Analysis of the hummingbird phenotype and IL-8 induction after co-culture of human AGS cells with isogenic H. pylori strains containing the engineered CagA molecules.

Panel A: AGS cells were co-cultured with the isogenic H. pylori strains at a multiplicity of infection (MOI) of 100:1 for 24 h; cell morphology was observed using microscopy. Red arrows indicate needle-like hummingbird cells. Panel B: The mean (+SD) proportion of hummingbird cells induced by the H. pylori isogenic cagA mutants during co-culture. *: p<0.05, Student’s T-test. Panel C: AGS cells were co-cultured with the isogenic H. pylori strains at a multiplicity of infection (MOI) of 100:1. The media were sampled at 24 h, centrifuged at 16,000 g, and supernatants collected. AGS cell IL-8 secretion (Mean+SD) was measured by an enzyme-linked immunosorbent assay. *: p<0.05, Student’s T-test.