FIG. 4.

Translocation and phosphorylation of the CagA protein in AGS cells infected with cagPAI⁺ and partial cagPAI-carrying H. pylori isolates. Western blot analysis of CagA translocation into AGS cells was performed with a polyclonal anti-CagA antibody, and detection of CagA phosphorylation was done with an anti-phosphotyrosine monoclonal antibody. Isolate 365a3 is a partial cagPAI-carrying (cagA negative) isolate; all other isolates (from 646a5 to 249c5) are cagPAI⁺. Isolate 236c6 was negative for Western blotting with anti-CagA but positive with anti-phospho-Tyr. Isolates with variability in biological activity levels are marked with circles or squares.