Location: Arthropod-borne Animal Diseases Research
Project Number: 3020-32000-020-009-R
Project Type: Reimbursable Cooperative Agreement
Start Date: May 18, 2026
End Date: Apr 30, 2028
Objective:
Research Objectives:
1. Quantify the host skin immune response to probing by uninfected Culicoides midges using a human skin model.
2. Compare the host skin immune response and infection dynamics to probing by Culicoides midges infected with a historical strain of Oropouche virus to the host response from probing by Culicoides midges infected with an outbreak strain of Oropouche virus using a human skin model.
Approach:
The project team assembled has a complex and complementary set of interdisciplinary scientific and practical skills necessary successfully complete the research under the proposed objectives.
Objective 1: Quantify the host skin immune response to probing by uninfected Culicoides midges using a human skin model.
Approach: We will establish an immunological baseline for cutaneous response to probing by uninfected midges on the skin explants. After the uninfected midges probe the skin for 30 minutes, the skin will be incubated for 2, 8 and 24 hours, samples will be collected and sent back to the University of Pittsburgh. The samples will be stained for immunofluorescence confocal microscopy to identify and differentiate immune cells and their spatial and temporal location.
Objective 2: Compare the host skin immune response and infection dynamics to probing by Culicoides midges infected with a historical strain of Oropouche virus to the host response from probing by Culicoides midges infected with an outbreak strain of Oropouche virus using a human skin model.
Approach: ARS will infect Culicoides midges with a known concentration of Oropouche virus via microinjection. After two weeks of incubation during which the virus will have disseminated to the salivary glands, the infected midges will be allowed to probe and interact with the skin explant as described in the approach for objective 1. The explant will be returned to the Univeristy of Pittsburgh for processing as described in objective 1, with the addition of virus-specific antibodies in the immunofluorenscence assays. ARS will test the midges that probed the skin explant to quantify their post-probe viral load.