Boosting Potassium Storage via Multifunctional Interface with High Lattice-Matching.

Atomic-scale interface engineering is a prominent strategy to address the large volume expansions and sluggish redox kinetics for reinforcing K-storage. Here, to accelerate charge transport and lower the activation energy, dual carbon-modified interfacial regions are synthesized with high lattice-matching degree, which is formed from a CoSe2 /FeSe2 heterostructure coated onto hollow carbon fibers. State-of-the-art characterization techniques and theoretical analysis, including ex-situ soft X-ray absorption spectroscopy, synchrotron X-ray tomography, ultrasonic transmission mapping, and density functional theory, are conducted to probe local atomic structure evolution, mechanical degradation mechanisms, and ion/electron migration pathways. The results suggest that the heterostructure composed of the same crystal system and space group can sharply regulate the redox kinetics of transition metal selenium and dual carbon-modified approach can tailor physicochemical degradation. Overall, this work presents the design of a stable heterojunction synergistic superior hollow carbon substrate, inspiring a pathway of interface engineering strategy toward high-performance electrode.

An Atypical Incontinentia Pigmenti Female with Persistent Mucocutaneous Hyperinflammation and Immunodeficiency Caused by a Novel Germline IKBKG Missense Mutation.

While most missense mutations of the IKBKG gene typically result in Ectodermal Dysplasia with Immunodeficiency, there have been rare reported instances of missense mutations of the IKBKG gene causing both Incontinentia Pigmenti (IP) and immunodeficiency in female patients. In this study, we described an atypical IP case in a 19-year-old girl, characterized by hyperpigmented and verrucous skin areas over the entire body. Remarkably, she experienced recurrent red papules whenever she had a feverish upper respiratory tract infection. Immunohistochemical staining unveiled a substantial accumulation of CD68+ macrophages alongside the TNF-α positive cells in the dermis tissue of new pustules, with increased apoptotic basal keratinocytes in the epidermis tissue of these lesions. Starting from the age of 8 years old, the patient suffered from severe and sustained chronic respiratory mucous membrane scar hyperplasia and occluded subglottic lumen. In addition to elevated erythrocyte sedimentation rate values, inflammatory cells were observed in the pathologic lesions of endobronchial biopsies and Bronchoalveolar Lavage Fluid (BALF) smear. Further histological analysis revealed a destructive bronchus epithelium integrity with extensive necrosis. Simultaneously, the patient experienced recurrent incomplete intestinal obstructions and lips contracture. The patient's BALF sample displayed an augmented profile of proinflammatory cytokines and chemokines, suggesting a potential link to systemic hyperinflammation, possibly underlying the pathogenic injuries affecting the subglottic, respiratory, and digestive systems. Furthermore, the patient presented with recurrent pneumonias and multiple warts accompanied by a T+BlowNKlow immunophenotype. Next generation sequencing showed that the patient carried a novel de novo germline heterozygous missense mutation in the IKBKG gene (c. 821T>C, p. L274P), located in the highly conserved CC2 domain. TA-cloning sequencing of patient's cDNA yielded 30 mutant transcripts out of 44 clones. In silico analysis indicated that the hydrogen bond present between Ala270 and Leu274 in the wild-type NEMO was disrupted by the Leu274Pro mutation. However, this mutation did not affect NEMO expression in peripheral blood mononuclear cells (PBMCs). Moreover, patient PBMCs exhibited significantly impaired TNF-α production following Lipopolysaccharide (LPS) stimulation. X-chromosome inactivation in T cells and neutrophils were not severely skewed. Reduced levels of IκBα phosphorylation and degradation in patient's PBMCs were observed. The NF-κB luciferase reporter assay conducted using IKBKG-deficient HEK293T cells revealed a significant reduction in NF-kB activity upon LPS stimulation. These findings adds to the ever-growing knowledge on female IP that might contribute to the better understanding of this challenging disorder.

Loop pathways are responsible for tuning the accumulation of C19- and C22-sterol intermediates in the mycobacterial phytosterol degradation pathway.

4-Androstene-3,17-dione (4-AD) and 22-hydroxy-23,24-bisnorchol-4-ene-3-one (BA) are the most important and representative C19- and C22-steroidal materials. The optimalization of sterol production with mycobacterial phytosterol conversion has been investigated for decades. One of the major challenges is that current industrial mycobacterial strains accumulate unignorable impurities analogous to desired sterol intermediates, significantly hampering product extractions and refinements. Previously, we identified Mycobacterium neoaurum HGMS2 as an efficient 4-AD-producing strain (Wang et al. in Microb Cell Fact. 19:187, 2020). Recently, we have genetically modified the HGMS2 strain to remove its major impurities including ADD and 9OH-AD (Li et al. in Microb Cell Fact. 20:158, 2021). Unexpectedly, the modified mutants started to significantly accumulate BA compared with the HGMS2 strain. In this work, while we attempted to block BA occurrence during 4-AD accumulation in HGMS2 mutants, we identified a few loop pathways that regulated metabolic flux switching between 4-AD and BA accumulations and found that both the 4-AD and BA pathways shared a 9,10-secosteroidial route. One of the key enzymes in the loop pathways was Hsd4A1, which played an important role in determining 4-AD accumulation. The inactivation of the hsd4A1 gene significantly blocked the 4-AD metabolic pathway so that the phytosterol degradation pathway flowed to the BA metabolic pathway, suggesting that the BA metabolic pathway is a complementary pathway to the 4-AD pathway. Thus, knocking out the hsd4A1 gene essentially made the HGMS2 mutant (HGMS2Δhsd4A1) start to efficiently accumulate BA. After further knocking out the endogenous kstd and ksh genes, an HGMS2Δhsd4A1 mutant, HGMS2Δhsd4A1/Δkstd1, enhanced the phytosterol conversion rate to BA in 1.2-fold compared with the HGMS2Δhsd4A1 mutant in pilot-scale fermentation. The final BA yield increased to 38.3 g/L starting with 80 g/L of phytosterols. Furthermore, we knocked in exogenous active kstd or ksh genes to HGMS2Δhsd4A1/Δ kstd1 to construct DBA- and 9OH-BA-producing strains. The resultant DBA- and 9OH-BA-producing strains, HGMS2Δhsd4A1/kstd2 and HGMS2Δkstd1/Δhsd4A1/kshA1B1, efficiently converted phytosterols to DBA- and 9OH-BA with the rates of 42.5% and 40.3%, respectively, and their final yields reached 34.2 and 37.3 g/L, respectively, starting with 80 g/L phytosterols. Overall, our study not only provides efficient strains for the industrial production of BA, DBA and 9OH-BA but also provides insights into the metabolic engineering of the HGMS2 strain to produce other important steroidal compounds.

Bioconversion of Phytosterols to 9-Hydroxy-3-Oxo-4,17-Pregadiene-20-Carboxylic Acid Methyl Ester by Enoyl-CoA Deficiency and Modifying Multiple Genes in Mycolicibacterium neoaurum.

Steroid drug precursors, including C19 and C22 steroids, are crucial to steroid drug synthesis and development. However, C22 steroids are less developed due to the intricacy of the steroid metabolic pathway. In this study, a C22 steroid drug precursor, 9-hydroxy-3-oxo-4,17-pregadiene-20-carboxylic acid methyl ester (9-OH-PDCE), was successfully obtained from Mycolicibacterium neoaurum by 3-ketosteroid-Δ1-dehydrogenase and enoyl-CoA hydratase ChsH deficiency. The production of 9-OH-PDCE was improved by the overexpression of 17ß-hydroxysteroid dehydrogenase Hsd4A and acyl-CoA dehydrogenase ChsE1-ChsE2 to reduce the accumulation of by-products. The purity of 9-OH-PDCE in fermentation broth was improved from 71.7% to 89.7%. Hence, the molar yield of 9-OH-PDCE was improved from 66.7% to 86.7%, with a yield of 0.78 g/L. Furthermore, enoyl-CoA hydratase ChsH1-ChsH2 was identified to form an indispensable complex in Mycolicibacterium neoaurum DSM 44704. IMPORTANCE C22 steroids are valuable precursors for steroid drug synthesis, but the development of C22 steroids remains unsatisfactory. This study presented a strategy for the one-step bioconversion of phytosterols to a C22 steroid drug precursor, 9-hydroxy-3-oxo-4,17-pregadiene-20-carboxylic acid methyl ester (9-OH-PDCE), by 3-ketosteroid-Δ1-dehydrogenase and enoyl-CoA hydratase deficiency with overexpression of 17ß-hydroxysteroid dehydrogenase acyl-CoA dehydrogenase in Mycolicibacterium. The function of the enoyl-CoA hydratase ChsH in vivo was revealed. Construction of the novel C22 steroid drug precursor producer provided more potential for steroid drug synthesis, and the characterization of the function of ChsH and the transformation of steroids further revealed the steroid metabolic pathway.

Machine learning in a real-world PFO study: analysis of data from multi-centers in China.

PURPOSE: The association of patent foreman ovale (PFO) and cryptogenic stroke has been studied for years. Although device closure overall decreases the risk for recurrent stroke, treatment effects varied across different studies. In this study, we aimed to detect sub-clusters in post-closure PFO patients and identify potential predictors for adverse outcomes. METHODS: We analyzed patients with embolic stroke of undetermined sources and PFO from 7 centers in China. Machine learning and Cox regression analysis were used. RESULTS: Using unsupervised hierarchical clustering on principal components, two main clusters were identified and a total of 196 patients were included. The average age was 42.7 (12.37) years and 64.80% (127/196) were female. During a median follow-up of 739 days, 12 (6.9%) adverse events happened, including 6 (3.45%) recurrent stroke, 5 (2.87%) transient ischemic attack (TIA) and one death (0.6%). Compared to cluster 1 (n = 77, 39.20%), patients in cluster 2 (n = 119, 60.71%) were more likely to be male, had higher systolic and diastolic blood pressure, higher body mass index, lower high-density lipoprotein cholesterol and increased proportion of presence of atrial septal aneurysm. Using random forest survival (RFS) analysis, eight top ranking features were selected and used for prediction model construction. As a result, the RFS model outperformed the traditional Cox regression model (C-index: 0.87 vs. 0.54). CONCLUSIONS: There were 2 main clusters in post-closure PFO patients. Traditional cardiovascular profiles remain top ranking predictors for future recurrence of stroke or TIA. However, whether maximizing the management of these factors would provide extra benefits warrants further investigations.

Facile Synthesis of Aminated Graphene Quantum Dots for Promising and Selective Detection of Cobalt and Copper Ions in Aqueous Media.

Due to the rapid development of industrialization, various environmental problems such as water resource pollution are gradually emerging, among which heavy metal pollution is harmful to both human beings and the environment. As a result, there are many metal ion detection methods, among which fluorescence detection stands out because of its rapid, sensitive, low cost and non-toxic characteristics. In recent years, graphene quantum dots have been widely used and studied due to their excellent properties such as high stability, low toxicity and water solubility, and have a broad prospect in the field of metal ion detection. A novel high fluorescence Cu2+, Co2+ sensing probe produced by graphene quantum hydrothermal treatment is reported. After heat treatment with hydrazine hydrate, the small-molecule precursor nitronaphthalene synthesized by self-nitrification was transformed from blue fluorescent GQDs to green fluorescent amino-functionalized N-GQDs. Compared with other metal ions, N-GQDs are more sensitive to Cu2+ and Co2+ on the surface, and N-GQDs have much higher selectivity to Cu2+ and Co2+ than GQDs. The strategy proposed here is simple and economical in design.

Compound heterozygous DCLRE1C mutations lead to clinically typical Severe Combined Immunodeficiency presenting with Graft Versus Host Disease.

Artemis (DCLRE1C) is involved in opening recombination-activating gene (RAG1/RAG2)-generated hairpins during V(D)J recombination, an essential process for the differentiation and maturation of T and B cells. Here, we reported a case of 5-month-old boy with recurrent respiratory infections, disseminated Bacille Calmette-Guérin (BCG) infection, generalized erythroderma, hepatosplenomegaly, lymphadenopathy, eosinophillia and failure to thrive, symptoms often observed in Omenn syndrome. Genetic analysis revealed compound heterozygous mutations of the DCLRE1C gene, including deletions of exons 1 and 2, and a c. 352G>T (p. G118X) nonsense mutation in exon 5. Flow cytometry analysis of the patient PBMCs indicated a TlowB-NK+ immunophenotype. Short tandem repeat (STR) analysis confirmed transplacental maternal lymphocytes engraftment in circulating blood of the patient. Collectively, we reported a patient showing atypical immunophenotypic and typical clinical presentations of Severe Combined Immunodeficiency (SCID) with Graft Versus Host Disease (GVHD) in the context of compound heterozygous mutations of the DCLRE1C gene. This study adds to the ever-growing knowledge on the broad immunological and clinical spectrum associated with DCLRE1C mutations.

Dynamic Covalent Nanoparticles for Acid-Responsive Nonaqueous Pickering Emulsions.

Acid-responsive nonaqueous (glycerol in n-decane) Pickering emulsions were prepared using preferentially oil-wetted dynamic covalent silica (SiO2-pDB) nanoparticles as the Pickering emulsifiers. The acid-responsive Pickering emulsifier SiO2-pDB was prepared based on a Schiff base reaction between amino silica (SiO2-NH2) and p-decanoxybenzaldehyde (pDBA). The formation of SiO2-pDB was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and elemental analysis. The preferentially oil-wetted character of SiO2-pDB was indicated by contact angle measurement. Stable nonaqueous Pickering emulsions were prepared using preferentially oil-wetted SiO2-pDB as the Pickering emulsifier. However, after adjusting the nonaqueous Pickering emulsions to an acidic environment, complete phase separation occurred. In the acidic environment, preferentially oil-wetted SiO2-pDB decomposed into hydrophilic SiO2-NH2 and hydrophobic pDBA due to the decomposition of the dynamic imine bond in the SiO2-pDB. Then, the hydrophilic SiO2-NH2 and hydrophobic pDBA desorbed from the two-phase interface, resulting in complete phase separation of the initially stable nonaqueous Pickering emulsions. The acid-responsive nonaqueous Pickering emulsions show great potential in application in water sensitive systems, such as oil-based drilling fluids.

Chlorine Modulation Fluorescent Performance of Seaweed-Derived Graphene Quantum Dots for Long-Wavelength Excitation Cell-Imaging Application.

Biological imaging is an essential means of disease diagnosis. However, semiconductor quantum dots that are used in bioimaging applications comprise toxic metal elements that are nonbiodegradable, causing serious environmental problems. Herein, we developed a novel ecofriendly solvothermal method that uses ethanol as a solvent and doping with chlorine atoms to prepare highly fluorescent graphene quantum dots (GQDs) from seaweed. The GQDs doped with chlorine atoms exhibit high-intensity white fluorescence. Thus, their preliminary application in bioimaging has been confirmed. In addition, clear cell imaging could be performed at an excitation wavelength of 633 nm.

Clinical and genetic characteristics of Chinese pediatric patients with chronic granulomatous disease.

BACKGROUND: Chronic granulomatous disease (CGD) is a rare disease in China, and very little large-scale studies have been conducted to date. We aimed to investigate the clinical and genetic features of CGD in Chinese pediatric patients. METHODS: Pediatric patients with CGD from Beijing Children's Hospital, Capital Medical University, China, were enrolled from January 2006 to December 2016. RESULTS: A total of 159 pediatric patients with CGD were enrolled. The median age of clinical onset was 1.4 months, and 73% (116/159) had clinical onset symptoms before the 1 year of age. The most common site of invasion was the lungs. The lymph nodes, liver, and skin were more frequently invaded in X-linked (XL) CGD patients than in autosomal recessive (AR) CGD patients (P < 0.05). Approximately 64% (92/144) of the pediatric patients suffered from abnormal response to BCG vaccination. The most frequent pathogens were Aspergillus and Mycobacterium tuberculosis. Gene analysis indicated that 132 cases (89%, 132/147) harbored CYBB pathogenic variants, 7 (5%, 7/147) carried CYBA pathogenic variants, 4 (3%, 4/147) had NCF1 pathogenic variants, and 4 (3%, 4/147) had NCF2 pathogenic variants. The overall mortality rate in this study was 43%, particularly the patients were males, with CYBB mutant and did not receive HSCT treatment. CONCLUSIONS: Chronic granulomatous disease is a rare disease affecting Chinese children; however, it is often diagnosed at a later age, and thus, the mortality rate is relatively high. The prevalence and the severity of disease in XL-CGD are higher than AR-CGD.

TFA-Mediated DMSO-Participant Sequential Oxidation/1,3-Dipolar Cycloaddition Cascade of Pyridinium Ylides for the Assembly of Indolizines.

A trifluoroacetic acid (TFA)-mediated cascade oxidation/1,3-dipolar cycloaddition reaction of stabilized pyridinium salts with dimethyl sulfoxide (DMSO) has been developed in the presence of K2S2O8 and trimethylethylenediamine (TMEDA). In this transition-metal-free reaction, DMSO acts as a one-carbon source, thus providing a convenient method for the efficient and direct synthesis of various indolizine derivatives.

A cascade oxidation/[4 + 1] annulation of sulfonium salts for synthesis of polyfunctional furans: DMSO as one carbon source.

A novel DMSO-involved cascade reaction of stabilized sulfonium salts has been established for direct construction of polyfunctional furans. This one-pot sequential reaction involving in situ generated α-methylene sulfonium salts was followed by [4 + 1] annulation with sulfur ylides. Notably, DMSO plays a very important role in this transformation, not only as a solvent but also as one carbon source.

The epidemiology of paediatric Mycoplasma pneumoniae pneumonia in North China: 2006 to 2016.

Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a major cause of community-acquired pneumonia in China. Data on epidemiology of paediatric MPP from China are little known. This study retrospectively collected data from June 2006 to June 2016 in Beijing Children's Hospital, Capital Medical University of North China and aims to explore the epidemiological features of paediatric MPP and severe MPP (SMPP) in North China during the past 10 years. A total of 27 498 paediatric patients with pneumonia were enrolled. Among them, 37.5% of paediatric patients had MPP. In this area, an epidemic took place every 2-3 years at the peak, and the positive rate of MPP increased during these peak years over time. The peak age of MPP was between the ages of 6 and 10 years, accounting for 75.2%, significantly more compared with other age groups (χ2 = 1384.1, P < 0.0001). The epidemics peaked in September, October and November (χ2 = 904.9, P < 0.0001). Additionally, 13.0% of MPP paediatric patients were SMPP, but over time, the rate of SMPP increased, reaching 42.6% in 2016. The mean age of paediatric patients with SMPP (6.7 ± 3.0 years old) was younger than that of patients with non-SMPP (7.4 ± 3.2 years old) (t = 3.60, P = 0.0001). The prevalence of MPP and SMPP is common in China, especially in children from 6 to 10 years old. Paediatric patients with SMPP tend to be younger than those with non-SMPP. MPP outbreaks occur every 2-3 years in North China. September, October and November are the peak months, unlike in South China. Understanding the epidemiological characteristics of paediatric MPP can contribute to timely treatment and diagnosis, and may improve the prognosis of children with SMPP.

Methods for Assessing and Optimizing Solar Orientation by Non-Planar Sensor Arrays.

Non-planar sensor arrays are used to determine solar orientation based on the orientation matrix formed by orientation vectors of the sensor planes. Solar panels or existing photodiodes can be directly used without increasing the size or mass of the spacecraft. However, a limiting factor for the improvement of the accuracy of orientation lies with the lack of an assessment-based approach. A formulation was developed for the supremum (i.e., the least upper bound) of orientation error of an arbitrary orientation matrix in terms of its influencing factors. The new formulation offers a way to evaluate the supremum of orientation error considering interference with finite energy and interference with infinite energy but finite average energy. For a given non-planar sensor array, a sub-matrix of the full orientation matrix would reach the optimal accuracy of orientation if its supremum of orientation error is the least. Principles for designing an optimal sensor array relate to the configuration of the orientation matrix, which can be pre-determined for a given number of sensors. Simulations and field experiment tested and validated the methods, showing that our sensor array optimization method outperforms the existing methods, while providing a way of assessment and optimization.

Sequential σ-Bond Insertion/Benzannulation Involving Arynes: Selective Synthesis of Polysubstituted Naphthalenes.

An interesting σ-bond insertion/benzannulation reaction for the synthesis of polysubstituted naphthalene derivatives has been developed from readily accessible ketones, arynes, and alkynoates. This practical and transition-metal-free method provides a novel route to diverse naphthalenes through a substrate-controlled rearrangement reaction with the cleavage of C-C bonds.

Continuous amperometric hydrogen gas sensing in ionic liquids.

We report an innovative amperometric hydrogen sensor that addresses current primary issues (i.e. signal drift, low selectivity and speed) in continuous and real-time gas sensing. Utilizing the unique properties and redox reactions of hydrogen in the ionic liquids (ILs), 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [Bmpy][NTf2] and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [Bmim][NTf2], we demonstrate the real-time and continuous sensing of hydrogen with high sensitivity, selectivity and repeatability in both anaerobic and aerobic conditions using simple constant potential amperometry. The varying adsorption of hydrogen at the IL-electrode interface in different ILs is shown to allow tuning of the sensitivity of the sensor. Taking advantage of oxygen in ambient conditions, we demonstrate that the unique chemical reaction of the analyte with the oxygen enables selective quantification of hydrogen in an ambient environment. A sensor calibration based on a kinetics analysis (i.e. the change of the rate of current signal (ΔI/Δt1/2)) rather than an equilibrium analysis was demonstrated to allow fast and quantitative analysis of hydrogen concentration. The ionic liquid hydrogen sensor exhibits high sensitivity, selectivity, speed, accuracy, repeatability and stability. Together with the miniaturization and affordability of amperometric sensor readout electronics, the IL-based electrochemical gas sensor is expected to enable area-wide sensing instead of point measurements for environmental, health and occupational safety applications.

A novel deletion mutation in IL2RG gene results in X-linked severe combined immunodeficiency with an atypical phenotype.

Severe combined immunodeficiency (SCID) is the most serious disorder among primary immunodeficiency diseases threatening children's life. Atypical SCID variant, presenting with mild reduced T cells subsets, is often associated with infection susceptibility but poor clinical diagnosis. The atypical X-SCID patient in the present study showed a mild clinical presentation with a TlowNK+B+ immunophenotype. The patient has reduced T- cell subpopulations with a subdued thymic output measured by sjTRECs. Further analysis showed that T cells maintained a normal proliferation and a broad Vß repertoire. NK cells, however, exhibited a skewed development toward immature CD3-CD16+CD56- cells. Genetic analysis revealed a novel deletion at nucleotide 52 in exon 1 of IL2RG gene. Sequence alignment predicted a truncated IL2RG protein missing signal peptide derived from a possible alternative reading frame. The novel mutation in IL2RG gene identified in our study may help the early diagnosis of atypical X-SCID.

Mycobacterial disease in patients with chronic granulomatous disease: A retrospective analysis of 71 cases.

BACKGROUND: Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by inborn errors of the phagocyte nicotinamide adenine dinucleotide phosphate oxidase complex. From the first year of life onward, most affected patients display multiple, severe, and recurrent infections caused by bacteria and fungi. Mycobacterial infections have also been reported in some patients. OBJECTIVE: Our objective was to assess the effect of mycobacterial disease in patients with CGD. METHODS: We analyzed retrospectively the clinical features of mycobacterial disease in 71 patients with CGD. Tuberculosis and BCG disease were diagnosed on the basis of microbiological, pathological, and/or clinical criteria. RESULTS: Thirty-one (44%) patients had tuberculosis, and 53 (75%) presented with adverse effects of BCG vaccination; 13 (18%) had both tuberculosis and BCG infections. None of these patients displayed clinical disease caused by environmental mycobacteria, Mycobacterium leprae, or Mycobacterium ulcerans. Most patients (76%) also had other pyogenic and fungal infections, but 24% presented solely with mycobacterial disease. Most patients presented a single localized episode of mycobacterial disease (37%), but recurrence (18%), disseminated disease (27%), and even death (18%) were also observed. One common feature in these patients was an early age at presentation for BCG disease. Mycobacterial disease was the first clinical manifestation of CGD in 60% of these patients. CONCLUSION: Mycobacterial disease is relatively common in patients with CGD living in countries in which tuberculosis is endemic, BCG vaccine is mandatory, or both. Adverse reactions to BCG and severe forms of tuberculosis should lead to a suspicion of CGD. BCG vaccine is contraindicated in patients with CGD.

Identification of anti-virulence compounds that disrupt quorum-sensing regulated acute and persistent pathogenicity.

Etiological agents of acute, persistent, or relapsing clinical infections are often refractory to antibiotics due to multidrug resistance and/or antibiotic tolerance. Pseudomonas aeruginosa is an opportunistic Gram-negative bacterial pathogen that causes recalcitrant and severe acute chronic and persistent human infections. Here, we target the MvfR-regulated P. aeruginosa quorum sensing (QS) virulence pathway to isolate robust molecules that specifically inhibit infection without affecting bacterial growth or viability to mitigate selective resistance. Using a whole-cell high-throughput screen (HTS) and structure-activity relationship (SAR) analysis, we identify compounds that block the synthesis of both pro-persistence and pro-acute MvfR-dependent signaling molecules. These compounds, which share a benzamide-benzimidazole backbone and are unrelated to previous MvfR-regulon inhibitors, bind the global virulence QS transcriptional regulator, MvfR (PqsR); inhibit the MvfR regulon in multi-drug resistant isolates; are active against P. aeruginosa acute and persistent murine infections; and do not perturb bacterial growth. In addition, they are the first compounds identified to reduce the formation of antibiotic-tolerant persister cells. As such, these molecules provide for the development of next-generation clinical therapeutics to more effectively treat refractory and deleterious bacterial-human infections.

The quorum sensing volatile molecule 2-amino acetophenon modulates host immune responses in a manner that promotes life with unwanted guests.

Increasing evidence indicates that bacterial quorum sensing (QS) signals are important mediators of immunomodulation. However, whether microbes utilize these immunomodulatory signals to maintain infection remain unclear. Here, we show that the Pseudomonas aeruginosa QS-regulated molecule 2-amino acetophenone (2-AA) modulates host immune responses in a manner that increases host ability to cope with this pathogen. Mice treated with 2-AA prior to infection had a 90% survival compared to 10% survival rate observed in the non-pretreated infected mice. Whilst 2-AA stimulation activates key innate immune response pathways involving mitogen-activated protein kinases (MAPKs), nuclear factor (NF)-κB, and pro-inflammatory cytokines, it attenuates immune response activation upon pretreatment, most likely by upregulating anti-inflammatory cytokines. 2-AA host pretreatment is characterized by a transcriptionally regulated block of c-JUN N-terminal kinase (JNK) and NF-κB activation, with relatively preserved activation of extracellular regulated kinase (ERK) 1/2. These kinase changes lead to CCAAT/enhancer-binding protein-ß (c/EBPß) activation and formation of the c/EBPß-p65 complex that prevents NF-κB activation. 2-AA's aptitude for dampening the inflammatory processes while increasing host survival and pathogen persistence concurs with its ability to signal bacteria to switch to a chronic infection mode. Our results reveal a QS immunomodulatory signal that promotes original aspects of interkingdom communication. We propose that this communication facilitates pathogen persistence, while enabling host tolerance to infection.