Wonders of tick saliva

doi:10.1016/j.ttbdis.2018.11.005

Ticks and Tick-borne Diseases

Volume 10, Issue 2, February 2019, Pages 470-481

https://doi.org/10.1016/j.ttbdis.2018.11.005 Get rights and content

Abstract

Saliva of ticks is arguably the most complex saliva of any animal. This is particularly the case for ixodid species that feed for many days firmly attached to the same skin site of their obliging host. Sequencing and spectrometry technologies combined with bioinformatics are enumerating ingredients in the saliva cocktail. The dynamic and expanding saliva recipe is helping decipher the wonderous activities of tick saliva, revealing how ticks stealthily hide from their hosts while satisfying their gluttony and sharing their individual resources. This review takes a tick perspective on the composition and functions of tick saliva, covering water balance, gasket and holdfast, control of host responses, dynamics, individuality, mate guarding, saliva-assisted transmission, and redundancy. It highlights areas sometimes overlooked – feeding aggregation and sharing of sialomes, and the contribution of salivary gland storage granules – and questions whether the huge diversity of tick saliva molecules is ‘redundant’ or more a reflection on the enormous adaptability wonderous saliva confers on ticks.

Section snippets

Composition of tick saliva

Tick saliva is a fluid secretion injected from the salivary glands of ticks into the feeding site where the tick attaches on a vertebrate host. Given the numerous functions of tick saliva (Section 2), not surprisingly the chemical composition of tick saliva is highly complex (Table 1). The complexity is produced by the pair of relatively large and intricate salivary glands formed by groups of cells in grape-like clusters (known as acini) attached to salivary ducts (Kemp et al., 1982) (Fig. 1).

Functions of tick saliva

Functional analysis of tick saliva constituents in relation to their host modulatory activity has been comprehensively reviewed (Kotál et al., 2015; Blisnick et al., 2017; Chmelař et al., 2017; Wikel, 2018). Table 3 provides a summary of the various activities of tick saliva and the principal mediators involved. This section aims to take a tick perspective on functionality.

Conclusions and future directions

Tick saliva is complex and has many different functions. The complexity and functionality change as feeding progresses, at least in ixodid species that take days to complete engorgement. Further comparative studies on the composition and activity of saliva from ixodid and argasid species, and the intriguing evolutionary relic, N. namaqua, should provide important new insights into how tick saliva has evolved with the different life strategies of this successful superfamily of obligate

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Wonders of tick saliva

Abstract

Section snippets

Composition of tick saliva

Functions of tick saliva

Conclusions and future directions

J. Biol. Chem.

Immunity

Int. J. Parasitol.

Parasitol. Today

Vet. Parasitol.

J. Proteom.

Blood

J. Proteom.

Trends Immunol.

Biochim. Biophys. Acta - Mol. Cell Biol. Lipids

Toxicon

Blood

Int. J. Parasitol.

J. Biol. Chem.

J. Proteom.

J. Biol. Chem.

Exp. Parasitol.

Insect Biochem. Mol. Biol.

Ticks Tick Borne. Dis.

J. Biol. Chem.

Mol. Cell

J. Mol. Biol.

Int. J. Parasitol.

Histology of bovine skin reactions to Ixodes holocyclus Neumann

Can. J. Comp. Med.

Ticks, Ixodes scapularis, feed repeatedly on white-footed mice despite strong inflammatory response: an expanding paradigm for understanding tick–host interactions

Front. Immunol.

Complement as a part of the skin immune system

Ixonnexin from tick saliva promotes fibrinolysis by interacting with plasminogen and tissue-type plasminogen activator, and prevents arterial thrombosis

Sci. Rep.

Dendritic cells in the immune system-history, lineages, tissues, tolerance, and immunity

Microbiol. Spectr.

Epidermis as a pro-inflammatory organ

Serine protease inhibitors in ticks: an overview of their role in tick biology and tick-borne pathogen transmission

Front. Cell. Infect. Microbiol.

Macrophage migration inhibitory factor expression and protein localization in Amblyomma americanum (Ixodidae)

Exp. Appl. Acarol.

Tick salivary glands: the physiology of tick water balance and their role in pathogen trafficking and transmission

Anaplasma phagocytophilum increases the levels of histone modifying enzymes to inhibit cell apoptosis and facilitate pathogen infection in the tick vector Ixodes scapularis

Epigenetics

The tick salivary protein sialostatin L2 inhibits caspase-1-mediated inflammation during Anaplasma phagocytophilum infection

Infect. Immun.

All for one and one for all on the tick – host battlefield

Trends Parasitol.

Protease inhibitors in tick saliva: the role of serpins and cystatins in tick-host-pathogen interaction

Front. Cell. Infect. Microbiol.

Variegin, a novel fast and tight binding thrombin inhibitor from the tropical bont tick

J. Biol. Chem.

The vast majority of CLA+ T cells are resident in normal skin

J. Immunol.

Ultrstructure of granule secretion in salivary glands of Argas (Persicargas) arboreus during feeding

Zentralblatt fur Parasitenkd.

Tick histamine release factor is critical for Ixodes scapularis engorgement and transmission of the lyme disease agent

PLoS Pathog.

Sialotranscriptomics of Rhipicephalus zambeziensis reveals intricate expression profiles of secretory proteins and suggests tight temporal transcriptional regulation during blood-feeding

Parasites Vectors

Prostaglandin in the saliva of the cattle tick Boophilus microplus

Aust. J. Exp. Biol. Med. Sci.

Clethrionomys glareolus, but not Apodemus flavicollis, acquires resistance to lxodes ricinus L, the main European vector of Borrelia burgdorferi

Parasite Immunol.

Analysis of the salivary gland transcriptome of unfed and partially fed Amblyomma sculptum ticks and descriptive proteome of the saliva

Front. Cell. Infect. Microbiol.

Observations on the mating behavior of ticks

Implication of haematophagous arthropod salivary proteins in host-vector interactions

Parasites Vectors

The role of saliva in tick feeding

Front. Biosci.

Chemical composition of the coxal fluid of the argasid tick Ornithodoros savignyi

J. Med. Entomol.

Cutting edge: CD4 is the receptor for the tick saliva immunosuppressor, Salp15

J. Immunol.