Toll-like receptors recognize distinct proteinase-resistant glycoconjugates in Campylobacter jejuni and Escherichia coli

•C. jejuni possesses multiple proteinase-resistant components (CjκB).•CjκB component activates transcriptional factor NF-κB in human monocytes.•CjκB-induced IL-6 production is reduced in MyD88−/− macrophages.•Loss of inflammatory capacity of CjκB in the absence of TLR2 and TLR4.•Gain of inflammatory capacity of CjκB in the presence of TLR2 and TLR4. Campylobacter jejuni causes gastroenteritis and autoimmune neuropathy Guillain–Barré syndrome. The mechanism by which C. jejuni infection results in such the hyperimmunity is not completely understood. Host immunity plays an important role in the disease pathogenesis; however, little is known how immune system recognizes this human pathogen. In this study, we report that Toll-like receptors recognize distinct proteinase K-resistant glycoconjugates in C. jejuni and Escherichia coli. Lipopolysaccharide is solely proteinase-resistant glycoconjugate in E. coli. In contrast, C. jejuni possesses at least five different components that are resistant to proteinase digestion and are capable of inducing NF-κB activation through TLR2 and TLR4. Possession of multiple activators of Toll-like receptors may be the unique strategy of C. jejuni to trigger hyperimmunity.