Evaluating Intestinal Proteins of Adult Brugia malayi Worms as Drug and Vaccine Targets
Abstract
Lymphatic filariasis (LF), a debilitating disease caused by the tissue invasive nematodes Wuchereria bancrofti, Brugia malayi, and Brugia timori, affects over 70 million people worldwide. Global eradication efforts have significantly reduced worldwide prevalence, but complete elimination has been hampered by limitations of current antifilarial drugs and the lack of a vaccine. The goal of this study was to evaluate Brugia malayi intestinal proteins as potential drug target and vaccine candidates. We first evaluated whether BmaiUGTis essential for adult filarial worms by inhibiting its expression with siRNA for24 hrs. This resulted in a 75 knockdown of Bma-iugt mRNA for 6 days and almost complete suppression of detectable Bma-iUGT by Western blot. Reduction in Bma-iUGT expression resulted in decreased worm motility for 6 days, 70 reduction in microfilaria (Mf) release from adult worms, and significant reduction in adult worm metabolism as detected by MTT assay. We then tested UGT inhibitors, sulfinpyrazone and probenecid, for in vitro activity against B. malayi. There was amarked macrofilaricidal effect with the lowest concentrations resulting in reducedworm motility being 200 M for sulfinpyrazone and 250 M for probenecid. Almost no microfilaricidal effect was observed in vitro at 250 M for probenecid. Because prior sensitization to a filarial antigen would be a contraindication for its use as a vaccine candidate, we tested plasma from infected and endemic normalpopulations for Bma-iUGT-specific IgE using a luciferase immunoprecipitationassay. All samples (n=30) tested negative. When we evaluated 8 other intestinal proteins in adult B. malayi worms, we found another promising candidate. We observed a 70.42 knockdown of Bmalad-2 mRNA 1-day post-siRNA incubation. This inhibition of Bma-LAD-2 expression resulted in a robust decrease in worm motility and Mf release as well as an 83.25 reduction in MTT metabolism. By transmission electron microscopy, we
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 15, 2018
- Accession Number
- AD1128272
Entities
People
- Alexander F Flynn
Organizations
- Uniformed Services University of the Health Sciences