A bioinformatics framework for human health risk assessment of externally applied dsRNA-based biopesticides

Abstract

Current plant protection methods rely predominantly on conventional chemical pesticides that can have negative human health and environmental impacts. Consequently, there is a pressing need to develop sustainable crop protection solutions that have improved safety profiles for humans and other non-target organisms (NTOs). RNA interference (RNAi) is a natural defense mechanism against viruses found in eukaryotes that silences viral genes in a sequence-specific manner. Recently, RNAi has been utilized to specifically target essential genes of pests with a novel class of topical, sprayable biopesticides based on dsRNA (double-stranded RNA). A critical step in the regulatory approval of such externally applied dsRNA-based biopesticides is a robust bioinformatics analysis of potential off-target effects to humans and other organisms. However, no generally applicable guidelines are available for risk assessment of dsRNA-based biopesticides for humans. Here, we address this gap by describing a bioinformatics framework for risk assessment in humans, informed by peer-reviewed literature, that quantifies potential off-targets with a primary focus on externally applied dsRNA-based biopesticides. The framework comprises three main components: bioinformatics tools for predicting off-target effects in humans, a mismatch tolerance for sequence divergence between dsRNA and unintended targets to delineate potential human off-target effects, and siRNA criteria for quantifying the possibility of theoretical gene silencing in the presence of mismatches in humans. This bioinformatics framework represents the most comprehensive approach described to date and has been used successfully for evaluating the potential risks of the externally applied dsRNA-based biopesticide Calantha^TM to humans.