title: Participation of T regulatory cells in equine recurrent airway obstruction.
abstract: Recurrent airway obstruction (RAO) is an equine immune-mediated disease with a high incidence worldwide. The aim of this work was to contribute to the understanding of RAO pathogenesis by studying T cells bearing regulatory markers in peripheral blood (PB) and in bronchoalveolar lavage fluid (BALF) recovered from the same group of susceptible horses before and after exposure to moldy hay, which has been shown to induce RAO signology in our horse herd. With this purpose, mononuclear cells were obtained from the BALF and PB from horses before and after antigenic challenge and were stained with fluorochrome-conjugated antibodies against CD4, CD25 and Foxp3 and subsequently analyzed by flow cytometry. The results indicated that the percentage of CD4+, Foxp3+ cells clearly increased in PB and BALF obtained from horses with RAO. In addition, the percentage of CD4+, CD25(high) cells was greatly augmented in BALF of RAO positive horses compared with a baseline. No changes were observed in the PB compartment. The percentage of CD4+, CD25(high), Foxp3+ cells in BALF increased in horses with active disease compared to horses in remission; this cell population also does not show changes in the PB compartment when RAO positive and RAO negative horses were compared. On the other hand, when the percentage of CD4, Foxp3 positive cells were compared with the percentage of CD4+, CD25(high) cells, the numbers were very similar. This observation was true for PB and BALF cells from non exposed horses as well as horses exposed to antigen. In all the experimental situations studied, the population expressing all of the markers CD4+, CD25(high), Foxp3+ represent only a minor percentage of CD4+, CD25(high) or CD4+, Foxp3 subpopulations; therefore, an significant number of CD4+, CD25(high), Foxp3- and CD4+, CD25(null), Foxp3+ cells must exist. Finally, we conclude that horses with RAO show an airway accumulation of T cells bearing regulatory markers that probably are modulating the course of this disease, and that these T cells may be involved in the resolution of immune-mediated bronchial inflammation.
authors: Immunology Department, Faculty of Medicine, Universidad Austral de Chile , Valdivia, Chile; Graduate School Faculty of Veterinary Sciences, Universidad Austral de Chile , Valdivia, Chile. Electronic address: henriquezclaudio@gmail.com.
authors: Claudio
authors: C
authors: Henríquez
authors: Pharmacology and Morphophysiology Department, Faculty of Veterinary Sciences, Universidad Austral de Chile, Valdivia, Chile.
authors: Barbara
authors: B
authors: Perez
authors: Immunology Department, Faculty of Medicine, Universidad Austral de Chile , Valdivia, Chile.
authors: Natalia
authors: N
authors: Morales
authors: Physiology Department, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile.
authors: José
authors: J
authors: Sarmiento
authors: Pathology Department, Regional Hospital of Valdivia, Universidad Austral de Chile, Valdivia, Chile.
authors: Cristian
authors: C
authors: Carrasco
authors: Pharmacology and Morphophysiology Department, Faculty of Veterinary Sciences, Universidad Austral de Chile, Valdivia, Chile.
authors: Gabriel
authors: G
authors: Morán
authors: Immunology Department, Faculty of Medicine, Universidad Austral de Chile , Valdivia, Chile.
authors: Hugo
authors: H
authors: Folch
mesh_terms: D000402:Airway Obstruction / Q000209:etiology / Q000276:immunology / Q000662:veterinary*; D000485:Allergens / Q000008:administration & dosage; D000818:Animals; D000946:Antigens, Fungal / Q000008:administration & dosage; D001232:Aspergillus fumigatus / Q000276:immunology / Q000472:pathogenicity; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D015704:CD4 Antigens / Q000378:metabolism; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000145:classification / Q000276:immunology; D002677:Chile; D031747:Echinochloa / Q000276:immunology / Q000382:microbiology; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006734:Horse Diseases / Q000209:etiology / Q000276:immunology*; D006736:Horses; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D012008:Recurrence; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D000485:Allergens; D000946:Antigens, Fungal; D015704:CD4 Antigens; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit
keywords: CD4+ CD25+ Foxp3+; Horses; Recurrent airway obstruction; Regulatory T cells