Taurine prevents interleukin-2-induced acute lung injury in rats

Background: The therapeutic efficacy of interleukin-2 (IL-2) has been limited by a dose-dependent vascular leak syndrome. This may be related to neutrophil-mediated endothelial injury. Taurine has been shown to decrease this injury in vitro. This study investigates the role of taurine in preventing IL-2-induced lung injury, and the role of neutrophil-endothelial interactions in mediating this injury. Methods: Study 1: Sprague-Dawley rats (n = 12/groups) were randomised to controls, IL-2-treated (1 × 10⁶ units), and IL-2-treated with taurine (4% solution, orally for 48 h prior to IL-2 therapy). Lung injury was measured by extravascular lung water (wet/dry weight) and bronchoalveolar lavage protein concentration. Neutrophil infiltration was evaluated by measuring myeloperoxidase activity and bronchoalveolar lavage neutrophil concentration. Study 2: Rats (n = 10/group) were randomised into the same groups as study 1. Neutrophil-endothelial interactions in mesenteric vessels were assessed by intravital microscopy at half-hourly intervals. Results: Taurine reduced IL-2-induced acute lung injury as reflected by a decrease in wet-to-dry lung weight ratio from 7.2 ± 0.5 in the IL-2 group to 4.7 ± 0.3 in the taurine group (p < 0.05), and a decrease in bronchoalveolar neutrophil concentration from 823 ± 19.5 in the IL-2 group to 538 ± 18 in the taurine group (p < 0.05). Intravital microscopy demonstrated that IL-2 increased leucocyte adhesion and migration in mesenteric vessels, and that this was significantly reduced by taurine. Conclusion: These data suggest that taurine prevents IL-2-induced tissue injury in part by decreasing neutrophil-endothelial interactions.