3, 7, 14, 21) after bleomycin injury. RESULTS: Intratracheal administration of DHA mitigated bleomycin-induced lung injury. Mice pretreated with DHA had significantly less weight loss and mortality after bleomycin injury. The lungs from DHA-pretreated mice had markedly less fibrosis. DHA pretreatment also protected the mice from the functional changes associated with bleomycin injury. Bleomycin-induced cellular inflammation in BALF and lung tissue was blunted by DHA pretreatment. These advantageous effects of DHA pretreatment were associated with decreased IL-6, LTB4, PGE2 and increased IL-10. CONCLUSIONS: Our findings demonstrate that intratracheal administration of DHA, a single PUFA, protected mice from the development of bleomycin-induced pulmonary inflammation and fibrosis. These results suggest that further investigations regarding the role of n-3 polyunsaturated fatty acids in fibrotic lung injury and repair are needed.

15-minute consultation: a structured approach to the assessment of chest pain in a child.

This article aims to provide a concise, structured approach to the child with chest pain. Chest pain is a common presenting symptom in children but, unlike in adults, the cause is rarely cardiac. We review the main causes of chest pain in children and discuss the important features that may alert those assessing paediatric chest pain to serious underlying pathology. In the vast majority of cases, reassurance is all that is required and a thorough initial consultation can exclude rare, serious disease and provide vital reassurance to children and families.

Enhancement of the photoresponse in organic field-effect transistors by incorporating thin DNA layers.

A mechanistic study of the DNA interfacial layer that enhances the photoresponse in n-type field-effect transistors (FET) and lateral photoconductors using a solution-processed fullerene derivative embedded with disperse-red dye, namely PCBDR, is reported. Incorporation of the thin DNA layer simultaneously leads to increasing the electron injection from non-Ohmic contacts into the PCBDR active layer in dark and to increasing the photocurrent under irradiation. Such features lead to the observation of the enhancement of the photoresponsivity in PCBDR FETs up to 10(3) . Kelvin probe microscopy displays that in the presence of the DNA layer, the surface potential of PCBDR has a greater change in response to irradiation, which is rationalized by a larger number of photoinduced surface carriers. Transient absorption spectroscopy confirms that the increase in photoinduced carriers in PCBDR under irradiation is primarily ascribed to the increase in exciton dissociation rates through the PCBDR/DNA interface and this process can be assisted by the interfacial dipole interaction.

Murine Model of Airway Fibrosis has Anatomic, Physiologic, and Molecular Congruency to Human iSGS.

OBJECTIVE: To narrow knowledge gaps in the pathophysiology of idiopathic subglottic stenosis (iSGS) through comparison of a murine subglottic stenosis model with iSGS. STUDY DESIGN: In vivo animal study. SETTING: Academic institution. METHODS: Murine samples/measurements were obtained from mice that underwent chemomechanical injury with a wire brush and bleomycin. Human samples/measurements were obtained from iSGS patients. Anatomic, physiologic, and epithelial molecular data were collected using histology, human peak expiratory flow (PEF) and murine airway conductance, gene expression analysis with quantitative polymerase chain reaction, and protein analysis with quantitative immunohistochemistry. RESULTS: Anatomic patterns of scars at the subglottis and proximal trachea seen in the murine model are similar to iSGS patients. Subglottic stenosis (SGS) mice had a decrease (P = .0194) in airway conductance compared to healthy controls, similar to a decrease (P = .0001) in predilation PEF versus postdilation in iSGS patients. There was decreased epithelial gene expression of E-cadherin (ECAD) (P < 0.01), occludin (OCLN) (P < .01), and cytokeratin-5 (CK5) (P < .05) and protein expression of ECAD (H/M: P < .001), OCLN (H: P < 0.05, M: P < .001), and CK5 (H: P < .001, M: P < .01) in murine SGS and iSGS versus controls. CONCLUSION: The murine SGS model shows anatomic, physiologic, and molecular congruency with human iSGS, making it a reasonable model to investigate iSGS. The molecular similarities in epithelial barrier dysfunction suggest it may best be suited to explore epithelial mechanisms of iSGS and therapies directed at epithelial reconstitution. This model provides a foundation to collect data that will improve understanding of iSGS, and, ultimately, translate into more accurate animal models for future use.