IL-15对异基因抗原刺激下人CD8+T细胞增殖分化影响的初步研究

Preliminary study of proliferation and differentiation for human CD8^+T cells by IL-15 stimulated by allogeneic antigen

目的:探讨IL-15对异基因抗原刺激下人CD8^+T细胞增殖分化的影响。方法:在IL-15存在的条件下,将从健康志愿者外周血中新鲜分离的CD8^+T细胞与HLA-A,-B,-DR完全错配的异体抗原提呈细胞(APCs)进行混合淋巴细胞培养(MLRs)。经9 d培养后,对诱导后产生的CD28^-CD8^+和CD28^+CD8^+T细胞亚群进行细胞毒功能测定和表型检测,并对CD8^+T细胞增殖分化过程中CD28分子的动态变化规律进行监测。结果:在IL-15诱导及异基因抗原刺激下,CD8^+T细胞增殖分化后产生的CD28+CD8^+T细胞具有细胞毒作用,与外周血新鲜分离的类似细胞相比,其高表达了Fas L、颗粒霉素-B和穿孔素;而CD28^-CD8^+抑制性T细胞不具有细胞毒作用,与外周血新鲜分离的类似细胞相比,低表达了Fas L、颗粒霉素-B和穿孔素。在异基因抗原提呈细胞刺激下,IL-15可诱导CD8^+T细胞增殖分化过程中CD28^-/CD28+细胞数比例升高(从0. 24到1. 01),并可诱导CD28+T细胞上的CD28分子丢失。结论:IL-15通过调节CD28分子的表达影响异基因抗原对CD8^+T细胞的增殖分化。

Objective:To study the effect of IL-15 on the proliferation and differentiation of human CD8+T cells stimulated by allogeneic antigen.Methods:As stimulators,APCs[CD2 depleted human peripheral blood mononuclear cells(PBMCs)]from HLA-A,B and DR mismatched volunteers and purified CD8+T cells from PBMCs were cultured for 9 days in the presence of IL-15.Then the cytotoxicity and phenotypic characteristics of CD28-CD8+and CD28+CD8+T cells expanded from CD8+T cells were analyzed,the dynamic expression CD28 molecules during the proliferation and differentiation of CD8+T were also analyzed.Results:In the present of IL-15 and the stimulation of allogeneic APCs,CD28+CD8+T cells originated from CD8+T cells displayed cytotoxicity and up-regulated the expression of FasL,GZM-B and Perforin when compared with their counterpart freshly isolated from human PBMC.At the same time,CD28-CD8+T suppressor cells originated from CD8+T cells did not exhibit cytotoxicity and expressed low levels of FasL,GZM-B and Perforin when compared with their freshly isolated counterparts.Under the stimulation of allogeneic APCs,IL-15 helps to increase the CD28-/CD28+cells ratios during the proliferation and differentiation of CD8+T cells(from 0.24 to 1.01).IL-15 was also found to induce the loss of CD28 on CD28+T cells.Conclusion:IL-15 affects the proliferation and differentiation of human CD8+T cells stimulated by allogeneic antigen through modulating the expression of CD28 molecules.