MicroRNAs of filarial nematodes: A new frontier in host-pathogen interactions

Abstract

Metazoan parasites, especially nematodes, are a highly diverse group of large organisms that typically sustain an infection for long periods of time with relatively modest pathology. This state is achieved by the release of parasite-derived immunomodulatory molecules which coerce the host into providing a relatively safe niche in which the parasite is able to carry out the host-housed aspects of its life cycle. It has recently been recognized that parasitic nematodes release microRNAs (miRNAs) in culture and in mammalian hosts, primarily in exosome-like vesicles, and that these parasite-derived miRNAs may target host genes involved in the immune response. This review focused primarily on data from filarial nematodes, which occupy tissue niches in humans and other animals, and provides a perspective on possible biological roles of these molecules and their therapeutic and evolutionary implications.