The Inhibitory Effect of C-Reactive Protein on Bacterial Phosphorylcholine Platelet-Activating Factor Receptor–Mediated Adherence Is Blocked by Surfactant

• Published in: The Journal of infectious diseases Vol. 186; no. 3; pp. 361 - 371
• Main Authors: Gould, Jane M., Weiser, Jeffrey N.
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 01-08-2002; University of Chicago Press; Oxford University Press
• Subjects: Bacteria; Bacterial Adhesion - drug effects; Bacterial Adhesion - physiology; Bacteriology; Biological and medical sciences; Blotting, Western; C-Reactive Protein - pharmacology; Epithelial cells; Fundamental and applied biological sciences. Psychology; Genetic variation; Haemophilus influenzae; Haemophilus influenzae - physiology; Humans; Immunohistochemistry; Inoculum; Lungs; Major Articles; Microbiology; Nasopharynx - pathology; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Phosphorylcholine - antagonists & inhibitors; Platelet Membrane Glycoproteins - antagonists & inhibitors; Platelet Membrane Glycoproteins - physiology; Pulmonary alveoli; Pulmonary Surfactants - physiology; Receptors; Receptors, Cell Surface; Receptors, G-Protein-Coupled; Streptococcus pneumoniae; Streptococcus pneumoniae - physiology; Surfactants; Tumor Cells, Cultured; Pasteurellaceae; Streptococcaceae; Bacteria; Micrococcales; Host agent relation; Surfactant; C reactive protein; Adhesion; Haemophilus influenzae; Platelet-activating factor receptor; Streptococcus pneumoniae
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1086/341658

Numerous major bacterial pathogens in the human respiratory tract, including Streptococcus pneumoniae and Haemophilus influenzae express cell-surface phosphorylcholine (ChoP), a ligand for the receptor for platelet-activating factor (rPAF). ChoP is also bound by C-reactive protein (CRP), which, in the presence of complement, may be bactericidal. This study found that CRP can block the attachment of bacteria expressing cell-surface ChoP to host cells. Concentrations of CRP equivalent to those on the mucosal surface of the human airway blocked most adherence of both S. pneumoniae and H. influenzae to human pharyngeal epithelial cells. ChoP-mediated adherence was also reduced in the presence of an rPAF antagonist. The antiadhesive effects of the rPAF antagonist and CRP were not additive, suggesting that CRP activity is specific to the area of adherence mediated by the receptor. The binding of CRP to ChoP and the effect of CRP on adherence were inhibited by human surfactant (primarily ChoP). The antiadhesive effect of CRP may be diminished in the terminal airway, where surfactant is abundant