title: Interplay of flagellar motility and mucin degradation stimulates the association of Pseudomonas aeruginosa with human epithelial colorectal adenocarcinoma (Caco-2) cells.
abstract: Pseudomonas aeruginosa can penetrate the extracellular mucin barrier formed by the intestinal epithelial cell layer and establish gut-derived sepsis in immunocompromised patients. We found that two efficient mechanisms, flagellar motility and mucin degradation, are needed for penetration of P. aeruginosa through the mucin barrier. Deletion of the flagellar motility-related gene, the filament protein gene fliC, the cap protein gene fliD, and the motor complex protein genes motABCD from P. aeruginosa PAO1 decreased association of P. aeruginosa with the apical surface of human epithelial colorectal adenocarcinoma (Caco-2) cells. A penetration experiment using an artificial mucin layer suggested that the decreased penetration is caused by attenuation of mucin penetration ability. Additionally, the presence of P. aeruginosa decreased the total mucin, including the secreted mucin protein MUC2, on the surface of the Caco-2 cell monolayer, regardless of flagellar motility. Construction of the PAO1 mutant series knocked out 12 putative serine protease genes and identified the mucD gene, which participated in degradation of total mucin, including MUC2. Furthermore, decreased association with the surface of the Caco-2 cell monolayer was observed in the mucD mutant, and the decrease was synergistically amplified by double knockout with fliC. We conclude that P. aeruginosa can penetrate the mucin layer using flagellar motility and mucin degradation, which is dependent on the MucD protease or the mucD gene-related protease.
authors: Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Yamashina, Kyoto, Japan.
authors: Naoki
authors: N
authors: Hayashi
authors: Mariko
authors: M
authors: Matsukawa
authors: Yuta
authors: Y
authors: Horinishi
authors: Katsuya
authors: K
authors: Nakai
authors: Ai
authors: A
authors: Shoji
authors: Yoshiki
authors: Y
authors: Yoneko
authors: Naomi
authors: N
authors: Yoshida
authors: Shu
authors: S
authors: Minagawa
authors: Naomasa
authors: N
authors: Gotoh
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D018938:Caco-2 Cells; D002465:Cell Movement / Q000502:physiology*; D005407:Flagella / Q000502:physiology*; D017353:Gene Deletion; D054884:Host-Pathogen Interactions; D006801:Humans; D009077:Mucins / Q000378:metabolism*; D009154:Mutation; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D012697:Serine Endopeptidases / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D009077:Mucins; C097649:MucD protein, Pseudomonas aeruginosa; D012697:Serine Endopeptidases