The roles and profiles of miRNAs during host feeding in a one-host tick, Rhipicephalus microplus, and a three-host tick, Ixodes scapularis

Ticks are important ectoparasites that can vector multiple pathogens. The salivary glands of the ticks are essential for feeding. Tick saliva contains many effectors with pharmaceutical properties that can diminish host immune responses and enhance pathogen transmission. One group of such effectors are microRNAs (miRNAs). miRNAs are short non-coding sequences that can regulate host gene expression at the tick-host interface. These small RNAs can be transported in the tick saliva via extracellular vesicles (EVs), which serve in inter- and intra-cellular mechanisms. Vesicles containing miRNAs have been described in the saliva of ticks. However, little is known about the roles and profiles of the miRNAs in tick salivary vesicles and glands. Furthermore, the study of vesicles and miRNAs in tick saliva requires tenuous procedures for the collection of tick saliva. The focus of this project is to develop and validate a method for isolating purified extracellular vesicles and miRNAs from ex vivo organ cultures. Herein, we described the materials and methodology needed to extract miRNAs from extracellular vesicles and tick salivary glands.