Review: Lymphocytes, cytokines, chemokines and the T-helper 1-T-helper 2 balance in canine atopic dermatitis

• Published in: Veterinary dermatology 2015-04, Vol.26 (2), p.124-e32
• Main Authors: Pucheu-Haston, Cherie M., Bizikova, Petra, Marsella, Rosanna, Santoro, Domenico, Nuttall, Tim, Eisenschenk, Melissa N. C.
• Format: Article
• Language: English
• Subjects: Animals; Chemokines - genetics; Chemokines - metabolism; Cytokines - genetics; Cytokines - metabolism; Dermatitis, Atopic - immunology; Dermatitis, Atopic - metabolism; Dermatitis, Atopic - veterinary; Dog Diseases - immunology; Dog Diseases - metabolism; Dogs; Lymphocytes - physiology; T-Lymphocytes, Helper-Inducer - classification; T-Lymphocytes, Helper-Inducer - physiology
• ISSN: 0959-4493; 1365-3164
• DOI: 10.1111/vde.12205

Background The development of atopic dermatitis (AD) and other cutaneous hypersensitivities involves the activation and differentiation of allergen‐specific lymphocytes. Although hypersensitivity is often considered to be a ‘T‐helper 2‐polarized’ lymphocyte response, recent evidence suggests that clinical disease is associated with the development of multiple lymphocyte phenotypes. Objectives The purpose of this paper is to review recent advances in the understanding of the roles of lymphocytes, cytokines and noncytokine factors in the pathogenesis of canine AD. Methods Citation databases, s and proceedings from international meetings published between 2001 and 2013 were reviewed in this update. Where necessary, older articles were included for background information. Results The development of canine AD is associated with changes in both cutaneous and circulating lymphocyte populations. These lymphocyte responses are characterized by the production of a complex variety of cytokines, including not only T‐helper 2 but also T‐helper 1, T‐helper 17 and regulatory T‐cell responses. In addition, microarray gene expression analysis has enabled the identification of a number of noncytokine factors that appear to be associated with atopic inflammation. These include the calcium‐binding protein S100A8, serum amyloid A and a number of protease inhibitors, as well as genes involved in epidermal barrier formation, innate immunity receptors, cell cycle proteins and apoptosis. Conclusions The development of AD in dogs is characterized by the development of a delicate balance between a variety of T‐cell phenotypes and inflammatory mediators, including cytokines, chemokines and noncytokine factors. Résumé Contexte Le développement de la dermatite atopique (AD) et des autres hypersensibilités cutanées implique la différenciation et l'activation des lymphocytes spécifiques d'allergènes. Bien que l'hypersensibilité soit souvent considérée comme étant une réponse lymphocytaire polarisée T‐helper‐2, une preuve récente suggère que la maladie clinique est associée au développement de phénotypes lymphocytaires multiples. Objectifs Le but de cet article est de revoir les données récentes dans la compréhension des rôles des lymphocytes, des cytokines et des facteurs non‐cytokiniques dans la pathogénie de la dermatite atopique canine. Méthodes Les bases de données, les résumés et les proceedings des congrès internationaux publiés entre 2001 et 2013 ont été revus dans cette mise à jo