Functional Genomic Approach to Macrofilaricide Discovery

DESCRIPTION (provided by applicant): River blindness and lymphatic filariasis, two disease caused by filarial nematodes, are among the most important tropical diseases. Blackfly transmission of the nematode Onchocercus volvulus leads to river blindness (onchocerciasis), while mosquito-transmitted filarial worms including Wucheria bancrofti and Brugia malayi are responsible for lymphatic filariasis. Adult worms survive in infected individuals for many years, continuously releasing microfilarial progeny into the blood. Coordinated global efforts to control these diseases have concentrated on vector control and the use of existing drug therapies. However, the current drugs primarily target the microfilarial stages and are not effective against the long-lived adult nematodes. Additionally, drug resistance to current therapies has been recently documented. Despite current efforts, eradication of these diseases will be extremely challenging. New classes of anthelmintic drugs are needed which target the macrofilaria (adult) stages of parasitic worms. In this research, recently generated nematode genomic data will be screened with bioinformatic filters for the identification of potential target genes in the filarial nematode Brugia malayi. B. malayi orthologs of C. elegans genes with severe RNAi phenotypes will be chosen, as well as a number of genes unique to parasitic nematodes. Nominated genes will be cloned from B. malayi, and tested for expression in adult females. Following confirmation of adult expression, 10-15 gene targets will be selected and tested by RNAi for effects on the biology of adult B. malayi female worms in vitro. Survival, morphology, and release of microfilaria will be monitored, as will target gene transcript levels by RT-PCR. The outcome of this work will be the selection and ranking of a limited number of high priority targets for macrofilaricide drug discovery.