title: Detection of circulating parasite-derived microRNAs in filarial infections.
abstract: Filarial nematodes cause chronic and profoundly debilitating diseases in both humans and animals. Applications of novel technology are providing unprecedented opportunities to improve diagnosis and our understanding of the molecular basis for host-parasite interactions. As a first step, we investigated the presence of circulating miRNAs released by filarial nematodes into the host bloodstream. miRNA deep-sequencing combined with bioinformatics revealed over 200 mature miRNA sequences of potential nematode origin in Dirofilaria immitis-infected dog plasma in two independent analyses, and 21 in Onchocerca volvulus-infected human serum. Total RNA obtained from D. immitis-infected dog plasma was subjected to stem-loop RT-qPCR assays targeting two detected miRNA candidates, miR-71 and miR-34. Additionally, Brugia pahangi-infected dog samples were included in the analysis, as these miRNAs were previously detected in extracts prepared from this species. The presence of miR-71 and miR-34 discriminated infected samples (both species) from uninfected samples, in which no specific miRNA amplification occurred. However, absolute miRNA copy numbers were not significantly correlated with microfilaraemia for either parasite. This may be due to the imprecision of mf counts to estimate infection intensity or to miRNA contributions from the unknown number of adult worms present. Nonetheless, parasite-derived circulating miRNAs are found in plasma or serum even for those species that do not live in the bloodstream.
authors.affiliation: Institute of Parasitology, Centre for Host-Parasite Interactions, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada.
authors.forename: Lucienne
authors.initials: L
authors.lastname: Tritten
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America; Filariasis Research Reagent Resource Center, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Erica
authors.initials: E
authors.lastname: Burkman
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America; Filariasis Research Reagent Resource Center, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Andrew
authors.initials: A
authors.lastname: Moorhead
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Satti
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: James
authors.initials: J
authors.lastname: Geary
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Charles
authors.initials: C
authors.lastname: Mackenzie
authors.affiliation: Institute of Parasitology, Centre for Host-Parasite Interactions, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada.
authors.forename: Timothy
authors.initials: T
authors.lastname: Geary
mesh_terms: D000818:Animals; D004183:Dirofilaria immitis / Q000235:genetics*; D004184:Dirofilariasis / Q000469:parasitology*; D004285:Dogs; D006790:Host-Parasite Interactions; D035683:MicroRNAs / Q000097:blood*; D018510:RNA, Helminth / Q000097:blood
chemical_list: D035683:MicroRNAs; D018510:RNA, Helminth