# Amblyomma cajennense Sensu Stricto (Fabricius, 1787) and Amblyomma sculptum (Berlese, 1888) Tick Saliva Elicit Immune‐Modulatory Activity in Isolated Murine Macrophages With an Insight Into Proteomic Analysis

## TL;DR

This study compares how tick saliva from two species affects mouse macrophages, revealing distinct immune-modulating effects.

## Contribution

First comparative evaluation of salivas from two species in the A. cajennense complex and their immune-modulatory effects.

## Key findings

- Saliva from both tick species increased ROS production and phagocytic activity in macrophages.
- A. sculptum saliva decreased IL-1β and increased TNF-α, while A. cajennense s.s. saliva increased IL-6 and IL-10.
- Proteomic analysis identified 221 and 303 secreted proteins in A. cajennense s.s. and A. sculptum, respectively.

## Abstract

Tick saliva is known to cause immunosuppression and help pathogen transmission.
Amblyomma sculptum
is a public health concern as a vector of
Rickettsia rickettsii
. Another close‐related species is
Amblyomma cajennense
sensu stricto (s.s.). The impact of saliva from these species on murine macrophages remains unclear. This study evaluated saliva from
A. cajennense
s.s. and
A. sculptum
in murine peritoneal macrophages, assessing cell viability, adhesion, morphology, reactive oxygen species (ROS) production, phagocytosis and cytokine secretion. Additionally, a proteomic analysis was conducted and the proteins that were secreted in salivas were estimated. Neither A. sculptum nor A. cajennense s.s. saliva did it affect viability, adhesion or morphology, but increased ROS production and phagocytic activity.
A. sculptum
saliva decreased IL‐1β and increased TNF‐α, whereas
A. cajennense
s.s. saliva increased IL‐6 and IL‐10. Proteomic analysis revealed 221 and 303 secreted proteins in
A. cajennense
s.s. and
A. sculptum
, respectively and the more abundant were vitellogenins, microplusins, serpins, cystatins, actin, beta actin and calponins. These findings suggest that saliva from each species modulates macrophage activity in distinct ways, eliciting pro‐ and anti‐inflammatory responses. This is the first comparative evaluation of salivas from two species of the
A. cajennense
sensu lato complex, providing new insights into their interaction with innate immune cells.