TLR5 and infection: In mice, however, the recognition of flagellin by TLR5 is required for airway epithelial cells to sense P. aeruginosa and to clear the infection [9,48,49,50,51], which may explain the prominent role of flagellin in the effect of bronchial epithelial Dnmt3b in regulating the mucosal immune response during Pseudomonas infection in vivo.