Recurrent airway obstruction (RAO) in horses is characterized by IFN-gamma and IL-8 production in bronchoalveolar lavage cells.

Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
Veterinary Immunology and Immunopathology (Impact Factor: 1.75). 12/2003; 96(1-2):83-91. DOI: 10.1016/S0165-2427(03)00142-9
Source: PubMed

ABSTRACT In horses prone to developing recurrent airway obstruction (RAO), we tested the hypotheses that the cytokine profile in the bronchoalveolar lavage (BAL) cells of affected horses would reflect a polarized Th-2 response; that cytokine and chemokine alterations would occur within 24 h of allergen exposure; and that allergen exposure would induce alterations in the expression of the transcription factor t-bet (t-box-expressed in T-cells). The expression levels of interleukin-4 (IL-4), IL-13, Interferon-gamma (IFN-gamma), t-bet, IL-8 and granulocyte-macrophage colony stimulating factor (GM-CSF) were measured in BAL cells obtained from control and RAO-susceptible horses during an asymptomatic phase and at 24 h and 5 weeks post-stabling and hay exposure. At each sampling time, BAL neutrophil percentages in the RAO-group exceeded controls. In the RAO-group, only IL-13 expression was decreased 2-fold during the asymptomatic phase. No differences in cytokine or chemokine expression were detected during the acute exposure phase. During the chronic phase, IFN-gamma and IL-8 expression levels were 2.5- and 3-fold greater, respectively, in the RAO-group. No other differences in gene expression were detected. We conclude that the cytokine profile of the airway cells does not reflect a polarized Th-2 response; that increases in IFN-gamma result from a t-bet independent pathway and that chemokines from epithelial or interstitial cells may contribute to early neutrophil influx.

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