FIG 8.
Long-term protection against systemic L. monocytogenes infection induced by immunization with topical or subcutaneous CpG adjuvant. Naive mice, mice treated with topical (ec, 250 μg) CpG adjuvant, and mice immunized with 100 μg OVA protein antigen subcutaneously (sc) without or with topical (ec, 250 μg) or subcutaneous (sc, 50 μg) CpG adjuvant were challenged with 5 × 105 CFU Lm-OVA intravenously 30 days postimmunization (after boost). Mice immunized with ΔactA-Lm-OVA intraperitoneally were analyzed in parallel as positive controls. (A) Schematic diagram of immunization, infection, and bacterial burden analysis timeline. (B) Scatter plots in log axis scale of bacterial counts in the spleen 3 days postinfection. Data summarize at least two independent experiments (n = 5 to 19) and are expressed in means ± SEM. **, P < 0.01; ns, no significance.