Decreased dissemination and parasite load after adoptive transfer of <i>Toxoplasma</i>-infected DC treated with GABAergic inhibitors.

<p>(<b>A</b>) BALB/c mice were challenged with 5×10⁴ cfu of freshly egressed PTGluc tachyzoites (Toxo), 5×10⁴ cfu of tachyzoite-infected DC (Toxo-DC) or 5×10⁴ cfu tachyzoite-infected DC treated with SNAP and SC (Toxo-DC + SNAP&SC). Photonic emissions were assessed by BLI on five consecutive days after inoculation of mice. Images show progression of infection and parasite biomass expansion in mice. Control shows non-infected mouse. Color scales indicate photo emission (photons/s/cm²/sr) during a 180 s exposure. Data are from one set of mice and representative of two independent experiments with three to five mice per group. (<b>B</b>) Total photon emission analysis from individual mice on days 1–5 post inoculation showed a decrease in parasite tissue burden in mice inoculated with GAD and GAT4 inhibitor-treated DC infected with <i>T. gondii</i> when compared with burdens from mice inoculated with untreated DC infected with <i>T. gondii</i>. Photonic emissions were assessed (photons/s/ROI) during a 180 s exposure. Data are from two independent experiments with 3–5 mice per group. Asterisks indicates a significant increase in photon emissions on day 4 and 5 post infection from mice in the “Toxo-DC” group compared to mice in the “Toxo” or “Toxo-DC (+SNAP&SC)” groups (P≤0.0004, GLM ANOVA, Tukeys Pairwise comparison). ROI – region of interest. (<b>C</b>) <i>Ex vivo</i> photonic emissions from spleen, MLN and brains of mice BALB/c mice challenged with 10⁵ cfu of tachyzoite-infected DC (Toxo-DC) or 10⁵ cfu tachyzoite-infected DC treated with SNAP and SC (Toxo-DC + SNAP&SC). Color scales indicate photonic emissions (photons/s/cm²/sr) during a 180 s exposure as indicated under <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003051#s4" target="_blank">Materials and Methods</a>. Representative images from day 2 and day 5 post-inoculation are shown. White arrows (lower panel) indicate signal from the brain tissue. (<b>D</b>) Box-plot and whiskers graph represents the lower, upper quartiles, median and minimum–maximum of photonic emissions <i>ex vivo</i> from the brains of infected mice. The white bars indicate brains from mice infected with tachyzoite-infected DC (Toxo-DC) and the dark grey bars indicate brains from mice infected with tachyzoite-infected DC treated with SNAP and SC (Toxo-DC + SNAP&SC) (<i>n = </i>4/group/day). Non-significant differences were observed between the treated and untreated groups (P≥0.05; Kruskal Wallis test) with significant differences on days 1 and 2 (P≤0.05, Student's t test, indicated by asterisks). (<b>E</b>) Parasite load in spleen, MLN and brain on days 1–6 post inoculation quantified by plaquing assays as indicated under <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003051#s4" target="_blank">Materials and Methods</a>. BALB/c mice were challenged with 10⁵ cfu of tachyzoite-infected DC (Toxo-DC, open circles) or 10⁵ cfu tachyzoite-infected DC treated with SNAP and SC (Toxo-DC + SNAP&SC, filled triangles). Mean parasite tissue load for each group is indicated (open and filled lines respectively) and dashed lines represent trendlines for the two groups (<i>n = </i>4/group/day). Significant differences in parasite load between groups were observed for spleen and brain (P≤0.022 and P≤0.02 respectively, Kruskal-Wallis test). Non-significant differences were observed in MLN (P≥0.05, Kruskal-Wallis test) with significant differences between groups on days 2, 4, 5, 6 (P≤0.05, Student's t-test).