FIG. 1.

H. pylori downregulates the CXCR1 and CXCR2 receptors on purified human neutrophils. Incubation of neutrophils with a cag⁺ H. pylori strain as well as with the corresponding cag deletion mutant resulted in complete downregulation of both chemokine receptors after only 0.5 h, as determined by FACS analysis. Neutrophils incubated with medium alone (labeled “medium control”) did not show any receptor downregulation. The x axis indicates fluorescence intensity measured on log₁₀ scale, and the y axis indicates event counts per channel on a linear scale.