What is in tick saliva? - briefly
«Tick saliva» contains a complex mixture of bioactive molecules, including anticoagulant proteins, immunosuppressive factors, anti‑inflammatory agents, and enzymes that aid blood feeding and pathogen transmission. The composition features salivary gland‑derived peptides, lipocalins, metalloproteases, and prostaglandin‑like substances.
What is in tick saliva? - in detail
Tick saliva is a complex mixture of bioactive molecules that facilitate blood feeding and modulate host responses. The main categories of components include proteins, enzymes, peptides, lipids and small metabolites.
Proteins and peptides
- Anticoagulants such as apyrase, which hydrolyzes adenosine diphosphate, preventing platelet aggregation.
- Anti‑inflammatory agents like prostaglandin‑E₂ synthase, reducing host inflammation at the bite site.
- Immunomodulators, for example, evasins that bind host chemokines, impairing leukocyte recruitment.
- Salivary gland‑derived proteases that degrade extracellular matrix, easing lesion formation.
Enzymes
- Metalloproteases that cleave host proteins, aiding tissue penetration.
- Phosphatases that dephosphorylate signaling molecules, dampening cellular activation.
- Lipases that modify host lipid mediators, influencing vascular permeability.
Lipids and small molecules
- Sphingolipids that interfere with host cell signaling pathways.
- Nucleotides and their derivatives, such as adenosine, which cause vasodilation and inhibit platelet function.
- Antioxidants like glutathione that protect the tick from oxidative stress during feeding.
Additional factors
- Salivary gland‑derived microRNAs, which may be transferred to host cells and alter gene expression.
- Glycans that mask tick antigens, reducing recognition by the host immune system.
The coordinated action of these substances enables prolonged attachment, efficient blood ingestion, and the transmission of pathogens. Understanding each component’s biochemical properties provides insight into tick‑borne disease mechanisms and potential targets for vaccine development.