Daily Respiratory Research Analysis
Analyzed 57 papers and selected 3 impactful papers.
Summary
Two mechanistic studies pinpoint immune and metabolic drivers of airway disease: IL-17C governs IL-17A pathogenicity and neutrophilic endotype switching in bronchiectasis-asthma overlap, and FABP4-driven lipophagy suppression links lipid droplets to epithelial barrier failure in lung ischemia/reperfusion injury. A meta-analysis of maternal RSVpreF vaccination shows robust immunogenicity and infant protection without increased perinatal risk.
Research Themes
- Immune pathway control of asthma endotypes (IL-17C–IL-17A–IL-17RE axis)
- Metabolic reprogramming and lipophagy in lung injury (FABP4–p38–ULK1)
- Maternal immunization to prevent infant respiratory morbidity (RSVpreF)
Selected Articles
1. Evidence for Interleukin-17C governing interleukin-17A pathogenicity and promoting asthma endotype switching in bronchiectasis.
In BAO, IL-17C correlates with IL-17A/ILC3s and mechanistically drives neutrophilic endotype switching via IL-17RE in ILC3s under chronic Pseudomonas infection plus allergen challenge. Genetic ablation of Il17re attenuates IL-17A responses and endotype switching; epithelial barrier injury promotes IL-17C production.
Impact: This study identifies IL-17C–IL-17RE signaling as a driver of IL-17A pathogenicity and asthma endotype switching in bronchiectasis, offering a plausible therapeutic target for a difficult-to-treat overlap syndrome.
Clinical Implications: Targeting IL-17C or IL-17RE may mitigate neutrophilic asthma endotype in bronchiectasis-asthma overlap, and IL-17C could serve as a biomarker for endotype stratification.
Key Findings
- Peripheral blood IL-17C levels positively correlated with IL-17A and ILC3s in BAO patients.
- In mice, IL-17C potentiated IL-17A via IL-17RE on ILC3s, driving neutrophilic asthma endotype switching under chronic Pseudomonas infection plus allergen challenge.
- Il17re ablation attenuated ILC3 responses and reduced IL-17A-mediated endotype switching.
- Epithelial barrier impairment by Pseudomonas exposure was associated with enhanced IL-17C production in vitro.
Methodological Strengths
- Integrated human correlative data with mechanistic in vivo mouse models including genetic ablation (Il17re).
- Use of a clinically relevant chronic Pseudomonas infection model followed by allergen challenge to mimic BAO.
Limitations
- Human sample size and detailed cohort characteristics were not provided in the abstract.
- Translational applicability and safety of IL-17C/IL-17RE targeting remain untested in clinical trials.
Future Directions: Validate IL-17C as a biomarker and therapeutic target in prospective BAO cohorts; assess safety/efficacy of IL-17C/IL-17RE blockade; dissect epithelial sources and triggers of IL-17C in human airway tissue.
The management of bronchiectasis-asthma overlap (BAO) is an important clinical issue to be addressed. Little is known regarding the endotype of BAO. Here we recruit patients with a primary diagnosis of bronchiectasis and co-existing asthma. The levels of interleukin (IL)-17C are positively correlated with the levels of IL-17A or group 3 innate lymphoid cells (ILC3s) in peripheral blood samples from patients with BAO. An in vivo mouse model of Pseudomonas aeruginosa chronic lower respiratory tract infection followed by ovalbumin-induced asthma shows that IL-17C potentiates IL-17A expression via interacting with IL-17 receptor E in ILC3s. Additionally, ablation of Il17re in mice attenuates ILC3 responses and IL-17A-mediated asthma endotype switching towards neutrophilic asthma driven by P. aeruginosa chronic lower respiratory tract infection. Lastly, impaired epithelial barrier integrity by P. aeruginosa exposure is associated with IL-17C production in vitro. Collectively, our study implicates evidence for IL-17C governing IL-17A pathogenicity and promoting asthma endotype switching in bronchiectasis, implicating IL-17C as a potential therapeutic target for individuals with BAO.
2. Maternal RSV vaccine: a systematic review and meta-analysis of immunogenicity and perinatal safety.
Across six RCTs (n=17,212), maternal RSVpreF vaccination significantly increased neutralizing antibodies against RSV-A and RSV-B and reduced infant RSV-associated lower respiratory tract illness by 49% within 180 days. No significant increases were observed in preterm birth, serious adverse events, or perinatal complications.
Impact: This meta-analysis consolidates high-level evidence that maternal RSVpreF vaccination is both immunogenic and perinatally safe while protecting infants, supporting implementation and policy decisions.
Clinical Implications: Supports maternal RSV vaccination to reduce infant RSV-related morbidity without increasing preterm birth; informs timing and counseling in prenatal care.
Key Findings
- Six RCTs (17,212 participants) included; RSVpreF significantly increased maternal neutralizing antibodies (SMD 1.40 for RSV-A; 1.11 for RSV-B).
- Infant RSV-associated lower respiratory tract illness within 180 days reduced by 49% (OR 0.51, 95% CI 0.40-0.64).
- No significant increase in preterm birth (OR 1.09, 95% CI 0.87-1.37) or serious adverse events/perinatal complications.
Methodological Strengths
- RCT-only meta-analysis with multi-database search and large pooled sample size.
- Clinically meaningful infant outcomes and maternal safety endpoints analyzed.
Limitations
- Potential heterogeneity across trials (population, dosing, timing) not detailed in abstract.
- Long-term infant outcomes beyond 180 days and rare adverse events require further study.
Future Directions: Evaluate durability of infant protection, optimal timing/window in varying RSV seasons, and real-world effectiveness alongside maternal co-immunizations.
This systematic review and meta-analysis assess the immunogenicity and maternal-fetal safety profile of RSV prefusion F (RSVpreF) vaccination during pregnancy. PubMed, Scopus, Embase, Cochrane, and Web of Science databases were searched for relevant studies. Only randomized controlled trials (RCTs) evaluating the safety, efficacy, and immunogenicity of RSVpreF vaccination in pregnant women were included. Six RCTs, involving 17,212 participants, were analyzed. The vaccine significantly boosted maternal anti-RSV neutralizing antibody levels, with a standardized mean difference (SMD) of 1.40 for RSV-A and 1.11 for RSV-B, both with high statistical significance. Infants born to vaccinated mothers had a 49% reduced risk of RSV-associated lower respiratory tract illness within 180 days post-vaccination (OR = 0.51, 95% CI: 0.40-0.64). Preterm birth rates did not differ significantly between the vaccine and placebo groups (OR = 1.09, 95% CI: 0.87-1.37). The vaccine was not associated with increased risks of serious adverse events or perinatal complications. Maternal RSVpreF vaccination significantly elevates neutralizing antibody levels against RSV subtypes A and B without increasing the risk of serious adverse events or preterm delivery. These findings support the safety and immunogenicity of RSV vaccination in pregnant women, reinforcing its potential utility in protecting neonates against RSV-related morbidity.
3. FABP4-mediated lipid droplet accumulation drives epithelial-mesenchymal transition and aggravates alveolar epithelial barrier disruption.
In LIRI models, autocrine FABP4 signaling in alveolar epithelium suppresses lipophagy via p38–ULK1, causing lipid droplet accumulation that drives EMT and disrupts the alveolar epithelial barrier. Pharmacologic/genetic inhibition of lipid droplets mitigated EMT and barrier failure, nominating FABP4 as a therapeutic target in CPB-associated ARDS.
Impact: This study uncovers a lipid metabolism–barrier integrity axis (FABP4–p38–ULK1–lipophagy) in lung injury, linking metabolic reprogramming to EMT and offering a tractable target to prevent post-CPB ARDS.
Clinical Implications: Therapeutic modulation of FABP4 or lipid droplet formation may preserve alveolar barrier function and reduce ARDS risk after cardiopulmonary bypass.
Key Findings
- LIRI induces autocrine FABP4 signaling in alveolar epithelial cells leading to lipid droplet accumulation and barrier disruption.
- FABP4 activates p38 MAPK, phosphorylates ULK1, suppresses lipophagy, and thereby promotes EMT.
- Pharmacologic/genetic inhibition of lipid droplets attenuates EMT and restores alveolar epithelial barrier integrity.
Methodological Strengths
- Combined in vivo and in vitro LIRI models with molecular, cellular, and functional readouts.
- Use of both pharmacological and genetic interventions to validate pathway causality.
Limitations
- Preclinical models; absence of human clinical validation or CPB patient data in the abstract.
- Potential species-specific differences and off-target effects of pathway modulation not fully addressed.
Future Directions: Translate FABP4 pathway findings to human CPB cohorts; develop/selective FABP4 or lipophagy modulators; evaluate timing/dosing to prevent ARDS in perioperative trials.
BACKGROUND: Acute respiratory distress syndrome (ARDS) frequently develops after cardiopulmonary bypass (CPB), with lung ischemia/reperfusion injury (LIRI) as a major contributing factor. However, the role of fatty acid-binding protein 4 (FABP4) in the pathogenesis of CPB-associated ARDS remains poorly understood. METHODS: Experimental LIRI models were established in vivo and in vitro to investigate the role of FABP4 in alveolar epithelial injury. Lipid droplets (LDs) accumulation, fatty acid (FA) metabolism, epithelial-mesenchymal transition (EMT), and alveolar epithelial barrier (AEB) integrity were assessed using molecular, cellular, and functional approaches. Pharmacological and genetic interventions were applied to evaluate the contribution of FABP4-mediated signaling pathways. RESULTS: LIRI induced autocrine FABP4 signaling in alveolar epithelial cells, leading to pronounced LDs accumulation and disruption of AEB integrity. FABP4 activation enhanced FA metabolism and promoted EMT, which played a critical role in epithelial barrier dysfunction. Mechanistically, FABP4 activated the p38 MAPK pathway, resulting in ULK1 phosphorylation, suppression of lipophagy, and subsequent LDs formation, thereby driving EMT. Inhibition of LDs accumulation effectively attenuated EMT and alleviated AEB disruption. CONCLUSION: FABP4 serves as a key metabolic regulator linking lipid reprogramming to EMT and alveolar epithelial barrier disruption during LIRI. Targeting FABP4-mediated lipid metabolism may represent a promising therapeutic strategy for preventing ARDS following CPB. KEY POINTS: LIRI induces autocrine FABP4 signaling in alveolar epithelial cells. FABP4 promotes lipid droplets accumulation by inhibiting lipophagy through p38 MAPKULK1 signaling. FABP4-driven lipid metabolic reprogramming triggers EMT and disrupts alveolar epithelial barrier integrity. Targeting FABP4 or lipid droplets accumulation may offer therapeutic potential for CPB-associated ARDS.