Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Vector”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources
PubMed2000

Adenovirus vector-mediated gene transfer to regional lymph nodes.

Regional lymph nodes (RLNs) possess important immune functions and represent a major pathway of metastasis for solid tumors. Given these facts, the ability to transfer exogenous genes to the RLNs with the goal of manipulating the local immunological milieu would be desirable. On the basis of the hypothesis that a significant proportion of adenovirus (Ad) gene transfer vectors traffic through the lymphatics, E1-E3- Ad vectors were injected into the hind footpad of C3H/He mice and the RLNs assessed for vector trafficking and transgene expression. A low dose (10(9) particles) of an Ad vector encoding the firefly luciferase gene (Ad-CMV.Luc) resulted in luciferase expression only in the injection site and RLNs, with no detectable systemic (liver, spleen, lung) expression. At a higher dose (10(11) particles), some expression could be detected systemically in addition to the RLNs, but at levels in liver 14-fold less than in the RLNs. Transgene expression in the RLNs was transient, peaking at 1 day, decreasing markedly by 7 days. At high doses (10(11) particles), interruption of draining lymphatics decreased the amount of systemic dissemination 22-fold, suggesting that a large proportion of the vector trafficks through the lymphatics before reaching the systemic circulation. Administration of a vector encoding the jellyfish green fluorescent protein gene (AdCMV.GFP, 10(11) particles) showed that transgene expression in the RLNs was primarily in the cortical area. After footpad injection of a fluorescent-labeled Ad vector (Cy3-AdCMV.Null), fluorescent virions were visualized in the draining lymph. Regional lymph collected from animals injected in the footpad with AdCMV.Luc (10(11) particles) contained functional vector. Augmentation of local immune function in the RLNs was achieved by footpad administration of an Ad vector encoding murine IL-12, resulting in high mIL-12 and IFN-gamma levels in the regional, but not distant, nodes. These data demonstrate that expression of exogenous genes in RLNs is easily accomplished with Ad vectors, Ad vector dissemination occurs primarily via the lymphatics after footpad administration in mice, and basic immune functions in the RLNs can be manipulated by Ad-mediated gene transfer in vivo.

Adenoviridae↗
PubMed2001

Adenovirus gene transfer vectors inhibit growth of lymphatic tumor metastases independent of a therapeutic transgene.

Adenovirus (Ad) gene transfer vectors traffic to regional lymph nodes (RLNs) after footpad injections in mice, resulting in localized production of interferon gamma (IFN-gamma). With this background, we evaluated the hypothesis that Ad vector administration may inhibit RLN tumor metastasis independent of the transgene in the expression cassette. Tumors of MM48, a cell line with a propensity toward lymphogenous metastasis, were established in the footpads of syngeneic C3H mice, and E1(-)E3(-) Ad vectors encoding no transgene (AdNull) or encoding an irrelevant transgene (AdCD; Escherichia coli cytosine deaminase with no 5-fluorocytosine administration) were administered (10(10) particles) in a peritumoral location. Both vectors suppressed the growth of tumor in the regional (popliteal) lymph node. This effect was localized to the regional, but not distant, lymph nodes (p < 0.05). Heat inactivation of the vector or decreasing the dose of the vector to 10(9) particles did not suppress RLN growth of the tumor when compared with 10(10) particles of active AdNull (p < 0.05 and p < 0.01, respectively). The ability of an E1(-)E4(-) vector expressing beta-galactosidase (AdRSVbetagal.11) to suppress RLN tumor growth showed that the E4 region of the Ad vector was not responsible for the effect. Blocking either IFN-gamma or natural killer (NK) cells with systemic antibody treatment in immunocompetent mice allowed rapid growth of RLN metastases despite Ad vector administration, and Ad vector injection into the footpads of tumor-free mice induced the accumulation of NK cells in the RLN. These data demonstrate that, in a metastatic murine tumor model, a low dose (10(10) particles) of replication-deficient Ad vectors inhibits RLN metastases independent of a therapeutic transgene, an effect that is mediated, at least in part, by IFN-gamma and NK cells.

Adenoviridae↗
PubMed2001

Development of an Rev-independent, minimal simian immunodeficiency virus-derived vector system.

Lentiviral vectors are attractive candidates for gene therapy because of their ability to integrate into nondividing cells. To date, conventional HIV-1-based vectors can be produced at higher titers, but concerns regarding their safety for human use exist because of the possibility of recombination leading to production of infectious virions with pathogenic potential. Development of lentivirus vectors based on nonhuman lentiviruses constitutes an active area of research. We described a novel HIV-SIV hybrid vector system in which an HIV-1-derived transfer vector is encapsidated by SIVmac1A11 core particles and pseudotyped with VSV glycoprotein G. In an effort to further develop this vector system, we modified the packaging plasmid by deletion of the SIV accessory genes. Specifically, versions of the packaging plasmid (SIVpack) lacking vif, vpr, vpx, and/or nef were constructed. Our results indicate that, as with HIV-1-based packaging plasmids, deletion of accessory genes has no significant effect on transduction in either dividing or nondividing cells. The SIV packaging plasmid was also modified with regard to the requirement for RRE and rev. Deletion of the RRE and rev from SIVpack led to dramatic loss of transduction ability. Introduction of the 5' LTR from the spleen necrosis virus to packaging plasmids lacking RRE/Rev was then sufficient to fully restore vector titer. A minimal SIV transfer vector was also developed, which does not require RRE/Rev and exhibits no reduction in transduction efficiency in two packaging systems. The SIV-based vector system described here recapitulates the biological properties of minimal HIV-1-derived systems and is expected to provide an added level of safety for human gene transfer. We suggest that the SIV-derived vector system will also be useful to deliver anti-HIV-1 gene therapy reagents that would inhibit an HIV-1-derived vector.

Cell Division↗
PubMed2001

A uniquely stable replication-competent retrovirus vector achieves efficient gene delivery in vitro and in solid tumors.

A major obstacle in cancer gene therapy is the limited efficiency of in vivo gene transfer by replication-defective retrovirus vectors in current use. One strategy for circumventing this difficulty would be to use vectors capable of replication within tumor tissues. We have developed a replication-competent retrovirus (RCR) vector derived from murine leukemia virus (MuLV). This vector utilizes a unique design strategy in which an internal ribosome entry site-transgene cassette is positioned between the env gene and the 3' long terminal repeat (LTR). The ability of this vector to replicate and transmit a transgene was examined in culture and in a solid tumor model in vivo. The RCR vector exhibited replication kinetics similar to those of wildtype MuLV and mediated efficient delivery of the transgene throughout an entire population of cells in culture after an initial inoculation with 1 plaque-forming unit (PFU) of vector per 2000 cells. After injection of 6 x 10(3) PFU of vector into established subcutaneous tumors, highly efficient spread of the transgene was observed over a period of 7 weeks, in some cases resulting in spread of the transgene throughout the entire tumor. MuLV-based RCR vectors show significant advantages over standard replication-defective vectors in efficiency of gene delivery both in culture and in vivo. This represents the first example of the use of an RCR vector in an adult mammalian host, and their first application to transduction of solid tumors.

3T3 Cells↗
PubMed2003

Optimization of the generation and propagation of gutless adenoviral vectors.

Adenoviral vectors devoid of all viral coding regions are referred to by many names, including gutless vectors. Gutless vectors display reduced toxicity and immunogenicity, increased duration of transgene expression, and increased coding capacity compared to early generation vectors, which contain the majority of the viral backbone genes. However, the production of gutless vectors at a scale and purity suitable for clinical use has limited the utility of this technology. In this work we describe the optimization of the production of gutless vectors. We constructed an improved helper virus and generated an alternative gutless vector producer cell line, PERC6-Cre. We demonstrated increased gutless vector yields, minimal helper virus contamination, and no replication-competent adenovirus contamination using the optimized system. Furthermore, the PERC6-Cre cells were adapted to serum-free suspension culture and high-titer gutless vector preparations were produced using bioreactor technology, suggesting the feasibility of gutless vector scale-up for clinical use. Finally, we observed that helper virus lacking a packaging signal could be packaged at a low frequency, revealing an inherent limitation to the differential packaging strategy for gutless vector propagation.

Adenoviridae↗
PubMed2003

In vivo ligand-inducible regulation of gene expression in a gutless adenoviral vector system.

Transcriptional regulation that is rapid, reversible, and repeatedly inducible would greatly enhance the safety and efficacy of many gene therapy strategies. We developed a chimeric ligand-inducible regulation system based on the human estrogen receptor. This system has two components, the responsive promoter driving expression of the transgene of interest, and the ligand-inducible chimeric transcription factor. The transcription factor is composed of a novel DNA binding domain and a modified estrogen receptor ligand-binding domain. A point mutation in the ligand-binding domain significantly reduces estrogen binding while allowing binding of the estrogen antagonist, tamoxifen. We used a gutless adenoviral vector system and incorporated both components into two separate vectors. A single gutless vector encoding both system components was also generated. The tamoxifen-mediated induciblity of transgene expression of the gutless vector system was compared in vitro and in vivo with the analogous components incorporated into early generation, E1/E2a/E3-deficient adenoviral vectors. In normal mice, both the gutless vector and early generation systems displayed inducibility in the presence of tamoxifen. Importantly, the gutless vector system was inducible to extremely high levels, at least four times over a 2-month period. In contrast, the early generation vector system was inducible only once. Furthermore, the early generation system displayed significant toxicity, as evidenced by extremely high liver enzyme levels, abnormal liver pathology, and rapid loss of vector DNA from the liver, while the gutless vector system displayed minimal toxicity. These data directly demonstrate the improved in vivo function of the tamoxifen-inducible transcriptional regulation system in the context of the gutless adenoviral vectors.

Adenoviridae↗
PubMed2004

Direct exposure of mouse spermatozoa to very high concentrations of a serotype-2 adeno-associated virus gene therapy vector fails to lead to germ cell transduction.

In a clinical safety trial involving an adeno-associated virus (AAV) gene therapy vector encoding human factor IX, intrahepatic administration of the vector was associated with the finding of vector DNA in semen that persisted for several weeks. Uncertainty remains as to the route by which the vector reached semen, but the finding raised the prospect that mature sperm could be exposed to the vector and sustain integration of vector DNA. To provocatively test for the ability of AAV vectors to transduce mature sperm, we exposed mouse sperm to concentrations of the same vector used in clinical studies at concentrations ranging from 840 to 3400 particles per sperm cell, performed in vitro fertilization and embryo transfer, and evaluated newborn pups by Southern analysis for the presence of vector sequences. Of 102 pups analyzed, none showed evidence of vector DNA integration. We conclude from these studies that exposure of mature sperm to AAV gene therapy vectors is highly unlikely to lead to germline transduction.

Adenoviridae↗
PubMed1999

Gene transfer to the nigrostriatal system by hybrid herpes simplex virus/adeno-associated virus amplicon vectors.

To improve gene transfer to CNS neurons, critical elements of herpes simplex virus 1 (HSV-1) amplicons and recombinant adeno-associated virus (AAV) vectors were combined to construct a hybrid amplicon vector, and then packaged via a helper virus-free system. We tested the HSV/AAV hybrid amplicon vectors for transduction efficiency and stability of transgene expression (green fluorescent protein) in primary neuronal cultures from rat fetal ventral mesencephalon, in comparison with traditional HSV amplicon, AAV, or adenovirus (Ad) vectors at the same multiplicity of infection. The HSA/AAV hybrid vectors transduced the highest number of primary neurons in culture 2 days after infection. As compared with all other vectors tested, only hybrid vectors containing the AAV rep gene maintained the 2-day level of transgene expression over 12 days in culture. This rep-containing hybrid vector was then tested for efficiency and safety in the brain. One month after injection into adult rat striatum (1 x 10(6) transducing units injected), transgene expression was observed within the striatum (ranging from 564 to 8610 cells) and the substantia nigra (via retrograde transport, ranging from 130 to 809 neurons). The HSV/AAV hybrid amplicon vectors transduced predominantly neurons within the striatum, and showed transduction efficacy similar to and in many cases higher than that of HSV amplicon vectors. No immune response was observed in the HSA/AAV hybrid vector-injected brains, as determined by immune markers specific for helper T lymphocytes, cytotoxic T lymphocytes, and microglia. This HSV/AAV hybrid system shows high transduction efficiency and stability in culture. The effective and safe transgene delivery into the nigrostriatal system illustrates its potential for therapeutic application for neurologic disorders, such as Parkinson and Huntington disease.

Animals↗
PubMed1999

Constructing adenoviral vectors by using the circular form of the adenoviral genome cloned in a cosmid and the Cre-loxP recombination system.

Recombinant adenoviral vectors have been generated either by the in vivo homologous recombination method or by the in vitro direct ligation method. However, the efficiency of adenoviral vector construction by these methods is low, because of the large size of the recombinant vectors. To improve the ease of constructing adenoviral vectors, we used the circular form of adenoviral DNA, which can generate infectious viruses with an efficiency comparable to that of virion DNA, after transfection into 293 cells constitutively producing adenovirus E1 protein. We replaced the E1 region of the circular form of adenoviral DNA with a cosmid vector flanked by loxP sites, resulting in a 41-kb cosmid, designated pALC. An expression cassette that bicistronically expresses IL-5 and green fluorescent protein (GFP) was readily inserted between the loxP-flanked cosmid backbone and the adenoviral genome of pALC, using the cosmid vector cloning system. Transfection of the resulting cosmid into 293 cells did not produce any infectious adenoviruses because its size (46 kb) was larger than the packing capacity of the adenoviral particles. However, cotransfection of a Cre-expression plasmid with this cosmid into 293 cells efficiently excised the loxP-flanked cosmid vector backbone, and produced the adenoviral vector expressing IL-5 and GFP. To simplify our method further, we have produced a 293 cell line constitutively expressing Cre recombinase. Transfection of pALC cosmid alone into this cell line efficiently generated adenoviral vector. The adenoviral vector construction method presented here is simple and efficient and should further facilitate the application of recombinant adenoviral vectors for in vivo and in vitro gene transfer.

Adenoviridae↗
PubMed2002

Adenovirus and adeno-associated virus vectors.

Recombinant adenovirus (rAd) and recombinant adeno-associated virus (rAAV) are among the most extensively used vectors in gene therapy studies to date. These two vectors share some similar features such as a broad host range and ability to infect both proliferating and quiescent cells. However, they also possess their own unique set of properties that render them particularly attractive for gene therapy applications. rAd vectors can accommodate larger inserts, mediate transient but high levels of protein expression, and can be easily produced at high titers. Development of gutted rAd vectors has further increased the cloning capacity of these vectors. The gaining popularity of rAAV use in gene therapy can be attributed to its lack of pathogenicity and added safety due to its replication defectiveness, and its ability to mediate long-term expression in a variety of tissues. Site-specific integration, as occurs with wild-type AAV, will be a unique and valuable feature if incorporated into rAAV vectors, further improving their safety. This paper describes these properties of rAd and rAAV vectors, and discusses further development and vector improvements that continue to extend the utility of these vectors, such as cell retargeting by capsid modification, differential transduction by use of serotypes, and extension of the cloning capacity of rAAV vectors by dual vector heterodimerization.

Adenoviridae↗
PubMed1996

Long-term survival in a rodent model of disseminated brain tumors by combined intrathecal delivery of herpes vectors and ganciclovir treatment.

Brain tumors that have disseminated into cerebrospinal fluid (CSF) pathways are an unresolved therapeutic problem, especially in pediatric neurooncology. Here a gene therapy approach using the herpes simplex virus type 1 thymidine kinase (HSV-TK)/ganciclovir (GCV) paradigm was tested using an HSV vector in a rodent model of disseminated central nervous system tumors. 9L-gliosarcoma cells were implanted simultaneously into the brain and the CSF of syngeneic rats. Five days later, resulting intracerebral and leptomeningeal tumors were treated by intrathecal injection of a replication-conditional HSV vector. This vector was defective for the ribonucleotide reductase gene, but contained an intact HSV-tk gene. Systemic GCV treatment was started 2 days after vector application and continued for 14 days. Tumor-free, long-term survival (LTS) was achieved in 90% of the animals treated with this combined therapeutic approach, whereas only 30% LTS was found in animals that had received the vector alone and 10% LTS in untreated animals. This therapeutic response probably involves oncolytic, on-site replication of the vector, activation of GCV by a HSV-TK, and a strong immune response both to the vector and to 9L cells. Apparent vector-related mortality was observed in 20% of animals without subsequent GCV therapy, but no vector-related mortality was found when the animals were treated with GCV after vector application. Given the successful outcome of this experimental treatment and the apparent potential of GCV to control HSV-related toxicity, intrathecal application of HSV vectors combined with GCV treatment may be a promising approach for treatment of disseminated brain tumors.

Animals↗
PubMed1996

A novel 'piggyback' packaging system for herpes simplex virus amplicon vectors.

Recombinant and amplicon vectors derived from herpes simplex virus type 1 (HSV-1) have proven to be an efficient means of gene delivery to cells in culture and in vivo. In this study, a system was developed to make propagation of the amplicon vector and helper virus mutually dependent on each other, in a "piggyback' fashion. This combined system supports maintenance and enrichment of the amplicon vector when propagating stocks, while allowing the helper virus to serve as a recombinant vector in its own right. Amplicons bearing a gene essential for HSV-1 replication, IE3, as well as the Escherichia coli lacZ marker gene, were propagated using a mutant virus (d120) deleted in the same essential gene. Vector stocks could be propagated in Vero cells and other cultured cells not transfected with the IE3 gene with markedly delayed cytopathic effects, as compared to wild-type virus. Relatively high titers of amplicon vectors (6 x 10(7) infectious units/ml) were achieved with this piggyback system in Vero cells, with an apparent ratio of amplicon vector: helper virus of up of 5:1 under some conditions; however, recombinant wild-type virus was also generated. Injection of these stocks into experimental gliomas in rodent brain revealed gene delivery to tumor cells mediated by both amplicon vectors (lacZ) and helper virus (HSV-thymidine kinase), with no apparent neuropathology of normal brain. This basic piggyback vector model is amenable to modifications to promote conditional propagation of vectors in vivo and to allow incorporation of multiple transgene elements into both the amplicon and recombinant helper virus vectors.

Animals↗
PubMed1997

Innate immune mechanisms dominate elimination of adenoviral vectors following in vivo administration.

To evaluate the contribution of the innate immune component of host defense in clearing the genome of adenovirus (Ad) vectors following in vivo administration, the Ad vectors AdCMV.beta gal (expressing beta-galactosidase) or AdCMV.Null (expressing no gene) were administered intravenously to immunocompetent or immunodeficient mice, and the amount of vector genome was quantified in the liver. Strikingly, 90% of vector DNA was eliminated within 24 hr. There was no increase in vector DNA in other tissues over this period, suggesting that rapid clearance of vector genome resulted from local degradation. After 24 hr, vector elimination was slow, with only 9% of the initial amount of vector genome cleared over the subsequent 3 weeks. Importantly, early phase (0-24 hr) elimination of vector DNA was independent of the transgene and similar in immunocompetent and nude animals. These observations suggest two phases of Ad vector elimination: a previously recognized late, immune-related elimination, and the early, innate immune elimination described in the present study. The early phase of vector loss is, by far, the dominant mechanism, an observation that has implications in developing strategies to maintain persistent expression of the newly transferred gene following in vivo gene therapy.

Adenoviridae↗
PubMed1997

Cytotoxic T lymphocyte responses to proteins encoded by heterologous transgenes transferred in vivo by adenoviral vectors.

Although replication-deficient adenovirus (Ad) vectors are efficient vehicles for in vivo gene transfer, persistence of expression of the Ad genome is limited in immunocompetent hosts by cellular immunity directed against the gene product of the vector. While most attention has been focused on cytotoxic T lymphocytes (CTL) directed against the low-level early and late Ad gene expression in the Ad vector-infected target cells, significant cellular immunity is likely also directed against the product of heterologous transgenes. To evaluate this concept, in vivo generation of CTL was evaluated in C57B1/6 and BALB/c mice with Ad vectors expressing a variety of heterologous transgenes, including Escherichia coli chloramphenicol acetyl transferase (CAT), beta-galactosidase (beta-Gal), cytosine deaminase, and human thrombopoietin (hTPO), with an Ad vector expressing no transgene ("null") as a control. Following intravenous administration of Ad vectors, spleen cells were harvested 2 weeks later, stimulated for 5 days with syngeneic cells infected with various Ad vectors, and then evaluated for CTL activity using 51Cr-release from syngeneic Ad vector-infected targets. In all cases, CTL directed against the heterologous transgene products was observed, although there were differences in the amounts of transgene-specific CTL. CTL directed against the transgene were also observed with other routes of administration, including intratracheal, subcutaneous, and intraperitoneal administration. These observations suggest that inclusion of a heterologous transgene in Ad vectors enhances the elimination of vector-infected cells, a circumstance that will be partially circumvented using autologous genes. For some applications, specific immune responses to products of transgenes delivered by Ad vectors might be exploited for therapeutic purposes.

Adenoviridae↗
PubMed1998

Toxicological comparison of E2a-deleted and first-generation adenoviral vectors expressing alpha1-antitrypsin after systemic delivery.

Second-generation adenoviral vectors, mutated in E2a, have been proposed to decrease host immune responses against transduced cells, reduce toxicity, and increase duration of expression as compared with first-generation vectors deleted only in E1. To test these hypotheses further, we have developed an E2a-deleted adenoviral vector expressing human alpha1-antitrypsin (hAAT). Toxicity of first-generation and E2a-deleted vectors, as determined by hematological indices, liver function tests, and histological analyses, was evaluated in C3H mice for 21 days after vector administration at increasing doses starting at 1 x 10(12) particles/kg. Both vectors induced dose-dependent abnormalities including transient thrombocytopenia, elevated ALT levels in serum, and increased hepatocyte proliferation followed by inflammation and then hypertrophy. Differences in the ratio of particles to plaque-forming units among vector preparations led to differences in hAAT expression at similar particle doses. There were no differences in toxicity between the two vectors when measured at matching levels of hAAT expression. However, the E2a-deleted vector was demonstrated to have slightly reduced hepatocyte toxicity at an intermediate particle dose. This suggests that hepatocyte toxicity is related primarily to viral entry and expression, rather than to the presence of noninfectious particles, and implies that vectors with complete elimination of viral gene expression, such as vectors with all viral coding sequences deleted, are likely to have substantial advantages in terms of safety and toxicity.

Adenoviridae↗
PubMed2005

Silencing and variegation of gammaretrovirus and lentivirus vectors.

Retrovirus vectors integrate into the genome, providing stable gene transfer, but integration contributes in part to transcriptional silencing that compromises long-term expression. In the case of gammaretrovirus vectors based on murine leukemia virus, many integration events are completely silenced in undifferentiated stem cells and in transgenic mice. Gammaretrovirus vectors are also subject to variegation in which sister cells bearing the same provirus differentially express, and cell differentiation can lead to extinction of vector expression. In contrast, lentivirus vectors based on human immunodeficiency virus type 1 appear to express more efficiently, although other reports indicate that lentivirus vectors can be silenced. This review summarizes the key features of gammaretrovirus vector silencing. The evidence for and against gene silencing of lentivirus vectors is described with special emphasis on the potential effects of vector design, provirus copy number, and integration site preferences on silencing. This analysis suggests that the difference between selfinactivating (SIN) lentivirus vectors and their modified SIN gammaretrovirus counterparts may be less dramatic than previously thought. It will therefore be important to further characterize the mechanisms of silencing, in order to create better gammaretrovirus and lentivirus vectors that consistently express at single copy for gene therapy.

Animals↗
PubMed2005

Widespread dispersion of adeno-associated virus serotype 1 and adeno-associated virus serotype 6 vectors in the rat central nervous system and in human glioblastoma multiforme xenografts.

The transduction patterns of recombinant adeno-associated virus serotype 1 (AAV1) and serotype 6 (AAV6) vectors were assessed in human glioblastoma multiforme (GBM) cell lines, in human GBM biopsy spheroids, and in tumor xenografts growing in nude rat brains. All the cell lines tested (A172, D37, GaMg, HF66, and U373Mg) were found to be permissive to both AAV1 and AAV6 vectors, and thus displayed a transduction pattern similar to AAV2 vectors. For every cell line tested, the transduction efficiency displayed by AAV2 vectors was better than by isogenic and isopromoter AAV1 vectors. Transduction efficiency was dependent on the viral particle number used, suggesting that the receptors for these vectors are widely distributed in GBM tissues. Interestingly, AAV1, AAV2, and AAV6 vectors were able to infect and transduce the same cells when added simultaneously to monolayer cultures. Infection of human GBM biopsy spheroids with AAV1 and AAV6 vectors resulted in transgene expression both at the surface layers and in the core of the spheroids. Following injection of AAV1 and AAV6 vectors into human GBM biopsy xenografts growing in nude rat brains, reporter gene expression was seen both in the periphery as well as in the central regions of the tumors. When injected into the normal rat brain, both AAV1 and AAV6 vectors were found to transduce several central nervous system (CNS) regions. The presented results suggest a potential therapeutic role for AAV1 and AAV6 vectors in gene therapy for GBM and also for other CNS malignancies.

Animals↗
PubMed2006

Adenovirus vectors based on human adenovirus type 19a have high potential for human muscle-directed gene therapy.

Until recently, adenovirus-based gene therapy has been almost exclusively based on human adenovirus serotype 5 (Ad5). The aim of this study was to systematically compare the efficiency of transduction of primary muscle cells from various species by two adenoviral vectors from subgroups C and D. Transduction of a panel of myoblasts demonstrated a striking specificity of an Ad19a-based replication-defective E1-deleted vector (Ad19aEGFP) for human cells, whereas the Ad5-based vector had high affinity for nonhuman primate myoblasts. Transgene expression correlated well with cell-associated vector genomes. Up to 6.59% of the initially applied Ad19aEGFP vector particles were taken up by human myoblasts, as compared with 0.1% of the corresponding Ad5 vector. Remarkably, Ad19aEGFP but not Ad5EGFP efficiently transduced differentiated human myotubes, an in vitro model for skeletal muscle transduction. Uptake of Ad19aEGFP vector particles in human myotubes was 12-fold more efficient than that of Ad5EGFP. Moreover, both vectors demonstrated an early block at the level of vector uptake in mouse myoblasts and rat L6 cells. Investigation of the underlying mechanism for binding and uptake of the two vectors by human myoblasts showed high susceptibility for Ad19a to neuraminidase and wheat germ agglutinin (WGA) lectin, whereas Ad5-mediated transduction was dependent on binding to the coxsackie-adenovirus receptor (CAR) and sensitive to soluble RGD peptide and heparin. Our study offers insights into species-dependent factors that determine Ad tropism and, moreover, provides a basis for application of the novel Ad19a-based vector for gene transfer into human skeletal muscle.

Adenoviruses, Human↗