Recombinant adeno-associated virus 8-mediated inhibition of microRNA let-7a ameliorates sclerosing cholangitis in a clinically relevant mouse model

BACKGROUND Primary sclerosing cholangitis(PSC)is characterized by chronic inflammation and it predisposes to cholangiocarcinoma due to lack of effective treatment options.Recombinant adeno-associated virus(rAAV)provides a promising platform for gene therapy on such kinds of diseases.A microRNA(miRNA)let-7a has been reported to be associated with the progress of PSC but the potential therapeutic implication of inhibition of let-7a on PSC has not been evaluated.AIM To investigate the therapeutic effects of inhibition of a miRNA let-7a transferred by recombinant adeno-associated virus 8(rAAV8)on a xenobiotic-induced mouse model of sclerosing cholangitis.METHODS A xenobiotic-induced mouse model of sclerosing cholangitis was induced by 0.1% 3,5-Diethoxycarbonyl-1,4-Dihydrocollidine(DDC)feeding for 2 wk or 6 wk.A single dose of rAAV8-mediated anti-let-7a-5p sponges or scramble control was injected in vivo into mice onset of DDC feeding.Upon sacrifice,the liver and the serum were collected from each mouse.The hepatobiliary injuries,hepatic inflammation and fibrosis were evaluated.The targets of let-7a-5p and downstream molecule NF-κB were detected using Western blot.RESULTS rAAV8-mediated anti-let-7a-5p sponges can depress the expression of let-7a-5p in mice after DDC feeding for 2 wk or 6 wk.The reduced expression of let-7a-5p can alleviate hepato-biliary injuries indicated by serum markers,and prevent the proliferation of cholangiocytes and biliary fibrosis.Furthermore,inhibition of let-7a mediated by rAAV8 can increase the expression of potential target molecules such as suppressor of cytokine signaling 1 and Dectin1,which consequently inhibit of NF-κB-mediated hepatic inflammation.CONCLUSION Our study demonstrates that a rAAV8 vector designed for liver-specific inhibition of let-7a-5p can potently ameliorate symptoms in a xenobiotic-induced mouse model of sclerosing cholangitis,which provides a possible clinical translation of PSC of human.

Packaging and Functional Identification of Recombinant Adeno-associated Virus Encoding cdc2-siRNA

Cyclin dependent kinases （cdks） play an important role in the pathogenesis of multiple neurodegenerative diseases. To explore the possibility of cdks-related gene therapy for neurodegen-erative diseases, we packed recombinant adeno-associated virus （rAAV） encoding cdc2-siRNA. The expressing plasmid pAAV-MCS-EGFP-U6-cdc2-siRNA was constructed by using molecular biological techniques. The rAAV encoding cdc2-siRNA （rAAV-EGFP-U6-cdc2-siRNA） was packed by calcium phosphate mediated co-transfection of the plasmid pAAV-MCS-EGFP-U6-cdc2-siRNA, p-RC and p-Helper into AAV-293 cells. DNA sequencing proved the successful construction of U6-cdc2-siRNA in pAAV-MCS-EGFP. Seventy-two h after packaging, the expression of EGFP could be detected in AAV-293 cells. Western blotting revealed that cdc2 gene expression in AAV-293 cells was down-regulated markedly after transfection with rAAV-EGFP-U6-cdc2-siRNA, which evidenced the satisfactory silencing effect of this virus. It was concluded that the packaging of rAAV encoding cdc2-siRNA was successful. rAAV encoding cdc2-siRNA could silence cdc2 gene effectively, which might offer a novel means for the treatment of neurodegenerative diseases.

Recombinant adeno-associated virus delivered human thioredoxin-PR39 prevents hypoxia-induced apoptosis of ECV304 cells

Human thioredoxin and antibacterial peptide, PR39, have been shown to have potent antioxidant effects that may prolong survival of cells during hypoxia. The pSSCMV/human thioredoxin-PR39 vector was successfully constructed in this study and used to infect ECV304 cells. Transfected ECV304 cells were incubated at 1%, 5% hypoxic, and normal oxygen conditions. We found that the number of apoptotic cells after transfection with recombinant adeno-associated virus-human thioredoxin -PR39 was significantly lower than controls, suggesting a protective effect of the recombinant human thioredoxin-PR39 protein on hypoxic cells.

The Helper Activities of Different Avian Viruses for Propagation of Recombinant Avian Adeno-Associated Virus

To compare the helper activities of different avian viruses for propagation of recombinant avian adeno-associated virus （rAAAV）, AAV-293 cells were cotransfected with the AAAV vector pAITR-GFP containing green fluorescent protein （GFP） gene, the AAAV helper vector pcDNA-ARC expressing the rep and cap genes, and the adenovirus helper vector pHelper expressing Ad5 E2A, E4, and VA-RNA genes. Chicken embryonic fibroblast （CEF） or chicken embryonic liver （CEL） cells were cotransfected with the AAAV vector and the AAAV helper vector, followed by infection with Marek＇s disease virus （MDV）, avian adenovirus, chicken embryo lethal orphan （CELO） virus or infectious bursal disease virus （IBDV）. Infectious rAAAV particles generated by the two strategies were harvested and titrated on CEF and CEL cells. A significantly higher viral titer was obtained with the helper activity provided by the pHelper vector than by MDV or CELO virus. Further experiments showed that rAAAV-mediated green fluorescent protein （gfp） expression was overtly enhanced by MDV or CELO virus super infection or treatment with sodium butyric acid, but not by IBDV super infection. These data demonstrated that MDV and CELO viruses could provide weak helper activity for propagation of rAAAV, and rAAAV- mediated transgene expression could be enhanced by super infection with the helper viruses.

Melittin analog p5RHH enhances recombinant adeno-associated virus transduction efficiency

Objective Melittin and its derivatives have been characterized to establish effective gene delivery systems.Their capability of facilitating endosomal release enhances the nanoparticles-based gene delivery.Nevertheless,little investigation has been conducted to explore its potential application in the context of viral vectors.Methods Various melittin-derived peptides were inserted into the loop VIII of the capsid proteins of recombinant adeno-associated virus vectors.These vectors carrying either gfp or fluc genes were subjected to qPCR assays and transduction assays of HEK293T cells to investigate the efficiency of vector production and gene delivery.In addition,the ability of a specific p5RHH-rAAV vector to deliver genes was examined through in vitro transduction of different cultured cells and in vivo tail vein administration to C57BL/6 mice.Finally,the intricate details of the vector-mediated transduction mechanisms were revealed by specific pharmacological inhibitors of every stage of the rAAV2 intracellular life cycle.Results A total of 76 melittin-related peptides were compiled from existing literature.Among them,cMA2,Melt13,p5RHH and aAR3 were found to significantly enhance the gene delivery efficiency of rAAV2 vectors.The p5RHH-rAAV2 vectors efficiently transduced not only rAAV-potent cell lines but also cell lines previously considered resistant to rAAV.Mechanistically,bafilomycin A1,a vacuolar endosome acidification inhibitor,completely inhibited the transgene expression mediated by the p5RHH-rAAV2 vectors.Most importantly,p5RHH-rAAV8 vectors also demonstrated increased hepatic transduction in vivo in C57BL/6 mice.Conclusion The incorporation of melittin analogues into the rAAV capsids results in a significant improvement in rAAV-mediated transgene expression.While further modifications remain an area of interest,our studies have substantially broadened the pharmacological prospects of melittin in the context of viral vector-mediated gene delivery.

A rabies virus-based toolkit for efficient retrograde labeling and monosynaptic tracing

Analyzing the structure and function of the brain's neural network is critical for identifying the working principles of the brain and the mechanisms of brain diseases.Recombinant rabies viral vectors allow for the retrograde labeling of projection neurons and cell type-specific trans-monosynaptic tracing,making these vectors powerful candidates for the dissection of synaptic inputs.Although several attenuated rabies viral vectors have been developed,their application in studies of functional networks is hindered by the long preparation cycle and low yield of these vectors.To overcome these limitations,we developed an improved production system for the rapid rescue and preparation of a high-titer CVS-N2c-ΔG virus.Our results showed that the new CVS-N2c-ΔG-based toolkit performed remarkably:(1)N2cG-coated CVS-N2c-ΔG allowed for efficient retrograde access to projection neurons that were unaddressed by rAAV9-Retro,and the efficiency was six times higher than that of rAAV9-Retro;(2)the trans-monosynaptic efficiency of oG-mediated CVS-N2c-ΔG was 2–3 times higher than that of oG-mediated SAD-B19-ΔG;(3)CVS-N2c-ΔG could delivery modified genes for neural activity monitoring,and the time window during which this was maintained was 3 weeks;and(4)CVS-N2c-ΔG could express sufficient recombinases for efficient transgene recombination.These findings demonstrate that new CVS-N2c-ΔG-based toolkit may serve as a versatile tool for structural and functional studies of neural circuits.

A novel and highly efficient production system for recombinant adeno-associated virus vector

Recombinant adeno-associated virus(rAAV) has proven to be a promising gene delivery vector for human gene therapy. However, its application has been limited by difficulty in obtaining enough quantities of high-titer vector stocks. In this paper, a novel and highly efficient production system for rAAV is described. A recombinant herpes simplex virus type 1(rHSV-1) designated HSV1-rc/△UL2, which expressed adeno-associated virus type2(AAV-2) Rep and Cap proteins, was constructed previously. The data confirmed that its functions were to support rAAV replication and packaging, and the generated rAAV was infectious. Meanwhile, an rAAV proviral cell line designated BHK/SG2, which carried the green fluorescent protein(GFP) gene expression cassette, was established by transfecting BHK-21 cells with rAAV vector plasmid pSNAV-2-GFP. Infecting BHK/SG2 with HSV1-rc/△UL2 at an MOI of 0.1 resulted in the optimal yields of rAAV, reaching 250 transducing unit(TU) or 4.28×104 particles per cell. Therefore, compared with the conventional transfection method, the yield of rAAV using this "one proviral cell line, one helper virus" strategy was increased by two orders of magnitude. Large-scale production of rAAV can be easily achieved using this strategy and might meet the demands for clinical trials of rAAV-mediated gene therapy.

A novel method for purification of recombinant adeno-associated virus vectors on a large scale

A novel method for recombinant adeno-associ-ated virus (rAAV) purification on large scale is described. The method involves three steps, including chloroform treatment, PEG/NaCl precipitation and chloroform extraction. The whole procedure can be performed in four hours. Using this purification method, we can reproducibly obtain, from 4 × 109 of proviral cells cultured in roller bottles, purified rAAV-GFP stocks with titers of around 5×1013 particles/mL and purity greater than 95%. The infectious titers of the vector stocks were up to 2×1012 TU/mL, thus particle-to-infectivity rate was about 25. Under an electronic microscope, most rAAV particles appeared full and a few were in intermediate form. Empty particles were rarely seen. The purified rAAV-GFP stocks have been successfully used in in vitro and in vivo transfection experiments. Therefore, this new method offers a simple, rapid and cost-effective way for large-scale rAAV purification.

不同途径导入rAAV-VEGF_(165)基因对大鼠脑缺血边缘区血管生成的影响

目的探讨脑池内及静脉导入重组腺病毒介导血管内皮细胞生长因子(rAAV—VEGF165)基因对大鼠脑缺血边缘区血管生成的影响。方法用线栓加环扎法建立SD大鼠持续性大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)模型。SD大鼠48只,随机分为脑脊液导入组、静脉导入组、单纯梗死组和假手术组,治疗组于术后24h内将rAAV—VEGF165基因通过小脑延髓池或静脉内导入。各组分别于7d和14d断头取脑,CD31免疫组化染色检测脑组织微血管密度。结果各组脑缺血边缘区CD31阳性细胞密度(个／高倍视野,×200)分别为:7d 组:脑脊液导入组92．73±5．18、静脉导入组77．40±5．43、单纯梗死组46．50±5．33和假手术组13．90±1．49(P< 0．05);14d组:脑脊液导入组104．05±4．30、静脉导入组89．88±5．77、单纯梗死组65．33±2．31和假手术组13．90± 1．49(P<0．05)。结论 rAAV—VEGF165基因可以通过脑池内及静脉内导入转染到大鼠缺血脑组织中并表达 VEGF,促进新生血管的形成和侧支循环的建立,治疗脑缺血。

rAAV-CD151基因在大鼠缺血后肢血管再生中的作用及血管造影评分

目的:研究肌肉转染重组腺相关病毒(recombinant adeno-associated virus,rAAV)介导的CD151基因在大鼠后肢缺血模型中促血管再生和血运重建的作用。方法:分别包装携带有CD151基因和GFP基因的重组腺相关病毒(rAAV-CD151,rAAV-GFP)。Wistar大鼠12只,随机分为实验组和对照组,每组各6只。实验组大鼠左下肢肌肉注射局部转染rAAV-CD151,对照组注射rAAV-GFP,基因转染2周后行股动脉切除术建立左侧大鼠后肢缺血模型。通过后肢血管造影和缺血肌肉组织毛细血管密度检测,观察缺血肢体血管再生和评价血运重建情况。Western blot检测两组大鼠局部缺血肢体CD151表达。结果:股动脉切除术4周(基因转染6周)后,后肢血管造影结果显示实验组缺血侧血管评分平均为2.56±0.37,对照组平均为1.57±0.39;实验组缺血后肢肌肉组织毛细血管密度为(609.00±83.89)/mm2,对照组为(517.00±70.65)/mm2;两组比较差异均有显著性意义(P<0.05)。Western blot检测结果显示实验组大鼠缺血侧肌肉组织CD151表达为对照组的2.96倍。结论:局部高表达CD151基因能够提高缺血组织的血管再生能力,促进缺血组织的血运重建;CD151将为缺血性疾病的血管再生治疗提供新的靶点。

rAAV介导的HIF-1α—RNAi载体的构建

目的构建以rAAV为载体、GFP为报告基因和HIF-1α为靶基因的RNA干扰。方法提取人基因组DNA，PCR扩增人H1启动子，插入载体质粒pAAV-hrGFP的CMV启动子前方Mlu Ⅰ单克隆位点，构建成pH1—hrGFP；根据HIF-1α的有效干扰位点，合成两条分别为58bp互补的寡核苷酸链，通过体外退火形成双链，然后插入pH1-hrGFP的H1启动子尾部Xba Ⅰ和MunⅠ位点，构建成pH1—siRNA；将载体质粒pH1-siRNA和辅助质粒pRC、pHelper共转染HEK293细胞，反复冻溶后收集上清，浓缩纯化，电镜观察病毒形态和ELISA法测定病毒滴度。结果构建的pH1-hrGFP质粒，通过酶切、PCR检测以及测序鉴定均正确；构建的pH1—siRNA，通过酶切及测序鉴定也正确；包装的rAAV经电镜检测形态正常，滴度达1．2×10^12 v．p／mL。结论成功构建了rAAV介导的HIF-1α—RNAi表达载体，为今后的体内外试验奠定了基础。

重组腺相关病毒(rAAV)介导基因SMCKA3999对Duchenne肌营养不良病理和功能的影响

目的 研究重组腺相关病毒 (rAAV)载体介导的dystrophin小基因SMCKA3999治疗DMD模型鼠mdx ,从病理和功能观察rAAVSMCKA3999治疗对DMD模型小鼠mdx的疗效。方法 以dystrophin小基因SMCK A3999为目的基因 ,将SMCKA3999克隆至rAAV并包装成rAAVSMCKA3999,以 5× 10 10 病毒颗粒单点注射于DMD模型鼠mdx腓肠肌 ,基因治疗后 4个月及 7个月 ,采用免疫荧光、光镜组织病理、肌电图等方法 ,从形态和功能观察rAAVSMCKA3999治疗对DMD模型小鼠mdx的疗效。 结果 rAAVSMCKA3999使肌膜缺失的dys trophin恢复并稳定表达持续 7个月以上 ,肌肉组织病理改变好转 ,肌病肌电图改变明显改善 ,疗效持续 4个月以上。 结论 rAAVSMCKA3999能改善mdx小鼠骨骼肌的病理及功能 ,采用rAAV介导的dystrophin小基因SMC KA3999对Duchenne肌营养不良基因治疗是有希望的治疗方法。

携带人肝癌细胞CDK2基因的rAAV载体的构建与鉴定

目的构建携带人肝癌细胞CDK2基因的重组腺相关病毒(rAAV)载体;方法设计能表达CDK2特异性的小干扰RNA(siRNA),构建pAKD-shRNA-CDK2重组质粒,采用磷酸钙共转染法将重组质粒pAKD-shRNACDK2、包装质粒pAAV-RC和辅助质粒pHelper共转染AAV-293细胞,采用定量PCR方法对病毒进行滴度测定;结果三质粒共转染AAV-293细胞48h后,荧光显微镜下检测到GFP绿色荧光,表明共转染成功,测定病毒平均滴度为3.56×1012v.g/ml。结论成功构建携带人肝癌细胞CDK2基因的重组腺相关病毒rAAV-shRNA-CDK2。

Specific cellular immune responses in mice immunized with DNA,adeno-associated virus and adenoviral vaccines of Epstein-Barr virus-LMP2 alone or in combination

Cellular immune responses,particularly those associated with CD3+CD8+ cytotoxic T lymphocytes (CTL),are critical factors in controlling viral infection.Nasopharyngeal carcinoma (NPC) is closely associated with persistent Epstein-Barr virus (EBV) infection.NPC vaccine studies have focused on enhancing specific antiviral CTL responses.In this study,three vaccines capable of expressing the EBV-latent membrane protein 2 (LMP2) (a DNA vector,an adeno-associated virus (AAV) vector,and a replication-defective adenovirus serotype 5 (Ad5) vector) were respectively used to immunize female Balb/c mice (4-6 weeks old) at weeks 0,2 and 4,either alone or in combination.Our results suggest that combined immunization with DNA,AAV,and adenovirus vector vaccines induced specific cellular immunity more effectively than any of these vectors alone or a combination of two of the three,constituting a sound vaccine strategy for the prevention and treatment of NPC.

Long-term modifications of blood pressure in normotensive and spontane-ously hypertensive rats by gene delivery of rAAV-mediated cytochrome P450 arachidonic acid hydroxylase

Arachidonic acid cytochrome P-450 （CYP） hydroxylase 4A isoforms, including 4A1, 4A2, 4A3 and 4A8 in the rat kidney, catalyze arachidonic acid to produce 19/20-Hydroxyeicosatetraenoic acids （20-HETE）, a biologically active metabolite, which plays an important role in the regulation of blood pressure. However, controversial results have been reported regarding the exact role of 20-HETE on blood pressure. In the present study, we used recombinant adenoassociated viral vector （rAAV） to deliver CYP 4A1 cDNA and antisense 4A1 cDNA into Sprague-Dawley （SD） rats and spontaneously hypertensive rats （SHR）, respectively, to investigate the effects of long-term modifications of blood pressure and the potential for gene therapy of hyperténsion. The mean systolic pressure increased by 14.2±2.5 mm Hg in rAAV.4A 1-treated SD rats and decreased by 13.7±2.2 mm Hg in rAAV.anti4A l-treated SHR rats 5 weeks after the injection compared with controls and these changes in blood pressure were maintained until the experiments ended at 24 weeks. In 4A1 treated animals CYP4A was overexpressed in various tissues, but preferentially in the kidney at both mRNA and protein levels. In anti-4Al-treated SHR, CYP4A mRNA in various tissues was probed, especially in kidneys, but 4A l protein expression was almost completely inhibited. These results suggest that arachidonic acid CYP hydroxylases contribute not only to the maintenance of normal blood pressure but also to the development of hypertension. rAAV-mediated anti4A administration strategy has the potential to be used as targeted gene therapy in human hypertension by blocking expression of CYP 4A in kidneys.

The use of miR122 and its target sequence in adeno-associated virus-mediated trichosanthin gene therapy

Objective:Plant-derived cytotoxic transgene expression,such as trichosanthin(tcs),regulated by recombinant adeno-associated virus(r AAV)vector is a promising cancer gene therapy.However,the cytotoxic transgene can hamper the vector production in the r AAV producer cell line,human embryonic kidney(HEK293)cells.Here,we explored micro RNA-122(miR122)and its target sequence to limit the expression of the cytotoxic gene in the r AAV producer cells.Methods:A miR122 target(122 T)sequence was incorporated into the 30 untranslated region of the tcs c DNA sequence.The firefly luciferase(fluc)transgene was used as an appropriate control.Cell line HEK293-mir122 was generated by the lentiviral vector-mediated genome integration of the mir122 gene in parental HEK293 cells.The effects of miR122 overexpression on cell growth,transgene expression,and r AAV production were determined.Results:The presence of 122 T sequence significantly reduced transgene expression in the miR122-enriched Huh7 cell line(in vitro),fresh human hepatocytes(ex vivo),and mouse liver(in vivo).Also,the normal liver physiology was unaffected by delivery of 122 T sequence by r AAV vectors.Compared with the parental cells,the miR122-overexpressing HEK293-mir122 cell line showed similar cell growth rate and expression of transgene without 122 T,as well as the ability to produce liver-targeting r AAV vectors.Fascinatingly,the yield of r AAV vectors carrying the tcs-122 T gene was increased by 77.7-fold in HEK293-mir122 cells.Moreover,the tcs-122 T-containing r AAV vectors significantly reduced the proliferation of hepatocellular carcinoma cells without affecting the normal liver cells.Conclusion:HEK293-mir122 cells along with the 122 T sequence provide a potential tool to attenuate the cytotoxic transgene expression,such as tcs,during r AAV vector production.

Prevalence of neutralizing antibodies against liver-tropic adeno-associated virus serotype vectors in 100 healthy Chinese and its potential relation to body constitutions

Recombinant adeno-associated virus （rAAV） serotype 2, 3 and 8 vectors are the most promising liver- tropic AAV serotype vectors. Liver diseases are significant problems in China. However, to date, few studies on AAV neutralizing antibodies （Nabs） were working with the Chinese population or with the rAAV3 vectors. The present study aimed to determine the prevalence of Nabs in Chinese population against wild-type AAV2, AAV3 and AAV8 capsids as well as additional two AAV3 variants. In addition, we performed a preliminary analysis to investigate the potential influence of traditional Chinese medicine body constitutions on AAV Nabs. Our work demonstrated that the majority of healthy Chinese subjects were positive for AAV Nabs, with the order of AAV2 〉 AAV3 = AAVLK03 〉 AAV8. There was no difference between： 1）AAV3 and its variants; 2） male and female subjects; and 3） different age cohorts （〈 35, 36- 50, and 〉 51 years old）. People in the Qi-deficiency constitution had significantly increased AAV8 Nabs than people in the Gentleness constitution. Our studies may have impact on the future clinical design of AAV-based gene therapy in the Chinese population.

导入酵母NDI1基因减少鱼藤酮诱导的分化型帕金森病细胞模型的损伤

目的探讨导入酵母NDI1基因能否替代人功能缺陷的线粒体复合体Ⅰ,为复合体Ⅰ功能障碍所致散发型帕金森病(PD)的基因治疗提供研究基础。方法将表达酵母NDI1的重组腺相关病毒(rAAV-NDI1)感染鱼藤酮诱导的分化型帕金森病细胞模型。设DMSO+空载、鱼藤酮+空载、鱼藤酮+NDI1共3组。用Western blot、免疫荧光染色、氧耗测定、ATP含量测定、ROS测定等方法检测细胞病理学、线粒体功能方面指标。结果鱼藤酮+NDI1组较鱼藤酮+空载组,细胞形态明显改善,细胞存活率显著上升(P<0.05),pS129α-突触核蛋白、全细胞自噬显著下降(P<0.05,P<0.001);复合体Ⅰ依赖性氧耗显著升高(P<0.01),细胞总ATP合成、线粒体氧化磷酸化偶联的ATP合成显著上升(P<0.01),线粒体ROS、线粒体自噬显著降低(P<0.01,P<0.001)。结论导入酵母NDI1基因可以在鱼藤酮诱导的分化型帕金森病细胞模型中,替代性弥补复合体Ⅰ的功能缺陷,对细胞病理学、线粒体功能的损伤具有改善作用。

三种逆行示踪工具标记小鼠前扣带回皮质传入核团的比较

目的:通过对小鼠前扣带回皮层(ACC)立体定位注射重组腺相关病毒(rAAV2⁃retro)、荧光乳胶微球(retrobeads)及狂犬病毒(RV)的方法,比较三种逆行示踪工具对ACC上游传入核团的标记效果。方法:将rAAV2⁃retro⁃hSyn⁃EGFP⁃P2A⁃Cre⁃WPRE⁃hGH⁃PA、retrobeads(Red)等量混合后注射到小鼠ACC脑区,待病毒表达3周后灌注取脑、切片观察。另外将rAAV2/9⁃EF1α⁃DIO⁃oRVG(19G)、rAAV2/9⁃EF1α⁃DIO⁃NLS⁃mCherry⁃P2A⁃TVA⁃T2A⁃RVG、rAAV2/9⁃CaMKIIα⁃Cre混合后注射到小鼠ACC脑区,待病毒表达2周后将RV⁃EnvA⁃ΔG⁃EGFP注射到相同部位,1周后灌注取脑、切片观察,比较三种策略标记到ACC上游传入核团的神经元数量及形态。结果:retrobeads标记到的核团最多,但无法标记神经元形态及树突结构;RV标记到的核团数量次之,胞体及树突结构标记完整,而且可以观察到清晰的树突棘;rAAV2⁃retro标记到的核团最少,能标记到树突,但无法标记树突棘。三者在内侧眶皮层、腹侧眶皮层、视皮层等区域均能够高效标记。其中,RV在丘脑腹前核和腹外侧核标记效率高于其他两种工具。结论:ACC接受脑内的广泛投射,而三种逆行示踪剂在标记效率和标记神经元结构完整性上各有优劣。

CD151对人舌鳞癌细胞Tca8113迁移作用的影响

背景与目的:CD151在肿瘤组织中的高表达与肿瘤的转移和预后密切相关,但其具体机制尚不清楚。本研究旨在探讨携带全长正义和反义CD151基因的重组腺相关病毒(rAAV-CD151,rAAV-antiCD151)对人舌鳞癌细胞Tca8113细胞迁移的影响。方法:利用含酶切位点的PCR引物克隆CD151基因,分别呈正向和反向插入包装质粒pAAV,并包装成rAAV-CD151,rAAV-antiCD151,斑点杂交测定病毒滴度;rAAV-CD151与rAAV-antiCD151分别转染Tca8113细胞2周后,Westernblot检测CD151表达,通过Boyden趋化小室研究其对Tca8113细胞迁移的影响。结果:斑点杂交结果显示rAAV-CD151和rAAV-antiCD151病毒滴度分别为2.0×1011pfu/ml,1.0×1011pfu/ml;转染rAAV-CD151后,Tca8113细胞CD151的表达较未转染组增加了108%,细胞迁移数(93.6±11.6)显著高于未转染组和转染rAAV-GFP对照组(53.0±6.6和46.0±7.0,P<0.05);转染rAAV-antiCD151后,Tca8113细胞CD151的表达较未转染组减少了79%,细胞迁移数(24.0±4.4)显著低于未转染组和转染rAAV-GFP对照组(P<0.05)。结论:CD151在肿瘤细胞的迁移中起重要的作用,是肿瘤转移的重要分子基础。携带反义CD151基因的重组腺相关病毒作为一种新的治疗工具,可以特异性阻断肿瘤细胞CD151表达,抑制肿瘤细胞的迁移。