FIG. 7.
Regulation of H. pylori ICAM-1 promoter activity by Egr-1. (A) Model of ICAM-1 constructs. pBLICAM-1 contains 1.1 kb of 5′ flanking sequence from the murine ICAM-1 gene cloned upstream of a CAT reporter, and the mutant construct pBLmICAM-1 contains the depicted 5-bp mutation at position −701 of the ICAM-1 promoter. AGS cells were transfected with the pCAT promoter of ICAM-1 and the pBLICAM-1 or pBLmICAM-1 construct, and after stimulation with H. pylori (6 × 108 CFU/ml) for 24 h, cell lysates were prepared and assayed for CAT activity. Acetylated (Ac-chl) and nonacetylated (non-Ac-chl) forms of chloramphenicol were separated by thin-layer chromatography, followed by autoradiography (B) and quantitation by scintillation counting (C), with the results expressed as relative CAT activities. One microgram of pSV-β-galactosidase control vector was simultaneously transfected as a control for transfection efficiency. Each experiment was performed three times with similar results, and the results of one experiment are shown as means ± SD.