Figure 1. Increased CD8⁺ T cell generation and protective immunity after MMC depletion.

(A) 8-10 week old LysM^+/eGFP mice were infected intravenously with 2.5x10⁴ wt L. monocytogenes for 12, 24, and 48 hours. At the indicated time spleens were excised, sectioned, and image using multi-photon microscopy. Multi-photon images of LysM^+/eGFP mice at 12, 24, and 48 hours after infection. Top panel (non-infected) –grayscale images. Dextran-TMR-red, LysM^+/eGFP- green, yellow dotted line-marginal zone, WP-white pulp, RP-red pulp (B) Relative GFP intensity inside individual WP nodule (A.U.). Data representative of 3 independent experiments. (C) Isolated naïve OT-I cells were transferred into 8-10 week old B6.SJL mice 24 hours prior to 250µg RB6-8C5 mAb. 5 hours after mAb treatment mice were infected i.v. with 1x10⁴ ΔactA/InlB L. monocytogenes expressing ova peptide. OT-I percentages as analyzed by FACs from blood day 7 post-infection. Bar graph (median plus range). Data representative of 3 independent experiments. (D) 8-10 week old C57BL/6 mice were treated with 250µg RB6-8C5 mAb and then immunized 5 hours later with 1x10³ ΔactA/InlB. 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.