Immunity to <i>T</i>. <i>gondii</i> does not diminish the potency of the antitumor response stimulated by uracil auxotrophs.

<p>(A) ID8DV ovarian tumors were established in C57BL/6 mice and groups of mice were treated with phosphate buffered saline (PBS) or mice were vaccinated i.p. with tachyzoites (the acute replicative form of <i>T</i>. <i>gondii</i>) of uracil auxotrophs (OMP [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006189#pgen.1006189.ref013" target="_blank">13</a>] or CPS [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006189#pgen.1006189.ref005" target="_blank">5</a>]) at 8, 20, and 32 d after tumor challenge (the three-dose treatment schedule). (B) ID8DV ovarian tumors were established in C57BL/6 mice and groups of mice were treated with PBS or were vaccinated once (8 d), twice (8, 20 d), three times (8, 20, 32 d), or five times (8, 20, 32, 44, 56 d) i.p. with tachyzoites of uracil auxotrophs. (C) Groups of C57BL/6 mice were vaccinated (VAC) with uracil auxotrophs to establish protective immunity or mice were treated with PBS (naive). Twelve months later ID8DV tumors were established in vaccinated or age matched naive mice and tumors were treated with PBS or were vaccinated with uracil auxotrophs using the three-dose treatment schedule. Data is representative of at least two independent experiments. ns was not significant, *p<0.05, **p<0.01, ***P<0.001, ****p<0.0001.