Drug Repurposing for Lymphatic Filariasis Enabled with Multi-Species Genomics Approaches
AdvisorHotopp, Julie C. Dunning
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AbstractFilarial diseases affect >200 million individuals worldwide, with another ~800 million individuals at risk across ~50 countries. The causative agents of filariasis are roundworms of the superfamily Filarioidea, also known as filarial nematodes. The most common human filarial disease is lymphatic filariasis, caused by one of three filarial nematodes: Wuchereria bancrofti, Brugia malayi, and Brugia timori. There are four different antihelminthic therapeutics for lymphatic filariasis—albendazole, diethylcarbamazine, ivermectin, and doxycycline. Three are primarily microfilaricidal and have limited efficacy on adult worms. The fourth therapeutic, doxycycline, adulticidal, but causes complications when administered to pregnant women or children <9 years of age. Combined with the emergence of drug resistance in filarial nematodes, new therapeutics are needed for the treatment for lymphatic filariasis. To identify potential drug targets, we conducted a multi-species transcriptomics analysis of B. malayi, its obligate mutualistic endosymbiont Wolbachia endosymbiont wBm, and its laboratory vector host A. aegypti across the entire B. malayi life cycle. We validated the use of the Agilent SureSelect RNA-Seq capture platform to enrich for B. malayi and wBm sequencing reads in low coverage samples, namely those taken during the B. malayi vector life stages in A. aegypti. For the analysis of wBm we developed FADU (Feature Aggregate Depth Utility), a quantification tool designed for prokaryotic RNA-Seq analyses, with an emphasis on accurately quantifying operonic genes. From our transcriptomics analysis, we identified an over-enrichment of the bromodomain and extra-terminal (BET) family of transcription factors, upregulated in the adult female, embryo, and microfilariae life stages. In previous studies, knockdowns of the BET proteins in Caenorhabiditis elegans lead to adult worm sterility and sometimes lethality. We treated adult female B. malayi in vitro with the BET inhibitor JQ1(+) and found that JQ1(+) induced sterility and worm death at lower concentrations than ivermectin, suggesting BET inhibitors may be promising antihelminthics. We also sequenced the genome of the Wolbachia endosymbiont of W. bancrofti, wWb, and used comparative genomics to identify conserved genes between lymphatic filariae Wolbachia. Additionally, we developed an approach for determining species using core genome alignments to reassess the supergroup designations in the genus Wolbachia.
Molecular Microbiology and Immunology
University of Maryland, Baltimore