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Updated: May 12, 2026
Bronchoalveolar Lavage of Murine Lungs to Analyze Inflammatory Cell Infiltration
Published on: May 4, 2017
Proteomic analysis of human bronchoalveolar lavage fluid after subsgemental exposure
Matthew W Foster1, J Will Thompson, Loretta G Que
1Division of Pulmonary, Allergy and Critical Care Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA. mwfoster@duke.edu
Insights
Bronchoalveolar lavage fluid proteomics identified peptidoglycan response protein 1 as a novel marker for neutrophilic inflammation. This study validates a workflow for analyzing airway fluid proteomes and highlights variability in lung subsegments.
Area of Science:
- Pulmonary Medicine
- Proteomics
- Immunology
Background:
- Bronchoalveolar lavage (BAL) fluid analysis offers a minimally invasive method to study lung biology.
- Understanding airway (patho)physiology requires advanced analytical techniques.
Purpose of the Study:
- To quantify the bronchoalveolar lavage fluid (BALF) proteome using immunodepletion and gel- and label-free LC-MS/MS.
- To identify novel protein biomarkers of lung inflammation and response.
- To explore intralobar variability in BALF proteomic profiles.
Main Methods:
- Immunodepletion coupled with gel- and label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS).
- Analysis of BALF samples from human subjects after instillation of saline, lipopolysaccharide (LPS), or house dust mite antigen.
- Quantification of over 200 unique proteins across nine samples from distinct lung subsegments.
Main Results:
- Neutrophil granule-derived and acute phase proteins were significantly enriched in LPS-exposed lung lobes.
- Peptidoglycan response protein 1 was validated as a novel marker of neutrophilic inflammation.
- BALF proteome analysis revealed response factors distinct from prior transcriptomic data.
- Enrichment of tracheal-expressed proteins in right lower lung lobes indicated constitutive intralobar variability.
Conclusions:
- A robust workflow for BALF proteomics was validated.
- Proteomic and genomic techniques are complementary for investigating airway physiology and pathology.
- Sampling multiple lung subsegments aids in identifying baseline protein signatures and understanding intralobar variability.
Abstract:
The analysis of airway fluid, as sampled by bronchoalveolar lavage (BAL), provides a minimally invasive route to interrogate lung biology in health and disease. Here, we used immunodepletion, coupled with gel- and label-free LC-MS/MS, for quantitation of the BAL fluid (BALF) proteome in samples recovered from human subjects following bronchoscopic instillation of saline, lipopolysaccharide (LPS) or house dust mite antigen into three distinct lung subsegments. Among more than 200 unique proteins quantified across nine samples, neutrophil granule-derived and acute phase proteins were most highly enriched in the LPS-exposed lobes. Of these, peptidoglycan response protein 1 was validated and confirmed as a novel marker of neutrophilic inflammation. Compared to a prior transcriptomic analysis of airway cells in this same cohort, the BALF proteome revealed a novel set of response factors. Independent of exposure, the enrichment of tracheal-expressed proteins in right lower lung lobes suggests a potential for constitutive intralobar variability in the BALF proteome; sampling of multiple lung subsegments also appears to aid in the identification of protein signatures that differentiate individuals at baseline. Collectively, this proof-of-concept study validates a robust workflow for BALF proteomics and demonstrates the complementary nature of proteomic and genomic techniques for investigating airway (patho)physiology.
