Most people find insect bites annoying. However, a group of scientists* have put insect bites to good use in a study of allergic reactions. Culicoides obsoletus, a European biting midge, causes a variety of reactions when it bites horses. Some animals respond to bites with Insect Bite Hypersensitivity (IBH) characterized by lesions on the skin. Other animals do not respond with IBH; their skin remains normal. What is the difference in the response?
Scientists* homogenized midges and injected the allergenic solution into Shetland ponies. They measured the response of the ponies’ immune system. Ponies that had a healthy response produced IFNγ-expressing CD4 T-cells (Type 1). Ponies that developed IBH responded by instead producing cytokine IL-4 T-cells (Type 2). This suggests that allergic reactions might be prevented by injection of an antigen in a way that teaches the immune system to produce a Type 1 (healthy) reaction rather than a Type 2 (unhealthy) reaction.
The use of insects to study diseases has increased due to the advent of molecular techniques and analysis. Such studies using insects may lead to better health.
*Meulenbroeks C, van der Lugt JJ, van der Meide NMA, Willemse T, Rutten VPMG, et al. (2015) Allergen-Specific Cytokine Polarization Protects Shetland Ponies against Culicoides obsoletus-Induced Insect Bite Hypersensitivity. PLoS ONE 10(4): e0122090. doi:10.1371/journal.pone.0122090