A new study from North Carolina State University found that neutrophils - white blood cells that are a key part of the immune system - play a role in the early stages of atopic dermatitis flares in dogs. The work is a first step toward understanding the role that these immune cells may play in the early stages of allergic skin response, and could have implications for human sufferers of atopic dermatitis.
Atopic dermatitis (AD) is a type of eczema associated with allergic reactions and characterized by inflamed itchy patches of skin. While the disease depends upon the interplay of several immune cell types, the role of neutrophils hadn't been extensively explored.
"We came across a previous study that showed an association between neutrophils and AD in a mouse model, so we wanted to follow up in a canine model," says Santosh Mishra, associate professor of molecular biomedical sciences at NC State and corresponding author of the new work.
The researchers compared skin samples from four dogs with house dust mite-induced AD with samples from five healthy, or control dogs. They used immunofluorescent staining to measure the neutrophil response in the AD samples at 24-, 48- and 96-hour timepoints after exposure.
The researchers found that neutrophils arrive at the site early in the allergic response, peak at around 48 hours and dissipate by the 96-hour mark.
"A neutrophil's main role in the immune system is to clear away foreign bodies," Mishra says. "They release chemicals that recruit other cells to the site to either dampen or heighten the immune response. At this point, we don't know whether they're there to recruit other immune cell types, or to clear invaders away - and it's possible that they're doing both - but 48 hours marks the peak of their activity."
The researchers hope that this work will pave the way for closer study of the neutrophil's role in AD throughout a flareup, and its relation to the other immune cells involved in the allergic response.
"Skin is a complex thing," Mishra adds. "That neutrophils played a role in allergic response in AD wasn't known until recently. Now we have another pathway to look at in trying to find therapeutics.
"There are important translational aspects here as well," Mishra says. "Dogs share our environment and many of our disease processes are similar. Improved understanding of how AD works in dogs will lead to better outcomes both for them and for humans."
The work appears in Frontiers in Allergy and was supported by NC State and the National Institutes of Health. Chie Tamamoto-Mochizuki, a former NC State postdoctoral researcher currently at the University of Tennessee Knoxville, is first author.
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