PP are required to sustain optimum egg transmission and limit host morbidity.

<p>(A) Quantitative analysis of adult schistosome worm recoveries following perfusion of the hepatic portal system in WT or PP^null mice. (B) Cytokine secretion by mLN cells from WT and PP^null mice 8 weeks post-infection following in vitro stimulation with anti-CD3 mAb, or soluble egg antigen. (C) Masson's Trichrome stained histological sections of duodenum (blue = collagen) at post-infection in WT or PP^null mice (red dotted lines = extent of egg granulomas). (D) Reduction in granuloma areas at 16 cf. 8 weeks; min 4 granulomas/mouse, **P<0.01, ***P<0.001, unpaired T test: nd = no difference between WT and PP^null. (E) Numbers of faecal eggs from WT and PP^null mice 8–16 weeks pi, and (F) tissue eggs in the small intestine and liver at week 16; both normalised to female worm burden. (G) Levels of AST enzyme in the serum of naïve or infected mice. (H) Incidence of morbidity of ‘moderate severity’; P = 0.0507, survival analysis. Statistical analysis is for PP^null versus WT mice, *P<0.05, **P<0.01, ***P<0.001, unpaired T test of log10-transformed data (E) or raw data (D, F, G & H). Data is mean+SEM of two independent experiments, (A, B & D; n = 4), or combined data of two independent experiments (E–H; n = 7–13).