FIG. 8.

Neither H. pylori culture supernatant nor conditioned medium decreases levels of IFN-γ-induced pYSTAT1. Confluent MKN45 cells were serum starved overnight and incubated for 6 h with either H. pylori strain LC11 culture supernatant (A) or conditioned medium from MKN45 cells infected with H pylori strain LC11 (B). Monolayers were then rinsed and stimulated with IFN-γ (1 ng/ml, 30 min), and whole-cell protein was extracted and analyzed by immunoblotting. Upper panels, MKN45 cells incubated with culture supernatant or conditioned medium did not change the levels of constitutive or IFN-γ induced pYSTAT1 compared to those incubated with control culture supernatant or conditioned medium. Lower panels, nonphosphorylated STAT1 levels are comparable between samples (n = 3).