<i>T. gondii</i> killing is associated with the rapid death of infected <i>Toxo1</i>-LEW macrophages.

<p>(<b>A</b>) Percentage of infected BN and LEW macrophages showing a condensed nucleus, 8 h after infection. Columns represent mean +/− SD of three different experiments. (<b>B</b>) Cell death was monitored by propidium iodide (PI) uptake. Percentage of induced-cell death on BN and LEW peritoneal macrophage, 6 h after either infection (n = 4 for BN and LEW) or incubation with lysed fibroblasts (lf) (n = 2). <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004005#s2" target="_blank">Results</a> represent differences between infected and uninfected cells. Columns represent mean +/− SD. _*: <i>p</i><0.05. (<b>C</b>) Death kinetics of both intracellular RH-YFP parasites and host macrophages. Parasite death was assessed by the percentage of YFP positive cells (dotted line), and host macrophage death by the percentage of PI positive cells (solid line). (<b>D</b>) Cell death induction is restricted to infected macrophages. LEW macrophages were infected with RH parasites for 6 h prior to fixation and stained with anti-GRA5 antibody, PI and Hoechst 33258. Columns represent mean +/− SD of two different experiments. (<b>E</b>) The percentage of cell death induction, in peritoneal macrophages, from BN (n = 7), LEW (n = 8) and congenic lines BN.LEWc10-Ce (n = 3), -Cf (n = 3), -Cg (n = 4), -Cga (n = 4), -Ch (n = 4), -Ci (n = 3), LEW.BNc10-F (n = 5) was monitored by PI uptake. Columns and bars show means +/− SD; _*: <i>p</i><0.05; _**: <i>p</i><0.01. Genotypes at the markers of the <i>Toxo1</i> locus in the used BN.LEWc10 congenic lines are specified (N: Homozygous for the BN genome; L: Homozygous for the LEW genome) and the grey zone indicates the <i>Toxo1</i> locus narrowed down to 0.89 Mb (boundary markers: D10GF49 and D10GF55; Physical distances are indicated between markers in kilobases).