STAT6-driven immunity decreases <i>N</i>. <i>brasiliensis</i> reproductive output and survival within host.

A. Experimental evolution design, N. brasiliensis (originally isolated from rat host, brown) were infected for several generations (n) through either WT (black or gray) or STAT6 KO (red) mouse hosts to produce adapted cohorts. Data in this figure is from either the 11th (D, individual female egg output in 24 hours), 15th (E, intestinal adult worms), 16th (B,C–eggs per gram of feces, EPG, output), or 21st (F, intestinal adult worms) infection generation of WT N. brasiliensis and the 10th, 14th, 15th, or 20th generation of STAT6 KO N. brasiliensis. B. EPG from each line were assessed for days 5–9 within their passage host genotype. C. Area under the curve (AUC) of EPG from days 5–9 by host genotype. D. 50 adult female N. brasiliensis from each line were isolated from the intestines of their passage host and assessed for 24-hour egg-release ex vivo. Shown are the proportions of 50 adult worms per condition releasing 0, 50 eggs. Note that N. brasiliensis females from STAT6 KO all produced some level of eggs and significantly more of them produced more than one egg each, as compared to WT. E. Number of adults per host isolated from the small intestine at day 7 post infection within passage-hosts (generations 15 or 14). F. Number of adults per host isolated from the small intestine at day 8 post infection within passage-hosts (generations 21 or 20). These are the results of two replicate experiments with 3–5 mice/genotype each. Unless otherwise indicated, data are individual values (circles) with mean ± SEM indicated (bars), * p < 0.05, **p < 0.01, by t-test (C, E, F) or Chi-squared test (D).