Effect of nicotine on the expression of Th1/Th2 cytokines and transcription factor T-bet/GATA-3 in cultured CD4+ T cell of rat sensitized by ovalbumin / 中华微生物学和免疫学杂志

ABSTRACT

ObjectiveTo investigate the effects of nicotine on the expression of Th1/Th2 cytokines and transcription factor T-bet/GATA-3 in cultured CD4+ T of rat sensitized by ovalbumin.Methods Two weeks after immunization by ovalbumin,splenic CD4+ T cells of Wistar rat were purified using CD4+T cell enrichment kit.Purified CD4+ T cells of rat were cultured and divided into 4 groupsa control group,1 μg/ml nicotine stimulated group,10 μg/ml nicotine stimulated group,100 μg/ml nicotine stimulated group.These cells,in their groups,were stimulated with or without nicotine and were all challenged simultaneously with OVA.Supernatants and cell pellets were harvested after being stimulated for 24 h.The concentration of IFN-γ and IL-4 in supernatants were measured by enzyme-linked immunosorbent assay (ELISA).Real-time PCR was used to determine the mRNA expression of T-bet and GATA-3 in CD4+T cells.Results ( 1 ) IFN-γproduction was significantly decreased in all nicotine treated groups [ ( 113.78±6.06) ng/L,(70.31±7.26) ng/L,(20.00±2.14) ng/L] compared with the control group[ (142.30± 5.89) ng/L],and the level of IL-4 was significantly increased in all nicotine treated groups [ (69.49±3.91) ng/L,(93.63±4.56) ng/L,(50.97±3.07) ng/L] compared with the control group[ (36.91±3.24) ng/L].(2) Expression of T-bet mRNA in all nicotine treated groups(0.73±0.03,0.57±0.04,0.31 ±0.00) was lower than that in the control group(0.98±0.09),but expression of GATA-3 mRNA in all nicotine treated groups (4.31±0.26,5.16±0.23,1.56±0.14) was significantly higher than that in the control group(1.00±0.07).Conclusion Nicotine may play a key role in the development of Th2-type allergic inflammation in asthma by promoting over-expression of GATA-3 mRNA and downregulating the expression of T-bet mRNA.