Pseudomonas-dominant microbiome elicits sustained IL-1β upregulation in alveolar macrophages from lung transplant recipients

Noel Britton, Andres Villabona-Rueda, Samantha A. Whiteside, Joby Mathew, Matthew Kelley, Sean Agbor-Enoh, John F. McDyer, Jason D. Christie, Ronald G. Collman, Andrea L. Cox, Pali Shah, Franco D'Alessio

Research output: Contribution to journalArticlepeer-review


Background: Isolation of Pseudomonas aeruginosa (PsA) is associated with increased BAL (bronchoalveolar lavage) inflammation and lung allograft injury in lung transplant recipients (LTR). However, the effect of PsA on macrophage responses in this population is incompletely understood. We examined human alveolar macrophage (AMΦ) responses to PsA and Pseudomonas dominant microbiome in healthy LTR. Methods: We stimulated THP-1 derived macrophages (THP-1MΦ) and human AMΦ from LTR with different bacteria and LTR BAL derived microbiome characterized as Pseudomonas-dominant. Macrophage responses were assessed by high dimensional flow cytometry, including their intracellular production of cytokines (TNF-α, IL-6, IL-8, IL-1β, IL-10, IL-1RA, and TGF-β). Pharmacological inhibitors were utilized to evaluate the role of the inflammasome in PsA-macrophage interaction. Results: We observed upregulation of pro-inflammatory cytokines (TNF-α, IL-6, IL-8, IL-1β) following stimulation by PsA compared to other bacteria (Staphylococcus aureus (S.Aur), Prevotella melaninogenica, Streptococcus pneumoniae) in both THP-1MΦ and LTR AMΦ, predominated by IL-1β. IL-1β production from THP-1MΦ was sustained after PsA stimulation for up to 96 hours and 48 hours in LTR AMΦ. Treatment with the inflammasome inhibitor BAY11-7082 abrogated THP-1MΦ IL-1β production after PsA exposure. BAL Pseudomonas-dominant microbiota elicited an increased IL-1β, similar to PsA, an effect abrogated by the addition of antibiotics. Conclusion: PsA and PsA-dominant lung microbiota induce sustained IL-1β production in LTR AMΦ. Pharmacological targeting of the inflammasome reduces PsA-macrophage-IL-1β responses, underscoring their use in lung transplant recipients.

Original languageEnglish (US)
Pages (from-to)1166-1174
Number of pages9
JournalJournal of Heart and Lung Transplantation
Issue number9
StatePublished - Sep 2023


  • Pseudomonas aeruginosa
  • lung allograft injury
  • lung transplant
  • macrophage
  • microbiome

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Transplantation
  • Pulmonary and Respiratory Medicine
  • Surgery


Dive into the research topics of 'Pseudomonas-dominant microbiome elicits sustained IL-1β upregulation in alveolar macrophages from lung transplant recipients'. Together they form a unique fingerprint.

Cite this