摘要
目的 研究IL 2基因修饰增强小鼠骨髓来源的树突状细胞 (DC)对肿瘤抗原提呈的功能和对MHCⅠ类限制性抗原多肽体内诱导的细胞毒性T淋巴细胞 (CTL)的激活作用及其相关的免疫机制。方法 用重组腺病毒介导IL 2基因修饰小鼠骨髓来源的DC ,ELISA法检测DC培养上清中IL 1 2和CTL上清中IFN γ的分泌水平 ,用流式细胞仪 (FACS)分析IL 2基因修饰对DC表面共刺激分子B7表达的调节和内吞卵清蛋白抗原八肽 (OVA)的作用 ,3H TdR掺入法检测DC对小鼠Lewis肺癌细胞株3LL肿瘤抗原的提呈能力 ;51 Cr释放法检测用 3LL细胞MHCⅠ类抗原多肽Mut1致敏IL 2基因修饰的DC对小鼠体内特异性CTL的诱导作用。结果 经IL 2基因修饰后 ,DC 48h能分泌高水平的IL 1 2(78.4± 6 .6)pg·(1× 1 0 6 细胞 ) - 1 ·ml- 1 ,DC表面的共刺激分子B7表达增加 ,DC内吞OVA多肽的作用也增强。经Mut1致敏后与同系 3LL细胞荷瘤的小鼠T淋巴细胞混合培养 ,3H TdR掺入量显著增高 ,用Mut1致敏IL 2基因修饰的DC免疫小鼠后 ,能在体内诱导出分泌高浓度IFN γ[(1 1 68.0± 58.4)pg/ml]的CTL活性。结论 IL 2基因修饰可活化DC抗原提呈的第二信号 ,增强DC对抗原多肽的捕获和提呈功能 ,经MHCⅠ类抗原多肽致敏后 ,在小鼠体内能更有效地诱导出CTL特异性抗肿瘤免疫应答。?
Objective To investigate the effects of IL 2 gene modification enhancement of the antigen presenting function of the mouse bone marrow derived dendritic cells and on the activation of CTL induced by MHC class Ⅰ molecule restricted antigen peptides as well as the related immunological mechanisms. Methods DCs were prepared from mouse bone marrow and modified by recombinant IL 2 adenovirus(DC IL 2). The IL 12 and IFN γ levels in culture supernatant of DC and CTL were examined by ELISA, the expression of costimulatory molecules and fluorescent intensity of endocytosis of OVA FITC in DC by FACS, the capacity of presenting 3LL cell tumor antigen by 3 H TdR incorporation method, the MHC class Ⅰ restricted tumor antigen peptide Mut1of 3LL cells pulsed DC IL 2 to induce CTL cytotoxicity by 51 ?Cr 4 hr releasing assay. Results After IL 2 gene modification, DC IL 2 could produce high level of IL 12[(78.4±6.6)pg·(1×10 6 cells) -1 ·ml -1 ]. The expression of costimulatory molecules on DC IL 2 was increased, the fluorescent intensity of DC captured OVA FITC was enhanced, and the proliferation of allo T cells from 3LL bearing mouse pulsed with Mut1 was also enhanced. Mut1 antigen peptide pulsed DC IL 2 could induce more potent antigen specific CTL cytotoxicity and excrete high concentration of IFN γ[(1?168±58.4)pg/ml] in vivo. Conclusion IL 2 gene modification of DC can activate second signal for DC presenting antigen, and enhance the function for capturing and presenting tumor antigen. DC IL 2 pulsed with MHC class Ⅰ restricted tumor antigen peptide can induce specific anti tumor immune response more effectively. Owing to IL 2 gene modification, the functions of IL 12 excretion and T cell activation of DC were promoted, so that the capacity of CTL excreting IFN γ was enhanced, which are relevant to the immune mechanism.
出处
《中华血液学杂志》
CAS
CSCD
北大核心
2002年第5期247-250,共4页
Chinese Journal of Hematology
