Daily Respiratory Research Analysis
Analyzed 211 papers and selected 3 impactful papers.
Summary
Analyzed 211 papers and selected 3 impactful articles.
Selected Articles
1. Macrophage-to-Myofibroblast Transdifferentiation Contributes to Pulmonary Fibrosis via the MERTK-SPP1-SRC-TKS5 Signaling Axis.
This mechanistic study demonstrates that macrophage-to-myofibroblast transdifferentiation is a key driver of pulmonary fibrosis mediated by a MERTK–SPP1–SRC–TKS5 signaling axis. Genetic and AAV-mediated interventions disrupting this pathway suppressed MMT and attenuated fibrosis in preclinical models, nominating a therapeutically actionable target.
Impact: Identifies a previously unappreciated, targetable cellular program (MMT) driving pulmonary fibrosis and defines a concrete signaling axis amenable to intervention.
Clinical Implications: Although preclinical, this work prioritizes MERTK–SPP1–SRC–TKS5 signaling as a candidate therapeutic pathway for antifibrotic drug development and suggests macrophage-focused interventions could modify disease course.
Key Findings
- Confirmed macrophage-to-myofibroblast transdifferentiation (MMT) in human IPF lungs and a bleomycin mouse model.
- Defined a GAS6–MERTK-triggered cascade via SPP1, SRC, and TKS5 that drives MMT.
- Macrophage-specific MERTK knockout or AAV-mediated TKS5 knockdown suppressed MMT and significantly attenuated pulmonary fibrosis by microCT, lung function, and histology.
Methodological Strengths
- Use of human IPF samples plus complementary in vivo murine models.
- Causal pathway interrogation with genetic knockout and AAV-mediated knockdown demonstrating mechanistic necessity.
Limitations
- Preclinical nature limits immediate translatability to patients.
- Potential off-target effects of pathway perturbations were not fully delineated.
Future Directions: Evaluate pharmacologic inhibitors or biologics targeting the MERTK–SPP1–SRC–TKS5 axis, define biomarkers of MMT activity in patients, and test efficacy in diverse fibrosis models and early-phase clinical trials.
In recent years, macrophage-to-myofibroblast transdifferentiation (MMT) has been found in fibrosis-related diseases. We confirmed the presence of MMT in human idiopathic pulmonary fibrosis (IPF) lungs and bleomycin-induced murine model using immunological and molecular methods. Mechanistically, ligand (GAS6)-mediated activation of MERTK on macrophages initiates a sequential signaling cascade involving SPP1, SRC, and TKS5, which collectively drives the transdifferentiation program. Conversely, knockout of MERTK specifically in macrophages or adeno-associated virus (AAV)-mediated knockdown of TKS5 effectively disrupted this MERTK-SPP1-SRC-TKS5 axis, potently suppressing MMT in vitro and in vivo. These interventions significantly attenuated the progression of pulmonary fibrosis, as evidenced by comprehensive assessments including microCT, pulmonary function test, and histopathological analysis. Our findings establish MMT as a key pathogenic mechanism and identify the MERTK-initiated signaling axis as a novel therapeutic target.
2. Genetic variability of SARS-CoV-2 in wastewater and associations with community transmission.
Analyzing 12,290 wastewater SARS-CoV-2 sequences, the study shows that genetic diversity measures correlate strongly with community COVID-19 incidence and outperform viral concentration as transmission indicators. Multiple diversity metrics converged, indicating robustness and expanding wastewater data utility for public health surveillance.
Impact: Establishes a practical, more reliable genomic metric for real-time outbreak monitoring that can enhance precision public health and early warning systems.
Clinical Implications: While not a bedside tool, adopting diversity-based wastewater metrics can improve regional surge detection, guide resource allocation, and complement case-based surveillance during respiratory virus seasons.
Key Findings
- Across 12,290 wastewater SARS-CoV-2 sequences, weekly genetic diversity correlated with weekly new COVID-19 infections.
- Genetic diversity outperformed viral concentration as a transmission indicator due to reduced sensitivity to wastewater noise.
- Multiple diversity measures yielded concordant results, supporting robustness and generalizability.
Methodological Strengths
- Large-scale dataset with 12,290 sequences enabling robust ecological inference.
- Convergent validation across multiple diversity metrics to mitigate measurement bias.
Limitations
- Ecological correlation cannot prove causation or precisely attribute sources.
- Generalizability may vary with sewer systems, sampling strategies, and sequencing platforms.
Future Directions: Prospective integration of diversity metrics into public dashboards, benchmarking against clinical case and hospitalization data, and extending to other respiratory pathogens.
Sequencing genetic material from community wastewater facilitates the study of virus diversity. Diversity can be estimated using the variation in nucleotides and number of variants identified, increasing the information obtained from one wastewater sample. Using 12,290 wastewater sequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we found that virus diversity is a strong indicator of disease transmission, with a significant correlation between average weekly diversity and average weekly new COVID-19 infections. Although the concentration of viruses is the common measure of disease transmission from wastewater, we found that diversity is a better indicator, as it is unhampered by the noise inherent in the wastewater. We show that multiple measures of diversity yield similar results, which suggests that genetic diversity could be useful for increasing the utility of wastewater data.
3. Nivolumab plus chemoradiotherapy followed by nivolumab with or without ipilimumab for untreated locally advanced stage III NSCLC: a randomized phase 3 trial.
In unresectable stage III NSCLC, adding nivolumab±ipilimumab to CCRT did not improve PFS or OS over CCRT followed by durvalumab, and pneumonitis was more frequent with nivolumab-containing regimens. The data support maintaining durvalumab consolidation as standard of care and caution against empiric dual checkpoint maintenance after CCRT.
Impact: High-quality phase 3 evidence directly informs practice by showing no benefit and increased toxicity with dual checkpoint blockade after CCRT versus durvalumab consolidation.
Clinical Implications: Durvalumab consolidation should remain standard after CCRT in unresectable stage III NSCLC. Avoid routine use of nivolumab±ipilimumab in this setting outside trials; monitor vigilantly for radiation-related pneumonitis when combining immunotherapy with CCRT.
Key Findings
- No PFS improvement with nivolumab+ipilimumab versus durvalumab (HR 0.95; P=0.65).
- No OS benefit with nivolumab+ipilimumab versus durvalumab (HR 1.12).
- Nivolumab alone did not improve PFS or OS versus durvalumab (PFS HR 0.84; OS HR 0.97).
- Higher pneumonitis rates occurred with nivolumab-containing arms compared to durvalumab.
Methodological Strengths
- Randomized, multi-arm phase 3 design with a contemporary standard-of-care comparator.
- Adequate median follow-up (30.5 months) enabling robust PFS/OS assessment.
Limitations
- Biomarker-defined subgroup analyses are not detailed in the abstract, limiting precision-medicine insights.
- Increased pneumonitis may reflect complex interactions with radiotherapy; regimen-specific RT details are not provided in the abstract.
Future Directions: Identify biomarkers and new strategies (e.g., novel agents, optimized sequencing) to improve outcomes post-CCRT while mitigating pneumonitis risk.
Over 50% of persons with unresectable stage III non-small cell lung cancer (NSCLC) treated with standard-of-care concurrent chemoradiotherapy (CCRT) and durvalumab consolidation progress or die within 18 months. Here adults with untreated, unresectable stage III NSCLC were randomized to nivolumab plus CCRT followed by consolidation with nivolumab plus ipilimumab (arm A) or nivolumab alone (arm B) or CCRT followed by consolidation with durvalumab (arm C). The primary endpoint was progression-free survival (PFS) in arm A versus arm C and secondary endpoints included overall survival (OS), PFS in arm B versus arm C, response rates and safety. At a median follow-up of 30.5 months, there was no statistically significant difference in the primary endpoint of PFS in the nivolumab plus ipilimumab arm versus durvalumab arm (hazard ratio (HR): 0.95, 96% confidence interval (CI): 0.77-1.19; P = 0.65). Descriptive OS analysis showed no improvement (HR: 1.12, 95% CI: 0.87-1.43). Nivolumab alone did not improve PFS or OS versus durvalumab (PFS, HR: 0.84, 95% CI: 0.69-1.04; OS, HR: 0.97, 95% CI: 0.76-1.24). Nivolumab plus ipilimumab and nivolumab alone plus CCRT resulted in increased pneumonitis. These results emphasize the need for novel efficacious treatments for these individuals. (ClinicalTrials.gov: NCT04026412 ).