Pseudomonas invasion of type I pneumocytes is dependent on the expression and phosphorylation of caveolin-2.
Pseudomonas aeruginosa is a major cause of pneumonia in patients with cystic fibrosis and other immuncompromising conditions. Here we showed that P. aeruginosa invades type I pneumocytes via a lipid raft-mediated mechanism. P. aeruginosa invasion of rat primary type I-like pneumocytes as well as a murine lung epithelial cell line 12 (MLE-12) is inhibited by drugs that remove membrane cholesterol and disrupt lipid rafts. Confocal microscopy demonstrated co-localization of intracellular P. aeruginosa with lipid raft components including caveolin-1 and -2. We generated caveolin-1 and -2 knockdowns in MLE-12 cells by using RNA interference techniques. Decreased expression of caveolin-2 significantly impaired the ability of P. aeruginosa to invade MLE-12 cells. In addition, the lipid raft-dependent tyrosine phosphorylation of caveolin-2 appeared to be a critical regulator of P. aeruginosa invasion.
Zaas
David W
DW
Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine Duke University Medical Center, Durham, North Carolina 27710, USA
Duncan
Mathew J
MJ
Li
Guojie
G
Wright
Jo Rae
JR
Abraham
Soman N
SN
D000818:Animals; D051242:Caveolin 1; D051243:Caveolin 2; D022461:Caveolins / Q000378:metabolism*; D002448:Cell Adhesion; D002460:Cell Line; D002478:Cells, Cultured; D004396:Coloring Agents / Q000494:pharmacology; D003550:Cystic Fibrosis / Q000378:metabolism; D004847:Epithelial Cells / Q000382:microbiology; D047468:Immunoprecipitation; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008168:Lung / Q000166:cytology / Q000382:microbiology* / Q000473:pathology; D021962:Membrane Microdomains / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D010766:Phosphorylation; D011549:Pseudomonas / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000378:metabolism; D034622:RNA Interference; D051381:Rats; D017207:Rats, Sprague-Dawley; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D014443:Tyrosine / Q000737:chemistry
C495541:Cav1 protein, mouse; C495537:Cav1 protein, rat; D051242:Caveolin 1; D051243:Caveolin 2; D022461:Caveolins; D004396:Coloring Agents; D008055:Lipids; D013778:Tetrazolium Salts; D013844:Thiazoles; D014443:Tyrosine; C022616:thiazolyl blue