The transient nature of the Th17 phenotype

CD4(+) Th lymphocytes represent a heterogeneous population of cells that play an essential role in adaptive immunity. In addition to type 1 (Th1) and type 2 (Th2) cells, a third subset of CD4(+) Th effector cells has recently been discovered, named type 17 (Th17) because of its unique ability to produce interleukin (IL)-17. Initial studies in mice suggested that Th17 cells are the pathogenic cells in autoimmune disorders, whereas Th1 cells are protective. Studies in humans have demonstrated the plasticity of Th17 cells and their ability to convert to Th1 cells. This Th17 to Th1 cell plasticity has also been confirmed in mice and, furthermore, it was found that Th17 cells appear to be pathogenic only when they shift to Th1 cells. A study in this issue of the European Journal of Immunology uses an IL-17 fate mapping mouse strain, which permits the identification of the cells that have been IL-17 producers, to provide definitive evidence that Th17 cells, either generated in vitro or in vivo, represent a transient phenotype that tend to convert into IFN-γ-producing cells. Our Commentary discusses this interesting point in light of previous data suggesting the same concept.     

T-bet质粒基因转染对哮喘小鼠支气管肺泡灌洗液白细胞介素13和内皮素1的影响

目的 观察气道内T-bet质粒基因转染对哮喘小鼠气道肺泡灌洗液白细胞介素13(IL13)、内皮素1(ET-1)的影响.方法 C57BL/6J小鼠32只,完全随机分为4组(n=8),即哮喘模型组(A组)、正常对照组(B组)、空质粒干预组(C组)和模型T-bet质粒干预组(D组).用卵白蛋白(OVA)抗原溶液小鼠腹腔注射致敏,滴鼻造模.B组用生理盐水代替卵白蛋白,C组和D组卵白蛋白激发48 h前,分别经鼻滴入50μg空质粒或重组T-bet质粒.免疫印迹检测和酶联免疫吸附法(ELISA)检测各组小鼠的支气管肺泡灌洗液中IL-13、ET-1的水平.结果 哮喘模型组小鼠支气管肺泡灌洗液(BALF)中Th2因子IL-13和ET-1水平比正常对照组升高[(2.32±0.40)ng/L比(0.38±0.16)ng/L,(40.07±6.52)ng/L比(14.16±0.51)ng/L,均P＜0.05];模型T-bet质粒干预组BALF中Th2因子IL-13和ET-1水平[(1.16±0.19)和(23.08±2.59)ng/L]比哮喘模型组降低(均P＜0.05).结论 气道内转染T-bet质粒能有效下调小鼠BALF中Th2因子IL-13及ET-1水平.