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Objective:To evaluate the safety and clinical effect of gene therapy for Leber hereditary optic neuropathy (LHON).Methods:A multi-center prospective non-randomized controlled trial was conducted.Eighty eyes of 40 LHON patients with mitochondrial DNA 11778 mutation were enrolled in Taihe Hospital from December 2017 to February 2018.Intravitreal injection of recombinant adeno associated virus 2-NADH dehydrogenase 4 (rAAV2- ND4) was carried out in the unilateral eye with worse visual acuity or the right eye (if the visual acuity of both eyes was equal) of each subject as the treated group and the fellow eyes as the untreated group.The best corrected visual acuity (BCVA) was detected using a standard logarithmic chart and intraocular pressure (IOP) was measured with a non-contact tonometer before treatment and 1, 3, 6, 12 months after treatment.The manifestations of the ocular anterior segment and fundus were examined by slit lamp microscopy and color photography.The changes of visual acuity and IOP before and after gene therapy were compared, and complications were evaluated between the treated group and the untreated group.The effective rate defined as visual acuity improved ≥0.3 LogMAR at the end of follow-up was assessed.This study adhered to the Declaration of Helsinki and the study protocol was approved by an Ethics Committee of Taihe Hospital (No.201807). Written informed consent was obtained from each subject prior to any medical examination and treatment. Results:The visual acuity improved 6 eyes in the treated group and 4 eyes in the untreated group, and 13 patients showed bilateral improvement.The visual acuity improvement ≥0.3 LogMAR in 23 patients with the effective rate 57.5%.The BCVA was (1.51±0.62) LogMAR and (1.62±0.58) LogMAR at the end of following-up in the untreated group and treated group, respectively, which were significantly higher than (1.75±0.46) LogMAR and (1.83±0.47) LogMAR before treatment (both at P<0.01), and no significant difference was found in BCVA between the two groups ( Fgroup=0.084, P=0.772). There was no significant difference in IOP between the two groups before and after treatment ( Fgroup=0.557, P=0.575; Ftime=2.314, P=0.106). No serious complications were found in all subjects during following-up. Conclusions:rAAV2- ND4 gene therapy is safe and effective for LHON, and binocular vision can be improved by monocular intravitreal injection of rAAV2- ND4 gene.
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OBJECTIVE@#Plant-derived cytotoxic transgene expression, such as trichosanthin (tcs), regulated by recombinant adeno-associated virus (rAAV) vector is a promising cancer gene therapy. However, the cytotoxic transgene can hamper the vector production in the rAAV producer cell line, human embryonic kidney (HEK293) cells. Here, we explored microRNA-122 (miR122) and its target sequence to limit the expression of the cytotoxic gene in the rAAV producer cells.@*METHODS@#A miR122 target (122T) sequence was incorporated into the 3' untranslated region of the tcs cDNA 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 rAAV production were determined.@*RESULTS@#The presence of 122T 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 122T sequence by rAAV vectors. Compared with the parental cells, the miR122-overexpressing HEK293-mir122 cell line showed similar cell growth rate and expression of transgene without 122T, as well as the ability to produce liver-targeting rAAV vectors. Fascinatingly, the yield of rAAV vectors carrying the tcs-122T gene was increased by 77.7-fold in HEK293-mir122 cells. Moreover, the tcs-122T-containing rAAV vectors significantly reduced the proliferation of hepatocellular carcinoma cells without affecting the normal liver cells.@*CONCLUSION@#HEK293-mir122 cells along with the 122T sequence provide a potential tool to attenuate the cytotoxic transgene expression, such as tcs, during rAAV vector production.
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Animals , Humans , Mice , Dependovirus/genetics , Genetic Therapy , Genetic Vectors/genetics , HEK293 Cells , MicroRNAs/genetics , TrichosanthinABSTRACT
Objective: To investigate the expression and expression efficiency of recombinant adeno-associated viral containing human thyrotropin receptor A subunit (rAAV2/9-hTSHR289-IRES-ZS Green) in mouse embryonic fibroblasts (NIH3T3) or in mice. Methods: NIH3T3 was infected by rAAV2/9-hTSHR289-IRES-ZsGreen and its TSHR289 protein expression was detected by Western blotting. Female BALB/c mice were intramuscularly injected with different doses of rAAV2/9-hTSHR289-IRES-ZsGreen; the expressions of the target protein in different organs were determined by immunofluorescence while the serum TSHR antibody (TRAb) titer was determined by radioimmunoassay. Results: NIH3T3 cells transfected with rAAV2/9-hTSHR289-IRES-ZsGreen expressed hTSHR289 protein both at 48 h and 72 h. The expression of target protein at 48 h or 72 h was significantly higher than that at 24 h (P<0.05). There were different levels of TSHR289 expression in leg skeletal muscle, heart, liver and spleen under fluorescence microscope. The results of radioimmunoassay showed that the higher dose injection produced a higher titer of TSHR antibody, but only the TRAb level in high dose and control injection exhibited a statistical difference (P<0.05) at week 4, week 8 and week 12. Furthermore, strong antibody response was observed in the mice injected with high dose and medium dose of rAAV2/9-hTSHR289-IRES-ZsGreen at week 4 and gradually weakened between 4 and 8 weeks. In addition, the antibody lasted for 12 weeks. Results: rAAV2/9-hTSHR289-IRES-ZsGreen can highly express hTSHR289 protein in vivo and in vitro, and the hTSHR289 protein displays strong immunogenicity. It indicates that rAAV2/9-hTSHR289-IRES-ZsGreen might become a more effective means of preparing Graves' disease model.
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Recombinant adeno-associated virus (rAAV)-based vector has shown great promise for human gene therapy, due to its advantage in eliciting long-term transgene expression, absence of adverse effect, infection ability to both dividing and non-dividing cells, non-genomic integration, and low immunotoxity. To date, three AAV-based products have been authorized to enter European and American markets, and more than 200 rAAV-based candidates are in the process of clinic trails. Nevertheless, domestic industry is facing the challenge of manufacturing clinical grade rAAV vector, and regulatory agencies are lack of practical experience in assessing such products. Herein, this paper summarizes the latest research progress of rAAV-based gene therapy products, and discusses some quality assessment concerns in raw materials, manufacturing process and quality control, expecting to promote its clinical transformation and application.
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Objective: To construct an adeno-associated viral vector serotype2/9 containing human thyrotropin receptor (rAAV2-9-hTSHR289-IRES-ZsGreen) so as to provide a better means for establishing an ideal animal model and the gene prevention against Graves' disease. Methods: AAV skeleton plasmid pAAV-IRES-ZsGreen and PDC315 plasmid containing hTSHR289 were digested by EcoR+BamH. The digestion products were connected. And pAAV-hTSHR289-IRES-ZsGreen vector was generated after transformation of JM109 by ligation products. The recombinant plasmid was identified by gel electrophoresis and sequencing. Three plasmids (pAAV-hTSHR289-IRES-ZsGreen, pHelper, and pAAV-2/9) were transfected into 293AAV cell line by calcium phosphate method and a large amount of rAAV2/9-hTSHR289-IRES-ZsGreen was obtained. After purification, the packaging efficiency of recombinant adeno-associated virus was observed by using fluorescence microscope, and its titer was determined by rQ-PCR. HEK293 cells were transfected with rAAV2/9-hTSHR289-IRES-ZsGreen; then the expression level of hTSHR289 was analyzed by ELISA at different time points. Results: The success of hTSHR289 gene inserted into the AAV skeleton vector was confirmed by double digestion and sequencing. After 72 h of transfection of 293AAV cells, the packaging efficiency of the virus was 92%-94% under fluorescence microscope. The titer of the recombinant adeno-associated virus was 1×1013vg/mL. ELISA assay showed that the expression level of hTSHR289 protein mediated by rAAV2/9 was significantly higher at 96 h than that at 72 h and 48 h. Conclusion: The rAAV2/9-hTSHR289-IRES-ZsGreen was successfully constructed. Furthermore, it could be transfected and expressed in cells effectively.
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Aim: To investigate the feasibility of recombinant adeno-associated virus serotype9 (rAAV9) mediated nerve growth factor (NGF) transfection in diabetic rats by intramyocardial injection, and to confirm the protective effect of this method on diabetic cardiac autonomic neuropathy. Methods: At 4th week after the establishment of diabetic model, recombinant adeno-associated virus (rAAV9-NGF) carrying NGF gene was injected into the heart of rats. Five weeks later, the distribution of NGF, calcitonin gene-related peptide (calcitonin gene-related peptide, CGRP) and nerve fibers were detected by immunofluorescence. Hemodynamic parameters were used to evaluate cardiac function, and ELISA method was used to detect the expression of NGF, CGRP in myocardium. Results: The exogenous gene NGF mediated by rAAV9 could be stably transfected and over-expressed in the myocardium of diabetic rats. The left ventricular systolic pressure, heart rate, and maximal rate of increase of left ventricular pressure significantly decreased, the left ventricular end-diastolic pressure and the maximal decrease rate of left ventricular pressure significantly increased, and the cardiac function was improved. NGF, CGRP protein in myocardial tissues were up-regulated, and immunofluorescence showed that the decrease of NGF, CGRP and nerve fibers in myocardial tissues could be partially reversed after transfection. Conclusions: Intramyocardial injection of NGF gene can effectively enhance the expression of NGF and promote the growth of nerve fiber, exerting a protective effect in diabetic rat heart.
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Background: Using recombinant adeno-associated virus 2 (rAAV-2), we attempted to establish a HEK293T cell line that is able to site-specifically integrate and stably express glial cell line-derived neurotrophic factor (GDNF). Results:Recombinant vector with enhanced green fluorescent protein (EGFP) and GDNF (pTR-P5-EGFP-IRES-GDNF), as well as that carrying Rep genes and SV40 promoters (pSVAV2) were constructed and packed. HEK293T cells were co-infected with rAAV-2/EGFP-GDNF and rAAV-2/SVAV2 virus separately at 1 x 10(4),1 x 10(5),and 1x10(6) of multiplicity of infection (MOI). The efficiency of transduction was detected using flow cytometry. Additionally, the infected HEK293T cells were separately validated by touchdown polymerase chain reaction (PCR) and Western-blot. After 72 h of transduction, the rate of EGFP positive cell was 22%, 45% and 49% at the MOIs of 1 x 10(4),1 x 10(5) and 1 x 10(6), respectively. On the 3rd, 6th and 9th day of cell passage, there was no significant difference in the cell viability and proliferation rate between transduction and control groups. Importantly, touchdown PCR showed that there was a specific PCR amplified product band in the lane of infected cells. Furthermore, GDNF expression was detected in the infected cells after 15 and 180 d of cultivation. Conclusions: A HEK293T cell line able to site-specifically integrate and stably express GDNF was established.
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Dependovirus , Glial Cell Line-Derived Neurotrophic Factor , HEK293 Cells , Recombination, Genetic , Transduction, Genetic , Cell Line , Polymerase Chain Reaction , Green Fluorescent Proteins , Genetic Vectors , Microscopy, FluorescenceABSTRACT
OBJECTIVE: To develop a reliable method to measure host cell protein(HCP)content of HEK293 cells in rAAV2-KAL vectors for clinic application. METHODS: The rAAV2-KAL vectors used for this study was purified by CsCl ultracentrifugation twice,then were subjected to by Western blot. The optimal linear range, minimum detection limit,and the accuracy and precision were verified by ELISA. Three batches of rAAV2-KAL were prepared by CsCl method. The change of HCP content during purification was determined to verify the method suitability and reliabilities. RESULTS: The optimal linear range of the method developed was 4-200 ng·mL-1, while the minimum detection limit of 4 ng·mL-1. The recovery rates of HEK293 cell protein at various concentrations were at range of 77.0%-115.0%,with a coefficient of variation of less than 20%. The HCP contents in three batches of rAAV2-KAL were less than 100 ng·mL-1, all data taken together indicated that HCP was effectively removed by CsCl ultracentrifugation. CONCLUSION: A reliable ELISA assay for residual host cell protein of HEK293 cells is successfully developed,which might be used for determination of HCP content in CsCl ultracentrifugation purified rAAV2-KAL for clinical application.
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Aim To investigate the curative effect of rAAV-PR39-ADM,which co-expressed the gene of an-tibacterial peptide (PR39 ) and adrenomedullin (ADM),in a rat cerebral ischemia/reperfusion (I/R) injury.Methods In vitro,Matrigel angiogenesis as-say was made with human umbilical vein endothelial cells.In vivo,the cerebral I/R model was established by the occlusion of the cerebral artery for 2h and then reperfused for 24 h.SD rats were randomly divided in-to sham group,I/R+normal saline group,I/R+null virus (AAV ) group, and IR +rAAV-PR39-ADM group.rAAV-PR39-ADM,saline and null virus were administered through the femoral vein after 24 h of the reperfusion in I/R group.MRI,neurological deficit score,TTC and HE staining were measured respective-ly 1 ,2,3 and 4 weeks after the injection in order to e-valuate the therapeutic efficacy.Results In vitro, rAAV-PR39-ADM group had significant angiogenic effect compared with sham group and null virus group. In vivo,successful I/R model was verified by the ima-ges of MRI.Compared with sham group,the nerve function defect score and the cerebral infarction size in each time nodes were significantly raised in I/R groups (P<0.01).There was no significant difference in in-farct size and nerve function defect score between I/R+normal saline group and I/R +null virus (AAV ) group,and obviously,the IR +rAAV-PR39-ADM group lowered these indexes compared with the other two groups.HE staining showed that the number of neurons,new capillaries vessels of I/R +PR39-ADM group were significantly more than those in group I/R and group I/R +null virus.Conclusion The treat-ment of rAAV-PR39-ADM promotes vascular forma-tion,neuron protection and reduces the infarct size in the model of cerebral ischemia/reperfusion.
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Objective To construct the recombinant adeno-associated virus vector carrying cancerous inhibitor of PP2A (CIP2A)short hairpin RNA (shRNA)for preparation of high-titer viruses.Methods The small hairpin RNA of CIP2A (CIP2A shRNA)was designed,synthesized and cloned into pDC31 6-EGFP-U6 plasmid which was double digested by Bam HⅠ and Hin dⅢ.The resultant plasmid pDC31 6-EGFP-shRNA was confirmed and served as template to appraise primers.EGFP-CIP2A shRNA sequence was amplified by PCR,double digested with Eco RⅠand Sal Ⅰ and ligated to pSNAV2.0 plasmid digested with the same enzyme pair.pSNAV2.0-EGFP-CIP2A shRNA plasmid DNA was prepared,purified,identified and transfected into BHK-21 cells.BHK-21 cells expressing CIP2A shRNA (BHK-21/CIP2A-shRNA ) were obtained and subsequently infected with VGTC’s proprietary AAV packaging system to package the rAAV2-CIP2A shRNA.After purification,the functional and infectious virus was obtained and the titer of virus was detected.Real-time PCR and Western blot methods were used to detect the expression of CIP2A after infection with HepG2 cells,and the empty viral vector rAAV2-EGFP was used as control. Results A recombinant adeno-associated virus-2 vector carrying CIP2A shRNA was constructed successfully.The presence of the target sequence in the vector was confirmed by double enzyme digestion and sequencing.By transfecting the pSNAV2.0-EGFP-CIP2A shRNA plasmid into BHK-21 cells,BHK-21/CIP2A shRNA cells were infected with helper virus HSV1-rc/ΔUL2 to package the rAAV2-CIP2A shRNA to obtain a functional and infectious virus.The titer of the recombinant virus was 0.25×10 1 2 v.g./mL.The expression of CIP2A mRNA and screening value of 1×10 5 MOI effected HepG2 cells.Conclusion A high-titer recombinant adeno-associated virus-2 vector carrying CIP2A shRNA has been constructed successfully.
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Objective To determine whether recombinant adeno-associated virus serotyoe 9 with CaMEK gene transfected on myocardial cells leads to reduce I/R-induced apoptosis.Methods Establish an ischemic/reperfusion(I/R) model of myocardial cells in vitro and the cells were divided into four experimental groups:(1) control group;(2) I/R group;(3) I/R+rAAV9-CBA-CaMEK group;(4) I/R+rAAV9-CBACaMEK+PD98059 group,respectively.The P-ERK1/2 and the Caspase-3,Bax were quqntitated by Western blot.Results These data clearly demonstrate that AAV9-mediated CaMEK gene transfected lead to active ERK1/2 and reduce I/R-induced apoptosis notablely.Conclusion rAAV9-mediated CaMEK gene transfected on myocardial cells can reduce I/R-induced apoptosis.
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Adeno-associated virus is a kind of DNA defective parvovirus which is non-pathogenic. Recombinant-adeno-associated virus vector comes from wild-type non-pathogenic adeno-associated virus and is highly secure, and it also has the advantages of broad host range. Recombinant-adeno-associated virus vector has become a hot spot for gene therapy and is widely used in gene therapy for cardiovascular diseases, especially for hypertension, heart failure, arteriosclerosis, and myocardial infarction.
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Objective To construct a recombinant adeno-associated virus(rAAV)vector containing a human anti-epidermal growth factor receptor(anti-EGFR)single-chain variable fragment antibody gene,and observe its inhibitory effects on pancreatic cancer cell lines.Methods Human anti-EGFR single-chain variable fragment antibody gene was inserted into the Kpn I and Bgl Ⅱ sites to construct a rAAV-anti EGFR vector,and then rAAV1-EGFP group and rAAV1-anti EGFR group were established.The expression of anti-EGFR antibody was observed.Antibody expression was detected by Western blot,and the inhibition and apoptosis rates of human pancreatic cancer cell lines(PCT-3,SW1990,Capan-1,ASPC-1,MiaPaCa-2 and PANC-1 cells)were detected by CCK-8 assay and flow cytometry,respectively.All data were analyzed using the t test.Results The results of Western blot assay demonstrated that anti-EGFR antibody was expressed in 6 pancreatic cancer cell lines.The inhibition rates of rAAV1-EGFP and rAAVl-anti EGFR on pancreatic ASPC-1 cells were 1.1%± 2.4% and 15.1%±3.5%,respectively,with a significant difference between the 2 groups(t =6.598,P ＜0.05).The apoptosis rates of PANC-1 cells were 7.0% ± 3.0% in the rAAV1-EGFP group and 1 1.4% ± 2.5% in the rAAV1-anti EGFR group,with no significant difference between the 2 grouvs(t = 1.952,P ＞0.05).The apoptosis rates of SW1990,ASPC-1,Capan-1,PCT-3,MiaPaCa-2 cells were 1.1% ± 0.8%,1.5% ± 0.7%,1.7% ± 1.2%,1.1%±0.7% and 2.2% ± 1.1% in the rAAV1-EGFP group,and 17.6% ± 2.2%,46.9% ± 3.9%,20.0% ±2.8%,12.1% ± 1.6% and 31.1% ±2.5% in the rAAV1-anti EGFR group,respectively,with significant differences between the 2 groups(t = 12.208,19.846,10.405,10.909,18.327,P ＜0.05).Conclusions A rAAV-anti EGFR vector with human anti-EGFR single-chain variable fragment antibody gene was constructed.Anti-EGFR antibody has obvious inhibition effects on pancreatic cancer cell lines.
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significantly attenuated the hyper-phosphorylation of tau proteins. These data suggested that inhibition of cdk-5 activity has neuropro-tective effect on neurons in NPC mice.
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Objective To evaluate the therapeutic effect of recombinant adeno-associated viral vector (rAAV) expressing human tissue kallikrein gene (rAAV-HK) on insulin resistance and renal complications in tyDe2 diabetic rats. Methods Male Wistar rats were injected low dose streptozotocin and fed with high fat and sucrose diets to form type 2 diabetic model. rAAV mediated HK gene (HK group) or LacZ gene (LacZ group) were introduced to the diabetic rats, and their systolic blood pressure, fasting blood glucose and insulin, serum creatinine, urine creatinine, urine osmolarity and urine microalbumin were measured. The homeostasis model assessment of insulin resistance (HOMA-IR), urinary albumin excretion rate (UAER) and creatinine clearance rate (Ccr) were calculated. The expression of PI3-kinase p11o catalytic subunit (p110) and Akt phosphorylation on Thr-308 were detected by Western blot. The morphology of kidney wag observed. Results Delivery of rAAVHK resulted in a reduction in blood pressure at 2 weeks and the hypotensive effect lasted for the duration of the study. The HOMA-IR was significantly lower in HK group than LacZ group (4.76±0.33 vs 8.36±0.48, P<0.01) at the end of the study, fasting insulin level was reduced [(8.19±2.45 vs 13.85±3.76)mIU/L. P<0.01], but there was no significant change in fasting blood glucose [(13.09±3.01 vs 13.58±2.88)mmol/L].The phosphorylation of p11o and Akt Thr-308 were significantly decreased in skeletal muscle and liver in LacZ group and were almost corrected by HK gene therapy. The UAER and Ccr were significantly lower and urinary osmolarity were higher in HK-treated rats compared with LaeZ rats. Histological assessment indicated that the renal complication was relieved by HK gene delivery. Conclusion The rAAV-mediated HK gene delivery efficiently attenuated insulin resistance partly through PI3K/Akt pathway and diabetic nephropathy in type 2diabetic rats.
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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 neurodegenerative diseases, we packed recombinant adeno-associated virus (rAAV) encoding cdc2-siRNA. The expressing plasmid pAAV-MCS-EGFP-U6-odc2-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.
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AIM:To study the feasibility of recombinant adeno-associated virus(rAAV)as a vector to transfer the green fluorescent protein(GFP)gene as a target gene into rabbit retina.METHODS:Intravitreal injection of rAAV-gfp was performed in either eye for each rabbit with the other eye taken as control.At the 3rd,7th,and 14th day after injection,the eyeballs were removed,and the retinas were flat-mounted on glass slides to inspect the retinal fluorescence,respectively.RESULTS:After intravitreal injection of rAAV-gfp,the presence of fluorescent spots in the cytoplasm of retinal cells indicated that GFP gene was efficiently transferred and expressed in the rabbit retina.CONCLUSION:Recombinant adeno-associated virus is a reliable and simple vector for transferring target gene,e.g.,GFP gene,to the retina.
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Objective To investigate the treatment of spinal cord injury (SCI) by recombinant adeno-associated virus (AAV) transducing the hNGF gene, and construct and produce the vector of hNGF recombinant AAV. Methods The resulting gene of hNGF was inserted into the KpnⅠ-BamHⅠ site of vector plasmid pSSHG-Neo to construct the vector of hNGF recombinant AAV. The recombinant AAV viral stock was packaged. Renal embryo 293 cell was co-transfected with the rAAV vector of plasmid pSSHG/hNGF, packaging plasmid pAAV/Ad and helper adenovirus pasmid pFG140 instead of adenovirus by calcium phosphate precipitation. Results The recombinant viral stock vector of plasmid pSSHG/hNGF was constructed successfully. The results of dot blot showed that we had obtained the rAAV stocks of high titre 1.46?10 12 PFU?mL -1. Conclusion We prepared the viral stock of rAAV-hNGF that can serve as the experimental study of gene therapy of SCI.