转染Foxp3的CD4+CD25-T细胞对NK细胞免疫活性影响的研究

目的:利用载有Foxp3基因的腺病毒载体转染,使小鼠CD4+CD25-T细胞强制性高表达Foxp3,并研究体外诱导获得的Foxp3高表达T细胞对NK细胞免疫活性的调节作用及其机制。方法:将载有Foxp3基因的逆转录病毒转染CD4+CD25-T细胞获得持续性高表达Foxp3的CD4+T细胞。CD4+Foxp3+T细胞与NK细胞共培养后,通过51Cr标记法检测NK细胞的杀伤毒性。在Transwell共培养实验体系中,通过TGF-β阻断实验来检测NK细胞杀伤毒性。结果:通过逆转录病毒转染幼稚CD4+CD25-T细胞获得了表达Foxp3的CD4+T细胞模型。CD4+Foxp3+T细胞在与NK细胞共培养后,能显著抑制NK细胞毒性杀伤作用。在共培养体系中加入抗TGF-β抗体后,其抑制率显著降低。与NK细胞直接接触的CD4+Foxp3+T细胞可以诱导NK细胞免疫抑制。结论:强制性表达Foxp3的CD4+CD25-T细胞可以在体外发挥免疫抑制作用,能抑制NK细胞的细胞毒性杀伤作用。转染Foxp3的CD4+CD25-T细胞对NK细胞发挥作用依赖于细胞之间的直接接触,与转染后T细胞表面表达TGF-β有关。

The effect of Foxp3-transduced CD4 + CD25-T lymphocytes on immunological activity of NK cells

Objective:To investigate the effect and mechanism of Foxp3-transduced CD4+CD25-T lymphocytes on the immunological activity of NK cells.Methods:CD4+CD25-T lymphocytes were retrovirally tranfected with Foxp3 gene.The transduced T lymphocytes were cultured with NK cells,and 51Cr labeling was used to detect NK cells cytotocixity.The anti-TGF-β antibody was added into the co-culture system to investigate the TGF-β blocking effect.Also the transwell co-culture system was used to investigate the regulatory effect of NK cells.Results:Foxp3-transduced CD4+CD25-T lymphocytes suppressed cytotocixity of NK cells significantly.After addition of anti-TGF-β antibody into the co-culture system,the inhibition rate of T lymphocytes decreased dramatically.Immunologic suppression of NK cells was induced by Foxp3-transduced CD4+CD25-T lymphocytes.Conclusion:CD4+Foxp3+ T lymphocytes can significantly inhibit the cytotoxicity of NK cells.Based on the pattern of cell-to-cell,Foxp3-transduced CD4+CD25-T lymphocytes affect NK cells,which was associated with the expression of TGF-β.