MMP-26基因siRNA真核表达载体的构建及鉴定

目的 构建基质金属蛋白酶-26（MMP-26）小干扰RNA（siRNA）表达质粒,以研究其对人肿瘤细胞MMP-26基因表达的沉默效果,探索肿瘤基因治疗的新途径.方法 根据MMP-26基因mRNA序列,设计有小发夹结构的3条寡核苷酸序列,克隆到空载体pSUPERIOR.puro中,构建重组质粒,同时设计构建分别针对GFP和β-actin的干扰质粒作为阴性对照和阳性对照,并进行酶切鉴定和测序分析.结果 酶切及测序证实重组质粒构建成功.结论 利用RNA干扰（RNAi）技术可成功构建siRNA表达载体.     

NgR特异性siRNA筛选及其表达载体构建

目的：将siRNA技术应用于NgR，筛选出高效的NgR（Nogo受体）特异性siRNA，并构建其表达载体。 方法：2005-03／2006-03，在杭州新瑞佳生物制药有限公司、解放军第二军医大学神经生物教研室设计筛选NgR特异性siRNA，按照Elbashir等设计原则和siRNA的要求，设计、合成4对siRNA，转染体外培养大鼠原代皮层和海马细胞，筛选出基因高沉默效率的NgR特异性siRNA；2004—03／2005-03上海生工生物工程公司将获得的高沉默效率siRNA设计成带有BamHⅠ、HindⅢ酶切粘性末端、终止识别序列和LOOP环的发卡式RNA，并将其克隆入载体pRNAT—U6．1／Neo，构建NgR特异性siRNA表达载体，然后进行酶切鉴定及基因测序。 结果：①对NgR特异siRNA中，siRNA199下调NgRmRNA的表达水平效率最高，转染72h效果最显著（96．04％）。NgR特异性siRNA199序列为：5’-CCGAAUCUCUUACGUGCCATT-3’。②将该序列的发卡式RNA成功克隆入载体pRNAT—U6．1／Neo，构建成NgR特异性siRNA199表达载体，酶切鉴定及基因测序表明设计序列完全相符，目的基因序列准确无误。 结论：NgR特异性siRNA199及其表达载体构建成功，为进一步合成病毒载体及观察NgR特异性RNA干扰抑制大鼠NgR mRNA表达对脊髓损伤的修复作用奠定了基础。     

靶向survivin基因的shRNA质粒表达载体的构建

目的:利用pGenesil-1质粒构建靶向survivin基因的2个短发夹RNA(short hairpin RNA,shRNA)表达载体。方法:设计2对shRNA,GC比在40%～55%之间,进而应用BLAST软件进行同源性剔除,保证所得shRNA序列靶向survivin基因,分别克隆至带有U6启动子的质粒pGenesil-1中,构建质粒表达载体,转化大肠杆菌DH5α菌株扩增,提取质粒,酶切鉴定后测序分析。双酶切重组质粒进行酶切鉴定。结果:成功构建靶向survivin基因的2个shRNA质粒表达载体,经双酶切鉴定及质粒测序结果完全符合设计要求。结论:经鉴定设计的2条shRNA已成功连接于质粒上,可以应用于进一步RNA干扰试验。     

mTOR特异性siRNA重组表达载体的构建及鉴定

目的构建mTORsiRNA重组表达载体,为探讨RNA干扰技术抑制巨噬细胞mTOR基因的相关研究奠定基础．方法设计具有短发夹结构的DNA序列,经退火成互补双链,再克隆至载体pGPU6／GFP／Neo中构建重组表达载体,转化DH5c~菌株,提取质粒行酶切鉴定后,并进行序列测定。再转染人巨噬细胞RAW264．7,进行荧光摄像和阳性克隆筛选。Westernblot方法检测巨噬细胞mTOR蛋白表达。结果DNA测序结果及PCR鉴定证实成功构建小鼠mTORsiRNA重组表达载体。Westernblot结果显示转染该重组载体的巨噬细胞mTOR蛋白表达下降约4l％。结论mTOR靶向RNA干扰重组表达载体构建成功,可以进行稳定筛选,该载体对巨噬细胞mTOR蛋白表达有抑制作用。     

特异性siRNA抑制XIAP基因表达对人内膜癌细胞凋亡的影响

【目的】探讨RNA干扰抑制内膜癌RL95-2细胞XIAP基因表达及对细胞凋亡的影响。【方法】设计并合成XIAP基因特异性siRNA,转染人内膜癌RL95-2细胞,Real time RT-PCR检测转染后XIAP mRNA的变化,Western Blot检测 XIAP蛋白的变化,MTT 及流式细胞仪法检测细胞增值和凋亡的变化。【结果】XIAP siRNA转染后,特异性转染组mRNA转录量的相对倍数值为0．04±0．06,相对蛋白表达量分别为0．590±0．178,较各对照组明显减少（P＜0．05）;特异性转染组细胞生长抑制率为（47．86±4．46）％,较对照组明显增高（P＜0．05）。【结论】体外实验表明,合成的 siRNA能在mRNA水平及蛋白水平有效抑制人内膜癌RL95-2细胞内 XIAP基因的转录及表达,进而显著的促进内膜癌细胞凋亡,其促凋亡机制仍有待进一步研究。     

特异性针对大鼠甲状旁腺激素受体1基因siRNA表达载体构建及鉴定

目的:构建并筛选携带针对大鼠甲状旁腺激素受体1基因的pSUPERretro-GFP/Neo干扰逆转录病毒载体及鉴定。方法:根据Genbank筛选甲状旁腺激素受体1基因3个阳性克隆及1个阴性克隆序列,定向克隆入逆转录病毒载体pSUPERretro-GFP/Neo,并用RT-PCR和测序鉴定,将其转染至胰岛素-1细胞中,Westernblot观察甲状旁腺激素受体1基因表达,鉴定其转染效率。结果:菌落RT-PCR及基因测序鉴定结果表明序列正确,并能成功转染到胰岛素-1细胞株中,Western blot筛选最佳抑制基因。结论:成功构建并筛选出特异性沉默大鼠甲状旁腺激素受体1基因的pSUPERretro-GFP/Neo干扰逆转录病毒载体,为深入探讨大鼠甲状旁腺激素受体1基因的抗凋亡作用奠定了试验基础。     

NgR特异性siRNA筛选及其表达载体构建

目的:将siRNA技术应用于NgR,筛选出高效的NgR(Nogo受体)特异性siRNA,并构建其表达载体。方法:2005-03/2006-03,在杭州新瑞佳生物制药有限公司、解放军第二军医大学神经生物教研室设计筛选NgR特异性siRNA,按照E1bashir等设计原则和siRNA的要求,设计、合成4对siRNA,转染体外培养大鼠原代皮层和海马细胞,筛选出基因高沉默效率的NgR特异性siRNA;2004-03/2005-03上海生工生物工程公司将获得的高沉默效率siRNA设计成带有BamHI、HindⅢ酶切粘性末端、终止识别序列和LOOP环的发卡式RNA,并将其克隆入载体pRNAT-U6.1/Neo,构建NgR特异性siRNA表达载体,然后进行酶切鉴定及基因测序。结果:①4对NgR特异siRNA中,siRNA199下调NgRmRNA的表达水平效率最高,转染72h效果最显著(96.04%)。NgR特异性siRNA199序列为:5’-CCGAAUCUCUUACGUGCCATT-3’。②将该序列的发卡式RNA成功克隆入载体pRNAT-U6.1/Neo,构建成NgR特异性siR-NA199表达载体,酶切鉴定及基因测序表明设计序列完全相符,目的基因序列准确无误。结论:NgR特异性siRNA199及其表达载体构建成功,为进一步合成病毒载体及观察NgR特异性RNA干扰抑制大鼠NgRmRNA表达对脊髓损伤的修复作用奠定了基础。     

分化型胚胎软骨发育基因1特异性小干扰RNA表达质粒的构建和鉴定

背景：分化型胚胎软骨基因1可调控肿瘤生长、凋亡、衰老相关因子,与肿瘤的发生发展有着重要的联系。目的：构建针对人分化型胚胎软骨基因1的小干扰RNA表达载体。方法：从NCBI中查找人分化型胚胎软骨基因1基因全长mRNA序列,利用Katahdin提供的在线小干扰RNA模板序列设计软件,设计针对分化型胚胎软骨基因1的2条shRNA的DNA模板单链,合成靶向分化型胚胎软骨基因1基因转录可形成茎环结构的寡聚核苷酸,退火后与酶切后的pGreenPuroTM shRNA Cloning and Expression Lentivector质粒连接,在JM-109菌株中扩增,并进行质粒DNA琼脂糖凝胶电泳分析、紫外分光光度计检测、菌落PCR以及测序鉴定。结果与结论：将含有分化型胚胎软骨基因1目标序列25bp的双链DNA插入片段,连接到pGreenPuroTM shRNA Cloning and Expression Lentivector质粒形成重组质粒。质粒DNA琼脂糖凝胶电泳和紫外分光光度计分析结果确认所提质粒纯度较高,可用于后续实验。菌落PCR结果表明产物大小约为170bp,与预期相符。测序结果表明pGreenPuroTM shRNA Cloning and Expression Lentivector质粒已经插入人分化型胚胎软骨基因1的干扰合成片段,无碱基突变。成功构建了靶向分化型胚胎软骨基因1-小干扰RNA表达载体。     

质粒介导RNAi靶向hTERT抑制K562细胞端粒酶活性的研究

本研究探讨质粒载体介导的RNAi靶向hTERT对白血病细胞株K562 hTERT基因封闭、端粒酶活性抑制的作用。针对hTERT mRNA化学合成3条siRNA链转染K562细胞,筛选2条高效特异的siRNA链,构建靶向hTERT mRNA的质粒载体pSUPER-U6-Kanr-hTERT-1、pSUPER-U6-Kanr-hTERT-2,在脂质体介导下转染K562细胞;48、72小时后分析靶基因hTERT mRNA的表达量,检测细胞端粒酶活性,同时检测细胞凋亡率。结果表明：3条siRNA链中,48小时目的基因表达抑制,但抑制率有差异,72小时后抑制作用渐消失;转染质粒pSUPER-U6-Kanr-hTERT-1（P-1组）、pSUPER-U6-Kanr-hTERT-2（P-2组）的K562细胞hTERT mRNA表达均下降,P-1组48小时时为0.39±0.13,72小时时为0.57±0.32,P-2组48小时时为0.55±0.20,72小时时为0.88±0.23;端粒酶活性P-1组48小时时为0.42±0.07,72小时时为0.31±0.08;P-2组48小时时为0.49±0.27,72小时时为0.39±0.03;两组均较阴性对照明显下降,且以P-1组作用明显。48小时细胞凋亡率P-1组为18.39±3.08%,P-2组为15.5±3.59%,与阴性对照组7.64±3.73%相比有显著性差异,72小时细胞凋亡率P-1组为13.2±1.18%、P-2组为12.86±3.09%,与阴性对照组8.07±0.19%相比无统计学差异。结论：靶向hTERT的RNAi可抑制目的基因hTERT mRNA表达,进而抑制端粒酶活性。此抑制作用与靶位点选择密切相关,实验中si-hTERT-1优于si-hTERT-2;si-hTERT-3几乎无作用。由质粒载体介导RNAi作用时间明显长于化学合成siRNA,前者72小时甚至更长,后者仅48小时。端粒酶活性被抑制后,48小时的细胞凋亡较对照组有所增加,72小时时与对照组无差别,推测端粒酶活性下调后部分细胞可能被诱导分化。     

靶向胆囊癌血管内皮生长因子基因短发夹样RNA表达质粒的构建与筛选

背景:已有研究通过RNA干扰技术,抑制结肠癌、前列腺癌和视网膜母细胞瘤细胞的血管内皮细胞生长因子基因的表达.尚未见关于RNA干扰血管内皮生长因子抑制胆囊癌肿瘤的相关研究.目的:创新性构建编码胆囊癌血管内皮生长因子基因的短发夹样RNA质粒表达载体,筛选出沉默血管内皮生长因子基因效果最明显的短发夹样RNA表达质粒.设计、时间及地点:基因工程观察实验,于2008/2009在中南大学湘雅医院卫生部肝胆肠外科研究中心实验室完成.材料:人胆囊癌细胞株GBC-SD购于同济大学肿瘤研究所.方法:设计4对针对血管内皮生长因子基因不同位点的短发夹样RNA片段.构建携带此短发夹样RNA片段的表达质粒(短发夹样RNA1-4)并行酶切鉴定分析.然后通过脂质体将重组质粒转染到胆囊癌细胞株GBC-SD中,48 h后测定转染率.主要观察指标:重组质粒酶切鉴定结果.转染效率.采用及荧光PCR检测血管内皮生长因子mRNA表达.结果:成功构建了靶向血管内皮生长因子基因的短发夹样RNA质粒表达载体,其中抑制效果最为明显的短发夹样RNA质粒表达载体为pDC316-EGFP-U6-shRNA2 质粒.重组质粒经酶切鉴定证实构建成功.质粒在GBC-SD细胞中的转染率约为58.6%.短发夹样RNA抑制血管内皮生长因子基因的mRNA表达,短发夹样RNA2抑制率最高,可达86%.结论:成功构建并筛选出的靶向血管内皮生长因子的短发夹样RNA表达质粒,其对胆囊癌GBC-SD细胞内的血管内皮生长因子表达具有明显抑制作用.短发夹样RNA2表达质粒抑制作用最明显.     

Development of targeted recombinant polymers that can deliver siRNA to the cytoplasm and plasmid DNA to the cell nucleus

One of the major limitations to effective siRNA delivery is the lack of a siRNA-specific delivery system. Currently, the same delivery systems that are used for plasmid DNA (pDNA) delivery to the cell nucleus are used for siRNA delivery to the cytoplasm. To fill this gap, the objective of this study was to design a biopolymer that can be programmed via its amino acid sequence to deliver siRNA specifically to cytoplasm. For pDNA delivery, a nuclear localization signal (NLS) was added to the biopolymer structure to facilitate active translocation of the genetic material towards nucleus. The biopolymers were complexed with pEGFP and GFP-siRNA and used to transfect SKOV-3 (HER2+) cells. The intracellular trafficking of the nanoparticles was also monitored in real-time and live cells. The results demonstrated that the biopolymer with NLS is a suitable carrier for pDNA delivery but not siRNA delivery. Conversely, the biopolymer without NLS was suitable for siRNA delivery to the cytoplasm but not pDNA to the cell nucleus. The potential use of the designed biopolymer for combination therapy of cancer cells with gene (thymidine kinase) and siRNA (BCL2) was also examined in SKOV-3 cancer cells.     

多发性骨髓瘤特异APE1siRNA表达载体的构建及鉴定

目的构建多发性骨髓瘤(MM)特异的 APE1siRNA 表达载体 pSilencer K-IE-IgP-APE1siRNA,观察其对 MM 细胞 APE1蛋白表达的特异性敲除作用。方法设计合成的 APE1siRNAcDNA 序列与线性化 pSilencer2.0-U6母本质粒连接后,用 BamH Ⅰ、EcoR Ⅰ双酶切,插入 IgP 寡核苷酸片段;随后用 EcoR Ⅰ酶切 pSilencer IgP-APE1siRNA,将线性化载体与回收 IEcDNA 片段用 T4 DNA 连接酶连接;再用 Xho Ⅰ酶切,与回收 Kappa cDNA 片段连接,克隆出 MM 特异表达载体 pSilencer K-IE-IgPAPE1siRNA,每次连接后均经酶切鉴定和测序确认。用脂质体转染法将重组质粒转染 KM3、HOS 和MDA-231细胞,Western blot 分析其对 KM3细胞 APE1的特异性敲除作用。结果 pSilencer K-IE-IgP-APE1siRNA 能特异且有效地敲除 KM3细胞 APE1蛋白表达,转染 siRNA 后培养2d 的 KM_3细胞 APE1相对表达水平为0.118±0.047,而单独脂质体转染组,APE1相对表达水平为0.988±0.029,基因缄默效率为90%。结论成功构建了针对 MM 的 APE1siRNA 表达载体。     

利用siRNA沉默VEGF对膀胱癌生长的影响

目的研究VEGF特异性RNA干扰对膀胱癌细胞体内外增殖的影响。方法针对VEGF构建siRNA真核表达载体Psilencer^TM -VEGF-siRNA，并转染至膀胱癌细胞T24。RT-PCR观察VEGF的基因沉默效果；MTT比色分析检测细胞体外增殖能力；流式细胞计数检测细胞的凋亡。同时，通过裸鼠移植瘤模型观察VEGF基因沉默效果及对膀胱癌体内治疗的效果。结果转染siVEGF后膀胱癌细胞的VEG基因的表达显著被抑制（最高抑制率达79％）。与对照组比较，转染siVEGF组T24细胞的增殖活性明显低于转染阴性对照质粒组和空白对照组（P〈0．01）；流式细胞计数结果显示细胞发生凋亡。裸鼠体内致瘤实验显示，转染siVEGF组T24细胞在裸鼠体内增殖显著降低，肿瘤生长减慢。结论siVEGF能够有效的抑制膀胱癌中VEGF的表达，从而有效抑制膀胱癌细胞的生长。     

荧光定量PCR检测TCR VγI-Jγ基因重排标准品质粒及标准曲线的构建

目的：构建荧光定量PCR检测TCR VγI-Jγ基因标准品重组质粒和标准曲线，为建立实时荧光定量PCR准确检测淋巴系肿瘤微小残留病奠定基础。方法：对TCR VγI-Jγ基因进行序列分析，利用引物设计软件设计出一对引物和一条荧光探针。提取急性淋巴细胞白血病患者的DNA，经PCR扩增，产物纯化后与pMD 18-T Vector连接，转化到大肠杆菌DH5α，筛选得到标准品的质粒。结果：重组质粒进行荧光定量PCR扩增出现强烈的荧光值增长，表明TCR VγI-Jγ基因已成功克隆。以10^0～10^-5不同稀释水平的标准品进行荧光定量PCR扩增，Ct值分别为21．08、24．34、27．53、30．58和33．25。统计学分析显示Ct值与标准品浓度的对数存在良好线性关系，回归系数为0．998。结论：所构建的TCR VγI-Jγ基因荧光定量PCR检测标准品特异性和线性关系好，准确可靠，利于统一标准。     

导入靶向survivin基因的shRNA质粒表达载体对大肠癌细胞生物学行为的影响

目的:合成靶向survivin基因的shRNA并构建pGenesil-1-shRNA质粒表达载体,研究其对大肠癌Lovo细胞生物学效应的影响。方法:设计2条特异性靶向survivin基因的shRNA,与pGenesil-1质粒载体连接,导入大肠癌Lovo细胞、筛选稳定细胞株,Western Blot检测蛋白表达,流式细胞技术检测细胞生长周期,MTT法描绘细胞生长曲线。结果:筛选的稳定表达细胞内survivin蛋白的表达水平降低,survivin基因低表达的Lovo细胞停滞于G2/M期从而导致细胞生长速度减慢。结论:靶向survivin基因的shRNA能有效降低survivin基因在体内的表达,抑制大肠癌细胞的生长,为大肠癌基因治疗的可行性提供了有力的证据。     

An effective gene-knockdown using multiple shRNA-expressing adenovirus vectors

Viral vectors expressing short hairpin RNA (shRNA) are attractive for efficient and tissue-specific RNA interference (RNAi) delivery. We and others previously reported that recombinant adenovirus (Ad) vector-mediated RNAi has great potential for a variety of applications in molecular biology studies and gene therapy. In the present study, we have developed an efficient Ad vector-mediated RNAi system, in which an Ad vector carries four shRNA-expression cassettes (Ad-multi-shRNA vector), a simple and effective strategy for enhancing the RNAi response per Ad vector particle. The data demonstrated that the Ad-multi-shRNA vectors showed an enhanced RNAi effect compared to conventional Ad vectors containing a single shRNA-expression cassette. An application of the Ad-multi-shRNA vector carrying four same shRNA-sequences against the RET finger protein, an oncogene known to desensitize cells to oxidative stress and cisplatin, resulted in an enhanced cytotoxic effect of cisplatin, demonstrating the advantages of the Ad-multi-shRNA vector for silencing target genes. Furthermore, an Ad-multi-shRNA carrying four different shRNA-sequences efficiently silenced the multiple target genes simultaneously. These data suggest the potential usefulness of the Ad-multi-shRNA vector not only in basic research but also in clinical gene therapy.     

Overcoming obstacles to develop effective and safe siRNA therapeutics

Background: RNA interference (RNAi) is a promising new therapeutic modality. By acting at the mRNA level, RNAi circumvents the druggability issue associated with many disease-driven genes. The lack of safe and effective methods to deliver RNAi therapeutics remains the primary technical hurdle that prevents full utilization of the potential of RNAi therapy. Objective: To examine progress in the therapeutic RNAi field and highlight remaining hurdles for the development of RNAi therapeutics. Methods: This review focuses on the design principles of delivery technologies that demonstrated target inhibition in vivo after systemic administration. Conclusion: Although many promising delivery technologies have been described, all current delivery platforms have limitations. However, using an optimal combination of disease indication, disease target and the most potent RNA trigger, it may be possible to advance RNAi therapeutics in the near term using an imperfect delivery vehicle. The availability of high-throughput assays to monitor/compare various delivery systems for their performance in vivo will be essential for programs that focus on siRNA delivery.     

Controlled release of plasmid DNA from cationized gelatin hydrogels based on hydrogel degradation

This paper shows achievement of the in vivo controlled release of a plasmid DNA from a biodegradable hydrogel and the consequent regulation of gene expression period. Cationization of gelatin was preformed through introduction of ethylenediamine and the gelatin prepared was crosslinked by various concentrations of glutaraldehyde to obtain cationized gelatin (CG) hydrogels as the carrier of plasmid DNA. In vivo release of plasmid DNA from the CG hydrogels was compared with the in vivo degradation of hydrogels. When CG hydrogels incorporating ¹²⁵I-labeled plasmid DNA were implanted into the femoral muscle of mice, the plasmid DNA radioactivity remaining decreased with time and the retention period prolonged with a decrease in the water content of hydrogels used. The higher the water content of ¹²⁵I-labeled CG hydrogels, the faster the hydrogel radioactivity remaining decreased with time. The time profile of plasmid DNA remaining in the hydrogels was in good accordance with that of hydrogel radioactivity, irrespective of the water content. Intramuscular implantation of plasmid DNA-incorporated CG hydrogels enhanced significantly expression of the plasmid DNA around the implanted site. The retention period of gene expression became longer as the hydrogel water content decreased. Fluorescent microscopic study revealed that the plasmid DNA–CG complex was detected around the hydrogel implanted even after 7-day implantation in marked contrast to the injection of plasmid DNA solution. It was concluded that in our hydrogel system, active plasmid DNA was released accompanied with the in vivo degradation of hydrogel, resulting in extended gene expression. The time profile of plasmid DNA release and the consequent gene expression was controllable by changing the water content of hydrogels.     

Biodegradable poly(ethylenimine) for plasmid DNA delivery

Poly(ethylenimine) (PEI) has been known as an efficient gene carrier with the highest cationic charge potential. High transfection efficiency of PEI, along with its cytotoxicity, strongly depends on the molecular weight. Synthesis of cationic copolymers derived from the low molecular weight of PEI and hydrophilic poly(ethylene glycol) (PEG), which are water soluble and degradable under physiological conditions, was investigated for plasmid delivery. Hydrophilic PEG is expected to reduce the toxicity of the copolymer, improve the poor solubility of the PEI and DNA complexes, and help to introduce degradable bonds by reaction with the primary amines in the PEI. Considering the dependence of transfection efficiency and cytotoxicity on the molecular weight of the PEI, high transfection efficiency is expected from an increased molecular weight of the copolymer and low cytotoxicity from the introduction of PEG and the degradation of the copolymer into low molecular weight PEIs. Reaction conditions were carefully controlled to produce water soluble copolymers. Results from a gel retardation assay and zetapotentiometer indicated that complete neutralization of the complexes was achieved at the charge ratios of copolymer/pSV-β-gal plasmid from 0.8 to 1.0 with the mean particle size of the polyplexes ranging from 129.8±0.9 to 151.8±3.4 nm. In vitro transfection efficiency of the synthesized copolymer increased up to three times higher than that of starting low molecular weight PEI, while the cell viability was maintained over 80%.     

mCD20-腺病毒穿梭质粒pDC315的构建

目的：构建腺病毒穿梭质粒pDC315-mCD20重组质粒，为探讨编码mCD20基因的腺病毒载体做好准备，为CD20基因治疗淋巴瘤的研究奠定基础。方法：采用RT-PCR方法将CD20基因克隆出来，通过分子生物学技术构建过渡质粒pcDNA3.1-mCD20质粒，用PCR、酶切进行鉴定后，将该基因cDNA片段插入腺病毒穿梭质粒中，转化至高效感受态DH5ａ细菌细胞中进行扩增，提取质粒，获得重组质粒腺病毒穿梭质粒pDC315-mCD20。结果：成功构建表达mCD20基因的重组质粒，有助于后续研究构建Ad mCD20。