FIG. 4.
Helicobacter-induced cytokine production by BMMC is not strain dependent. Mast cells were grown from mouse bone marrow cells for 4 weeks, and then 2 × 105 cells were stimulated with 100 μg/ml of bacterial lysate prepared from one of seven H. pylori strains of various genotypes and phenotypes or from H. felis. Cell culture supernatants were assessed for TNF-α and KC at 24 h by ELISA. Assays were performed in quadruplicate. Error bars indicate standard deviations from the means. *, P < 0.05; **, P < 0.01; ***, P < 0.001 (compared to stimulation with H. pylori SS1). LPS, lipopolysaccharide.