Elevated circulating Th2 but not group 2 innate lymphoid cell responses characterize canine atopic dermatitis

Area of Science:

• Immunology
• Veterinary Dermatology
• Genomics

Background:

• Atopic dermatitis (AD) is a prevalent allergic skin disease in dogs, posing clinical challenges.
• Understanding the immunologic pathways of canine AD is crucial for developing new treatments.
• Type 2 inflammation, driven by Th2 cells and group 2 innate lymphoid cells (ILC2s), is implicated in human and mouse AD models.

Purpose of the Study:

• To characterize canine Th2 cells and ILC2-like cells involved in AD pathogenesis.
• To investigate the role of these cells in type 2 inflammation in canine AD.
• To identify novel therapeutic targets for canine AD.

Main Methods:

• Ex vivo analysis of canine immune cells.
• Measurement of type 2 cytokine production.
• Expression analysis of the transcription factor Gata3.
• Single-cell RNA sequencing of T cells from dogs with AD.
• Correlation analysis of circulating Th2 cells with chronic canine AD.

Main Results:

• Previously uncharacterized canine ILC2-like cells and Th2 cells were identified.
• These cells produced type 2 cytokines and expressed Gata3.
• Increased circulating Th2 cells were associated with chronic canine AD.
• Single-cell RNA sequencing revealed a unique gene expression signature in T cells of dogs with AD.

Conclusions:

• Pro-allergic Th2 cells play a significant role in orchestrating canine AD.
• The study provides new insights into the immunologic basis of canine AD.
• Identified cell types and pathways offer potential for developing improved canine AD therapies.