Cellular Tight Junctions Prevent Effective Campylobacter jejuni Invasion and Inflammatory Barrier Disruption Promoting Bacterial Invasion from Lateral Membrane in Polarized Intestinal Epithelial Cells

Campylobacter jejuni invasion is closely related to C. jejuni pathogenicity. The intestinal epithelium contains polarized epithelial cells that form tight junctions (TJs) to provide a physical barrier against bacterial invasion. Previous studies indicated that C. jejuni invasion of non-polarized cells involves several cellular features, including lipid rafts. However, the dynamics of C. jejuni invasion of polarized epithelial cells are not fully understood. Here we investigated the interaction between C. jejuni invasion and TJ formation to characterize the mechanism of C. jejuni invasion in polarized epithelial cells. In contrast to non-polarized epithelial cells, C. jejuni invasion was not affected by depletion of lipid rafts in polarized epithelial cells. However, depletion of lipid rafts significantly decreased C. jejuni invasion in TJ disrupted cells or basolateral infection and repair of cellular TJs suppressed lipid raft-mediated C. jejuni invasion in polarized epithelial cells. In addition, pro-inflammatory cytokine, TNF-a treatment that induce TJ disruption promote C. jejuni invasion and lipid rafts depletion significantly reduced C. jejuni invasion in TNF-a treated cells. These data demonstrated that TJs prevent C. jejuni invasion from the lateral side of epithelial cells, where they play a main part in bacterial invasion and suggest that C. jejuni invasion could be increased in inflammatory condition. Therefore, maintenance of TJs integrity should be considered important in the development of novel therapies for C. jejuni infection.

内容要旨・審査要旨・論文本文の公開
本論文は, 著者Sho Hatayamaの学位論文として提出され, 学位審査・授与の対象となっている。

© 2018 Hatayama, Shimohata, Amano, Kido, Nguyen, Sato, Kanda, Tentaku, Fukushima, Nakahashi, Uebanso, Mawatari and Takahashi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) ( https://creativecommons.org/licenses/by/4.0/ ). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.