Expression of costimulatory molecules on antigen presenting cells treated with Ixodes scapularis and Amblyomma americanum recombinant saliva proteins

Ticks are bloodsucking ectoparasites that can parasitize animals of different groups such as mammals, birds, reptiles, amphibians and even spiders. The impact of direct tick feeding activity and the cost controlling tick-borne diseases amounts to huge losses globally. Since the 1980s, following description of the spirochete that cause Lyme disease, the impact of human TBD in public has significantly increased. In the USA, alone ticks are known to transmit 14 reportable TBD agents, 9 of which are transmitted by Amblyomma americanum and Ixodes scapularis. It is known that the success of ticks as pests and vectors is dependent on their ability to evade host defense mechanisms. The ability to evade host defense is due to the action of bioactive components present in the tick saliva. In this study we evaluated the effect of recombinant tick saliva proteins on macrophage activation. Here we measured expression of co-stimulatory markers: CD86, CD40 and CD80, as a marker for activation. Of fifteen recombinant tick saliva proteins investigated, six induced expression of co-stimulatory markers. Additionally pro-inflammatory and anti-inflammatory cytokines released by these macrophages on action with recombinant tick saliva proteins will be analyzed. Our data demonstrate the effect of tick saliva proteins on macrophage function. Understanding how ticks modulate host immunity could lead to novel medicinal applications: adjuvant and biomedical target discovery.