Interpretive Summary: Proteomic profiling of plasma-derived small extracellular vesicles: a novel tool for understanding the systemic effects of tick burden in cattle
By: Natalie Turner, Pevindu Abeysinghe, Hassendrini Peiris, Kanchan Vaswani, Pawel Sadowski, Nick Cameron, Nathanael McGhee, Jayden Logan, and Murray D. Mitchell
Cattle ticks are a significant burden to cattle industries globally. Current methods to treat cattle ticks are costly and inefficient in the long term. It has been noted that while some cattle may exhibit a natural resistance to ticks, others carry a heavy tick burden. The study of small extracellular vesicles, or exosomes (EXs), isolated from cattle blood plasma provides a noninvasive way of analyzing changes at the cellular level and may be of use in understanding the systemic effects of tick burden or factors leading to natural resistance. The aim of this study was to assess high (HTR) and low tick resistance (LTR) cattle identified using a tick burden scoring system by analyzing the protein content of circulating EXs via qualitative proteomics analysis. We found that a class of proteins related to defense/immunity comprised 50% of proteins unique to HTR cattle, while this protein class was not detected in proteins unique to LTR cattle. Additionally, epidermal growth factor–calcium-binding protein domains were 2-fold increased in LTR cattle compared with HTR cattle, indicating a possible mechanism for widespread metabolic change. This is the first study to employ proteomic analysis of exosomal cargo as an approach to understanding the systemic effects of tick burden in cattle.