Figure 4. Inhibition of cell-mediated immunity despite MMC depletion.

(A) 5x10⁴ naïve OT-I cells from C57BL/6 mice were transferred into 8-10 week old B6.SJL mice 24 hours prior to RB6-8C5 mAb (250µg) treatment. 5 hours after antibody treatment mice were infected intravenously with 1x10⁴ ΔactA/InlB or ΔactA/InlB L.p.FlaA L. monocytogenes both expressing ova peptide. OT-I percentages as analyzed by FACS from blood day 7 post-infection. Data representative of one experiment. (B) Bar graph (median plus range) of OT-I percentages as analyzed by FACS from blood day 7 post-infection. Data combined from three independent experiments. (C) 8-10 week old C57Bl/6 mice were treated with 250µg RB6-8C5 mAb and then immunized 5 hours later with 1x10³ ΔactA/InlB or ΔactA/InlB L.p.FlaA L. monocytogenes. 30 days post immunization mice were infected with 2x10⁵ wt L. monocytogenes for 3 days. Bacterial CFUs in liver and spleen day 3 post-infection. Dotted line – limit of detection. Data are representative of four independent experiments. *P < 0.05 by Mann-Whitney test.