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The Innate Immune Response in the Airways and in Blood is Altered by Training in Horses
Author(s) -
Frellstedt L,
Waldschmidt I,
DupuisTricaud M,
Lekeux P,
Art T
Publication year - 2014
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/evj.12267_17
Subject(s) - tlr2 , tlr4 , immunology , medicine , innate immune system , receptor , immune system , cytokine , horse , biology , paleontology
Lower airway diseases are common problems in sports and racing horses. In humans, exercise causes increased susceptibility to respiratory infections associated with down‐regulated expression of Toll‐like receptors ( TLRs ), co‐stimulatory and antigen‐presenting molecules. Because numerous cell types are implicated in important defense mechanisms against airborne infections, we aimed to assess the effect of training on innate immune responses of pulmonary alveolar macrophages ( PAM ), equine bronchial epithelial cells ( EBEC ) and blood monocytes. Methods PAM , EBEC and monocytes were collected at rest and after a standardized exercise test ( SET ) from eight untrained, trained and deconditioned horses. We compared their respective expression of TLR 1‐9 by qPCR and their cytokinic responses following exposure to various TLR ligands by ELISA . Data were reported as least square means and analyzed by a global linear mixed model. Results The m RNA expression of TLR 3 was down‐regulated by training in PAM (P<0.0001) and monocytes (P<0.015), whereas the m RNA expression of TLR4 was up‐regulated in monocytes (P = 0.0004) only. Monocytes stimulated with TLR2‐ and TLR4‐ligands showed increased cytokine secretion after training and deconditioning (P<0.025). EBEC from trained horses produced less TNF ‐alpha (P<0.05) after treatment with ligands of TLR2 and TLR 3 compared with EBEC from untrained horses. The production of TNF ‐alpha (P<0.001) and IFN ‐beta (P<0.001) in non‐stimulated and stimulated PAM was decreased in trained and deconditioned horses. Conclusions The impaired cytokine production in PAM and EBEC after a training period might explain the increased susceptibility to respiratory viral infections and is associated with the activation of cells at the systemic level. Ethical Animal Research This work was approved by the Animal Ethics Committee of the National Veterinary School of Alfort (agreement number: 13/12/11‐9). Sources of funding: Hippolia Foundation, the Conseil Regional de Basse‐Normandie, the European Regional Development Fund and the Fonds unique interministeriel. Competing interests: none.