Invasion-related antigens of Campylobacter jejuni.

A HEp-2 cell culture model was used to investigate the antigens required for epithelial cell penetration by Campylobacter jejuni. Penetration of HEp-2 epithelial cells by C. jejuni was significantly inhibited (P less than .05) with C. jejuni lysate and a monoclonal antibody (MAb 1B4) in competitive inhibition assays. Immunogold electron microscopy revealed that MAb 1B4 bound to the flagella and cell surface of low-passage (invasive) C. jejuni M 96, whereas only the flagella of high-passage (noninvasive) C. jejuni M 96 were labeled. Western blot analysis revealed that MAb 1B4 identified an epitope on antigens of 64-44 kDa in lysates prepared from invasive and noninvasive isolates. In addition, antigens of 42-38 kDa were recognized in lysates prepared from only invasive C. jejuni strains. Proteinase K and sodium meta-periodate chemical treatment of C. jejuni M 96 lysate changed the mobility of antigens recognized by MAb 1B4. The increase in mobility demonstrated a decrease in size of molecules and suggested that antigens required for HEp-2 cell invasion by Campylobacter species may be glycoprotein in nature.