Infection studies and in vitro cleavage assays showed that C. jejuni’s HtrA triggers shedding of the extracellular E-cadherin NTF domain (90 kDa) of non-polarised INT-407 and polarized MKN-28 epithelial cells, but fibronectin was not cleaved as seen for H. pylori’s HtrA. This evidence concerns the gene HTRA1 and infection.