Th17 cells and its role in the pathogenesis of bronchial asthma

T helper cell 1 （Thl）/Th2 pathway has been regarded as the classical pathway of bronchial asthma （asthma）. In recent years,Thl7 cells which is a helper CD4＋ T cell has been found, Thl7 cells mainly produce interleukin 17 （IL-17）, and it plays an important role in the pathogenesis of asthma. The IL-17 secreted by Thl7 ceils is a highly pro-inflammatory cytokines,it has been found that IL-17 is associated with moderate to severe asthma. This paper reviews the discovery of Th17 cells and their biological characteristics, some cytokines associated with the differentiation and development of Thl7 cells. Th17 cells in mechanisms of the pathogenesis of asthma. Researches on Thl7 cells contribute to further complete the mechanisms of pathogenesis of asthma, which is helpful for the diagnosis and treatment of asthma in the future. Key words: Bronchial asthma ;  Thl 7 cells ;  Interleukin 17