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PLUNC: a multifunctional surfactant of the airways
Journal article

PLUNC: a multifunctional surfactant of the airways

Jennifer Bartlett, Lokesh Gakhar, Jon Penterman, Pradeep Singh, Rama K Mallampalli, Edith Porter and Paul B McCray
Biochemical Society transactions, Vol.39(4), pp.1012-1016
08/2011
DOI: 10.1042/BST0391012
PMCID: PMC3572202
PMID: 21787339
url
https://www.ncbi.nlm.nih.gov/pmc/articles/3572202View
Open Access

Abstract

PLUNC (palate, lung and nasal epithelium clone) protein is an abundant secretory product of epithelia throughout the mammalian conducting airways. Despite its homology with the innate immune defence molecules BPI (bactericidal/permeability-increasing protein) and LBP (lipopolysaccharide-binding protein), it has been difficult to define the functions of PLUNC. Based on its marked hydrophobicity and expression pattern, we hypothesized that PLUNC is an airway surfactant. We found that purified recombinant human PLUNC exhibited potent surfactant activity by several different measures, and experiments with airway epithelial cell lines and primary cultures indicate that native PLUNC makes a significant contribution to the overall surface tension in airway epithelial secretions. Interestingly, we also found that physiologically relevant concentrations of PLUNC-inhibited Pseudomonas aeruginosa biofilm formation in vitro without acting directly as a bactericide. This finding suggests that PLUNC protein may inhibit biofilm formation by airway pathogens, perhaps through its dispersant properties. Our data, along with reports from other groups on activity against some airway pathogens, expand on an emerging picture of PLUNC as a multifunctional protein, which plays a novel role in airway defences at the air/liquid interface.
innate immunity lung and nasal epithelium clone (PLUNC) conducting airway surfactant biofilm palate

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