Location: Arthropod-borne Animal Diseases ResearchTitle: Innate Mammalian Immune Response to Culicoides Feeding Author
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/19/2017
Publication Date: 7/31/2017
Citation: Drolet, B.S., Lehiy, C.J., Reister-Hendricks, L.M., Ruder, M.G., Mcvey, D.S. 2017. Innate Mammalian Immune Response to Culicoides Feeding. Meeting Abstract. 1. Interpretive Summary:
Technical Abstract: Hematophagous Culicoides spp. biting midges are of great agricultural importance as livestock and wildlife pests and as vectors of orbiviruses such as bluetongue, epizootic hemorrhagic disease, and African horse sickness viruses, as well as vesicular stomatitis, bovine ephemeral fever and Schmallenberg viruses. During feeding on susceptible animal hosts, virus-infected saliva is deposited which contains anti-hemostatic factors and protease inhibitors to facilitate feeding and immunomodulate host defenses to protect the insect. Although evidence exists for vector-enhanced virus transmission by midge feeding, exact mechanisms remain unclear. One reason for this is that very little is known about the effects of Culicoides feeding on mammalian hosts, particularly in the hours directly after a blood meal has been taken; a critical time period for transmitted viral particles to establish infection. Using a mouse model, we examined skin, lymph node cell populations and cytokines in the first three days after midge feeding to characterize immune responses to midge bites and gain insight as to why Culicoides are such efficient vectors for orbiviruses. Culicoides midge feeding elicited a Th-mediated cellular response with significant mast cell activation, hemorrhaging, edema and vasodilation, as well as rapid dermal infiltration of CD16/32+ granulocytes, known infection targets of orbiviruses. Effects on the dermal vasculature and lymphoid tissues led to a local, then systemic immunological state that would be highly favorable for orbivirus infection and dissemination.