PTD-HBcAg体外诱导小鼠髓源性树突状细胞成熟及在T淋巴细胞增殖中的作用

目的 观察融合蛋白PTD-HBcAg诱导体外培养的小鼠髓源性树突状细胞(DC)成熟及对T淋巴细胞增殖的作用.方法 体外分离培养近交系BALB/C小鼠髓源性DC加入重组粒细胞-巨噬细胞集落刺激因子(rgM-CSF)、重组IL-4培养5 d,再加人TNF-a、HBcAg和PTD-HBcAg诱导DC成熟.激光共聚焦显微镜观察免疫荧光在细胞中的分布及定位,流式细胞计数仪测定DC表面分子表达,ELISA法测定DC培养上清液中IL-12 p70的水平,CCK-8试剂盒检测T淋巴细胞增殖反应.组间数据比较采用t检验.结果 成功体外诱导培养小鼠髓源性DC,HBcAg主要定位于DC膜表面,而PTD-HBcAg能够穿透DC膜进入细胞质.PTD-HBcAg能明显上调DC表面分子CD80、CD86和主要组织相容性复合体(MHC)II类分子表达;50 mg/L和100 mg/L PTD-HBcAg诱导DC分泌IL-12 p70水半分别为(142.50±18.31)ng/L和(124.30±15.12)ng/L,明显高于HBcAg诱导组的(42.31±4.21)ng/L(t=9.234和9.045,均P＜0.05);PTD-HBcAg诱导DC刺激T淋巴细胞增殖能力明显高于HBcAg组及阳性对照TNF-a组.结论 PTD-HBcAg具有穿透DC膜能力,并能促进DC分化、成熟,明显上调表面共刺激分子表达,增强DC刺激T淋巴细胞增殖能力及分泌IL-12 p70的水平.

Effects of PTD-HBcAg induced murine bone marrow-derived dendritic cells maturation on T lymphocyte proliferation in vitro

Objective To observe the effects of PTD-hepatitis B core antigen (HBcAg) induced murine bone marrow-derived dendritic cells (DCs) maturation on T lymphocyte proliferation in vitro.Methods Bone marrow derived DCs isolated from BALB/c mice were cultured with recombinant granu|ocyte-macrophage colony-stimulating factor (rGM-CSF) and recombinant interleutin-4 (rIL-4)for 5 days.Tumor necrosis factor (TNF)-a,HBcAg and PTD-HBcAg were added to induce DCs maturation.The distribution and localization of intracellular immunofluorescence were observed by confocal microscopy,and DCs phenotypes were analyzed by flow cytometry.The level of IL-12 p70 in the supernatant was detected by enzyme linked immunosorhent assay (ELISA).The proliferation of T lymphocytes was performed by using cell counting kit-8 (CCK-8).All data were analyzed using t test.Results DCs were cultured and identified successfully.Recombinant PTD-HBcAg could penetrate into DCs cytoplasm while recombinant HBcAg was detected on the surface of cells.DCs surface molecules,such as CD80,CD86 and major histocompability complex (MHC) II were upregulated by PTDHBcAg;IL-12 p70 levels induced by 50 mg/L and 100 mg/L recombinant PTD-HBcAg were (142.50±18.31) ng/L and (124.30±15.12) ng/L,respectively,which were significantly higher than those induced by recombinant HBcAg (42.31±4.21 ) ng/L,t = 9.234 and 9.045,respectively,P＜0.05].The proliferation of T lymphocytes induced by PTD-HBcAg was much higher than that in HBcAg group or positive control TNF-a group.Conclusions PTD-HBcAg could penetrate membrane of DCs and promote the differentiation and maturation of DCs.PTD-HBcAg could up-regulate the expressions of costimulatory molecules on cell surface of DCs,and enhance the ability of DCs on stimulating T lymphocytes proliferation and IL-12 p70 production.