Production of IL-12 upon challenge with live vs. gentamicin-killed gonococci. THP-1 cells (1 × 106/ml) were challenged with either 1 × 105/ml live or gentamicin-killed gonococci. At 18 hrs post challenge, IL-12 was measured by ELISA. These data represent one experiment, performed in triplicate. Error bars indicate the standard deviation.