负载HIP的耐受性树突状细胞对BDC2.5 T细胞的免疫调节作用

The immunoregulatory effect of HIPs-loaded tolerogenic dendritic cells on BDC2.5 T cells

目的:探究负载HIP(hybrid insulin peptide)的耐受性树突状细胞(tolerogenic dendritic cell,tolDC)对致糖尿病性BDC2.5 T细胞的免疫调节作用。方法:采用细胞因子诱导生成NOD(non-obese diabetic)小鼠骨髓细胞来源的未成熟树突状细胞(immature dendritic cell,iDC),培养过程中额外加入维生素D3可生成tolDC,脂多糖(lipopolysaccharide,LPS)刺激24 h后可以分别获得LPS-iDC、LPS-tolDC,收集其上清液检测细胞因子白介素(interleukin,IL)-12p70及转化生长因子-β(transforming growth factor-β,TGF-β),通过形态学及流式细胞术鉴定上述树突状细胞(dendritic cell,DC)的表型。将致糖尿病性T细胞即BDC2.5 CD4+T细胞与负载HIP的4组DC共孵育72 h后,检测T细胞增殖、活化以及调节性T细胞(regulatory T cell,Treg)的产生情况。结果:表型鉴定结果显示tolDC呈现低表达共刺激分子CD80和CD86、高表达共抑制分子PD-L1的耐受性表型,在脂多糖的刺激下仍保持稳定,且与LPS-iDC相比,LPS-tolDC分泌低水平的IL-12p70、高水平的TGF-β。负载HIP的tolDC及LPS-tolDC均可以抑制BDC2.5 T细胞的增殖和活化,诱导抗原特异性Treg的产生。结论:负载HIP的tolDC可以通过其稳定的耐受表型及功能抑制致糖尿病性BDC2.5 T细胞的增殖活化,诱导抗原特异性Treg的产生。

Objective:To investigate the immunoregulatory effect of tolerogenic dendritic cells(tolDCs)loaded with hybrid insulin peptides(HIPs)on diabetogenic BDC2.5 T cells.Methods:Bone marrow derived imature DCs(iDCs)of non-obese diabetic(NOD)mice were induced with cytokines,and additional vitamin D3 was added to generate tolDCs.After 24 h stimulation with lipopolysaccharide(LPS),the supernatants of LPS-iDCs and LPS-tolDCs were collected to detect cytokines IL-12p70 and TGF-β,and the phenotype of the above DCs was identified by morphology and flow cytometry.Diabetogenic T cells,namely BDC2.5 CD4+T cells were incubated with HIPs-loaded DCs for 3 days,and the proliferation,activation and regulatory T cells(Tregs)production were detected.Results:Phenotypic identification results showed that tolDCs had low expression of costimulatory molecules CD80,CD86,and high expression of coinhibitory molecule PD-L1.The phenotype of tolDCs remained stable under the stimulation of LPS,and the secretion of IL-12p70 was low while the secretion of TGF-βwas high compared with LPS-iDCs.Both tolDCs and LPS-tolDCs loaded with HIPs could inhibit the proliferation and activation of BDC2.5 T cells and induce the production of antigen-specific Tregs.Conclusion:HIPs loaded tolerogenic dendritic cells can inhibit the proliferation and activation of diabetogenic BDC2.5 T cells and promote the production of Tregs through their stable tolerance phenotype and function.