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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Note to editors: An abstract follows.
“Investigation of neutrophil infiltration in the acute canine atopic dermatitis model”
DOI: 10.3389/falgy.2025.1716716
Authors: Chie Tamamoto-Mochizuki, North Carolina State University and University of Tennessee Knoxville; Santosh K. Mishra, North Carolina State University
Published: Dec. 16, 2025 in Frontiers in Allergy
Abstract:
Atopic dermatitis (AD) is an inflammatory skin condition associated with chronic itch and inflammation in both humans and animals. While this disease depends upon various immune cell types, the precise role and kinetics of neutrophils remain elusive, particularly in relevant large-animal models. Given a recent report suggesting the involvement of neutrophils in a mouse model, we aimed to characterize the temporal presence and infiltration of these cells in a canine model of house dust mite (HDM)-induced AD. AD was induced in canines via HDM exposure, and skin biopsies were analyzed over a time course (0–96 h) using standard H&E staining and specific immunofluorescent (IF) staining for canine neutrophils. Our results showed general cellular infiltration with the H&E method, while IF further confirmed detectable neutrophil immunoreactivity starting between 24 and 96 h post-challenge in atopic skin. Quantitation demonstrated a significant increase in neutrophil infiltration (cells/mm2) in atopic skin at 48 h following HDM exposure compared to baseline (p = 0.041). Collectively, our data confirms time-dependent infiltration of neutrophils into the skin of the canine AD model following allergen challenge, supporting the hypothesis that this previously overlooked immune cell may play a role in the acute phase of AD pathogenesis and sensitization.
Journal
Frontiers in Allergy
Method of Research
Experimental study
Subject of Research
Animal tissue samples
Article Title
Investigation of neutrophil infiltration in the acute canine atopic dermatitis model
COI Statement
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.