Outer membrane vesicle contributes to the Pseudomonas aeruginosa resistance to antimicrobial peptides in the acidic airway of bronchiectasis patients

Abstract

Pseudomonas aeruginosa is the predominant pathogen causing chronic infection in the airway of patients with bronchiectasis (BE), a chronic respiratory disease with high prevalence worldwide. Environmental factors are vital for bacterial successful colonization. Here, with sputa and bronchoalveolar lavage fluids, we determined that the concentration of airway antimicrobial peptide LL-37 and lactate was elevated in BE patients, especially in those infected with P. aeruginosa. The in vitro antibacterial assay revealed the bactericidal activity of LL-37 against the clinical P. aeruginosa isolates, which were dampened in the acidic condition. P. aeruginosa production of outer membrane vesicles (OMVs) enhanced in the lactate-adjusted acidic condition. Transcriptomic analysis suggested that OMVs induce the hyperproduction of the chemical compound 2-heptyl-4-quinolone (HHQ) in the bacterial population, which was verified by high-performance liquid chromatography. The positively charged HHQ interfered with the binding of LL-37 to bacterial cell membrane, potentiating the P. aeruginosa resistance to LL-37. To our knowledge, this is a new resistance mechanism of P. aeruginosa against antimicrobial peptides and may provide theoretical support for the development of new antibacterial therapies.

Keywords

2-heptyl-4-quinolone / antimicrobial peptides resistance / bronchiectasis / lactate / outer membrane vesicles / Pseudomonas aeruginosa

References

[1] Chalmers JD, Chang AB, Chotirmall SH, Dhar R, McShane PJ. Bronchiectasis. Nat Rev Dis Primers. 2018; 4(1): 45.

[2] Rossi E, La Rosa R, Bartell JA, et al. Pseudomonas aeruginosa adaptation and evolution in patients with cystic fibrosis. Nat Rev Microbiol. 2021; 19(5): 331-342.

[3] Flume PA, Chalmers JD, Olivier KN. Advances in bronchiectasis: endotyping, genetics, microbiome, and disease heterogeneity. Lancet. 2018; 392(10150): 880-890.

[4] Liu Y, Xie YZ, Shi YH, et al. Airway acidification impaired host defense against Pseudomonas aeruginosa infection by promoting type 1 interferon beta response. Emerg Microbes Infect. 2022; 11(1): 2132-2146.

[5] Jiang YY, Xiao W, Zhu MX, et al. The effect of human antibacterial peptide LL-37 in the pathogenesis of chronic obstructive pulmonary disease. Respir Med. 2012; 106(12): 1680-1689.

[6] Barlow PG, Beaumont PE, Cosseau C, et al. The human cathelicidin LL-37 preferentially promotes apoptosis of infected airway epithelium. Am J Respir Cell Mol Biol. 2010; 43(6): 692-702.

[7] Ridyard KE, Overhage J. The potential of human peptide LL-37 as an antimicrobial and anti-biofilm agent. Antibiotics. 2021; 10(6): 650.

[8] Zhou YQ, Shi Y, Yang L, et al. Genetically engineered distal airway stem cell transplantation protects mice from pulmonary infection. EMBO Mol Med. 2020; 12(1): e10233.

[9] Bergsson G, Reeves EP, McNally P, et al. LL-37 complexation with glycosaminoglycans in cystic fibrosis lungs inhibits antimicrobial activity, which can be restored by hypertonic saline. J Immunol. 2009; 183(1): 543-551.

[10] Bucki R, Byfield FJ, Janmey PA. Release of the antimicrobial peptide LL-37 from DNA/F-actin bundles in cystic fibrosis sputum. Eur Respir J. 2007; 29(4): 624-632.

[11] McQuade R, Roxas B, Viswanathan VK, Vedantam G. Clostridium difficile clinical isolates exhibit variable susceptibility and proteome alterations upon exposure to mammalian cationic antimicrobial peptides. Anaerobe. 2012; 18(6): 614-620.

[12] Thwaite JE, Hibbs S, Titball RW, Atkins TP. Proteolytic degradation of human antimicrobial peptide LL-37 by Bacillus anthracis may contribute to virulence. Antimicrob Agents Chemother. 2006; 50(7): 2316-2322.

[13] Martynowycz MW, Rice A, Andreev K, et al. Salmonella membrane structural remodeling increases resistance to antimicrobial peptide LL-37. ACS Infect Dis. 2019; 5(7): 1214-1222.

[14] Uhlmann J, Rohde M, Siemens N, et al. LL-37 triggers formation of Streptococcus pyogenes extracellular vesicle-like structures with immune stimulatory properties. J Innate Immun. 2016; 8(3): 243-257.

[15] Sibila O, Perea L, Canto E, et al. Antimicrobial peptides, disease severity and exacerbations in bronchiectasis. Thorax. 2019; 74(9): 835-842.

[16] Giam YH, Richardson H, Smith A, et al. Immunometabolic markers and the sputum microbiome in bronchiectasis. Eur Respir J. 2021; 58(suppl 65):OA1314.

[17] Worlitzsch D, Meyer KC, Doring G. Lactate levels in airways of patients with cystic fibrosis and idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. 2013; 188(1): 111.

[18] Kottmann RM, Kulkarni AA, Smolnycki KA, et al. Lactic acid is elevated in idiopathic pulmonary fibrosis and induces myofibroblast differentiation via pH-dependent activation of transforming growth factor-beta. Am J Respir Crit Care Med. 2012; 186(8): 740-751.

[19] Snoussi M, Talledo JP, Del Rosario NA, et al. Heterogeneous absorption of antimicrobial peptide LL37 in Escherichia coli cells enhances population survivability. Elife. 2018; 7: e38174.

[20] Soheili V, Tajani AS, Ghodsi R, Bazzaz BSF. Anti-PqsR compounds as next-generation antibacterial agents against Pseudomonas aeruginosa: a review. Eur J Med Chem. 2019; 172: 26-35.

[21] Zhou Z, Ma S. Recent advances in the discovery of PqsD inhibitors as antimicrobial agents. ChemMedChem. 2017; 12(6): 420-425.

[22] Tate S, MacGregor G, Davis M, Innes JA, Greening AP. Airways in cystic fibrosis are acidified: detection by exhaled breath condensate. Thorax. 2002; 57(11): 926-929.

[23] Papaioannou AI, Loukides S, Minas M, et al. Exhaled breath condensate pH as a biomarker of COPD severity in ex-smokers. Respir Res. 2011; 12(1): 67.

[24] Ye C, Li W, Yang Y, et al. Inappropriate use of antibiotics exacerbates inflammation through OMV-induced pyroptosis in MDR Klebsiella pneumoniae infection. Cell Rep. 2021; 36(12): 109750.

[25] Zhang X, Qian C, Tang M, et al. Carbapenemase-loaded outer membrane vesicles protect Pseudomonas aeruginosa by degrading imipenem and promoting mutation of antimicrobial resistance gene. Drug Resist Updat. 2023; 68: 100952.

[26] Dhital S, Deo P, Bharathwaj M, et al. Neisseria gonorrhoeae-derived outer membrane vesicles package beta-lactamases to promote antibiotic resistance. Microlife. 2022; 3: uqac013.

[27] Tang B, Yang A, Liu P, et al. Outer membrane vesicles transmitting bla(NDM-1) mediate the emergence of carbapenem-resistant hypervirulent Klebsiella pneumoniae. Antimicrob Agents Chemother. 2023; 67(5): e0144422.

[28] Johansson J, Gudmundsson GH, Rottenberg ME, Berndt KD, Agerberth B. Conformation-dependent antibacterial activity of the naturally occurring human peptide LL-37. J Biol Chem. 1998; 273(6): 3718-3724.

[29] Chen X, Deng S, Wang W, et al. Human antimicrobial peptide LL-37 contributes to Alzheimer’s disease progression. Mol Psychiatry. 2022; 27(11): 4790-4799.

[30] Yang N, Gong F, Liu B, et al. Magnesium galvanic cells produce hydrogen and modulate the tumor microenvironment to inhibit cancer growth. Nat Commun. 2022; 13(1): 2336.

[31] Mi P, Kokuryo D, Cabral H, et al. A pH-activatable nanoparticle with signal-amplification capabilities for non-invasive imaging of tumour malignancy. Nat Nanotechnol. 2016; 11(8): 724-730.

[32] Hill AT, Sullivan AL, Chalmers JD, et al. British Thoracic Society guideline for bronchiectasis in adults. Thorax. 2019; 74(Suppl 1): 1-69.

[33] Hu X, Wu M, Ma T, et al. Single-cell transcriptomics reveals distinct cell response between acute and chronic pulmonary infection of Pseudomonas aeruginosa. MedComm. 2022; 3(4): e193.

[34] Adhikari S, Baral P. Protocol for neonatal respiratory syncytial virus infection in mice and immune analysis of infected lungs and bronchoalveolar lavage fluid. STAR Protoc. 2023; 4(3): 102434.

RIGHTS & PERMISSIONS

2025 The Author(s). MedComm published by Sichuan International Medical Exchange & Promotion Association (SCIMEA) and John Wiley & Sons Australia, Ltd.