Use of a cytochrome P450 humanized mouse model to refine schistosomiasis drug discovery.

Abstract

Control of schistosomiasis, a neglected tropical disease caused by infection with <i>Schistosoma spp</i>., remains reliant on a single chemotherapy, praziquantel (PZQ). This strategy presents a risk to global health should PZQ-resistant schistosomes establish in endemic areas and justifies the search for new drugs. However, species-specific metabolic differences between humans and preclinical models hinder the optimization of next-generation anti-schistosomal therapeutics. Here, to bypass these species-specific limitations, we exploited a humanized mouse model, 8HUM, engineered to express the principal human Phase I cytochrome P450 enzymes (CYP1A1/2, CYP2C9, CYP2D6, CYP3A4/7) as well as the transcription factors constitutive androstane receptor and pregnane X receptor in place of 35 murine orthologs. We characterized <i>Schistosoma mansoni</i> development, immunopathology, hepatic transcriptomic responses, intestinal microbiome changes, and PZQ metabolism as well as PZQ efficacy in 8HUM vs. wild-type (WT) mice. 8HUM mice supported normal <i>S. mansoni</i> maturation, infection-associated microbiome dysbiosis, Th2-dominant immune responses, and characteristic hepatic pathology. PZQ intrinsic clearance in 8HUM hepatic microsomes mirrored human levels and was >10-fold lower than that found for WT microsomes. Oral dosing revealed human-like PZQ exposures of (<i>R</i>)-PZQ and 4OH-PZQ in 8HUM mice at 25 mg/kg bodyweight and >90% reductions in worm burdens at 100 mg/kg bodyweight (equivalent to that seen in WT mice administered PZQ at 400 mg/kg bodyweight). Our results revealed that 8HUM mice recapitulate key features of murine schistosomiasis while exhibiting human-relevant drug metabolism. These findings establish 8HUM as a refined translational platform for anti-schistosomal drug development, improving predictive accuracy and accelerating therapeutic discovery.