A comparison of IL-1β and IL-8 mRNA and their respective proteins in equine bronchoalveolar lavage fluid during recurrent airway obstruction.

A comparison of IL-1β and IL-8 mRNA and their respective proteins in equine bronchoalveolar lavage fluid during recurrent airway obstruction, Online J Vet Res., 15 (3): 215-228, 2011. The role of different cytokines in triggering airway inflammation during recurrent airway obstruction (RAO) has become the focus of recent investigations. The majority of published papers are principally concerned with cytokine mRNA while there are fewer papers which deal with their respective proteins alone or their correlation with mRNA in the same trial. In the present study IL-1β and IL-8 mRNAs and their respective proteins were quantified by Real Time RT-PCR and western blot and related to bronchoalveolar lavage fluid (BALF) cytology in 8 horses during an RAO attack induced by stabling on straw. The results were compared to those obtained from 4 susceptible horses kept in a pasture. Significant changes in cytokine profile and BALF pattern were observed in the challenge group during the study (12 days) while no modifications were detected in the control group. An increase in IL-1β mRNA and protein preceded the increase of the same parameters as IL-8, but the related mRNA and respective protein levels did not strictly follow the same pattern. The rise in IL-1β protein, but not mRNA, continued over the entire period and was correlated with BALF neutrophilia. On the contrary, the increase in both IL-8 mRNA and protein were transient, and the peak of the protein (day 8) followed the peak of BALF neutrophilia. The increase of IL-1β, paralleled by neutrophil and epithelial cell accumulation in the BALF, is indicative of the active production of the cytokine by these cells. This reinforces the pivotal role of cells other than the macrophages in driving airway inflammation during RAO