D3015: Characterization and evaluation of extracellular vesicles as anti-tick vaccine candidates

Of all the agricultural sectors, livestock is the most developed and prolific economically. The livestock promotes economic stability globally. Ticks can transmit pathogens, such as Anaplasma marginale (causative agent of Bovine Anaplasmosis), directly impacting the cattle industry. Bovine Anaplasmosis is a tick-borne disease that results in estimated losses of over 300 million USD per year in the US agricultural sector. Currently, there is no effective treatment or vaccine approved in the US. Extracellular vesicles are small membrane vesicles that act in cell-to-cell communication and can be divided into exosomes and microvesicles. Exosomes carry proteomic material and can be used as vaccine candidates and treatments for diseases. We hypothesize that the extracellular vesicles carry proteomic material that is conserved among tick species and are good vaccine candidates. Nevertheless, variations in proteomic cargo may impact cross-reactivity between tick species. We hypothesize that vesicles will present significant conserved cargo between tick species, which could lead to cross-protective vaccines. To test this hypothesis, we will: Determine the morphological and proteomic differences in vesicle populations secreted by Dermacentor andersoni, Amblyomma americanum, and Rhipicephalus microplus ticks, and 2) Define the differences in vesicle transmission between different tick species. Our results indicate significant variation in the vesicle populations and mark differences in their proteomic profile. These profiles vary significantly depending on the host, time of feeding, and organ from which they originated.