Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Front Plant Sci ; 14: 1173063, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37692438

RESUMO

Bacterial blight disease of rice caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious constraints in rice production. The most sustainable strategy to combat the disease is the deployment of host plant resistance. Earlier, we identified an introgression line, IR 75084-15-3-B-B, derived from Oryza officinalis possessing broad-spectrum resistance against Xoo. In order to understand the inheritance of resistance in the O. officinalis accession and identify genomic region(s) associated with resistance, a recombinant inbred line (RIL) mapping population was developed from the cross Samba Mahsuri (susceptible to bacterial blight) × IR 75084-15-3-B-B (resistant to bacterial blight). The F2 population derived from the cross segregated in a phenotypic ratio of 3: 1 (resistant susceptible) implying that resistance in IR 75084-15-3-B-B is controlled by a single dominant gene/quantitative trait locus (QTL). In the F7 generation, a set of 47 homozygous resistant lines and 47 homozygous susceptible lines was used to study the association between phenotypic data obtained through screening with Xoo and genotypic data obtained through analysis of 7K rice single-nucleotide polymorphism (SNP) chip. Through composite interval mapping, a major locus was detected in the midst of two flanking SNP markers, viz., Chr11.27817978 and Chr11.27994133, on chromosome 11L with a logarithm of the odds (LOD) score of 10.21 and 35.93% of phenotypic variation, and the locus has been named Xa48t. In silico search in the genomic region between the two markers flanking Xa48t identified 10 putatively expressed genes located in the region of interest. The quantitative expression and DNA sequence analysis of these genes from contrasting parents identified the Os11g0687900 encoding an NB-ARC domain-containing protein as the most promising gene associated with resistance. Interestingly, a 16-bp insertion was noticed in the untranslated region (UTR) of the gene in the resistant parent, IR 75084-15-3-B-B, which was absent in Samba Mahsuri. The association of Os11g0687900 with resistance phenotype was further established by sequence-based DNA marker analysis in the RIL population. A co-segregating PCR-based INDEL marker, Marker_Xa48, has been developed for use in the marker-assisted breeding of Xa48t.

2.
3 Biotech ; 13(9): 290, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37547917

RESUMO

The plant proliferation is linked with auxins which in turn play a pivotal role in the rate of growth. Also, auxin concentrations could provide insights into the age, stress, and events leading to flowering and fruiting in the sessile plant kingdom. The role in rejuvenation and plasticity is now evidenced. Interest in plant auxins spans many decades, information from different plant families for auxin concentrations, transcriptional, and epigenetic evidences for gene regulation is evaluated here, for getting an insight into pattern of auxin biosynthesis. This biosynthesis takes place via an tryptophan-independent and tryptophan-dependent pathway. The independent pathway initiated before the tryptophan (trp) production involves indole as the primary substrate. On the other hand, the trp-dependent IAA pathway passes through the indole pyruvic acid (IPyA), indole-3-acetaldoxime (IAOx), and indole acetamide (IAM) pathways. Investigations on trp-dependent pathways involved mutants, namely yucca (1-11), taa1, nit1, cyp79b and cyp79b2, vt2 and crd, and independent mutants of tryptophan, ins are compiled here. The auxin conjugates of the IAA amide and ester-linked mutant gh3, iar, ilr, ill, iamt1, ugt, and dao are remarkable and could facilitate the assimilation of auxins. Efforts are made herein to provide an up-to-date detailed information about biosynthesis leading to plant sustenance. The vast information about auxin biosynthesis and homeostasis is consolidated in this review with a simplified model of auxin biosynthesis with keys and clues for important missing links since auxins can enable the plants to proliferate and override the environmental influence and needs to be probed for applications in sustainable agriculture. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03709-6.

3.
Indian J Med Ethics ; VIII(3): 209-215, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36945850

RESUMO

BACKGROUND: Medical ethics teaching has received little attention in India's undergraduate medical curriculum, so the National Medical Commission's formal inclusion of medical ethics in the new competency-based curriculum (CBME) is creditable. However, the policymakers have left out the most crucial stakeholders - the teachers. This study was conducted to find out how physiology educators in Delhi felt about the implementation of ethics teaching in physiology in the CBME. METHODS: This was a pilot, cross-sectional, observational, feasibility study conducted using a questionnaire, involving faculty and senior residents (post-MD) in the departments of Physiology at nine medical colleges in Delhi, conducted over the period from February to October 2020. RESULTS: The response rate was 76% (60/79), of which 40% (24/60) were senior residents and 60% (36/60) were faculty. Around 55% (n=33) felt bioethics and clinical ethics are not synonymous; 53% (n=32) believed ethics education can be accomplished in a large group setting; 75% (n=45) believed it should be the responsibility of the physiology faculty, rather than the clinical faculty, and 61.7% (n=37) wanted it to be included in the formative assessment. The respondents shared ethical concerns that should be included in the physiology curriculum and the best candidates to teach them to achieve integration. Despite the challenges, the majority 65% (n=39) felt ethics in the physiology CBME should be an inseparable part of teaching in all instructional modalities. CONCLUSION: Early clinical exposure was considered preferable to the Attitude, Ethics, and Communication (AETCOM) programme. Using the five W's and one H method, we talk about how our findings can be used as a road map to help physiologists teach ethics to medical students in the new CBME.


Assuntos
Currículo , Educação de Graduação em Medicina , Humanos , Estudos de Viabilidade , Estudos Transversais , Ética Médica , Índia , Ensino
4.
Mol Cancer Ther ; 21(3): 460-470, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35027480

RESUMO

Oncolytic adenoviruses (OAd) represent an attractive treatment option for cancer. Clinical efficacy of commonly utilized human adenovirus type 5 (Ad5)-based oncolytic viruses is limited by variable expression levels of the coxsackie- and adenovirus receptor (CAR) in tumor cells and high prevalence of neutralizing antibodies against human Ad5. However, previous studies have highlighted alternative human Ad types as promising candidates for oncolytic therapy. In this study, we generated novel OAds based on Ad1, -2, -5, and -6 derived from species C Ads. These OAds contain a 24-bp deletion in the early gene E1A for tumor selective replication and express the RNAi inhibitor P19. We examined these OAds for in vitro anticancer activity on various cancer cell lines derived from lung, colon, gynecologic, bone, and pancreatic carcinoma. In most surveyed cell lines, OAds based on Ad1, -2, and -6 demonstrated higher cell lysis capability compared with Ad5, suggesting enhanced oncolytic potential. Moreover, enhanced oncolytic activity was associated with P19 expression in a cell type-dependent manner. We further explored a A549 tumor xenograft mouse model to compare the novel OAds directly with Ad5 and H101, an oncolytic adenovirus used in clinical trials. These P19-containing OAds based on Ad1, -2, and -6 showed significantly decelerated tumor progression compared with H101, indicating better antitumor potency in vivo. Our studies provide a novel path for OAd development based on alternative Ad types with improved effectiveness by RNA interference suppression.


Assuntos
MicroRNAs , Terapia Viral Oncolítica , Vírus Oncolíticos , Adenoviridae/genética , Animais , Linhagem Celular Tumoral , Feminino , Vetores Genéticos , Humanos , Camundongos , MicroRNAs/metabolismo , Vírus Oncolíticos/genética , Vírus Oncolíticos/metabolismo , Replicação Viral , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Biology (Basel) ; 10(12)2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34943170

RESUMO

Globally, soil salinity has been on the rise owing to various factors that are both human and environmental. The abiotic stress caused by soil salinity has become one of the most damaging abiotic stresses faced by crop plants, resulting in significant yield losses. Salt stress induces physiological and morphological modifications in plants as a result of significant changes in gene expression patterns and signal transduction cascades. In this comprehensive review, with a major focus on recent advances in the field of plant molecular biology, we discuss several approaches to enhance salinity tolerance in plants comprising various classical and advanced genetic and genetic engineering approaches, genomics and genome editing technologies, and plant growth-promoting rhizobacteria (PGPR)-based approaches. Furthermore, based on recent advances in the field of epigenetics, we propose novel approaches to create and exploit heritable genome-wide epigenetic variation in crop plants to enhance salinity tolerance. Specifically, we describe the concepts and the underlying principles of epigenetic recombinant inbred lines (epiRILs) and other epigenetic variants and methods to generate them. The proposed epigenetic approaches also have the potential to create additional genetic variation by modulating meiotic crossover frequency.

7.
3 Biotech ; 9(9): 326, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31406648

RESUMO

[This corrects the article DOI: 10.1007/s13205-019-1797-2.].

8.
3 Biotech ; 9(7): 270, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31218181

RESUMO

Medicinally important ancient Navara rice (GI Kerala, India 2007) is a very short duration (60-70 days) variety with a yield of only 0.5 tonnes/hectare costing ~ Rs. 400/kg. It is used for indigenous treatment for chronic diseases by local and oral consumption. In this study, scutellum-derived calli were generated from mature Navara seeds and these were inoculated on different CIM-1 to CIM-5 media supplemented with 2.5 mg/l 2,4-dichlorophenoxyacetic acid. Regeneration of calli on different regeneration media RI, RII and RIII media were performed. Regeneration of 30-day-old calli on RI media showed 30%, for RII it showed no regeneration and on RIII media only 12% regeneration was obtained. The addition of glutamine and proline showed a 30-40% improvement in somatic embryogenesis. The 74-88% callus induction frequency was obtained on CIM-1 to CIM-5. The fresh weight (mg) of 30-day-old calli is CIM-2 < CIM-3 < CIM-4 < CIM-1 << CIM-5 and corresponding size shows CIM-2-CIM-3 < CIM-5 < CIM-1 < CIM-4. A negative correlation between the callus fresh weight and the regeneration efficiency was observed. In CIM-5, 20-25 days 3.4-fold increase and 25-30 days a 1.7-fold increase in fresh weight of calli is noted. The 20-day-old calli transfer to RI media shows 80% regeneration frequency and 6-7 plantlets/callus, which are twofold higher as compared with 30-day-old calli. The somatic embryogenesis and its regeneration on synthetic media provide an alternative for biotechnological intervention for yield improvement, in turn cost reduction for Navara rice.

9.
Sci Rep ; 8(1): 13442, 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-30194327

RESUMO

More than 70 human adenoviruses with type-dependent pathogenicity have been identified but biological information about the majority of these virus types is scarce. Here we employed multiple sequence alignments and structural information to predict receptor usage for the development of an adenoviral vector with novel biological features. We report the generation of a cloned adenovirus based on human adenovirus type 17 (HAdV17) with high sequence homology to the well characterized human adenovirus type 37 (HAdV37) that causes epidemic keratoconjunctivitis (EKC). Our study revealed that human CD46 (CD46) is involved in cell entry of HAdV17. Moreover, we found that HAdV17 infects endothelial cells (EC) in vitro including primary cells at higher efficiencies compared to the commonly used human adenovirus type 5 (HAdV5). Using a human CD46 transgenic mouse model, we observed that HAdV17 displays a broad tropism in vivo after systemic injection and that it transduces ECs in this mouse model. We conclude that the HAdV17-based vector may provide a novel platform for gene therapy.


Assuntos
Adenovírus Humanos/fisiologia , Células Endoteliais , Proteína Cofatora de Membrana/metabolismo , Transdução Genética , Tropismo Viral/fisiologia , Internalização do Vírus , Animais , Células CHO , Cricetulus , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Células Endoteliais/virologia , Vetores Genéticos , Células HEK293 , Células Endoteliais da Veia Umbilical Humana , Humanos , Células Jurkat , Proteína Cofatora de Membrana/genética , Camundongos Transgênicos
10.
Semin Cancer Biol ; 53: 90-109, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29966677

RESUMO

Metastasis is one of the most challenging issues in cancer patient management, and effective therapies to specifically target disease progression are missing, emphasizing the urgent need for developing novel anti-metastatic therapeutics. Cancer stem cells (CSCs) gained fast attention as a minor population of highly malignant cells within liquid and solid tumors that are responsible for tumor onset, self-renewal, resistance to radio- and chemotherapies, and evasion of immune surveillance accelerating recurrence and metastasis. Recent progress in the identification of their phenotypic and molecular characteristics and interactions with the tumor microenvironment provides great potential for the development of CSC-based targeted therapies and radical improvement in metastasis prevention and cancer patient prognosis. Here, we report on newly uncovered signaling mechanisms controlling CSC's aggressiveness and treatment resistance, and CSC-specific agents and molecular therapeutics, some of which are currently under investigation in clinical trials, gearing towards decisive functional CSC intrinsic or surface markers. One special research focus rests upon subverted regulatory pathways such as insulin-like growth factor 1 receptor signaling and its interactors in metastasis-initiating cell populations directly related to the gain of stem cell- and EMT-associated properties, as well as key components of the E2F transcription factor network regulating metastatic progression, microenvironmental changes, and chemoresistance. In addition, the study provides insight into systems biology tools to establish complex molecular relationships behind the emergence of aggressive phenotypes from high-throughput data that rely on network-based analysis and their use to investigate immune escape mechanisms or predict clinical outcome-relevant CSC receptor signaling signatures. We further propose that customized vector technologies could drastically enhance systemic drug delivery to target sites, and summarize recent progress and remaining challenges. This review integrates available knowledge on CSC biology, computational modeling approaches, molecular targeting strategies, and delivery techniques to envision future clinical therapies designed to conquer metastasis-initiating cells.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias/metabolismo , Células-Tronco Neoplásicas/metabolismo , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/antagonistas & inibidores , Resistencia a Medicamentos Antineoplásicos , Humanos , Metástase Neoplásica , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Transdução de Sinais/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos
11.
Adv Drug Deliv Rev ; 120: 89-107, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28736304

RESUMO

Cancer progression to metastatic stages is still unmanageable and the promise of effective anti-metastatic therapy remains largely unmet, emphasizing the need to develop novel therapeutics. The special focus here is on cancer stem cells (CSC) as the seed of tumor initiation, epithelial-mesenchymal transition, chemoresistance and, as a consequence, drivers of metastatic dissemination. We report on targeted therapies gearing towards the CSC's internal and membrane-anchored markers using agents such as antibody derivatives, nucleic therapeutics, small molecules and genetic payloads. Another emphasis lies on novel proceedings envisaged to deliver current and prospective therapies to the target sites using newest viral and non-viral vector technologies. In this review, we summarize recent progress and remaining challenges in therapeutic strategies to combat CSC.


Assuntos
Neoplasias/terapia , Células-Tronco Neoplásicas/patologia , Animais , Antineoplásicos/uso terapêutico , Humanos , Neoplasias/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos
12.
Cell Rep ; 19(8): 1698-1709, 2017 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-28538186

RESUMO

Adenoviruses (Ads) are large human-pathogenic double-stranded DNA (dsDNA) viruses presenting an enormous natural diversity associated with a broad variety of diseases. However, only a small fraction of adenoviruses has been explored in basic virology and biomedical research, highlighting the need to develop robust and adaptable methodologies and resources. We developed a method for high-throughput direct cloning and engineering of adenoviral genomes from different sources utilizing advanced linear-linear homologous recombination (LLHR) and linear-circular homologous recombination (LCHR). We describe 34 cloned adenoviral genomes originating from clinical samples, which were characterized by next-generation sequencing (NGS). We anticipate that this recombineering strategy and the engineered adenovirus library will provide an approach to study basic and clinical virology. High-throughput screening (HTS) of the reporter-tagged Ad library in a panel of cell lines including osteosarcoma disease-specific cell lines revealed alternative virus types with enhanced transduction and oncolysis efficiencies. This highlights the usefulness of this resource.


Assuntos
Adenoviridae/genética , Biblioteca Gênica , Engenharia Genética , Vetores Genéticos/metabolismo , Sequência de Bases , Clonagem Molecular , Genes Reporter , Genoma Viral , Ensaios de Triagem em Larga Escala , Humanos
13.
Microrna ; 6(2): 136-142, 2017 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-28215140

RESUMO

BACKGROUND: miRNA are the post transcriptional regulator of the genes. The conserved miR168 family is evaluated for position based nucleotide preference in higher plants. Low density lipoprotein receptor adaptor protein 1 (LDLRAP1) target validated for miR168a obtained from rice origin is reported. METHODS: The mature miRNA sequences include miR168-5p and miR168-3p, were obtained from miRBase (v21, June 2014) for 15 families (28 plants). The preferred position based nucleotide sequences were obtained using Data Analysis in Molecular Biology and Evolution software. The miR168-5p was subjected to cross kingdom analysis using psRNATarget. Target expression and functional annotation was analyzed by using Human Protein Atlas database WEB-based Gene SeTAnaLysis Toolkit. RESULTS: miR168-5p shows same nucleotides at positions 1-6, 8-9, 11-12, 15-17 and 19. Also, miR168-3p is present in 3 families (10 plants) shows the same nucleotide at position 1-11, 13-15 and 17-21. The 123 targets in human transcriptome were identified showing 58% cleavage and 41% translation repression. Low density lipoprotein receptor adaptor protein 1 (LDLRAP1) target validated for miR168a obtained from rice origin, could also be targeted from miR168 from any other plant sources. The randomly selected 10 targets include some important genes likeRPL34, ATXN1, AKAPI3 and ALS2 and is involved in transcription, cell trafficking, cell metabolism and neurodegenerative disorder. CONCLUSION: Our work suggests that miR168 family has conserved sequence in higher plants. The seed region position 2-8 shows 70-95% pairing with human targets. Cleavage site at position 10-14 and these were analysed for the base preference with the targets showed 80-96% Watson Crick pairing.


Assuntos
Genes de Plantas , Mamíferos/genética , MicroRNAs/genética , Plantas/genética , RNA de Plantas/genética , Animais , Sequência de Bases , Regulação da Expressão Gênica de Plantas , Humanos
14.
J Pharm Bioallied Sci ; 8(3): 248-52, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27413355

RESUMO

OBJECTIVES: Evaluation and comparison of ethical standards of published drug promotional literatures (DPLs) between different Indian and non-Indian scientific medical journals regarding compliance to the World Health Organization (WHO) and International Federation of Pharmaceutical Manufacturers and Associations (IFPMAs) guidelines. MATERIALS AND METHODS: A cross-sectional, observational study was carried out at pharmacology department. DPLs published in Indian and non-Indian scientific medical journals available at central library of medical college during the period of 6 months were collected according to selection criteria. DPLs were evaluated and compared for compliance to ethical standards of drug promotion laid by the WHO and IFPMA. Data were analyzed using Fisher's exact test. RESULTS: Out of total 178 DPLs, 103 DPLs were from Indian journals and 75 DPLs were from non-Indian journals. When compared regarding compliance to all the 11 ethical criteria of WHO, no significant difference was found between DPLs published in Indian and non-Indian journals. However, DPLs from indian journals contained significantly less information regarding dosage regimen (P = 0.0096), adverse drug reactions (P = 0.0028), warnings (P = 0.0104) and major drug interactions (P < 0.0001) as compared to non-Indian journals. Compliance to all the five IFPMA criteria was significantly higher in DPLs of non-Indian journals (88%) than Indian journals (39%) (P < 0.0001). CONCLUSION: Noncompliance to ethical standards of WHO and IFPMA guidelines is more common in DPLs of Indian journals as compared to non-Indian journals. Thus strict implementation of regulatory measures regarding DPLs published in Indian medical journals is recommended.

15.
Mol Ther Nucleic Acids ; 5(7): e337, 2016 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-27434682

RESUMO

For efficient delivery of required genetic elements we utilized high-capacity adenoviral vectors in the past allowing high transgene capacities of up to 36 kb. Previously we explored the hyperactive Sleeping Beauty (SB) transposase (HSB5) for somatic integration from the high-capacity adenoviral vectors genome. To further improve this hybrid vector system we hypothesized that the previously described hyperactive SB transposase SB100X will result in significantly improved efficacies after transduction of target cells. Plasmid based delivery of the SB100X system revealed significantly increased integration efficiencies compared with the previously published hyperactive SB transposase HSB5. After optimizing experimental setups for high-capacity adenoviral vectors-based delivery of the SB100X system we observed up to eightfold and 100-fold increased integration efficiencies compared with the previously published hyperactive SB transposase HSB5 and the inactive transposase mSB, respectively. Furthermore, transposon copy numbers per cell were doubled with SB100X compared with HSB5 when using the identical multiplicity of infection. We believe that this improved hybrid vector system represents a valuable tool for achieving stabilized transgene expression in cycling cells and for treatment of numerous genetic disorders. Especially for in vivo approaches this improved adenoviral hybrid vector system will be advantageous because it may potentially allow reduction of the applied viral dose.

16.
J Vis Exp ; (107): e52894, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26863087

RESUMO

High-capacity adenoviral vectors (HCAdV) devoid of all viral coding sequences represent one of the most advanced gene delivery vectors due to their high packaging capacity (up to 35 kb), low immunogenicity and low toxicity. However, for many laboratories the use of HCAdV is hampered by the complicated procedure for vector genome construction and virus production. Here, a detailed protocol for efficient cloning and production of HCAdV based on the plasmid pAdFTC containing the HCAdV genome is described. The construction of HCAdV genomes is based on a cloning vector system utilizing homing endonucleases (I-CeuI and PI-SceI). Any gene of interest of up to 14 kb can be subcloned into the shuttle vector pHM5, which contains a multiple cloning site flanked by I-CeuI and PI-SceI. After I-CeuI and PI-SceI-mediated release of the transgene from the shuttle vector the transgene can be inserted into the HCAdV cloning vector pAdFTC. Because of the large size of the pAdFTC plasmid and the long recognition sites of the used enzymes associated with strong DNA binding, careful handling of the cloning fragments is needed. For virus production, the HCAdV genome is released by NotI digest and transfected into a HEK293 based producer cell line stably expressing Cre recombinase. To provide all adenoviral genes for adenovirus amplification, co-infection with a helper virus containing a packing signal flanked by loxP sites is required. Pre-amplification of the vector is performed in producer cells grown on surfaces and large-scale amplification of the vector is conducted in spinner flasks with producer cells grown in suspension. For virus purification, two ultracentrifugation steps based on cesium chloride gradients are performed followed by dialysis. Here tips, tricks and shortcuts developed over the past years working with this HCAdV vector system are presented.


Assuntos
Adenovírus Humanos/genética , Clonagem Molecular/métodos , Técnicas de Transferência de Genes , Vetores Genéticos/genética , Vírus Auxiliares/genética , Adenovírus Humanos/fisiologia , Sequência de Bases , Vetores Genéticos/fisiologia , Células HEK293 , Vírus Auxiliares/fisiologia , Humanos , Integrases , Plasmídeos/genética , Transfecção , Transgenes
17.
J Gen Virol ; 97(1): 160-168, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26519158

RESUMO

Commonly used human adenovirus (HAdV)-5-based vectors are restricted by their tropism and pre-existing immunity. Here, we characterized novel HAdV-5 vectors pseudotyped with hypervariable regions (HVRs) and surface domains (SDs) of other HAdV types. Hexon-modified HAdV-5 vectors (HV-HVR5, HV-HVR12, HV-SD12 and HV-SD4) could be reconstituted and amplified in human embryonic kidney cells. After infection of various cell lines, we measured transgene expression levels by performing luciferase reporter assays or coagulation factor IX (FIX) ELISA. Dose-dependent studies revealed that luciferase expression levels were comparable for HV-HVR5, HV-SD12 and HV-SD4, whereas HV-HVR12 expression levels were significantly lower. Vector genome copy numbers (VCNs) from genomic DNA and nuclear extracts were then determined by quantitative real-time PCR. Surprisingly, determination of cell- and nuclear fraction-associated VCNs revealed increased VCNs for HV-HVR12 compared with HV-SD12 and HV-HVR5. Increased nuclear fraction-associated HV-HVR12 DNA molecules and decreased transgene expression levels were independent of the cell line used, and we observed the same effect for a hexon-modified high-capacity adenoviral vector encoding canine FIX. In conclusion, studying hexon-modified adenoviruses in vitro demonstrated that HVRs but also flanking hexon regions influence uptake and transgene expression of adenoviral vectors.


Assuntos
Adenovírus Humanos/fisiologia , Proteínas do Capsídeo/imunologia , Proteínas do Capsídeo/metabolismo , Vetores Genéticos , Tropismo Viral , Adenovírus Humanos/genética , Adenovírus Humanos/imunologia , Linhagem Celular , DNA Viral/análise , Fator IX/análise , Fator IX/genética , Perfilação da Expressão Gênica , Genes Reporter , Humanos , Luciferases/análise , Luciferases/genética , Reação em Cadeia da Polimerase em Tempo Real
18.
Hum Gene Ther Methods ; 26(1): 25-34, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25640117

RESUMO

High-capacity adenoviral vectors (HCAdVs) are promising tools for gene therapy as well as for genetic engineering. However, one limitation of the HCAdV vector system is the complex, time-consuming, and labor-intensive production process and the following quality control procedure. Since HCAdVs are deleted for all viral coding sequences, a helper virus (HV) is needed in the production process to provide the sequences for all viral proteins in trans. For the purification procedure of HCAdV, cesium chloride density gradient centrifugation is usually performed followed by buffer exchange using dialysis or comparable methods. However, performing these steps is technically difficult, potentially error-prone, and not scalable. Here, we establish a new protocol for small-scale production of HCAdV based on commercially available adenovirus purification systems and a standard method for the quality control of final HCAdV preparations. For titration of final vector preparations, we established a droplet digital polymerase chain reaction (ddPCR) that uses a standard free-end-point PCR in small droplets of defined volume. By using different probes, this method is capable of detecting and quantifying HCAdV and HV in one reaction independent of reference material, rendering this method attractive for accurately comparing viral titers between different laboratories. In summary, we demonstrate that it is possible to produce HCAdV in a small scale of sufficient quality and quantity to perform experiments in cell culture, and we established a reliable protocol for vector titration based on ddPCR. Our method significantly reduces time and required equipment to perform HCAdV production. In the future the ddPCR technology could be advantageous for titration of other viral vectors commonly used in gene therapy.


Assuntos
Adenoviridae/genética , Vetores Genéticos/normas , Reação em Cadeia da Polimerase/métodos , Adenoviridae/química , Sequência de Bases , Linhagem Celular Tumoral , Vetores Genéticos/química , Vetores Genéticos/genética , Células HEK293 , Humanos , Dados de Sequência Molecular , Controle de Qualidade
19.
Nucleic Acids Res ; 43(8): e50, 2015 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-25609697

RESUMO

Recombinant adenoviruses containing a double-stranded DNA genome of 26-45 kb were broadly explored in basic virology, for vaccination purposes, for treatment of tumors based on oncolytic virotherapy, or simply as a tool for efficient gene transfer. However, the majority of recombinant adenoviral vectors (AdVs) is based on a small fraction of adenovirus types and their genetic modification. Recombineering techniques provide powerful tools for arbitrary engineering of recombinant DNA. Here, we adopted a seamless recombineering technology for high-throughput and arbitrary genetic engineering of recombinant adenoviral DNA molecules. Our cloning platform which also includes a novel recombination pipeline is based on bacterial artificial chromosomes (BACs). It enables generation of novel recombinant adenoviruses from different sources and switching between commonly used early generation AdVs and the last generation high-capacity AdVs lacking all viral coding sequences making them attractive candidates for clinical use. In combination with a novel recombination pipeline allowing cloning of AdVs containing large and complex transgenes and the possibility to generate arbitrary chimeric capsid-modified adenoviruses, these techniques allow generation of tailored AdVs with distinct features. Our technologies will pave the way toward broader applications of AdVs in molecular medicine including gene therapy and vaccination studies.


Assuntos
Adenoviridae/genética , Clonagem Molecular/métodos , Engenharia Genética , Vetores Genéticos , Recombinação Genética , Cromossomos Artificiais Bacterianos , DNA Viral , Células HEK293 , Humanos
20.
Curr Gene Ther ; 15(3): 255-65, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25619886

RESUMO

Rare genetic diseases account for a considerable amount of fatalities and even their 'mild' or 'non-lethal' forms can produce drastic and undesirable discomfort to affected individuals. Various gene therapeutic approaches were tested for developing novel therapeutic concepts to treat these genetic diseases. Sleeping Beauty (SB) transposase represents one of these gene therapeutic systems which can be utilized for stable phenotypic correction. It is a transposable element which was resurrected and optimized for transposing genetic elements resulting in somatic integration of the transgene. Because of its versatile activity in many different organs, SB transposase has been explored for ex-vivo gene delivery and in vivo gene delivery including recently launched clinical trials based on engineered T-cells for tumor therapy and approaches to treat retinal degenerations. Here we will provide a state-of-the-art overview of preclinical studies for treatment of rare genetic diseases based on the SB transposase system for stable correction of the genetic defect. In this review, diseases affecting the blood system, the connective tissue, the immune system, the metabolism, and the nervous system and their treatment utilizing the SB transposase system will be discussed. Moreover, advantages and disadvantages of SB transposase-based gene therapeutic approaches will be mentioned. Although improvements of the SB transposase systems regarding genotoxicity and efficient delivery especially for applications in large mammals are desirable, the SB transposase system remains to hold great promise for curing rare genetic disease.


Assuntos
Doenças Genéticas Inatas/terapia , Vetores Genéticos , Doenças Raras/terapia , Transposases/genética , Animais , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA