转染肝癌总RNA的树突状细胞疫苗对肝癌的抑制作用及其机制

目的探讨转染肝癌细胞总RNA转染的树突状细胞(DC)疫苗抑制肝癌作用及其机制。方法采用粒/巨噬细胞集落刺激因子(GM-CSF)和白细胞介素(IL)-4联合培养6 d成小鼠骨髓来源不成熟DC(iDC),质脂体转染肝癌细胞系Hepa1-6 RNA入iDC,用LPS刺激后成为Hepal-6 RNA/DC疫苗,对照组为iDC组、LPS/DC组Saline组,以每只2×10~6个细胞腹腔注射免疫小鼠每周1次共3次,然后接种5×10~5 Hepal-6细胞,观察肿瘤生长情况、特异性CTL活性的测定以及抗体阻断实验。结果实验组Hepal-6 RNA/DC组肿瘤在第8周为(8．5±3．6)mm,而iDC组、LPS/ DC组、Saline对照组分别为(36．6±3．6)、(31．3±4．7)、(32．2±4．0)mm,与实验组比较差异均有统计学意义(P＜0．05)。实验组脾细胞对Hepal-6细胞有特异性杀伤效应,而对肺癌LLC细胞无杀伤活性。所诱导的抗肿瘤效应细胞包括CD~(8+)、CD~(4+)T淋巴细胞。结论肝癌细胞的总RNA转染的DC肿瘤疫苗能诱导CD~(8+)、CD~(4+)T细胞免疫,是较有临床应用前景的肝癌免疫治疗方法。     

转染可溶性CD40基因的树突状细胞在体外对T淋巴细胞功能的抑制作用

目的探讨转染可溶性CD40(sCD40)基因的树突状细胞(DC)在体外对T淋巴细胞增殖和细胞毒性T淋巴细胞(CTL)的细胞毒活性的影响。方法采用脂质体转染法,将携带鼠CD40胞外区和绿色荧光蛋白的融合基因的质粒pEGFP-N1/sCD40转染小鼠DC细胞株(DC 2.4)。以Balb/c小鼠淋巴细胞为反应细胞,分别以转染组DC、空载体转染组(空载体组)DC和未行转染处理的DC(空白DC)作为刺激细胞,进行单向混合淋巴细胞培养,四唑氮化合物比色法检测细胞增殖情况。用乳酸脱氢酶释放试验和流式细胞术检测转染组DC及其培养上清液对CTL细胞毒活性及其凋亡的影响。结果转染组DC及其培养上清液对同种细胞刺激的淋巴细胞增殖反应有显著的抑制作用(P<0.05),并对特异性CTL的细胞毒活性具有明显的抑制作用(P<0.05);转染组DC可诱导CTL凋亡(P<0.05)。结论稳定表达sCD40-EGFP融合蛋白的DC,在体外对T淋巴细胞的增殖和CTL的细胞毒活性具有明显的抑制作用,并可诱导CTL凋亡。     

肝癌细胞甲胎蛋白mRNA转染活化的B淋巴细胞诱导细胞毒性T淋巴细胞的抗肿瘤效应

目的 研究肝癌细胞AFP mRNA转染活化的B淋巴细胞诱导细胞毒性T淋巴细胞的抗肿瘤作用.方法 分离、纯化B淋巴细胞,重组人可溶性CIM0配体(sCD40L)活化人外周血B淋巴细胞;构建PGEM4Z/AFP/A64-EGFP质粒,加入T7RNA聚合酶,转录具有PolyA尾端的AFP mRNA;将提取的AFPmRNA电转染B淋巴细胞作为实验组,选取GAPDH mRNA转染者作为阴性对照组,未转染的B淋巴细胞作为空白对照组.检测各组B淋巴细胞表面抗原提呈细胞标记分子(CD19、CD20、CD21、CD40、CD80、CD83)及主要组织相容性抗原的表达情况;将3组B淋巴细胞与T淋巴细胞分别按1∶40,1∶20,1∶10和1∶5的比例混合培养、诱导、扩增抗原激活T淋巴细胞并测定吸光度值以检测T淋巴细胞增殖能力;以T淋巴细胞作为效应细胞,肝癌细胞系SMMC7721为靶细胞,检测T淋巴细胞对肝癌细胞的杀伤活性.两两比较采用配对t检验,多组比较采用单因素方差分析,方差不齐时采用Tamhane's T2检验.结果 实验组B淋巴细胞表面标志分子CD19、CD20、CD21、CD40、CD80和CD83的表达水平分别为74±11、78 ±8、80±10、90±11、82±6、56±5,显著高于阴性对照组的51±5、60±7、53±5、73±8、50±5、49±6,以及空白对照组的46±3、54±5、41±3、56±5、52±6、21 ±4(t =5.302、4.812、7.627、5.932、9.142、7.813,11.581、7.036、13.592、12.873、9.235、14.619,P＜0.01).实验组吸光度值显著高于阴性对照组和空白对照组(t=18.203、23.714、15.062、9.417,16.833、19.392、13.871、6.592,P＜0.01).当T淋巴细胞与肝癌细胞系SMMC7721按照40∶1、20∶1和10∶1的比例混合后,实验组B淋巴细胞诱导产生的T淋巴细胞对肝癌细胞的杀伤率分别为43％±4％、32％±4％和22％±3％,显著高于阴性对照组的15％±5％、7％±3％和6％±2％,以及空白对照组的7％±3％、8％±3％和9％±4％(t=9.141、13.272、11.901,14.372、12.835、9.507,P＜0.01).结论 肝癌细胞AFP mRNA转染的B淋巴细胞可有效诱导T淋巴细胞杀伤肝癌细胞.     

转染肿瘤mRNA的树突状细胞疫苗诱导抗肝癌免疫研究

目的探讨转染原发性肝癌(HCC)mRNA的树突状细胞(DC)能否诱导抗肿瘤特异性细胞毒性T淋巴细胞(CTL)。方法采用HCC患者外周血单核细胞(PBMC)体外刺激分化为DC细胞；从人肝癌HepG-2细胞和3例HCC患者的肝癌组织中体外扩增mRNA。以mRNA转染DC细胞，并与PBMC混合培养诱导扩增CTL。流式细胞计数仪检测培养细胞中CD3^ 、CD4^ 、CD8^ 细胞的比例。^51Cr释放法测定CTL的杀瘤活性。结果经扩增人肝癌HepG-2mRNA和2例AFP( )患者的AFP( )HCCmRNA诱导3周后，CD3^ 、CD8^ 细胞占淋巴细胞总数由诱导前的27．8％、26．5％、29．6％升高至89．3％、73．6％、86．8％；而经扩增AFP(-)HCCmRNA诱导3周后，CD3^ 、CD8^ 细胞占淋巴细胞总数由诱导前的25．4％升高至53．6％。转染HepG-2细胞和AFP( )的患者HCCmRNA的DC诱导的CTL对HepG-2细胞杀瘤活性明显高于AFP(-)的患者，其杀瘤特性由MHC-I限制的CD8^ T细胞所介导。结论HCCmRNA体外转染DC能诱导肿瘤特异性CTL，可为肝癌的免疫治疗提供新的有效手段。     

淋巴细胞与肝癌细胞混合培养诱导特异性细胞毒T淋巴细胞的形成

目的 通过肝癌细胞和淋巴细胞混合培养，体外诱导产生高活性的肝癌特异性细胞T淋巴细胞（H－S－CTL）。方法 采用淋巴细胞和肝癌细胞混合培养技术，在IL－1，IL－2，IL－4和IL－6刺激下，诱导产生H－S－CTL，应用间接免疫荧光法和^51Cr释放法检测其对靶细胞的杀伤效应。结果 H－S－CTL与自身LAK相比，CD3＋，CD4＋和CD8＋细胞明显增多，抗肿瘤效应明显增强。结论 采用淋巴细胞和肝癌细胞混合培养同时应用白细胞介素可获得大量扩增的高活性的H－S－CTL。     

转4-1BBL基因小鼠肝癌细胞瘤苗体外诱导抗肿瘤免疫应答的研究

目的　研究转 4 1BBL基因小鼠肝癌细胞疫苗体外诱导淋巴细胞特异性杀伤活性及刺激同系小鼠脾细胞产生细胞因子 (IL 2、TNF α和GM CSF)的能力。方法　采用脂质体介导法将真核表达质粒 pCDNA3 1( ) m4 1BBL导入小鼠肝癌细胞Hepa1 6 ,经G4 18筛选后获得稳定高表达克隆 ,以丝裂霉素C(MMC)处理后 ,制成肿瘤细胞疫苗 (TCV) ,经体外与同系小鼠脾淋巴细胞共同培养后 ,测定淋巴细胞特异性杀伤活性及对脾细胞产生细胞因子 (IL 2、TNF α和GM CSF)的影响。结果转染 4 1BBL的Hepa1 6细胞能够高表达 4 1BBL蛋白 ,并且经MMC处理后制成的瘤苗在培养 4 8h仍能表达m4 1BBL。与野生型的Hepa1 6细胞相比 ,上述瘤苗能诱导淋巴细胞产生针对亲本的小鼠肝癌细胞Hepa1 6的特异性杀伤作用 (P <0 0 5 ) ,但是对于小鼠肝癌细胞H2 2及成纤维细胞NIH3T3无效 ;此瘤苗在体外能显著增强脾细胞分泌细胞因子IL 2、TNF α和GM CSF的能力。结论　转 4 1BBL基因小鼠肝癌细胞疫苗能诱导有效的抗肝癌免疫反应。     

脂多糖所致脓毒症诱导的急性肺损伤肺组织T淋巴细胞活化及共刺激分子表达的研究

目的研究腹腔注射脂多糖(LPS)诱导的小鼠急性肺损伤(ALI)模型肺组织T淋巴细胞活化状态。方法健康雄性C57BL/6随机分为生理盐水(NS)腹腔注射组,LPS腹腔注射组,每组4只。模型建立后3 h,获取两组小鼠肺组织细胞并进行T淋巴细胞各亚群及活化指标染色,采用流式细胞术检测。结果与对照组(NS)相比,LPS腹腔注射组小鼠肺组织内抑制性共刺激分子PD-1、CD40/CD40L、CTLA-4在CD4~+和CD8~+T细胞表达水平均显著升高(P0.05),协同共刺激分子CD28(MFI:298.50±4.44)表达水平降低;与对照组相比,早期活化分子CD69在LPS诱导的急性肺损伤模型小鼠肺组织内CD4~+T(MFI:848.30±95.57;t=6.8670,P0.001)和CD8~+T淋巴细胞的表达水平显著升高(MFI:606.00±95.54;t=4.8780,P0.01);晚期活化分子CD38在CD4~+T细胞表达显著升高(MFI:69.38±2.86;t=4.1150,P0.01),在CD8~+T细胞表达无明显升高。结论 LPS诱导的急性肺损伤能够导致肺组织内T淋巴细胞早期活化,并且能够上调其多种抑制性共刺激分子表达,提示T淋巴细胞可能在ALI中发挥重要作用。     

小鼠端粒酶蛋白亚单位转染树突状细胞体外诱导特异性抗肝癌细胞免疫应答

目的 观察携带小鼠端粒酶蛋白亚单位(mTERT)基因蕈组腺病毒载体(AdmTERT)转染树突状细胞(DC)后诱发免疫效应细胞产生特异性抗肝癌细胞免疫应答的研究.方法 用流式细胞仪分析及电镜观察培养6 d DC的细胞表型及形态,Ad-mTERT重组腺病毒转染体外培养的小鼠DC,Western blot检测mTERT融合蛋白表达;用负载mTERT的DC刺激同型淋巴细胞,免疫磁珠分选CD8~+T细胞做为效应细胞,小鼠肝癌细胞株(H22)及小鼠结肠癌细胞(CT26)作为靶细胞,用酶联免疫吸附试验(ELISA)及酶联免疫斑点法(ELISPOT)检测干扰索(IFN)-γ分泌量和释放抗原特异性IFN-γ的T细胞数,~(51)Cr释放法检测细胞毒性T淋巴细胞(CTL)对肝癌细胞的杀伤活性.结果 细胞表型及形态观察证实小鼠骨髓来源的DC为成熟的树突状细胞;AdmTERT转染DC后能正确表达mTERT融合蛋白,用AdmTERT转染DC致敏的淋巴细胞IFN-γ分泌量(208.6μg/L)和分泌IFN-γ的特异性T细胞的数量(341/10~6脾细胞)都高于Ad-GFP转染的DC组(14.2μg/L,33/10~6脾细胞)和单纯DC组(12.1μg/L,19/10~6脾细胞,P＜0.05).AdmTERT修饰DC刺激产生的效应T细胞在效靶比为90:1时,对H22细胞的杀伤率(54.2%)明显高于AdGFP致敏组(8.2%)和未致敏DC组(4.5%,P＜0.05),而对CT26细胞无明显杀伤作用.结论 AdmTERT修饰的DC体外能够诱导出针对mTERT抗原特异性的CTL效应,可特异性杀伤mTERT阳性的肝癌细胞.     

微波消融灭瘤联合瘤内接种树突状细胞诱导特异性抗肝癌免疫

目的 探讨微波消融(MWA)灭瘤联合瘤内接种树突状细胞(DCs)诱导特异性抗肝癌免疫的效能.方法 采用GM-CSF联合IL-4体外培养C57BL/6小鼠骨髓来源的DCs,于第6天收集使用.建立C57BL/6小鼠皮下Hepa1-6肝癌模型,随机分为对照组、瘤内接种DCs组(DC组)、肿瘤微波消融组(MWA组)及肿瘤微波消融+瘤内接种DCs组(MWA+DC组).免疫组织化学法检测肿瘤组织内CD4+和CD8+T细胞的浸润,MTT法检测小鼠脾脏细胞对Hepa1-6的特异性杀伤活性,观测各组小鼠肿瘤生长情况.结果 免疫组织化学法检测显示MWA+DC组肿瘤组织内有大量的CD4+和CD8+T淋巴细胞浸润,显著高于其它组(P<0.05).MwA+DC组脾细胞对Hepa1-6细胞有特异性杀伤效能,在E/T=40和100时,MWA+DC组脾细胞对Hepa1-6细胞的特异性杀伤力显著高于对照组、DC组及MWA组(P<0.05).MWA+DC组小鼠肿瘤完全消退率显著高于其它各组(P<0.05).结论 MWA联合瘤内接种DCs可有效诱导机体产生特异性抗肝癌免疫,是预防MwA治疗后肝瘤复发的一种有效方法 .     

RNA干扰阻断OX40/OX40L共刺激通路对CD4+CD25+T调节细胞的影响

目的 探讨慢病毒介导的RNA干扰技术诱导小鼠树突状细胞OX40L基因沉默对调节性T细胞的影响. 方法 设计针对小鼠OX40L基因的RNA于扰序列,通过外源筛靶筛选出干扰效果最佳的序列.以293T为包装细胞,制备含OX40L的siRNA序列的慢病毒载体OX40L-RNAi-LV和阴性对照载体NC-GFP-LV.采用磁式分选器分离培养骨髓来源的小鼠树突状细胞(DCs),以MOI为25进行转染,分别将转染OX40L-RNAi-LV(实验组)、转染NC-GFP-LV(阴性对照组)和未转染(空白对照组)的DCs与磁式分选器分选得到的CD4+CD25+T调节细胞共培养,6 d后通过流式细胞仪检测T调节细胞的增殖和凋亡情况. 结果外源筛靶筛选出干扰效果最佳的RNA干扰序列(靶序列为GCTCATACAAGAATGAGTA),OX40L蛋白表达的抑制率为73.1%.感染复数为25时,慢病毒载体感染DCs的效率为86.4%.DCs与CD4+CD25+T调节细胞共培养后,实验组的凋亡细胞比例为8.7%,显著低于阴性对照组(20.1%)和空白对照组(19.8%),F=244.22,P=0.000;而增殖细胞前体频率为38.3%,明显高于阴性对照组(24.5%)和空白对照组(22.9%),F=95.40,P=0.000.结论 小鼠OX40L的siRNA慢病毒载体可以有效降低树突状细胞OX40L的表达,对体外培养的CD4+CD25+T调节细胞具有显著地促进增殖、减少凋亡的作用.     

逆转录病毒载体介导的外源性主要组织相容性抗原复合体基因转移及其在T细胞的表达

目的 建立一个在胸腺内表达外源性主要组织相容性抗原复合体(MHC)抗原的实验模型,为下一步研究作准备。方法 应用逆转录病毒载体介导的基因转移技术,首次将外源性MHC基因转移到T淋巴表达并应用聚合酶链反应(PCR)及反转录聚合酶链反应(RT-PCR)检测转染T细胞DNA及mRNA。结果 外源性MHC基因已整合到靶细胞染色体DNA并有效地转录;单克隆抗体免疫荧光染色流式细胞仪检测显示在转染T细胞膜有外源性MHC分子表达;转染效率为46.2％。结论 外源性MHC基因可以转移到T细胞稳定表达,为今后的研究提供了经验。     

Involvement of Lymphocyte Infiltration in the Progression of Mouse Peritoneal Fibrosis Model

Peritoneal fibrosis is a serious complication in patients with severe chronic kidney disease who are undergoing peritoneal dialysis (PD). One of the pathological characteristics of peritoneal fibrosis is the infiltration of macrophages in the thickened submesothelial compact zone. In addition, infiltration of lymphocytes, including T and B lymphocytes, is observed in the fibrotic peritoneum. However, the relationship between lymphocyte infiltration and progression of peritoneal fibrosis remains unclear. In this study, we investigated the role of lymphocytes in the development of peritoneal fibrosis induced by chlorhexidine gluconate (CG) by comparing the histological changes observed in severe combined immunodeficient (SCID) mice (largely lacking functional T and B lymphocytes) with those observed in wild-type (WT) mice. As expected, CG-injected WT mice showed a thickening of the submesothelial compact zone together with massive collagen deposition accompanied by increased numbers of infiltrating macrophages and T and B lymphocytes. In the peritoneum of SCID mice, the submesothelial compact zone was thicker and the number of macrophages and B lymphocytes was significantly higher than that observed in control immunodeficient and WT mice. In contrast, the number of T lymphocytes in the peritoneum of SCID mice was significantly lower than that in the peritoneum of WT mice. These results suggest that T and B lymphocytes modulate the process of peritoneal fibrosis via macrophage infiltration.     

Involvement of lymphocyte infiltration in the progression of mouse peritoneal fibrosis model

Peritoneal fibrosis is a serious complication in patients with severe chronic kidney disease who are undergoing peritoneal dialysis (PD). One of the pathological characteristics of peritoneal fibrosis is the infiltration of macrophages in the thickened submesothelial compact zone. In addition, infiltration of lymphocytes, including T and B lymphocytes, is observed in the fibrotic peritoneum. However, the relationship between lymphocyte infiltration and progression of peritoneal fibrosis remains unclear. In this study, we investigated the role of lymphocytes in the development of peritoneal fibrosis induced by chlorhexidine gluconate (CG) by comparing the histological changes observed in severe combined immunodeficient (SCID) mice (largely lacking functional T and B lymphocytes) with those observed in wild-type (WT) mice. As expected, CG-injected WT mice showed a thickening of the submesothelial compact zone together with massive collagen deposition accompanied by increased numbers of infiltrating macrophages and T and B lymphocytes. In the peritoneum of SCID mice, the submesothelial compact zone was thicker and the number of macrophages and B lymphocytes was significantly higher than that observed in control immunodeficient and WT mice. In contrast, the number of T lymphocytes in the peritoneum of SCID mice was significantly lower than that in the peritoneum of WT mice. These results suggest that T and B lymphocytes modulate the process of peritoneal fibrosis via macrophage infiltration.     

Usefulness of inhibiting the lymph node metastasis in human gastric carcinoma by B7-1 gene transfection

INTRODUCTION: Lymph node metastasis is one of the crucial prognostic factors in gastric cancer. We have reported that ICAM-1 gene transfection was effective against lymph node metastases of gastric cancer. B7-1, one of the co-stimulatory factors, was reported to induce cytotoxic T lymphocytes when using melanoma and bladder cancer cell lines, as well as ICAM-1. In this study, we investigated the inhibitory effect of B7-1 on lymph node metastasis by B7-1 gene transfection into gastric cancer cells. MATERIALS AND METHODS: We transfected B7-1 genes into a gastric cancer cell line (OCUM-2MLN) and analyzed the effect of B7-1 transduction on lymph node metastasis, the in vitro adhesiveness and cytotoxicity assay of mononuclear lymphocytes to cancer cells and lymph node metastatic ability after orthotopic implantation of gastric cancer cells in vivo. RESULTS: We revealed that mononuclear lymphocytes showed significantly stronger adherence and cytotoxicity to B7-1 transfected cells (2MLN/B7) than its parent OCUM-2MLN cells. The tumor growth rate of 2MLN/B7 xenograft was significantly slower than OCUM-2MLN xenograft in nude mice. In orthotopic implantation experiments for nude mice, 2MLN/B7 cells in stomach developed significantly less lymph node metastasis than OCUM-2MLN cells. Histologic findings showed that leukocytes were intensively infiltrated in both the 2MLN/B7 tumors and its metastatic lesions, however, were scarcely observed in the lesions associated with 2MLN cells. CONCLUSION: B7-1 may play an important role in inhibiting lymph node metastasis by the mechanism of enhanced immunogenicity, and that B7-1 gene transduction might be effective against lymph node metastases of gastric cancer.     

转染组织因子胞内段siRNA阻抑人脐静脉内皮细胞凋亡的体外实验

目的 探讨转染组织因子胞内段小片段干扰RNA(siRNA)对血管内皮细胞凋亡的影响.方法 体外设计组织因子胞内段siRNA Ⅰ和siRNAⅡ,插入质粒DNA后用脂质体将其转入人脐静脉内皮细胞株(HUVEC)中.3组HUVEC分别转染siRNAⅠ质粒(siRNAⅠ组)、siRNAⅡ质粒(siRNAⅡ组)和pc DNA~(TM)6.2GW/-miR质粒(对照组).取各组HUVEC细胞,分别与CD8~+ T淋巴细胞进行混合淋巴细胞反应.用流式细胞仪检测混合淋巴细胞反应中HUVEC的凋亡率,用磁珠法检测混合淋巴细胞反应上清液中活化部分凝血活酶时间(APTT).结果 插入的siRNA经过测序,证实为正确序列.HUVEC转染siRNA后24 h及48 h,siRNAⅠ组和siRNAⅡ组HUVEC的凋亡率均低于对照组(P<0.01).siRNA Ⅰ组HUVEC的凋亡率低于siRNAⅡ组(P<0.05).3组上清液的APTT较对照(RPMI 1640培养基)缩短(4±0.46)s(P<0.05).siRNA Ⅰ组和siRNAⅡ组与对照组相比较,APTT的差异无统计学意义(P>0.05).结论 组织因子胞内段siRNA构建成功.转染该siRNA可在不影响凝血功能的情况下对混合淋巴细胞反应中的内皮细胞起到一定保护作用,减少内皮细胞的凋亡.     

T cells or active epstein-barr virus infection in the development of lymphoproliferative disease in human B cell-injected severe combined immunodeficient mice

Background: Severe combined immunodeficient (SCID) mice develop Epstein-Barr virus (EBV) containing human lymphoproliferative disease (LPD) tumors when reconstituted with human peripheral blood leukocytes (PBLs) from EBV-seropositive donors, but LPD tumors do not develop in the presence of immunosuppressive agents, such as cyclosporine A or corticosteroids. Methods: Therefore, LPD development in SCID mice was used as a model to explore the relationship among B cells, T cells, and EBV in vivo. SCID mice were engrafted with PBLs isolated by leukapheresis from a single EBV-seropositive donor. Purified populations of CD3⁺ lymphocytes (T cells) or CD19⁺ lymphocytes (B cells) were isolated and engrafted into SCID mice. Results: SCID mice engrafted with purified CD3⁺ lymphocytes (T cells) or CD19⁺ lymphocytes (B cells) did not develop LPD. In contrast, mice engrafted with purified B cells developed LPD if they were co-engrafted with purified T cells or if they were inoculated with infections EBV. Conclusions: This study confirms the requirement of T cells or active EBV infection in the development of LPD in animals engrafted with B cells latently infected with EBV. A greater understanding of the cellular and viral interactions leading to transformation and malignancy may allow the development of specific interventional therapies for malignancies in the immunosuppressed host. Presented at the 46th Annual Cancer Symposium of The Society of Surgical Oncology, Los Angeles, California, March 18–21, 1993.     

Immune modulation by silencing CD80 and CD86 production in dendritic cells using small hairpin RNA to reduce heart transplant rejection

RNA interference (RNAi) plays a potential role in organ transplantation. Small hairpin RNA (shRNA) is an artificial RNA molecule with a tight hairpin turn that can be used to silence the expression of a target gene. We constructed shRNA targeting on the cluster of differentiation 80 (CD80, B7-1) and the cluster of differentiation 86 (CD86, B7-2) and transfected it into dendritic cells (DCs). Fluorescence real-time PCR and flow cytometry confirmed the gene-silencing effect. Interleukin-2 (IL-2) mRNA expression level decreased in T cells that were cocultured with pB7-shRNA-transfected DCs. For in-vivo experiment, we built mice models of abdominal heterotopic heart transplantation and transfused the models with pB7-shRNA-transfected donor-derived DCs. The survival time of the transplanted heart increased; the grade of organ rejection decreased. IL-2 mRNA expression level decreased and it was positively correlated with the grade of organ rejection.     

Keratinocytes induce local tolerance to skin graft by activating interleukin-10-secreting T cells in the context of costimulation molecule B7-H1

BACKGROUND: Intermingled skin grafting using autologous skin islets inlaid in allogeneic skin sheets was found to delay graft rejection, contributing to a significant reduction in mortality for patients with severe burns. In this study we examine the down-regulatory mechanisms underlying the effect of the autologous skin islets. METHODS: Mixed culture of lymphocytes with epidermal cells of autologous and allogeneic origin were performed with a comparing of cell activity from cytokine-knockout mice. And the Th1/Th2-related cytokine profiles were examined. RESULTS: Autologous keratinocytes act as potent inducers of suppression in the mixed culture by making a shift of the cytokine profile from Th1 to Th2. The observed suppression is predominantly mediated by interleukin (IL)-10, because the effect could be reversed by application of a neutralizing antibody to IL-10. The results of reconstitution experiments in BALB/c mice, with or without IL-10 gene-knockout, are consistent with this finding. These demonstrated that T cells were main effective components for the IL-10-related suppression. Furthermore, a newly identified member of the human B7 family (B7-H1) is found to play an important role in activating human IL-10-secreting lymphocytes. When transfected with the CD80 gene, autologous keratinocytes lost the ability to down-regulate the mixed cell culture, which effect could be reversed by introduction of the anti-CD80 antibody. CONCLUSIONS: Our study provides new evidence that autologous keratinocytes present in intermingled skin grafts are inducers for local immune tolerance by expression of B1-H1 in their activation of the IL-10-secreting T cells.     

小干扰RNA对小鼠淋巴细胞cbl-b基因表达的抑制作用

目的 设计合成及筛选自身免疫关键基因--cbl-b (Casitas B-cell lineage lymphoma-b,cbl-b)基因小分子干扰RNA(siRNA).方法 应用RNA设计软件,模拟cbl-b小鼠cbl-b mRNA二级结构,设计并合成针对cbl-b mRNA的4对21核苷酸(nt)siRNA,96孔板转染小鼠淋巴细胞,以空白及转染非特异siRNA(与cbl-b mRNA无同源性的21nt siRNA)作为对照,应用蛋白免疫印迹(Western blot)方法 检测小鼠淋巴细胞cbl-b蛋白表达.结果 cbl-b基因siRNA工作浓度为100nmol/L时转染小鼠淋巴细胞转染率最高,可达(87.48±1.94)%,平均荧光强度最强,可达33.09±1.77.与对照相比,转染cbl-b siRNA的小鼠淋巴细胞蛋白表达明显下调,以siRNA-4最显著,抑制率达85%,转染非特异性siRNA的小鼠淋巴细胞cbl-b蛋白表达水平无明显变化.结论 得到cbl-b siRNA转染小鼠淋巴细胞最佳转染条件,成功筛选能高效抑制cbl-b蛋白表达的siRNA-4,其有效抑制时间约为48h,有望通过沉默cbl-b基因直接活化淋巴细胞,增强机体主动免疫杀伤肿瘤细胞.

Abstract：

Objective To design, synthesize screen small interfering RNA (siRNA) targeting to Casitas B-cell lineage lymphoma-b (cbl-b).Methods Four pairs of 21 nucleotide siRNAs directed to Cbl-b mRNA were designed and synthesized by utilizing RNA design software to simulate secondary structure of cbl-b mRNA in mice. These siRNAs were respectively transfected into lymphocytes in 96 shadows mask by oligofectamine package, and untreated and unspecific siRNA-transfected lymphocytes served as controls. The expression of cbl-b protein was detected by Western blotting.Results When the work concentration of siRNA was 100 nmol/L, transfection efficiency of lymphocytes was highest, up to (87.48±1.94)% and the mean fluorescence intensity was strongest, up to 33.09±1.77. Compared with bland controls, the expression of cbl-b protein level was markedly down-regulated in siRNA-transfected lymphocytes. The inhibitory rate of the siRNA of the target-4 was highest, up to 85%. The expression of cbl-b protein in unspecific siRNA-transfected lymphocytes had no significant changes.Conclusion siRNA-4, which can highly effectively inhibit protein expression of cbl-b gene, was screened successfully, and its inhibition effect can maintain near 48 h. It is hopeful that the cbl-b siRNA will activate lymphocytes directly by cbl-b gene silencing, and kill tumor by activate immunization.