Acquired tick resistance: The trail is hot

Abstract

Acquired tick resistance is a phenomenon wherein the host elicits an immune response against tick salivary components upon repeated tick infestations. The immune responses, potentially directed against critical salivary components, thwart tick feeding, and the animal becomes resistant to subsequent tick infestations. The development of tick resistance is frequently observed when ticks feed on non-natural hosts, but not on natural hosts. The molecular mechanisms that lead to the development of tick resistance are not fully understood, and both host and tick factors are invoked in this phenomenon. Advances in molecular tools to address the host and the tick are beginning to reveal new insights into this phenomenon and to uncover a deeper understanding of the fundamental biology of tick-host interactions. This review will focus on the expanding understanding of acquired tick resistance and highlight the impact of this understanding on anti-tick vaccine development efforts.

Tick hypersensitivity and human tick‐borne diseases

“…They have a diversity of function that includes attachment to the host with cement-like protein, preventing coagulation of host blood, blocking the effects of oxidants and histamine and suppressing host immune responses against salivary proteins. 11,42,43,68,70,[72][73][74][75][76][77][78][79][87][88][89][90][91][92][93][94][95][96][97][98][99][100] The specific function and kinetics of salivary proteins are just beginning to be documented but it is clear that alteration of protein types during feeding and redundancy of function are common. Salivary proteins that promote tick feeding and pathogen transmission change during the 3 to 5 day tick feed, a process known as 'sialome switching'.…”

“…Salivary proteins that promote tick feeding and pathogen transmission change during the 3 to 5 day tick feed, a process known as 'sialome switching'. 11,78,99,101 Sequential protein secretion and functional redundancy shared by different salivary proteins are likely host immune evasion mechanisms that also help ticks avoid reliance on a single host. The salivary proteins secreted into one host vary from those secreted into another.…”

“…More than 200 salivary proteins are introduced during tick attachment and feeding. They have a diversity of function that includes attachment to the host with cement‐like protein, preventing coagulation of host blood, blocking the effects of oxidants and histamine and suppressing host immune responses against salivary proteins 11,42,43,68,70,72‐79,87‐100 . The specific function and kinetics of salivary proteins are just beginning to be documented but it is clear that alteration of protein types during feeding and redundancy of function are common.…”

“…The specific function and kinetics of salivary proteins are just beginning to be documented but it is clear that alteration of protein types during feeding and redundancy of function are common. Salivary proteins that promote tick feeding and pathogen transmission change during the 3 to 5 day tick feed, a process known as ‘sialome switching’ 11,78,99,101 . Sequential protein secretion and functional redundancy shared by different salivary proteins are likely host immune evasion mechanisms that also help ticks avoid reliance on a single host.…”

Tick host immunity: vector immunomodulation and acquired tick resistance

“…In fact, in the past few decades we have witnessed significant advances in our understanding of the immunobiology of tick-host associations [16], which likely involve multifactorial immunological cascades. We highlight these exciting theories, and experimental evidence, which attempt to explain both the lack of acquired tick immunity in natural hosts and the development of ATR in incidental hosts [25]. It is possible that the arsenal of tick activities against host immune responses may target a small, defined number of natural vertebrate species that are necessary to maintain the vector population.…”