Lipooligosaccharide Ligands from Respiratory Bacterial Pathogens Enhance Cellular Uptake of Nanoparticles

Abstract

Several bacterial pathogens contain membrane ligands that facilitate their binding and internalization into human tissues. In this study, lipooligosaccharides (LOS) from the respiratory pathogen non-typeable Haemophilus influenzae (NTHi) were isolated from the bacterial surface and evaluated as a nanoparticle coating material to facilitate uptake into the respiratory epithelium. NTHi clinical isolates were screened to select a strain with high binding potential due to their elevated phosphorylcholine content. The association of particles with human bronchial epithelial cells was investigated as a function of particle surface chemistry and incubation time, and the uptake mechanism was evaluated via chemical inhibitor and receptor activation studies. A more than two-fold enhancement in particle uptake was achieved by coating the particles with LOS compared to uncoated or gelatin-coated particles, which was further increased by activating the platelet-activating factor receptor (PAFR). These findings demonstrate that bacterial-derived LOS ligands can enhance the targeting and binding of nanoparticles to lung epithelial cells.

Keywords

• endocytosis
• platelet-activating factor receptor
• lipooligosaccharides
• non-typeable haemophilus influenzae
• nanoparticle
• bronchial epithelial cells