1. Volume 127, Issue 2, Pages 514-523 (August 2004)
Determinants and consequences of different levels of CagA phosphorylation for clinical isolates of Helicobacter pylori 
Richard H. Argent, Mark Kidd, Robert J. Owen, Rachael J. Thomas, Marie C. Limb, John C. Atherton 
Gastroenterology 
Volume 127, Issue 2, Pages (August 2004)
DOI: /j.gastro

2. Figure 1
CagA expression, translocation, and phosphorylation and IL-8 secretion by H. pylori strains. (A) Western blots showing CagA expression by H. pylori strains and translocation of CagA into and phosphorylation within AGS cells following coculture for 6 hours. Samples were probed with anti-CagA monoclonal antibodies (H. pylori alone and after AGS cell coculture) or anti-phosphotyrosine monoclonal antibodies (AGS cell coculture). This shows that of the H. pylori strains shown here, strains GC90, HP186, HP501, HP465, HP467, and HP471 do not express CagA. (B) IL-8 secretion from AGS cells following coculture with H. pylori strains for 6 hours, expressed as a percentage of the reference strain ATCC The strains have been separated into 2 populations based on their ability to induce high levels of IL-8 (P < , 2-tailed Student t test).
Gastroenterology  , DOI: ( /j.gastro )

3. Figure 2
The degree of CagA phosphorylation increases with increasing numbers of EPIYA motifs. (A) AGS cells were cocultured with H. pylori strains for 6 hours before the cells were lysed and the samples subjected to sodium dodecyl sulfate/polyacrylamide gel electrophoresis and Western blotting with anti-phosphotyrosine monoclonal antibodies (upper panel). The blots were then stripped and reprobed with anti-CagA polyclonal antibodies (lower panel). The densities of the CagA and phosphorylated CagA bands were determined and plotted as a ratio. This figure shows results from 5 representative strains, each with different numbers of CagA EPIYA motifs. (B) An AGS cell-free extract (cfe) was incubated with H. pylori water extracts for 2 minutes at 37°C before the samples were analyzed as described in A. This figure shows 7 representative strains with different numbers of CagA EPIYA motifs. These experiments were repeated 3 times each, with representative blots shown.
Gastroenterology  , DOI: ( /j.gastro )

4. Figure 3
The level of IL-8 secretion is independent of the degree of CagA phosphorylation. H. pylori strains expressing CagA with 3–6 EPIYA motifs, or a strain lacking the PaI, were cocultured with AGS cells for 6 hours in quadruplicate, along with control cells not cultured with H. pylori, before the concentration of IL-8 secreted from the cells was determined by ELISA.
Gastroenterology  , DOI: ( /j.gastro )

5. Figure 4
CagA possessing greater numbers of TPMs increases the number of hummingbird AGS cells and increases the length of cellular protrusions. H. pylori strains expressing CagA with greater numbers of variable region TPMs increase (A) the number of AGS cells displaying the hummingbird phenotype, (B) the mean length of hummingbird protrusion, and (C) the number of hummingbird cells >6 μm long. AGS cells were cocultured with 3 representative strains expressing CagA with 3 EPIYA motifs, 2 representative strains expressing CagA with 4 EPIYA motifs, and one strain each expressing CagA with 5 or 6 EPIYA motifs that were grouped together for statistical analysis (A and B). Values presented are means ± SE. ∗P < 0.001, ∗∗P < , ∗∗∗P < (D) Hummingbird cell formation by representative H. pylori strains expressing CagA with 3–6 TPMs or a strain lacking the cag PaI.
Gastroenterology  , DOI: ( /j.gastro )