Role of alginate O acetylation in resistance of mucoid Pseudomonas aeruginosa to opsonic phagocytosis.
Establishment and maintenance of chronic lung infections with mucoid Pseudomonas aeruginosa in patients with cystic fibrosis (CF) require that the bacteria avoid host defenses. Elaboration of the extracellular, O-acetylated mucoid exopolysaccharide, or alginate, is a major microbial factor in resistance to immune effectors. Here we show that O acetylation of alginate maximizes the resistance of mucoid P. aeruginosa to antibody-independent opsonic killing and is the molecular basis for the resistance of mucoid P. aeruginosa to normally nonopsonic but alginate-specific antibodies found in normal human sera and sera of infected CF patients. O acetylation of alginate appears to be critical for P. aeruginosa resistance to host immune effectors in CF patients.
Pier
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GB
Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115-5804, USA. gpier@channing.harvard.edu
Coleman
F
F
Grout
M
M
Franklin
M
M
Ohman
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DE
D000107:Acetylation; D000464:Alginates; D016667:Bacterial Capsules; D003167:Complement Activation; D003170:Complement Pathway, Alternative; D003550:Cystic Fibrosis / Q000150:complications; D006801:Humans; D008171:Lung Diseases / Q000150:complications / Q000209:etiology; D009895:Opsonin Proteins; D010587:Phagocytosis; D011552:Pseudomonas Infections / Q000150:complications / Q000209:etiology; D011550:Pseudomonas aeruginosa / Q000472:pathogenicity*
D000464:Alginates; D009895:Opsonin Proteins