Analysis of IL-15 level in serum and effect of dexamethasone on it in asthmatic mice

Objective To investigate the change of serum interleukin-15(IL-15) levels in an asthma mouse model and action of dexamethasone intervention.Methods Mice were randomly divided into three groups:asthma group(group A),dexamethasone group(group B),and normal control group(group C).Mice in group A and B were sensitized by intraperitoneal injections of OVA and Al(OH)3 on 0,14d.On 18,19,20d,the animals were challenged with 10g/L OVA aerosol for 20 min.Mice in group B were intraperitoneal injections of dexamethasone before challenged with OVA.Mice in group C were sensitized and challenged with saline instead.To observe and evaluate all animals′ symptoms of asthma.To determine the serum interleukin-15 levels at 1h,8h,24h,48h,96h,7d with the enzyme linked immunosorbent assay.Results The waveform of serum IL-15 level in an asthma mouse model is similar to that of serum IL-4 level.Compared with the control group,the level of IL-15 is significantly increased in the asthmatic group and the dexamethasone group((16.48±2.02,11.78±2.22,9.61±1.75)pg/ml,P0.05) at 1h after stimulating;at 8h after it((16.58±3.08,13.46±1.65,10.35±2.34)pg/ml,P0.05);at 24 h after it((18.73±3.07,14.04±1.58,9.26±1.87)pg/ml P0.05);at 48h after it((15.97±2.50,12.18±1.33,10.04±2.32)pg/ml,P0.05);at 96h after it((12.03±2.68,10.19±2.39,9.66±1.53)pg/ml,P0.05);but the level of IL-15 is not significantly increased at 7d after stimulating((9.93±1.97,10.26±1.44,10.84±2.56)pg/ml,P0.05).Conclusion IL-15 maybe play an important role in asthma.Dexamethasone could decrease the levels of serum interleukin-15 and relieve animals′ symptoms of asthma through this pathway.