Fig 4.

Cytokine production by DC. DC were uninfected or infected with 35000HP and 35000HP-RSM208 (neuA mutant) grown on chocolate agar plates with and without 1 mM Neu5Ac supplementation at an MOI of 10:1 for 24 h. Culture supernatants were assayed for IL-6 (n = 7), IL-12 (n = 4), TNF-α (n = 7), and IL-10 (n = 7) by ELISA. Due to donor-to-donor variation in cytokine production, cytokine levels were normalized to that of DC incubated with 35000HP grown in the absence of 1 mM Neu5Ac, which was set at 100%. Bars are means ± SDs. There were no significant differences in the levels of production of each cytokine among the groups in these assays.