Cystic Fibrosis
Effects of simulated smoke condensate generated from combustion of selected military burn pit contents on human airway epithelial cells
Part Fibre Toxicol. 2024 Oct 8;21(1):41. doi: 10.1186/s12989-024-00604-7.
ABSTRACT
BACKGROUND: Exposure to military burn pit smoke during deployment is associated with different respiratory and non-respiratory diseases. However, information linking smoke exposure to human pulmonary health is lacking. This study examined the effects of simulated burn pit smoke condensates on human airway epithelial cells (HAECs) from twelve donors (smokers/non-smokers, biological female/male) cultured at an air-liquid interface and exposed to condensates from three simulated burn pit waste materials (cardboard, plywood, and plastic) incinerated at two combustion conditions: smoldering and flaming. Cellular gene expression was analyzed using bulk RNA sequencing, and basolateral media cytokine levels were assessed using multiplex immunoassay.
RESULTS: Flaming smoke condensates caused more significant differentially expressed genes (DEGs) with plywood flaming smoke being the most potent in altering gene expression and modulating cytokine release. Cardboard and plywood flaming condensates primarily activated detoxification pathways, whereas plastic flaming affected genes related to anti-microbial and inflammatory responses. Correlation analysis between smoke condensate chemicals and gene expression to understand the underlying mechanism revealed crucial role of oxygenated polycyclic aromatic hydrocarbons (PAHs) and aluminum, molybdenum, and silicon elements; IL6 expression was positively correlated with most PAHs. Stratification of data based on HAEC donor demographics suggests that these affect gene expression changes. Enrichment analysis indicated similarity with several deployment-related presumptive and reported diseases, including asthma, emphysema, and cancer of different organs.
CONCLUSIONS: This study highlights that simulated burn pit smoke exposure of HAECs causes gene expression changes indicative of deployment-related diseases with more pronounced effects seen in smokers and females. Future studies are needed to further characterize how sex and smoking status affect deployment-related diseases.
PMID:39380034 | PMC:PMC11460082 | DOI:10.1186/s12989-024-00604-7
Patent Foramen Ovale and Oxygenation in Patients with Cystic Fibrosis
Respiration. 2024 Oct 8:1-16. doi: 10.1159/000541892. Online ahead of print.
ABSTRACT
INTRODUCTION: Patent foramen ovale (PFO) affects about 25% of the population. We studied outcomes in cystic fibrosis (CF).
METHODS: We conducted a case-control study of patients with CF (PwCF) and age and sex-matched controls who underwent agitated saline contrast (bubble) echocardiography, 1998-2020. We assessed PFO impacts using linear, logistic, quasipoisson and proportional hazards models.
RESULT: 59 of 64 PwCF and 88 of 93 controls underwent bubble studies to investigate unexplained hypoxemia or dyspnea. PwCF had higher mean pulmonary artery pressure (PAP, 6.9 mm Hg, 95% Confidence Interval [CI] = 2.35-11.4), reduced tricuspid annular plane systolic excursion (TAPSE, -3.78 mm, CI = -5.64 to -1.93) and similar right ventricular diastolic sizes. Absent hypoxemia, PFO incidence was similar between PwCF and controls; with hypoxemia, PFO was more common in CF (Odds Ratio [OR] = 5.00, CI = 1.32-19.0). In CF, oxygen supplementation occurred at a percent predicted forced expiratory volume in 1 s (FEV1%) 22.5 points higher with PFO. Adjusted for FEV1%, PFO was associated with 0.59 more prior year pulmonary exacerbations (CI = 0.20-0.98) and shorter time to next exacerbation (Hazard Ratio = 1.86, CI = 1.06-3.26). Associations between PFO and hypoxemia or exacerbations were insensitive to PAP, TAPSE and CF transmembrane regulator protein modulator treatments. PFO was not associated with CF time to death or lung transplantation (median 1.87 years) adjusted for age, sex, FEV1% and prior year exacerbation counts.
CONCLUSION: PFO in CF is associated with hypoxemia at higher FEV1% and more pulmonary exacerbations but not survival.
PMID:39378862 | DOI:10.1159/000541892
Characterization of <em>Pseudomonas aeruginosa</em> from subjects with diffuse panbronchiolitis
Microbiol Spectr. 2024 Oct 8:e0053024. doi: 10.1128/spectrum.00530-24. Online ahead of print.
ABSTRACT
Diffuse panbronchiolitis (DPB) is a rare, idiopathic inflammatory disease primarily diagnosed in East Asian populations. DPB is characterized by diffuse pulmonary lesions, inflammation of the respiratory bronchioles, and bacterial infections of the airway. Historically, sputum cultures reveal Pseudomonas aeruginosa in 22% of DPB patients, increasing to 60% after 4 years from disease onset. Although DPB patients have a known susceptibility to respiratory P. aeruginosa infections, as is observed in other chronic lung diseases such as cystic fibrosis (CF), the characterization of DPB P. aeruginosa strains is limited. In this study, we characterized 24 strains obtained from a cohort of DPB patients for traits previously associated with virulence, including growth, motility, antibiotic susceptibility, lipopolysaccharide structure, and genomic diversity. Our cohort of DPB P. aeruginosa strains exhibits considerable genomic variability when compared with isolates from people with cystic fibrosis chronically colonized with P. aeruginosa and acute P. aeruginosa infection isolates. Similar to CF, DPB P. aeruginosa strains produce a diverse array of modified lipid A structures. Antibiotic susceptibility testing revealed increased resistance to erythromycin, a representative agent of the macrolide antibiotics used to manage DPB patients. Differences in the O-antigen type among P. aeruginosa strains collected from these different backgrounds were also observed. Ultimately, the characterization of DPB P. aeruginosa strains highlights several unique qualities of P. aeruginosa strains collected from chronically diseased airways, underscoring the challenges in treating DPB, CF, and other obstructive respiratory disease patients with P. aeruginosa infections.
IMPORTANCE: Diffuse panbronchiolitis (DPB), a chronic lung disease characterized by persistent P. aeruginosa infection, serves as an informative comparator to more common chronic lung diseases, such as cystic fibrosis (CF). This study aimed to better address the interplay between P. aeruginosa and chronically compromised airway environments through the examination of DPB P. aeruginosa strains, as existing literature regarding DPB is limited to case reports, case series, and clinical treatment guidelines. The evaluation of these features in the context of DPB, in tandem with prevailing knowledge of P. aeruginosa strains collected from more common chronic lung diseases (e.g., CF), can aid in the development of more effective strategies to combat respiratory P. aeruginosa infections in patients with chronic lung diseases.
PMID:39377602 | DOI:10.1128/spectrum.00530-24
Collaboration between registered dietitians and gastroenterologists in cystic fibrosis care: Results of an international cross-sectional survey
Nutr Clin Pract. 2024 Oct 8. doi: 10.1002/ncp.11219. Online ahead of print.
ABSTRACT
BACKGROUND: Collaboration between registered dietitians and gastroenterologists has not been evaluated in cystic fibrosis (CF). We surveyed registered dietitians and gastroenterologists regarding the current participation of gastroenterologists in CF centers and identified possible areas to enhance partnership between the two disciplines.
METHODS: An anonymous online survey was distributed targeting registered dietitians and gastroenterologists involved in CF care through three international listservs (CF Nutrition, CF DIGEST, and PEDGI) over a 6-week period. SurveyMonkey was used, and informed consent was obtained.
RESULTS: A total of 131 respondents participated in this survey, including 80 registered dietitians and 51 gastroenterologists (41 pediatric and 10 adult gastroenterologists). Most respondents (82%) were from the United States, and two-thirds had ≥5 years of experience in CF. A significant number of registered dietitians reported the nonavailability of gastroenterologists for collaboration and there was greater availability of gastroenterologists in pediatric centers. Barriers to interdisciplinary collaboration included lack of CF expertise and dedicated time among the gastroenterologists and difficulties in coordinating the gastroenterology clinics. More gastroenterologists than registered dietitians perceived that they worked collaboratively with the other discipline in various domains (clinical care, quality improvement, research, presentations, and publications). Both disciplines had mutual respect and interest to further the collaboration.
CONCLUSION: There is an increased need for gastroenterologist participation and collaboration (particularly in adult centers) in CF alongside registered dietitians to enhance comprehensive patient care. Future efforts should focus on training more gastroenterologists in CF and facilitating easier access to gastroenterologists for the CF population.
PMID:39377560 | DOI:10.1002/ncp.11219
Elimination of cDC1 cells by regulatory T cells jeopardizes cancer immunotherapy
Oncoimmunology. 2024 Oct 4;13(1):2412874. doi: 10.1080/2162402X.2024.2412874. eCollection 2024.
ABSTRACT
Recent findings revealed that neoantigen-specific cytotoxic type 1 regulatory T (TR1) CD4 T cells can subvert cancer immunotherapy by killing type 1 conventional dendritic cells (cDC1s) that present tumor antigens bound to MHC class II. This underlines the importance of cDC1s for eliciting anticancer immunity but poses a novel clinical challenge.
PMID:39376580 | PMC:PMC11457612 | DOI:10.1080/2162402X.2024.2412874
Lessons learned from the RE(ACT) conference on medical devices for rare diseases
Eur J Med Genet. 2024 Oct 5;72:104976. doi: 10.1016/j.ejmg.2024.104976. Online ahead of print.
ABSTRACT
The field of rare disease therapeutics has witnessed significant growth in recent years, highlighting the need for diverse therapeutic approaches to cater to the unique needs of individuals with rare diseases. Rare disease therapies encompass a broad spectrum of interventions, including orphan medicinal products, orphan medical devices, rehabilitative therapies, and digital therapeutics, with the lines between these categories blurring. This paper covers the session of the RE (ACT)-IRDiRC Conference 2023 and delves into the landscape of orphan medical device research and development, shedding light on the challenges and opportunities in this burgeoning field. It provides a short overview of the different international legislations in the field. In addition, it highlights several exemplary orphan medical devices. The first example is an exoskeleton for boys with Duchenne Muscular Dystrophy, enabling them to maintain arm functionality and independence. Another example presented was an EEG device linked to an app detecting seizures in rare epilepsy conditions, which alerts caregivers to seizures in real-time but also facilitates objective seizure reporting for clinicians, aiding in diagnosis and treatment optimization. It also showcases the role of gamification and enabling technologies in addressing rare diseases, by showing a game designed for children with cystic fibrosis, and a telemedicine system for rehabilitation therapy. Both solutions aim to improve patients' understanding of their conditions and enhance their self-management. In conclusion, this paper underscores the critical need for patient-centric orphan and pediatric medical devices to provide therapeutic options for individuals with rare diseases. It highlights the impact of existing devices on enhancing the quality of life for rare disease patients and emphasizes the necessity for greater incentives and support for research and development in this field.
PMID:39374774 | DOI:10.1016/j.ejmg.2024.104976
Novel gain-of-function mutants identify a critical region within CFTR membrane-spanning domain 2 controlling cAMP-dependent and ATP-independent channel activation
Cell Mol Life Sci. 2024 Oct 7;81(1):426. doi: 10.1007/s00018-024-05431-9.
ABSTRACT
CFTR is an anion channel that has evolved from the mold of an ABC transporter. It possesses specific structural features, including a lateral portal between the cytoplasmic extensions of its transmembrane helices TM4 and TM6. This TM4-TM6 portal is lined by basic residues attracting anions from the cytosol towards the intracellular vestibule. Even though a symmetric, open portal is not observed at the level of the TM10/TM12 interface, basic amino acids are also present at this level, exposed to solvent in the vicinity of the regulatory R region, whose phosphorylation enables channel activation. Here, using all-atom molecular dynamics simulations in combination with functional and biochemical assays, we investigate the importance of these basic amino acids (R1158 and R1030), and of a neighboring aromatic amino acid (W846) in the regulation of CFTR activity. Results indicate that mutation of these amino acids globally increased channel activity and enabled channel opening by potentiators without the need to elevate cAMP levels. These effects (i) were observed even when the binding site of the potentiator VX-770 was mutated, revealing a probable independent mechanism, and (ii) were additive to one gain-of-function mutant within the selectivity filter. Taken together, our results indicate that the region of the membrane-spanning domain 2 (MSD2), symmetric to the lateral portal located between MSD1 TM4 and TM6, is a novel critical actor of CFTR regulation.
PMID:39373784 | PMC:PMC11458853 | DOI:10.1007/s00018-024-05431-9
Development of a Polymicrobial Colony Biofilm Model to Test Antimicrobials in Cystic Fibrosis
J Vis Exp. 2024 Sep 20;(211). doi: 10.3791/67213.
ABSTRACT
A range of bacteria biofilm models exist for the testing of antibiotics. However, many of these are limited to a single experimental output, such as colony-forming units or metabolic activity. Furthermore, many biofilm models do not reflect the biological and physiochemical properties of the human host environment. This is an important issue in many conditions, but most noticeably in cystic fibrosis (CF). A large proportion of people with CF suffer from both chronic and intermittent infections, and in vitro, antibiotic susceptibility testing poorly correlates with patient treatment outcomes. Some biofilm models incorporate CF lung-relevant media, including synthetic sputum mimics, but do not consider the polymicrobial nature of the environment, which alters biofilm architecture, physiology, and the way microbes respond to treatment. The solid-air interface colony biofilm model described here is highly adaptable and incorporates both CF-relevant media and a polymicrobial context. This model can also be used for mid-throughput screening of antimicrobials and to study their effect on polymicrobial dynamics. Output measurements from the model can be colony-forming units, metabolic activity, and confocal microscopy analysis. The model can easily be adapted to different microorganisms, media, temperatures, and variable oxygen conditions and can be used to test a wide range of chemical, biological, and physical treatments.
PMID:39373511 | DOI:10.3791/67213
Safety profile of drugs used in non-cystic fibrosis bronchiectasis: a narrative review
Ther Adv Drug Saf. 2024 Sep 30;15:20420986241279213. doi: 10.1177/20420986241279213. eCollection 2024.
ABSTRACT
Non-cystic fibrosis bronchiectasis is a long-term lung disease characterised by abnormal dilatation of the bronchi, with patients experiencing chronic productive cough and recurrent exacerbations. Currently, there are no licensed drugs for use in bronchiectasis while clinical trials have been conducted to either test new drugs or repurpose existing ones. These drugs target the underlying pathophysiology of bronchiectasis which is known to include infection, inflammation, mucus hypersecretion and retention. Most of the drugs used in daily clinical practice for bronchiectasis are off-label with no randomised trials exploring their safety. This review aims at exploring the safety profile of drugs frequently used in clinical practice to manage bronchiectasis, including antibiotics (e.g. macrolides, aminoglycosides, polymyxins, fluoroquinolones, aztreonam), mucoactive therapy (e.g. hypertonic saline, mannitol, DNase and carbocisteine), anti-inflammatory therapy (inhaled corticosteroids) and drugs currently in development for use in bronchiectasis (e.g. brensocatib, benralizumab and itepekimab).
PMID:39372891 | PMC:PMC11450733 | DOI:10.1177/20420986241279213
Hidden in Plain Sight-A Rare Presentation of Cystic Fibrosis with Pseudo-Bartter Syndrome
Indian J Nephrol. 2024 Sep-Oct;34(5):541. doi: 10.25259/ijn_53_23. Epub 2024 May 18.
NO ABSTRACT
PMID:39372621 | PMC:PMC11450897 | DOI:10.25259/ijn_53_23
Nationwide Survey of Cystic Fibrosis Knowledge and Resource Accessibility in Egypt
ATS Sch. 2024 Aug 13;5(3):386-391. doi: 10.34197/ats-scholar.2023-0156BR. eCollection 2024 Sep 30.
NO ABSTRACT
PMID:39371241 | PMC:PMC11448822 | DOI:10.34197/ats-scholar.2023-0156BR
Lung-Kidney Axis in Cystic Fibrosis: Early Urinary Markers of Kidney Injury Correlate with Neutrophil Activation and Worse Lung Function
medRxiv [Preprint]. 2024 Sep 19:2023.11.10.23298378. doi: 10.1101/2023.11.10.23298378.
ABSTRACT
BACKGROUND: Adult people with cystic fibrosis (PwCF) have a higher risk of end-stage kidney disease than the general population. The nature and mechanism of kidney disease in CF are unknown. This study quantifies urinary kidney injury markers and examines the hypothesis that neutrophil activation and lung infection are associated with early kidney injury in CF.
METHODS: Urinary total protein, albumin, and markers of kidney injury and neutrophil activation, normalized to creatinine, as well as urinary immune cells, were quantified in CF (n = 48) and healthy (n = 33) cohorts. Infection burden and chronicity were defined by sputum culture and serum titers of anti-bacterial antibodies.
RESULTS: PwCF had increased urinary protein levels, consisting of low-molecular-weight tubular injury markers, independent of glomerular filtration rate (eGFR). This finding suggests subclinical renal injury processes. Urinary analysis of the CF cohort identified different associations of urinary injury markers with aminoglycoside exposure, lung function, and neutrophil activation. High urinary KIM-1 levels and increased prevalence of neutrophils among urine immune cells correlated with decreased lung function in PwCF. The relationship between tubular injury and decreased lung function was most prominent in patients harboring chronic Pseudomonas aeruginosa infection.
CONCLUSIONS: Increased urinary tubular injury markers in PwCF suggest early subclinical renal injury not readily detected by eGFR. The strong association of high urinary KIM-1 and neutrophils with diminished lung function and high Pseudomonas aeruginosa burden suggests that pulmonary disease may contribute to renal injury in CF.
PMID:39371147 | PMC:PMC11451629 | DOI:10.1101/2023.11.10.23298378
Room to breathe: The promise of a more flexible cystic fibrosis care model
J Cyst Fibros. 2024 Oct 5:S1569-1993(24)01792-2. doi: 10.1016/j.jcf.2024.09.024. Online ahead of print.
NO ABSTRACT
PMID:39370311 | DOI:10.1016/j.jcf.2024.09.024
Recursive dynamics of GspE through machine learning enabled identification of inhibitors
Comput Biol Chem. 2024 Sep 28;113:108217. doi: 10.1016/j.compbiolchem.2024.108217. Online ahead of print.
ABSTRACT
Type II secretion System has been increasingly recognized as a key driver of virulence in many pathogenic bacteria including Achromobacter xylosoxidans. ATPase GspE is the powerhouse of the T2SS. It powers the entire secretion process by binding with ATP and hydrolyzing it. Therefore, targeting it was thought to have a profound effect on the normal functioning of the whole T2SS. A. xylosoxidans is a Gram-negative bacterium that poses a rising concern to immunocompromised people. It is responsible for many opportunistic infections mostly in people with cystic fibrosis. Due to its intrinsic and acquired resistance mechanisms, it is challenging to treat. In this current study, an extensive machine learning-enabled computational investigation was carried out. Drug libraries were screened using machine learning random forest algorithm trained on non-redundant dataset of 8722 antibacterial compounds with reported IC50 values. Active compounds were then further subjected to molecular docking. To unravel the dynamics and better understand the stability of complexes, the top complexes were subjected to MD Simulations followed by various post-simulation analyses including Trajectory analysis, Atom Contacts, SASA, Hydrogen Bond, RDF, binding free energy calculations, PCA, and AFD analysis. Findings from the study unanimously unveiled Asinex-BAS00263070-28551 as the best inhibitor as it instigated the recursive dynamics of the target by making key hydrogen bond interactions with Walker A motif, suggesting it could serve as the promising drug candidate against GspE. Further experimental in-vivo and in-vitro validation is still required to authenticate the therapeutic effects of these drugs.
PMID:39369611 | DOI:10.1016/j.compbiolchem.2024.108217
Correction: Trends in hospitalizations of children with respiratory syncytial virus aged less than 1 year in Italy, from 2015 to 2019
Ital J Pediatr. 2024 Sep 3;50(1):160. doi: 10.1186/s13052-024-01719-5.
NO ABSTRACT
PMID:39227853 | DOI:10.1186/s13052-024-01719-5
Impact of the expanded label for elexacaftor-tezacaftor-ivacaftor in people with cystic fibrosis with no F508del variant in the United States
Eur Respir J. 2024 Sep 3:2401146. doi: 10.1183/13993003.01146-2024. Online ahead of print.
NO ABSTRACT
PMID:39227072 | DOI:10.1183/13993003.01146-2024
Chaperoning system: Intriguing target to modulate the expression of CFTR in cystic fibrosis
Eur J Med Chem. 2024 Aug 28;278:116809. doi: 10.1016/j.ejmech.2024.116809. Online ahead of print.
ABSTRACT
The correction of protein folding is fundamental for cellular functionality and its failure can lead to severe diseases. In this context, molecular chaperones are crucial players involved in the tricky process of assisting in protein folding, stabilization, and degradation. Chaperones, such as heat shock proteins (HSP) 90, 70, and 60, operate within complex systems, interacting with co-chaperones both to prevent protein misfolding and direct to the correct folding. Chaperone targeting drugs could represent a challenging approach for the treatment of cystic fibrosis (CF), an autosomal recessive genetic disease caused by mutations in the CFTR gene, encoding for the CFTR chloride channel. In this review, we discuss the potential role of molecular chaperones as proteostasis modulators affecting CFTR biogenesis. In particular, we focused on HSP90 and HSP70, for their key role in CFTR folding and trafficking, as well as on HSP60 for its involvement in the inflammation process.
PMID:39226706 | DOI:10.1016/j.ejmech.2024.116809
Recent Advances in Therapeutics and Manufacturing Processes of Recombinant Adeno-Associated Virus for the Treatment of Lung Diseases
Curr Gene Ther. 2024 Sep 2. doi: 10.2174/0115665232294935240826061311. Online ahead of print.
ABSTRACT
Developing delivery vectors capable of transducing genetic material across the lung epithelia and mucus barrier is a major challenge and of great interest to enable gene therapies to treat pulmonary diseases. Recombinant Adeno-associated Viruses (rAAVs) have emerged as attractive candidates among viral and non-viral vectors due to their broad tissue tropism, ability to transduce dividing and quiescent cells, and their safety profile in current human applications. While rAAVs have demonstrated safety in earlier clinical trials for lung disease applications, there are still some limitations regarding rAAV-transgene delivery in pulmonary cells. Thus, further improvements in rAAV engineering are needed to enhance the effectiveness of rAAV-based therapies for lung diseases. Such therapies could benefit patients with chronic lung diseases, such as asthma, chronic obstructive pulmonary disease, pulmonary hypertension, and cystic fibrosis, among others, by regulating hereditary gene mutations or acquired gene deregulations causing these conditions. Alongside therapeutic development, advances in the rAAV production process are essential to meet increasing production demands, while reducing manufacturing costs. This review discusses current challenges and recent advances in the field of rAAV engineering and manufacturing to encourage the clinical development of new pulmonary gene therapy treatments.
PMID:39225214 | DOI:10.2174/0115665232294935240826061311
Activity of antibiotics against Burkholderia cepacia complex in artificial sputum medium
J Antimicrob Chemother. 2024 Sep 3:dkae299. doi: 10.1093/jac/dkae299. Online ahead of print.
ABSTRACT
BACKGROUND: Burkholderia cepacia complex (Bcc) is a collection of intrinsically drug-resistant Gram-negative bacteria that cause life-threatening disease in people with cystic fibrosis (CF). Standard antimicrobial susceptibility testing methods have poor predictive value for clinical outcomes in Bcc infections, probably due in part to differences between in vitro testing conditions and the environment in which Bcc grow in the lungs of people with CF.
OBJECTIVES: To compare the activity of commonly used antibiotics under standard in vitro testing conditions with activity in conditions mimicking those found in vivo.
METHODS: Two Bcc strains were grown alone and with six different antibiotics (minocycline, ceftazidime, meropenem, tobramycin, levofloxacin, trimethoprim-sulfamethoxazole) in two different media: standard cation-adjusted Mueller-Hinton broth and an artificial sputum medium designed to simulate the environment in the lungs of people with CF through addition of components including mucin, free DNA and amino acids. Two different starting conditions were used for time-kill assays: a standard ∼5 × 106 cfu/mL inoculum, and a high-density inoculum in which bacteria were grown for 72 hours before addition of antibiotics. Growth detection was performed by colony enumeration and by detection of resazurin reduction.
RESULTS: There were major discrepancies between standard susceptibility results and activity in our models. Some antibiotics, including ceftazidime, showed minimal activity in all time-kill assays despite low minimal inhibitory concentrations, while others, notably tobramycin, were more active in high-density growth conditions than in standard time-kill assays.
CONCLUSIONS: This work underscores the urgent need to develop more clinically relevant susceptibility testing approaches for Bcc.
PMID:39224940 | DOI:10.1093/jac/dkae299
Phosphatidylserine liposomes induce a phagosome acidification-dependent and ROS-mediated intracellular killing of <em>Mycobacterium abscessus</em> in human macrophages
Front Cell Infect Microbiol. 2024 Aug 19;14:1443719. doi: 10.3389/fcimb.2024.1443719. eCollection 2024.
ABSTRACT
Mycobacterium abscessus (Mab) is an opportunistic nontuberculous mycobacterium responsible of difficult-to-treat pulmonary infections in vulnerable patients, such as those suffering from Cystic Fibrosis (CF), where it represents a major cause of morbidity and mortality. Additionally, due to the intrinsic extensive antimicrobial resistance spectrum displayed by this species and the side effects reported for some available antibiotics, the therapeutic management of such infections remains extremely difficult. In the present study, we show that phosphatidylserine liposomes (PS-L) enhance intracellular mycobacterial killing of Mab infected human macrophages with functional or pharmacologically inhibited cystic fibrosis conductance regulator (CFTR), by a mechanism involving phagosome acidification and reactive oxygen species (ROS) production. Additionally, PS-L significantly reduce proinflammatory response of Mab infected macrophages in terms of NF-kB activation and TNF-α production, irrespective of CFTR inhibition. Altogether, these results represent the proof of concept for a possible future development of PS-L as a therapeutic strategy against difficult-to-treat Mab infection.
PMID:39224705 | PMC:PMC11366698 | DOI:10.3389/fcimb.2024.1443719