Flagella are bacterial virulence factors allowing microorganisms to move over surfaces. Flagellin, the structural component of flagella, is
sensed by the host via Toll and NOD-like receptors and triggers pro-inflammatory responses. The use of Toll-like receptors agonists to modulate
innate immune responses has aroused great interest as an alternative to improve the treatment of diverse infectious diseases.Proteus mirabilisis
a Gram negative bacterium that causes urinary tract infections in humans. In the present work we used different approaches to study the ability of
P. mirabilisflagellin to induce an innate immune response. We demonstrated thatP. mirabilisflagellin has the ability to induce pro-inflammatory
chemokines expression in T24 bladder cultures cells and in the mouse bladder after instillation. It was evidenced also that flagellin from different
P. mirabilisstrains differed in their capacity to induce an innate immune response in the CacoCCL20-Luc system. Also, flagellin elicited
inflammation, with recruitment of leukocytes to the bladder epithelium. Flagellin instillation before an experimental P. mirabilisinfection
showed that the inflammatory response due to flagellin did not help to clear the infection but favored bacterial colonization. Thus, induction of
inflammatory response in the bladder did not contribute to P. mirabilisinfection neutralization.
2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.