Alloiococcus otitidis is a ligand for collectins and Toll-like receptor 2, and its phagocytosis is enhanced by collectins

来自 Wiley

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作者：

Masanori，Konishi，Chiaki，Nishitani，Hiroaki，Mitsuzawa，Takeyuki，Shimizu，Hitomi，Sano

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摘要：

Alloiococcus otitidis has been found to be associated with otitis media with effusion. In this study we investigated whether TLR2 and collectins, surfactant protein A (SP-A) and mannose-binding lectin (MBL), interacted with A. otitidis. Both SP-A and MBL bound to A. otitidis in a Ca2+-dependent manner. A. otitidis induced IL-8 secretion from U937 cells and NF-κB activation in TLR2-transfected HEK293 cells. However, the cells transfected with the mutant TLR2P681H did not respond to A. otitidis. In addition, A. otitidis co-sedimented a recombinant soluble form of the extracellular TLR2 domain, indicating direct binding of the bacterium to TLR2. SP-A and MBL augmented the phagocytosis of A. otitidis by J774A.1 cells. The collectin-stimulated phagocytosis of A. otitidis was significantly attenuated when fucoidan and polyinosinic acid were co-incubated. Immunoblotting analysis revealed that MBL was present in the middle ear effusion from patients with otitis medi

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关键词：

Alloiococcus otitidis Collectin Mannose-binding lectin Surfactant protein A TLR2