FIG. 3.

NO_x production of human monocytic cells after PMA stimulation and Salmonella infection. The accumulation of stable metabolites of NO (NO_x) in the cell-free supernatants of U937 cells transfected with either DNA containing the gene for HLA-A2 or HLA-B27 or cDNA encoding HLA-B27 is shown. The cells were pretreated with PMA and infected with S. enteritidis or left uninfected. The concentration of NO_x in fresh culture medium was taken as a baseline. Values are means ± standard deviations of the cumulative NO_x values of two independent experiments with triplicate wells. S. ent, S. enteritidis.