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Recurrent airway obstruction (RAO) in horses is characterized by IFN-γ and IL-8 production in bronchoalveolar lavage cells
- Ainsworth, Dorothy M., Grünig, Gabriele, Matychak, Mary Beth, Young, Jean, Wagner, Bettina, Erb, Hollis N, Antczak, Douglas F.
- Veterinary immunology and immunopathology 2003 v.96 no.1-2 pp. 83-91
- T-lymphocytes, acute exposure, allergens, gene expression, granulocyte-macrophage colony-stimulating factor, hay, horses, interferon-gamma, interleukin-13, interleukin-4, interleukin-8, neutrophils, transcription factors
- 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-γ), 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-γ 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-γ result from a t-bet independent pathway and that chemokines from epithelial or interstitial cells may contribute to early neutrophil influx.