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The success of using the insect cell-baculovirus expression technology (BEST) relies on the efficient construction of recombinant baculovirus with genetic stability and high productivity, ideally within a short time period. Generation of recombinant baculoviruses requires the transfection of insect cells, harvesting of recombinant baculovirus pools, isolation of plaques, and the expansion of baculovirus stocks for their use for recombinant protein production. Moreover, many options exist for selecting the genetic elements to be present in the recombinant baculovirus. This chapter describes the most commonly used homologous recombination systems for the production of recombinant baculoviruses, as well as strategies to maximize generation efficiency and recombinant protein or baculovirus production. The key steps for generating baculovirus stocks and troubleshooting strategies are described.
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Baculoviridae , Proteínas Recombinantes , Baculoviridae/genética , Animais , Proteínas Recombinantes/genética , Vetores Genéticos/genética , Transfecção/métodos , Recombinação Homóloga , Células Sf9 , Linhagem Celular , Spodoptera/virologia , Insetos/genética , Insetos/virologiaRESUMO
The piscine orthomyxovirus called infectious salmon anemia virus (ISAV) is one of the most important emerging pathogens affecting the salmon industry worldwide. The first reverse genetics system for ISAV, which allows the generation of recombinant ISA virus (rISAV), is an important tool for the characterization and study of this virus. The plasmid-based reverse genetics system for ISAV includes the use of a novel fish promoter, the Atlantic salmon internal transcribed spacer region 1 (ITS-1). The salmon, viral, and mammalian genetic elements included in the pSS-URG vectors allow the expression of the eight viral RNA segments. In addition to four cytomegalovirus (CMV)-based vectors that express the four proteins of the ISAV ribonucleoprotein complex, the eight pSS-URG vectors allowed the generation of infectious rISAV in salmon cells.
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Doenças dos Peixes , Isavirus , Infecções por Orthomyxoviridae , Orthomyxoviridae , Animais , Isavirus/genética , DNA Complementar/genética , Linhagem Celular , Orthomyxoviridae/genética , RNA Viral/genética , Infecções por Orthomyxoviridae/veterinária , Salmão/genética , Mamíferos/genéticaRESUMO
RNA nanoparticles are promising therapeutic platforms to improve radiotherapy since they can be functionalized with multiple small interfering RNAs (RNAi) to simultaneously silence critical radioresistance genes. Here we describe the transfer of RNA rings to mammalian cancer cells through reverse transfection, followed by in vitro irradiation and biological assays as surrogates' endpoints for radiotherapy efficacy.
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OBJECTIVE: The purpose of this study was to develop a method for the isolation, culture, and PEG-mediated protoplast transfection from leaves of in vitro-grown plants of Ricinus communis. RESULTS: Factors such as the enzymatic composition and the incubation time were evaluated. The enzymatic solution, containing 1.6% Cellulase-R10 and 0.8% Macerozyme-R10, with 16 h of incubation, was the best condition to achieve a high protoplast yield (481.16 × 104 protoplasts/g FW) with a high percentage of viability (95%). The combination and concentration of enzymes have been shown to affect the protoplast isolation efficiency significantly. Furthermore, we found that a higher number of protoplasts (8.5 × 105 protoplast/g FW) was obtained at a longer incubation time, but their viability decreased. We obtained a simple and efficient protocol to isolate protoplast from Ricinus communis leaves and culture. A PEG-mediated protoplast transfection protocol was also established to introduce plasmid DNA into Ricinus communis genotypes cultivated in Colombia. Thus, strengthening advances in the genetic improvement processes for this crop are presented.
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Ricinus communis , Ricinus communis/genética , Protoplastos , Ricinus/genética , Folhas de Planta/genética , TransfecçãoRESUMO
BACKGROUND: Previous work showed that the microRNA (miRNA) miR-671-5p was upregulated in monocyte-derived dendritic cells (moDCs) stimulated with Bifidobacterium animalis subsp. lactis BB12 (BB12) with no increase in IL-10 after six hours of stimulation. In this work, we performed an in silico prediction of genes targeted by miR-671-5p and which are the terms and pathways involved with it. Also, miR-671-5p was transiently downregulated to assess its effect on IL-10 regulation. METHODS AND RESULTS: First, we performed a Gene Ontology enrichment analysis to predict immune response terms and pathways involved with miR-671-5p. Some of the terms and pathways found were related to the immune response promoted by the probiotic, as the terms "negative regulation of the inflammatory response to an antigenic stimulus" and "cancer" were highlighted. Then, to assess the role of miR-671-5p in IL-10 regulation, moDCs were derived from porcine peripheral blood and later transfected with miR-671-5p antisense oligonucleotide (ASO). Flow cytometry was employed to evaluate the transfection efficiency. Then, the moDCs were stimulated with BB12, and the expression of IL-10 was assessed by RT-qPCR and ELISA. An increase in IL-10 transcript in miR-671-5p-ASO-transfected moDCs stimulated with BB12 was observed compared with moDCs stimulated with BB12 but not transfected. These results suggest the participation of miR-671-5p as a negative regulator of IL-10. CONCLUSION: These findings suggest that miR-671-5p participates in the downregulation of IL-10, as previously predicted in silico by our work group. miR-671-5p could play an essential role in the immunomodulation promoted by the probiotic BB12.
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MicroRNAs , Probióticos , Suínos , Animais , Interleucina-10/genética , Interleucina-10/metabolismo , Regulação para Baixo/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Monócitos/metabolismo , RNA Mensageiro/metabolismo , Probióticos/farmacologiaRESUMO
Microfluidic tools have recently made possible many advances in biological and biomedical research. Research in fields such as physics, engineering, chemistry and biology have combined to produce innovation in microfluidics which has positively impacted diverse areas such as nucleotide sequencing, functional genomics, single-cell studies, single molecules assays and biomedical diagnostics. Among these areas, regenerative medicine and stem cells have benefited from microfluidics since these tools have had a profound impact on their applications. In this study, we present a high-performance droplet-based system for transfecting individual human-induced pluripotent stem cells. We will demonstrate that this system has great efficiency in single cells and captured droplets, like other microfluidic methods but with lower cost. Moreover, this microfluidic approach can be associated with the PiggyBac transposase-based system to increase its transfection efficiency. Our results provide a starting point for subsequent applications in more complex transfection systems, single-cell differentiation interactions, cell subpopulations and cell therapy, among other potential applications.
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MicroRNAs (miRNAs) are short non-coding RNA molecules acting as important posttranscriptional gene and protein expression regulators in cancer. The study goal was to examine VEGFA (vascular endothelial growth factor A) expression in hepatocellular carcinoma (HCC) cell lines upon transfection miR-612, miR-637, or miR-874. Methods: MiR-612 mimics, miR-637 mimics, or miR-874 inhibitors were transfected using Lipofectamine RNAiMax in both HCC cell lines, HepG2 and HuH-7. Real-time PCR, Western blotting, and ELISA methods were used to evaluate VEGFA regulation by the miRNAs. Results: Gene and protein expression levels of VEGFA were down-expressed in both cell lines, HepG2 and HuH-7, transfected with miR-612 or miR-637. Transfection with miR-874 inhibitor showed an increase in VEGFA gene expression in HepG2 and HuH-7 cell lines; however, no regulation was observed on VEGFA protein expression by miR-874 inhibition. Correlation analysis between miRNAs and VEGFA protein expression showed that miR-637 and miR-874 expression present inversely correlated to VEGFA protein expression. Conclusions: VEGFA was down-regulated in response to hsa-miR-612 or hsa-miR-637 overexpression; however, the modulation of VEGFA by miR-874 was observed only at the gene expression and thus, needs further investigation.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Transient gene expression (TGE) is an important tool for generating recombinant proteins in a short period of time. The human cell line HEK293 is widely used for this purpose since it can grow in suspension to a high cell density in serum-free media. In addition, this cell line is amenable to several transfection methods and produces recombinant proteins in satisfactory quantities for functional and structural analysis. This chapter describes the methodology for TGE using the Expi293 system, which provides higher expression levels than other HEK293-based systems.
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Polietilenoimina , Expressão Gênica , Células HEK293 , Humanos , Polietilenoimina/química , Proteínas Recombinantes/genética , TransfecçãoRESUMO
Cells from different origins behave differently regarding the incorporation of exogenous DNA and formation of transgenic cells. Milk production of recombinant antibody may benefit from efficient transfection protocols to produce transgenic animals. In this context, the objective of this study was to verify the transfection potential of bovine mesenchymal stem cells from Wharton's jelly (MSC-WJ) and adipose tissue (MSC-AT), comparing co-transfection protocols with vectors pBC1-anti-CD3 and pEF-NEO-GFP, using transfection reagents Lipofectamine LTX with Plus Reagent or Xfect. Skin fibroblasts (FIB) were used as the control group. Forty-eight hours after transfection, neomycin was added and cells cultured for 2 weeks. Treated cells were submitted to fluorescence microscopy, flow cytometry, and PCR evaluations. Wharton's jelly cells were sensitive to treatments and started necrosis. In the flow cytometry assay, the median fluorescence was higher in adipocytes than fibroblasts, for both the Xfect (20.057 ± 1.620,7 and 10.601 ± 702,86, respectively, p < 0.05) and LTX (19.590 ± 113,84 and 10.518 ± 442,65, respectively, p < 0.05). These results, associated with evaluation of epifluorescence, demonstrated that adipocytes presented a better response to transfection than other cells, independent of the kit used. Performing PCR on co-transfected cells demonstrated the presence of anti-CD3, making this approach feasible for future experiments.
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Células-Tronco Mesenquimais , Geleia de Wharton , Bovinos , Animais , Células Cultivadas , Geleia de Wharton/metabolismo , Transfecção , Adipócitos , Diferenciação CelularRESUMO
Optogenetics is a molecular biological technique involving transfection of cells with photosensitive proteins and the subsequent study of their biological effects. The aim of this study was to evaluate the effect of blue light on the survival of HeLa cells, transfected with channelrhodopsin-2 (ChR2). HeLa wild-type cells were transfected with a plasmid that contained the gene for ChR2. Transfection and channel function were evaluated by real-time polymerase chain reaction (RT-PCR), fluorescence imaging using green fluorescent protein (GFP) and flow cytometry for intracellular calcium changes using a Fura Red probe. We developed a platform for optogenetic stimulation for use within the cell culture incubator. Different stimulation procedures using blue light (467 nm) were applied for up to 24 h. Cell survival was determined by flow cytometry using propidium iodide and rhodamine probes. Change in cell survival showed a statistically significant (p < 0.05) inverse association with the frequency and time of application of the light stimulus. This change seemed to be associated with the ChR2 cis-trans-isomerization cycle. Cell death was associated with high concentrations of calcium in the cytoplasm and stimulation intervals less than the period of isomerization. It is possible to transfect HeLa cells with ChR2 and control their survival under blue light stimulation. We suggest that this practice should be considered in the future development of optogenetic systems in biological or biomedical research.
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Sobrevivência Celular/fisiologia , Cálcio/metabolismo , Ciclo Celular/fisiologia , Channelrhodopsins/genética , Channelrhodopsins/metabolismo , Células HeLa , Humanos , Optogenética , TransfecçãoRESUMO
The development of genetic manipulation of Plasmodium falciparum in the 1980s was key to study malaria biology. Genetically modified parasites have been used to study several aspects of the disease, such as red blood cell invasion, drug resistance mechanisms, gametocyte development and mosquito transmission. However, biological and genetic differences between P. falciparum and the other human malaria parasites make P. falciparum a poor model to study different species. The lack of robust systems of long-term in vitro culture of P. vivax and the other human malaria parasites lagged the genetic manipulation of these species. Here we review the efforts to generate genetically modified non-falciparum human malaria parasites, in vivo and in vitro. Using in vivo models - infection of non-human primates such as rhesus macaques and saimiri monkeys - researchers were able to generate transgenic lines of P. knowlesi, P. cynomolgi, and P. vivax. The development of long-term in vitro culture of P. knowlesi in the 2000's, using rhesus and human red blood cells, created a platform to genetically manipulate non-falciparum malaria parasites. Recently, the use of CRISPR/Cas9 technology to genome edit P. knowlesi provides another tool to non-falciparum malaria research, extending the possibilities and allowing researchers to study different aspects of the biology of these parasites and understand the differences between these species and P. falciparum.
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Malária Vivax , Malária , Parasitos , Plasmodium knowlesi , Animais , Humanos , Macaca mulatta , Plasmodium knowlesi/genética , Plasmodium vivax/genéticaRESUMO
Cell lines can be good models for the disease they are derived from but can also be used to study general physiological and pathological processes. They can also be used to generate cell models of diseases when primary cultures are not available. Recent genome editing tools have been very promising tools toward creating cell models to mimic diseases in vitro. In this chapter, we highlight techniques used to obtain genome-edited cell lines, including cell line selection, transfection and gene editing tools available, together with methods of phenotype characterization and, lastly, a few examples of how in vitro disease models were created using CRISPR-Cas9.
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Sistemas CRISPR-Cas , Edição de Genes , Sistemas CRISPR-Cas/genética , Linhagem Celular , Fenótipo , TransfecçãoRESUMO
Giardiavirus is the only virus that infects Giardia duodenalis, a highly prevalent parasite worldwide, especially in low-income and developing countries. This virus belongs to the Totiviridae family, being a relative of other viruses that infect fungi and protozoa. It has a simple structure with only two proteins encoded in its genome and it appears that it can leave the cell without lysis. All these characteristics make it an interesting study model; however, its research has unfortunately made little progress in recent years. Thus, in this review, we summarize the currently available data on Giardiavirus, from their structure, genome and main proteins, to the uses that have been given to them and the possible health applications for the future.
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Giardia lamblia/virologia , Giardiavirus/fisiologia , Animais , HumanosRESUMO
Bovine babesiosis is a tick-borne disease caused by apicomplexan parasites of the Babesia genus that represents a major constraint to livestock production worldwide. Currently available vaccines are based on live parasites which have archetypal limitations. Our goal is to identify candidate antigens so that new and effective vaccines against Babesia may be developed. The perforin-like protein (PLP) family has been identified as a key player in cell traversal and egress in related apicomplexans and it was also identified in Babesia, but its function in this parasite remains unknown. The aim of this work was to define the PLP family in Babesia and functionally characterize PLP1, a representative member of the family in Babesia bovis. Bioinformatic analyses demonstrate a variable number of plp genes (four to eight) in the genomes of six different Babesia spp. and conservation of the family members at the secondary and tertiary structure levels. We demonstrate here that Babesia PLPs contain the critical domains present in other apicomplexan PLPs to display the lytic capacity. We then focused on the functional characterization of PLP1 of B. bovis, both in vitro and in vivo. PLP1 is expressed and exposed to the host immune system during infection and has high hemolytic capacity under a wide range of conditions in vitro. A B. bovis plp1 knockout line displayed a decreased growth rate in vitro compared with the wild type strain and a peculiar phenotype consisting of multiple parasites within a single red blood cell, although at low frequency. This phenotype suggests that the lack of PLP1 has a negative impact on the mechanism of egression of the parasite and, therefore, on its capacity to proliferate. It is possible that PLP1 is associated with other proteins in the processes of invasion and egress, which were found to have redundant mechanisms in related apicomplexans. Future work will be focused on unravelling the network of proteins involved in these essential parasite functions.
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Babesia bovis , Babesia , Babesiose , Doenças dos Bovinos , Parasitos , Animais , Babesia bovis/genética , Bovinos , PerforinaRESUMO
Sperm-mediated gene transfer (SMGT) has a potential application in the generation of transgenic animals. Capillary electroporation consists of the application of electrical pulses, resulting in an increased transfection rate. Little is known about the impacts of the transfection of exogenous DNA on sperm epigenetics. MicroRNAs are epigenetic factors that are related to sperm motility. MiRNA-122-5p regulates genes that influence motility, and consequently, the fertilizing potential of sperm. Therefore, we aimed at identifying whether epigenetic factors such as microRNAs could be altered after DNA transfection, using the capillary electroporation technique. In this study, bull sperm was electroporated using voltages of 600 V, 1500 V, and 0 V (control group), with or without exogenous DNA. Parameters of sperm quality were analyzed using CASA and flow cytometry, and expression of the miRNA-122-5p was analyzed using RT-qPCR. It was observed that electroporation increased the internalization of exogenous DNA (P < 0.05), but did not impair the mitochondrial activity (P > 0.05). It reduced sperm motility (P < 0.05). The expression of miRNA-122-5p was upregulated in sperm electroporated at 1500 V, and the presence of exogenous DNA did not affect its expression. Thus, we can conclude that electroporation influences the expression of miRNA-122-5p from bull sperm cells.
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Eletroporação , Técnicas de Transferência de Genes/efeitos adversos , MicroRNAs/biossíntese , Motilidade dos Espermatozoides/fisiologia , Espermatozoides/fisiologia , Animais , Animais Geneticamente Modificados/genética , Bovinos , Regulação da Expressão Gênica/fisiologia , Masculino , MicroRNAs/genética , Motilidade dos Espermatozoides/genética , Espermatozoides/citologiaRESUMO
Baculovirus expression vector systems (BEVS) have been widely used for production of recombinant proteins in insect cells. However, baculoviruses superinfection and repeated passages originate defective interfering particle (DIP) mutants, which is a limitation to a continuous large-scale production. Accordingly, a classical chemical transfection method performed on monolayer of Spodoptera frugiperda insect cells (Sf9) was modified to produce recombinant baculoviruses with high efficiency. Modifications consist to transfect exponentially growing cells in suspension after concentration by tenfold through centrifugation. Ten different constructions of recombinant baculoviruses with insert varying in size from 180 bp to 2,395 bp, were obtained through employment of the Bac-to-Bac expression system (ThermoFisher/Invitrogen). The transfection efficiency of the modified protocol varied from 45 to 57%, independent of the insert size, while classical method present transfection efficiency of 2 to 20%. After transfection of 6 × 106 cells, the recombinant baculoviruses titer obtained with modified method was about 2 × 107 pfu/ mL in a total volume of 12 mL, which is scalable to 24 liters of 1 × 108 pfu/ mL, after only two amplification rounds, contributing to improve large scale heterologous protein production in insect cells, with low amplification passages.
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Rabies is a neurological disease with 100% lethality. Some of the rare human patients who survived after multiple drug treatment had severe sequelae. The present study showed that after 48 h of RABV inoculation, mice injected intracerebrally with anti-RABV F (ab')2 plus Bioporter® showed 70% survival compared to the control group, suggesting that transfection of anti-RABV antibodies to the brain may prevent or delay the spread of RABV at an early stage of infection. This result may provide important protocol results in intracellular antibody delivery to prevent the fatal outcome of the disease.
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Anticorpos Antivirais/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Fragmentos Fab das Imunoglobulinas/administração & dosagem , Vacina Antirrábica/administração & dosagem , Vírus da Raiva/efeitos dos fármacos , Raiva/prevenção & controle , Vacinação/métodos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/virologia , Modelos Animais de Doenças , Feminino , Fluoresceína-5-Isotiocianato/química , Corantes Fluorescentes/química , Humanos , Injeções Intraventriculares , Camundongos , Raiva/imunologia , Raiva/mortalidade , Raiva/virologia , Vírus da Raiva/imunologia , Vírus da Raiva/patogenicidade , Análise de Sobrevida , Transfecção/métodosRESUMO
In order to make more efficient chitosan-based nanoparticles for transfection in physiological condition, chitosomes composed of chitosan modified with arginine and complexed with DOTAP/DOPE lipids are synthesized (named chitosomes) by reverse phase evaporation technique. Structure analyses of chitosomes with or without plasmid DNA (pDNA) are performed by electrophoresis, zeta potential, dynamic light scattering, small angle X-ray scattering and isothermal titration calorimetry, and transfection efficiency and cytotoxicity are performed in HEK293 T cells. Chitosomes have a positive surface charge (X¯= 52â¯mV) with an average size of 116â¯nm, and interaction with pDNA are favored thermodynamically and do not suffer aggregation significantly. In our experimental conditions, the transfection efficiency average reaches 86%⯱â¯3, while the Lipofectamine® reaches 87%⯱â¯5 in vitro. Cytotoxicity of chitosomes are tolerable. Structural analyses show that that chitosomes-pDNA complexes appear to have multilamellar vesicle structures hosting pDNA in-between bilayers which favor interaction with cell membrane and delivery of pDNA. Results show that synthesized chitosomes are promising carriers for gene delivery.
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Arginina/química , Quitosana/química , DNA/química , Técnicas de Transferência de Genes , Arginina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Quitosana/farmacologia , DNA/genética , Células HEK293 , Humanos , Lipossomos/química , Lipossomos/farmacologia , Estrutura Molecular , Tamanho da Partícula , Plasmídeos , Propriedades de SuperfícieRESUMO
Aim: Investigate the apoptotic mechanisms of two new aldehyde biphenyl chalcones on leukemia cells. Materials & methods: From a series of 71 new chalcones, we selected the two most cytotoxic. Results: JA3 and JA7 were cytotoxic not only against hematological malignancies but also against solid tumor and cancer stem cells, yet with no toxicity to normal cells. Moreover, they induced immunogenic apoptotic-like cell death independently of promyelocytic leukemia protein, with extensive mitochondrial damages downstream of endoplasmic reticulum stress. Preventing endoplasmic reticulum stress and the upregulation of proapoptotic machinery inhibited JA3- and JA7-induced cell death. Likewise, blocking receptor Fas protected cells from killing. They increased the antileukemic effect of cytarabine and vincristine and killed leukemic cells collected from patients with different acute leukemia subtypes. Conclusion:JA3 and JA7 represent new promising prototypes for the development of new chemotherapeutics.
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Aldeídos/farmacologia , Antineoplásicos/farmacologia , Compostos de Bifenilo/farmacologia , Chalconas/farmacologia , Aldeídos/química , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Compostos de Bifenilo/química , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Chalconas/síntese química , Chalconas/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos , Camundongos , Relação Estrutura-AtividadeRESUMO
One of the most versatile gene transfer methods involves the use of recombinant lentiviral vectors since they can transduce both dividing and nondividing cells, are considered to be safe and provide long-term transgene expression since the integrated viral genome, the provirus, is passed on to daughter cells. These characteristics are highly desirable when a modified cell must continue to express the transgene even after multiple cell divisions. Lentiviral vectors are often used to introduce protein encoding cDNAs, such as reporter genes, or for noncoding sequences, such as mediators of RNA interference or genome editing, including shRNA or gRNA, respectively. In the gene therapy setting, lentiviral vectors have been used successfully for the modification of hematopoietic stem cells, resulting in restored immune function or correction of defects in hemoglobin, to name but a few examples. The success of chimeric antigen receptor (CAR) T cells for the treatment of B cell leukemias and lymphomas has been particularly striking and this approach has relied heavily on lentivirus-mediated gene transfer. Here we present a typical protocol for the production of lentivirus, concentration by ultracentrifugation and determination of virus titer. The resulting virus can then be used in laboratory assays of gene transfer, including the establishment of CAR T cells.