Anti-tick microbiota vaccines: how can this actually work?

The main importance of ticks resides in their ability to harbor and transmit microorganisms that cause disease to animals and humans. In addition to pathogens, ticks coexist and interact with symbionts, and commensal bacteria that together form an ecological unit, the tick holobiont. The holobiont is an additional organismal level on which natural selection operates. The components of the tick hologenome, composed of host and microbiome genomes, are complimentary. In agreement with this proposition, antibiotic treatment produces disturbance of the tick-microbiota homeostasis which in turn decreases tick fitness and affects tick-pathogen interactions. Accordingly, we hypothesized that immune targeting of key members of the bacterial community of the tick microbiome by host antibodies could cause microbial dysbiosis with consequences for tick physiology and vector competence. Anti-tick microbiota vaccines were recently introduced as a tool to target the microbiota of vector arthropods by immunizing the vertebrate hosts against live keystone bacteria or tick microbiota bacterial proteins. This tool can also be used to target tick endosymbionts. Decreased abundance of selected keystone bacteria and/or endosymbionts may reshape the structure of tick microbial communities in a predictable manner. This tool can be used to manipulate the tick microbiome against ticks and transmitted pathogens. In this opinion, we explore the possibilities of this methodology for the control of ticks and tick-borne diseases.