FIG. 3.

CXCR1 and CXCR2 receptor downregulation on neutrophils cannot be attributed to increased IL-8 and TNF-α concentrations. Human neutrophils did not express IL-8 (a) and TNF-α (b) 0.5 h after incubation with H. pylori, as determined by ELISA. Three hours after incubation with H. pylori, IL-8 was strongly increased and TNF-α was moderately increased in the neutrophil cell culture. The IL-8 level was higher after incubation with the cag⁺ than with the cag deletion H. pylori strain. IL-8 measurements were performed in triplicate, and TNF-α measurements were performed in duplicate. Mean values and standard deviations are shown.