Fig. 9

Summary of results. Allergic type reactions to tick salivary compounds and protective mechanisms in response to mycobacteria. Summarized immune effects and molecular mechanismsin zebrafish gut caused by I. ricinus tick saliva treatment and water-borne exposure to M. marinum. Injection of I. ricinus tick saliva containing the glycan α-Gal and proteins like metalloproteases and p23 activates antigen presenting cells (APCs) controlled by the overexpression of cathepsin S (ctss2.1) and other immune modulators. APCs charged with toll like receptors 2 (TLR2) activate Th2 responsive cells that produce interleukin 4 (IL-4), which leads to basophil and mast cell recruitment. This type of response is common in allergic inflammation and parasitic infection. On the other hand, bacterial infection by M. marinum is responsible for the activation of alternative pathway of complement, measured through the genetic expression of C3a. Furthermore, a Th1 driven response is present, marked by TLR2 signaling, activation of pro-inflammatory mediators like DNA-dependent protein kinase (prkdc) and cytokines such as interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α).