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Journal of Leukocyte Biology Jun 2024Chronic obstructive pulmonary disease (COPD) is caused by the inhalation of noxious particles such as cigarette smoke. The pathophysiological features include airway...
Chronic obstructive pulmonary disease (COPD) is caused by the inhalation of noxious particles such as cigarette smoke. The pathophysiological features include airway inflammation, alveolar destruction and poorly reversible airflow obstruction. A sub-group of COPD patients have higher blood eosinophil counts (BECs), associated with an increased response to inhaled corticosteroids and increased biomarkers of pulmonary type 2 (T2) inflammation. Emerging evidence shows that COPD patients with increased pulmonary eosinophil counts have an altered airway microbiome. Higher BECs are also associated with increased lung function decline, implicating T2 inflammation in progressive pathophysiology in COPD. We provide a narrative review of the role of eosinophils and T2 inflammation in the pathophysiology of COPD, encompassing the lung microbiome, pharmacological targeting of T2 pathways in COPD, and the clinical use of BEC as a COPD biomarker.
PubMed: 38941350
DOI: 10.1093/jleuko/qiae153 -
ELife Jun 2024Genetic diversity is a hallmark of RNA viruses and the basis for their evolutionary success. Taking advantage of the uniquely large genomic database of SARS-CoV-2, we...
Genetic diversity is a hallmark of RNA viruses and the basis for their evolutionary success. Taking advantage of the uniquely large genomic database of SARS-CoV-2, we examine the impact of mutations across the spectrum of viable amino acid sequences on the biophysical phenotypes of the highly expressed and multifunctional nucleocapsid protein. We find variation in the physicochemical parameters of its extended intrinsically disordered regions (IDRs) sufficient to allow local plasticity, but also observe functional constraints that similarly occur in related coronaviruses. In biophysical experiments with several N-protein species carrying mutations associated with major variants, we find that point mutations in the IDRs can have nonlocal impact and modulate thermodynamic stability, secondary structure, protein oligomeric state, particle formation, and liquid-liquid phase separation. In the Omicron variant, distant mutations in different IDRs have compensatory effects in shifting a delicate balance of interactions controlling protein assembly properties, and include the creation of a new protein-protein interaction interface in the N-terminal IDR through the defining P13L mutation. A picture emerges where genetic diversity is accompanied by significant variation in biophysical characteristics of functional N-protein species, in particular in the IDRs.
Topics: SARS-CoV-2; Coronavirus Nucleocapsid Proteins; Mutation; COVID-19; Humans; Intrinsically Disordered Proteins; Phosphoproteins; Nucleocapsid Proteins; Thermodynamics; Protein Stability
PubMed: 38941236
DOI: 10.7554/eLife.94836 -
American Journal of Respiratory and... Jun 2024Sarcoidosis is a granulomatous disorder of unclear cause notable for abnormal elevation of blood and tissue angiotensin converting enzyme 1 (ACE1) levels and activity....
Sarcoidosis is a granulomatous disorder of unclear cause notable for abnormal elevation of blood and tissue angiotensin converting enzyme 1 (ACE1) levels and activity. ACE1 regulates the renin-angiotensin-aldosterone system (RAAS), the terminal product of which is aldosterone, which selectively engages mineralocorticoid receptors (MR) to promote inflammation. We sought to determine whether the RAAS promotes sarcoidosis granuloma formation and related inflammatory responses. Using an established model, we first determined whether aldosterone was produced by sarcoidosis granulomas and verified the presence of CYP11B2, the enzyme required for its production. We then evaluated the effects of selective inhibitors of ACE1 (captopril), angiotensin type 1 receptor (losartan) and MR (spironolactone, eplerenone) on granuloma formation, reflected by computer image analysis-generated granuloma area, and selected cytokines incriminated in sarcoidosis pathogenesis. Aldosterone was spontaneously produced by sarcoidosis PBMCs, and both intra- and extracellular levels steadily increased during granuloma formation. In parallel, PBMCs were shown to express more CYP11B2 during granuloma formation. Significant inhibition of sarcoidosis granulomas and related cytokines (TNFα, IL-1β, IFNγ, IL-10) was observed in response to pretreatments with captopril, losartan, spironolactone or eplerenone, comparable to that of prednisone. The RAAS is intact in sarcoidosis granulomas and contributes significantly to early granuloma formation and to related inflammatory mediator responses with important implications for clinical management.
PubMed: 38941161
DOI: 10.1164/rccm.202402-0265OC -
JMIR Research Protocols Jun 2024Pulmonary rehabilitation is widely recommended to improve functional status and as secondary and tertiary prevention in individuals with chronic pulmonary diseases....
Assessing Functional Capacity in Directly and Remotely Monitored Home-Based Settings in Individuals With Chronic Respiratory Diseases: Protocol for a Multinational Validation Study.
BACKGROUND
Pulmonary rehabilitation is widely recommended to improve functional status and as secondary and tertiary prevention in individuals with chronic pulmonary diseases. Unfortunately, access to timely and appropriate rehabilitation remains limited. To help close this inaccessibility gap, telerehabilitation has been proposed. However, exercise testing is necessary for effective and safe exercise prescription. Current gold-standard tests, such as maximal cardiopulmonary exercise testing (CPET) and the 6-minute walk test (6MWT), are poorly adapted to home-based or telerehabilitation settings. This was an obstacle to the continuity of services during the COVID-19 pandemic. It is essential to validate tests adapted to these new realities, such as the 6-minute stepper test (6MST). This test, strongly inspired by 6MWT, consists of taking as many steps as possible on a "stepper" for 6 minutes.
OBJECTIVE
This study aims to evaluate the metrological qualities of 6MST by (1) establishing concurrent validity and agreement between the 6MST and CPET, as well as with the 6MWT; (2) determining test-retest reliability in a home-based setting with direct and remote (videoconferencing) monitoring; and (3) documenting adverse events and participant perspectives when performing the 6MST in home-based settings.
METHODS
Three centers (Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec in Québec, Groupement des Hôpitaux de l'Institut Catholique de Lille in France, and FormAction Santé in France) will be involved in this multinational project, which is divided into 2 studies. For study 1 (objective 1), 30 participants (Québec, n=15; France, n=15) will be recruited. Two laboratory visits will be performed to assess anthropometric data, pulmonary function, and the 3 exercise tolerance tests (CPET, 6MWT, and 6MST). Concurrent validity (paired sample t tests and Pearson correlations) and agreement (Bland-Altman plots with 95% agreement limits) will be evaluated. For study 2 (objectives 2 and 3), 52 participants (Québec, n=26; France, n=26) will be recruited. Following a familiarization trial (trial 1), the 6MST will be conducted on 2 separate occasions (trials 2 and 3), once under direct supervision and once under remote supervision, in a randomized order. Paired sample t test, Bland-Altman plots, and intraclass correlations will be used to compare trials 2 and 3. A semistructured interview will be conducted after the third trial to collect participants' perspectives.
RESULTS
Ethical approval was received for this project (October 12, 2023, in Québec and September 25, 2023, in France) and the first participant was recruited in February 2024.
CONCLUSIONS
This study innovates by validating a new clinical test necessary for the development and implementation of new models of rehabilitation adapted to home and telerehabilitation contexts. This study also aligns with the United Nations Sustainable Development Goals by contributing to augmenting health care service delivery (goal 3) and reducing health care access inequalities (goal 11).
TRIAL REGISTRATION
ClinicalTrials.gov NCT06447831; https://clinicaltrials.gov/study/NCT06447831.
INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)
DERR1-10.2196/57404.
Topics: Humans; Chronic Disease; Exercise Test; Reproducibility of Results; COVID-19; Male; Female; Adult; Middle Aged; Telerehabilitation; Walk Test; Telemedicine
PubMed: 38941132
DOI: 10.2196/57404 -
Cancer Biology & Medicine Jun 2024Radiotherapy has achieved remarkable effects in treating non-small cell lung cancer (NSCLC). However, radioresistance remains the major obstacle to achieving good...
OBJECTIVE
Radiotherapy has achieved remarkable effects in treating non-small cell lung cancer (NSCLC). However, radioresistance remains the major obstacle to achieving good outcomes. This study aims at identifying potential targets for radiosensitizing NSCLC and elucidating the underlying mechanisms.
METHODS
Lentivirus-based infection and CRISPR/Cas9 technology were used to modulate the expression of microRNA-384 (miR-384). Cell clonogenic formation assays and a xenograft tumor model were used to analyze radiosensitivity in NSCLC cells. Fluorescence-activated cell sorting was used to assess the cell cycle and cell death. Immunofluorescence staining, Comet assays, and homologous recombination or non-homologous end-joining I-SceI/GFP reporter assays were used to study DNA damage and repair. Western blotting and quantitative real-time polymerase chain reaction were used to identify the targets of miR-384. Chromatin immunoprecipitation and polymerase chain reaction were performed to evaluate upstream regulators of miR-384.
RESULTS
MiR-384 was downregulated in NSCLC. Overexpression of miR-384 increased the radiosensitivity of NSCLC cells and , whereas knockout of miR-384 led to radioresistance. Upregulation of miR-384 radiosensitized NSCLC cells by decreasing G2/M cell cycle arrest, inhibiting DNA damage repair, and consequently increasing cell death; miR-384 depletion had the opposite effects. Further investigation revealed that ATM, Ku70, and Ku80 were direct targets of miR-384. Moreover, miR-384 was repressed by NF-κB.
CONCLUSIONS
MiR-384 is an ionizing radiation-responsive gene repressed by NF-κB. MiR-384 enhances the radiosensitivity of NSCLC cells targeting ATM, Ku80, and Ku70, which impairs DNA damage repair. Therefore, miR-384 may serve as a novel radiosensitizer for NSCLC.
PubMed: 38940672
DOI: 10.20892/j.issn.2095-3941.2024.0146 -
Journal of Bacteriology Jun 2024The cystic fibrosis (CF) lung environment is conducive to the colonization of bacteria as polymicrobial biofilms, which are associated with poor clinical outcomes for...
UNLABELLED
The cystic fibrosis (CF) lung environment is conducive to the colonization of bacteria as polymicrobial biofilms, which are associated with poor clinical outcomes for persons with CF (pwCF). spp. are highly prevalent in the CF airway, but its role in the CF lung microbiome is poorly understood. Some studies have shown spp. to be associated with better clinical outcomes for pwCF, while others show that high abundance of spp. is correlated with exacerbations. Our lab previously reported a polymicrobial culture system consisting of four CF-relevant pathogens that can be used to study microbial behavior in a more clinically relevant setting. Here, we use this model system to identify genetic pathways that are important for survival in the context of the polymicrobial community. We identified genes related to reactive oxygen species as differentially expressed in monoculture versus growth of this microbe in the mixed community. Genetic studies identified Dpr as important for survival in the community. We show that Dpr, a DNA-binding ferritin-like protein, and PerR, a peroxide-responsive transcriptional regulator of Dpr, are important for protecting from phenazine-mediated toxicity in co-culture with and when exposed to hydrogen peroxide, both of which mimic the CF lung environment. Characterizing such interactions in a clinically relevant model system contributes to our understanding of microbial behavior in the context of polymicrobial biofilm infections.
IMPORTANCE
spp. are recognized as a highly prevalent pathogen in cystic fibrosis (CF) airway infections. However, the role of this microbe in clinical outcomes for persons with CF is poorly understood. Here, we leverage a polymicrobial community system previously developed by our group to model CF airway infections as a tool to investigate a - interaction involving reactive oxygen species (ROS). We show that protection against ROS is required for survival in a clinically relevant polymicrobial system. Using this model system to study interspecies interactions contributes to our broader understanding of the complex role of spp. in the CF lung.
PubMed: 38940597
DOI: 10.1128/jb.00176-24 -
Microbiology Spectrum Jun 2024Traditionally, successful vaccines rely on specific adaptive immunity by activating lymphocytes with an attenuated pathogen, or pathogen subunit, to elicit heightened...
UNLABELLED
Traditionally, successful vaccines rely on specific adaptive immunity by activating lymphocytes with an attenuated pathogen, or pathogen subunit, to elicit heightened responses upon subsequent exposures. However, recent work with and other pathogens has identified a role for "trained" monocytes in protection through memory-like but non-specific immunity. Here, we used an co-culture approach to study the potential role of trained macrophages, including lung alveolar macrophages, in immune responses to the Live Vaccine Strain (LVS) of is an intracellular bacterium that replicates within mammalian macrophages and causes respiratory as well as systemic disease. We vaccinated mice with LVS and then obtained lung alveolar macrophages, or derived macrophages from bone marrow. LVS infected and replicated comparably in both types of macrophages, whether naïve or from LVS-vaccinated mice. LVS-infected macrophages were then co-cultured with either naïve splenocytes, splenocytes from mice vaccinated intradermally, or splenocytes from mice vaccinated intravenously. For the first time, we show that immune (but not naïve) splenocytes controlled bacterial replication within alveolar macrophages, similar to previous results using bone marrow-derived macrophage. However, no differences in control of intramacrophage bacterial replication were found between co-cultures with naïve macrophages or macrophages from LVS-vaccinated mice; furthermore, nitric oxide levels and interferon-gamma production in supernatants were largely comparable across all conditions. Thus, in the context of co-cultures, the data do not support development of trained macrophages in bone marrow or lungs of mice vaccinated with LVS intradermally or intravenously.
IMPORTANCE
The discovery of non-specific "trained immunity" in monocytes has generated substantial excitement. However, to date, training has been studied with relatively few microbes (e.g., Bacille Calmette-Guérin, a live attenuated intracellular bacterium used as a vaccine) and microbial substances (e.g., LPS), and it remains unclear whether training during infection is common. We previously demonstrated that vaccination of mice with Live Vaccine Strain (LVS), another live attenuated intracellular bacterium, protected against challenge with the unrelated bacterium . The present study therefore tested whether LVS vaccination engenders trained macrophages that contributed to this protection. To do so, we used a previous co-culture approach with murine bone marrow-derived macrophages to expand and study lung alveolar macrophages. We demonstrated that alveolar macrophages can be productively infected and employed to characterize interactions with LVS-immune lymphocytes. However, we find no evidence that either bone marrow-derived or alveolar macrophages are trained by LVS vaccination.
PubMed: 38940590
DOI: 10.1128/spectrum.00028-24 -
Journal of Virology Jun 2024Coronavirus disease 2019 (COVID-19) has claimed millions of lives since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and lung disease...
UNLABELLED
Coronavirus disease 2019 (COVID-19) has claimed millions of lives since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and lung disease appears the primary cause of death in COVID-19 patients. However, the underlying mechanisms of COVID-19 pathogenesis remain elusive, and there is no existing model where human disease can be faithfully recapitulated and conditions for the infection process can be experimentally controlled. Herein we report the establishment of an human precision-cut lung slice (hPCLS) platform for studying SARS-CoV-2 pathogenicity and innate immune responses, and for evaluating the efficacy of antiviral drugs against SARS-CoV-2. We show that while SARS-CoV-2 continued to replicate during the course of infection of hPCLS, infectious virus production peaked within 2 days, and rapidly declined thereafter. Although most proinflammatory cytokines examined were induced by SARS-CoV-2 infection, the degree of induction and types of cytokines varied significantly among hPCLS from individual donors. Two cytokines in particular, IP-10 and IL-8, were highly and consistently induced, suggesting a role in the pathogenesis of COVID-19. Histopathological examination revealed focal cytopathic effects late in the infection. Transcriptomic and proteomic analyses identified molecular signatures and cellular pathways that are largely consistent with the progression of COVID-19 in patients. Furthermore, we show that homoharringtonine, a natural plant alkaloid derived from , not only inhibited virus replication but also production of pro-inflammatory cytokines, and thus ameliorated the histopathological changes caused by SARS-CoV-2 infection, demonstrating the usefulness of the hPCLS platform for evaluating antiviral drugs.
IMPORTANCE
Here, established an human precision-cut lung slice platform for assessing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, viral replication kinetics, innate immune response, disease progression, and antiviral drugs. Using this platform, we identified early induction of specific cytokines, especially IP-10 and IL-8, as potential predictors for severe coronavirus disease 2019 (COVID-19), and uncovered a hitherto unrecognized phenomenon that while infectious virus disappears at late times of infection, viral RNA persists and lung histopathology commences. This finding may have important clinical implications for both acute and post-acute sequelae of COVID-19. This platform recapitulates some of the characteristics of lung disease observed in severe COVID-19 patients and is therefore a useful platform for understanding mechanisms of SARS-CoV-2 pathogenesis and for evaluating the efficacy of antiviral drugs.
PubMed: 38940558
DOI: 10.1128/jvi.00794-24 -
Microbiology Spectrum Jun 2024We used phage display, antibody engineering, and high-throughput assays to identify antibody-accessible targets of . We report the discovery of monoclonal antibodies...
We used phage display, antibody engineering, and high-throughput assays to identify antibody-accessible targets of . We report the discovery of monoclonal antibodies (mAbs) binding to type 3 fimbrial proteins, including MrkA. We found that anti-MrkA mAbs were cross-reactive to a diverse panel of clinical isolates, representing different O-serotypes. mAbs binding to MrkA have previously been described and have been shown to provide prophylactic protection, although only modest protection when dosed therapeutically in a murine lung infection model. Here, we used a combination of binding and opsonophagocytic killing studies using a high-content imaging platform to provide a possible explanation for the modest therapeutic efficacy reported in that model. Our work shows that expression of type 3 fimbriae in culture is not homogenous within a bacterial population. Instead, sub-populations of bacteria that do, and do not, express type 3 fimbriae exist. In a high-content opsonophagocytic killing assay, we showed that MrkA-targeting antibodies initially promote killing by macrophages; however, over time, this effect is diminished. We hypothesize the reason for this is that bacteria not expressing MrkA can evade opsonophagocytosis. Our data support the fact that MrkA is a conserved, immunodominant protein that is antibody accessible on the surface of and suggest that additional studies should evaluate the potential of using anti-MrkA antibodies in different stages of infection (different sites in the body) as well as against biofilms in the body during infection and associated with medical devices.IMPORTANCEThere is an unmet, urgent need for the development of novel antimicrobial therapies for the treatment of infections. We describe the use of phage display, antibody engineering, and high-throughput assays to identify antibody-accessible targets of . We discovered monoclonal antibodies (mAbs) binding to the type 3 fimbrial protein MrkA. The anti-MrkA mAbs were found to be highly cross-reactive, binding to all strains tested from a diverse panel of clinical isolates, and were active in an opsonophagocytic killing assay at pM concentrations. MrkA is important for biofilm formation; thus, our data support further exploration of the use of anti-MrkA antibodies for preventing and/or controlling in biofilms and during infection.
PubMed: 38940542
DOI: 10.1128/spectrum.00400-24 -
Medeniyet Medical Journal Jun 2024While the coronavirus disease-2019 (COVID-19) pandemic has generally resulted in milder illness among children than adults, persistent respiratory symptoms have been...
OBJECTIVE
While the coronavirus disease-2019 (COVID-19) pandemic has generally resulted in milder illness among children than adults, persistent respiratory symptoms have been increasingly reported in this population.
METHODS
We conducted a prospective, single-center cohort study focusing on children experiencing prolonged respiratory symptoms after contracting COVID-19. Spirometry, 6- minute walk tests (6MWTs), and tests of lung volume, the diffusing capacity of the lungs for carbon monoxide (DLCO), and fractional exhaled nitric oxide (FeNO) were performed on COVID-19 survivors at least 4 weeks after infection and a group of healthy control subjects.
RESULTS
Fifty-five children with long-term COVID and 55 healthy control subjects were recruited. The weight, height, and body mass index Z-scores were similar in the groups. Within a median duration of 85 days (minimummaximum: 35-194) following COVID-19 infection, a restrictive pattern was observed to be more common in the study group (p=0.021). In children with long COVID, 6MWT distances, DLCO Z-scores, and the predicted values of spirometry and lung volume tests were found to be significantly lower but in the normal range. The average predicted values for DLCO, FeNO, and 6MWT were similar in the two groups.
CONCLUSIONS
Prolonged respiratory symptoms often persist long after COVID-19 infection, necessitating comprehensive evaluation of affected children. Close monitoring, including spirometry and lung volume assessments, is crucial for children with abnormalities in lung imaging. However, FeNO measurements were found to be ineffective in monitoring long COVID.
PubMed: 38940402
DOI: 10.4274/MMJ.galenos.2024.15853