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PubMed2002

Homing and survival of thymidine kinase-transduced human T cells in NOD/SCID mice.

The herpes simplex virus thymidine kinase (HSV-tk) gene conferring ganciclovir (GCV)-specific sensitivity to transduced cells might control Graft-versus-Leukemia (GvL)/Graft-versus-Host Disease (GvHD). Human T lymphocytes were engineered with an LSN-tk retroviral vector encoding tk and neomycin resistance (NeoR) genes. A total of 80 x 10(6) tk(+) lymphocytes were injected intraperitoneally in NOD-SCID mice. Engraftment was evaluated by human CD45(+)/CD3(+) cytofluorimetric analysis and NeoR-based polymerase chain reaction (PCR) on peripheral blood, bone marrow, liver, thymus, and spleen on day +5. After 14 days, GCV (10 mg/kg daily) cytofluorimetric analysis and PCR were repeated (day +19). Immunohistological studies with anti-CD3 monoclonal antibody followed by alkaline phosphatase and monoclonal anti-alkaline phosphatase staining were performed on spleen and liver at the same time points. Human CD45(+)/CD3(+) cells were engrafted in all tissues on day +5 according to cytofluorimetry, immunohistology, and PCR. Lymphocytes "homed" to the white pulp T-cell area and to the red pulp; liver localization is prevalently at the periportal area. After GCV (day +19), cytofluorimetry and immunohistology showed very few CD3(+) cells. PCR identified the transgene in 22% tissue samples (positive only in thymus and spleen). GvHD did not occur in any animal. These data demonstrate elevated doses of human-transduced CD3(+) cells engraft in NOD/SCID mice; after GCV, very few CD3(+) cells can be detected and those that escape treatment can be found in the thymus and in the spleen on day +19. Lack of full response to GCV may account for cases of GvHD in patients receiving tk-transduced T lymphocytes.

Animals↗
PubMedDate not supplied

Persistence of Agrobacterium tumefaciens in transformed conifers.

Previous studies have shown that the widely used plant transformation vector Agrobacterium tumefaciens can persist in genetically engineered plants in vitro and in transgenic greenhouse-grown plants, despite the use of counter-selective antibiotics. However, little is known regarding Agrobacterium persistence in tree species. To understand the kinetics of A. tumefaciens decline and persistence in transformation experiments, we assayed for the presence of A. tumefaciens in spruce and pine embryogenic tissue for up to 10 weeks post-transformation. The A. tumefaciens populations declined rapidly in the first five days post-cocultivation but generally declined more slowly in pine, relative to spruce. No bacteria were detected in spruce embryogenic tissue beyond four weeks after cocultivation, however in pine there were -100 colony forming units per g tissue at 10 weeks post-cocultivation. We present evidence that the detection limit for PCR using virD2 primers to detect A. tumefaciens in a background of pine needle DNA was approximately 10(9)-10(10) A. tumefaciens cells per g of tissue. We also assayed for A. tumefaciens in transgenic pine and spruce embryogenic tissue and from needles, branches, stems and roots of transformed plants, up to four years post-inoculation. Occasionally A. tumefaciens was detected in embryogenic tissue up to 12 months post-inoculation. A. tumefaciens was never detected in cultured embryogenic tissue more than twelve months after inoculation, nor in developing somatic embryos or germinating plantlets, nor any of the parts of greenhouse-grown plants. From these data we conclude that if A. tumefaciens persists in transgenic conifers, it does so beneath our ability to detect it.

Agrobacterium tumefaciens↗
PubMed1998

Chimeric anti-angiogenin antibody cAb 26-2F inhibits the formation of human breast cancer xenografts in athymic mice.

Angiogenin (Ang), an inducer of neovascularization, is secreted by several types of human tumor cells and appears critical for their growth. The murine anti-Ang monoclonal antibody (mAb) 26-2F neutralizes the activities of Ang and dramatically prevents the establishment and metastatic dissemination of human tumor cell xenografts in athymic mice. However, for use clinically, the well-documented problem of the human anti-globulin antibody response known to occur with murine antibodies requires resolution. As a result, chimeric as well as totally humanized antibodies are currently being evaluated as therapeutic agents for the treatment of several pathological conditions, including malignancy. Therefore, we have constructed a chimeric mouse/human antibody based on the structure of mAb 26-2F. Complementary DNAs from the light and heavy chain variable regions of mAb 26-2F were cloned, sequenced, and genetically engineered by PCR for subcloning into expression vectors that contain human constant region sequences. Transfection of these vectors into nonproducing mouse myeloma cells resulted in the secretion of fully assembled tetrameric molecules. The chimeric antibody (cAb 26-2F) binds to Ang and inhibits its ribonucleolytic and angiogenic activities as potently as mAb 26-2F. Furthermore, the capacities of cAb 26-2F and its murine counterpart to suppress the formation of human breast cancer tumors in athymic mice are indistinguishable. Thus cAb 26-2F, with its retained neutralization capability and likely decreased immunogenicity, may be of use clinically for the treatment of human cancer and related disorders where pathological angiogenesis is a component.

Amino Acid Sequence↗
PubMed2003

Telomere-independent homologue pairing and checkpoint escape of accessory ring chromosomes in male mouse meiosis.

We analyzed transmission of a ring minichromosome (MC) through mouse spermatogenesis as a monosome and in the presence of a homologue. Mice, either monosomic or disomic for the MC, produced MC+ offspring. In the monosomic condition, most univalents underwent self-synapsis as indicated by STAG3, SCP3, and SCP1 deposition. Fluorescent in situ hybridization and three-dimensional fluorescence microscopy revealed that ring MCs did not participate in meiotic telomere clustering while MC homologues paired at the XY-body periphery. Self-synapsis of MC(s) and association with the XY-body likely allowed them to pass putative pachytene checkpoints. At metaphase I and II, MC kinetochores assembled MAD2 and BUBR1 spindle checkpoint proteins. Unaligned MCs triggered the spindle checkpoint leading to apoptosis of metaphase cells. Other MCs frequently associated with mouse pericentric heterochromatin, which may have allowed them to pass the spindle checkpoint. Our findings indicate a telomere-independent mechanism for pairing of mammalian MCs, illuminate escape routes to meiotic checkpoints, and give clues for genetic engineering of germ line-permissive chromosomal vectors.

Animals↗
PubMed1992

Structural and functional analysis of three D/L-like class I molecules from H-2v: indications of an ancestral family of D/L genes.

Three cDNA with D region gene features have been identified from the H-2v haplotype. Provisionally, the sequences have been designated as D/Lv1, D/Lv2, and D/Lv3. The coding segments for the antigen binding domain (ABD) of all three D/Lv genes were engineered into a class I genomic expression vector and expressed in L cells. FACS analysis of the three D/Lv-Ld gene transfectants revealed that the D/Lv1 molecules were recognized by both monoclonal antibodies (mAbs) 141 and 142, and the D/Lv2 molecules were recognized by mAb 143. In addition to the D/Lv1 molecules, the mAb 141 also recognized the D/Lv3 molecules. Both the D/Lv1-Ld and D/Lv2-Ld transfectants were killed efficiently by H-2Dv region-specific alloreactive CTL. The D/Lv3 gene is the first identified D region gene other than D and L that is transcribed abundantly in spleen and the D/Lv3 RNA is present as two alternatively spliced forms. Structural analysis of the D/Lv3 hybrid molecules showed that it was susceptible to proteolysis and thermolabile at 37 degrees C, suggesting D/Lv3 is a transcribed pseudogene. A parsimony tree analysis of three D/Lv sequences with a set of class I gene sequences revealed that the H-2v sequences clustered with D region genes. The presence of a third gene with D/L-like features in H-2v, yet structurally different from the known D/L alleles, raises the possibility that the current D/L genes evolved from a family of D/L-like genes, some of which are no longer represented among many of the mouse major histocompatibility complex haplotypes. The observation that D region alleles cluster into subgroups suggests that the alleles are not all related to each other by linear descent through a single locus. We propose that current alleles are derived from more than one ancestral locus in a manner similar to the origin of the gamma 2 a immunoglobulin constant region alleles.

Alleles↗
PubMed1992

Helper virus induced T cell lymphoma in nonhuman primates after retroviral mediated gene transfer.

Moloney Murine Leukemia Virus (MoMuLV) causes T cell neoplasms in rodents but is not known to be a pathogen in primates. The core protein and enzyme genes of the MoMuLV genome together with an amphotropic envelope gene are utilized to engineer the cell lines that generate retroviral vectors for use in current human gene therapy applications. We developed a producer clone that generates a very high concentration of retroviral vector particles to optimize conditions for gene insertion into pluripotent hematopoietic stem cells. This producer cell line also generates a much lower concentration of replication-competent virus that arose through recombination. Stem cells from rhesus monkeys were purified by immunoselection with an anti-CD34 antibody, incubated in vitro for 80-86 h in the presence of retroviral vector particles with accompanying replication-competent virus and used to reconstitute recipients whose bone marrow had been ablated by total body irradiation. The retroviral vector genome was detected in circulating cells of five of eight transplant recipients of CD34+ cells and in the circulating cells of two recipients of infected, unfractionated bone marrow mononuclear cells. Three recipients of CD34+ cells had a productive infection with replication-competent virus. Six or seven mo after transplantation, each of these animals developed a rapidly progressive T cell neoplasm involving the thymus, lymph nodes, liver, spleen, and bone marrow. Lymphoma cells contained 10-50 copies of the replication-competent virus, but lacked the retroviral vector genome. We conclude that replication-competent viruses arising from producer cells making retroviral vectors can be pathogenic in primates, which underscores the importance of carefully screening retroviral producer clones used in human trials to exclude contamination with replication-competent virus.

Animals↗
PubMed2005

Immunological responses and the pattern of disease in mice infected with transfected Leishmania major constitutively expressing active IL-1alpha.

Immunity against leishmaniasis is mediated mainly by CD4+ T lymphocytes, which function by secreting cytokines, which in turn activate various effector mechanisms. Interleukin 1 (IL-1) represents one of the most pleiotropic proinflammatory cytokines and is required for normal regulation of Th1/Th2 responses. The aim of this study was to induce the expression of the inflammatory cytokine IL-1alpha by Leishmania parasites and to determine its effect on the parasite development. Leishmania constitutively producing IL-1alpha was engineered, using the pX63Hyg-IL-1alpha vector. IL-1alpha was produced by both promastigotes and amastigotes, and remained unchanged after transformation and development in mice. The protection against the disease achieved in BALB/c mice by the transfected parasites was superior to that obtained with the wild type. One month after infection a nodule was demonstrated in 22% and 60% of the mice inoculated with transfected parasites and the wild type, respectively. This tendency continued for an additional 2.5 months, after which the rate of infection increased to 90% and 100% in these two groups, respectively. The present study suggests that, during initial infection, the pathway of IL-1alpha production and its accessibility to the immunological cells might be important in the outcome of leishmanial infection.

Animals↗
PubMed2026

Virus-induced gene silencing as a tool for functional genomics in weeds: Challenges and future directions.

Virus-induced gene silencing (VIGS) has evolved from a conceptual demonstration of antiviral defense into a pivotal reverse-genetics platform for plant functional genomics. By exploiting engineered DNA- or RNA-based viral vectors, VIGS enables rapid, sequence-specific transcript knockdown through RNA-mediated degradation of target transcripts. Recent refinements in vector design, inoculation strategies, and viral species selection, such as TRV, BSMV, and FoMV, have expanded its application to previously recalcitrant plants, including major crops and emerging weed models. In weeds, functional genomics remains particularly challenging due to high genetic variability, limited genomic resources, and incompatibility with conventional viral vectors and transformation systems. In this context, VIGS provides a tractable approach to investigate genes associated with herbicide resistance, metabolic adaptation, and stress tolerance. Beyond weed biology, its application to studies of immune signaling, hormonal crosstalk, and secondary metabolism highlights VIGS as a versatile biotechnology for elucidating gene function and supporting next-generation strategies in plant improvement and integrated pest management.

Journal Article↗
PubMed2004

Insulin expression in livers of diabetic mice mediated by hydrodynamics-based administration.

AIM: Transfer and expression of insulin gene in vivo are an alternative strategy to improve glycemic control in type 1 diabetes. Hydrodynamics-based procedure has been proved to be very efficient to transfer naked DNA to mouse livers. The basal hepatic insulin production mediated by this rapid tail vein injection was studied to determine its effect on the resumption of glycemic control in type 1 diabetic mice. METHODS: Engineered insulin cDNA was inserted into plasmid vectors under a CMV promoter, and transferred into STZ induced diabetic mice by hydrodynamic procedure. Glucose levels, body weight of treated mice, insulin levels, immunohistology of the liver, and quantity of insulin mRNA in the liver were assayed to identify the improvement of hyperglycemic complication after plasmid administration. Sleeping Beauty, a transposon system, was also used to prolong the insulin expression in the liver. RESULTS: After plasmid administration, Plasma insulin was significantly increased in the diabetic mice and the livers were insulin-positive by immunostaining. At the same time the hyperglycemic complication was improved. The blood glucose levels of mice were reduced to normal. Glucose tolerance of the treated diabetic mice was improved. Body weight loss was also ameliorated. The rapid tail vein injection did not cause any fatal result. CONCLUSION: Our results suggested that insulin gene could be efficiently transferred into the livers of diabetic mice via rapid tail vein injection and it resulted in high level of insulin expression. The basal hepatic insulin production mediated by hydrodynamics-based administration improved the glycemic control in type 1 diabetes dramatically and ameliorated diabetic syndromes. Hydrodynamics-based administration offers a simple and efficient way in the study of gene therapy for type 1 diabetes.

Animals↗
PubMed1999

BHV-1: new molecular approaches to control a common and widespread infection.

BACKGROUND: Herpesviruses are widespread viruses, causing severe infections in both humans and animals. Eradication of herpesviruses is extremely difficult because of their ability to establish latent and life-long infections. However, latency is only one tool that has evolved in herpesviruses to successfully infect their hosts; such viruses display a wide (and still incompletely known) panoply of genes and proteins that are able to counteract immune responses of their hosts. Envelope glycoproteins and cytokine inhibitors are two examples of such weapons. All of these factors make it difficult to develop diagnostics and vaccines, unless they are based on molecular techniques. MATERIALS AND METHODS: Animal herpesviruses, because of their striking similarity to human ones, are suitable models to study the molecular biology of herpesviruses and develop strategies aimed at designing neurotropic live vectors for gene therapy as well as engineered attenuated vaccines. RESULTS: BHV-1 is a neurotropic herpesvirus causing infectious rhinotracheitis (IBR) in cattle. It is a major plague in zootechnics and commercial trade, because of its ability to spread through asymptomatic carrier animals, frozen semen, and embryos. Such portals of infections are also important for human herpesviruses, which mainly cause systemic, eye, and genital tract infections, leading even to the development of cancer. CONCLUSIONS: This review covers both the genetics and molecular biology of BHV-1 and its related herpesviruses. Epidemiology and diagnostic approaches to herpesvirus infections are presented. The role of herpesviruses in gene therapy and a broad introduction to classic and engineered vaccines against herpesviruses are also provided. http://link.springer-ny. com/link/service/journals/00020/bibs/5n5p261.html

Animals↗
PubMed1999

Therapeutic mammalian artificial episomal chromosomes.

Two general strategies are being developed to engineer mammalian artificial chromosomes (MACs) as therapeutic vectors: (i) in vitro MAC cloning by enzymatic ligation of the individual MAC components followed by propagation in single cell organisms such as bacteria or yeast; and (ii) in situ MAC assembly by co-introduction of the various MAC elements into an 'incubator' mammalian tissue culture cell and use of it as a 'foster parental' donor cell. Because of their organizational compactness, in vitro built MACs are stuitable for somatic-based human gene therapy. In contrast, the long-term persistence of in situ built MACs can be capitalized on to generate husbandry transgenic animals expressing therapeutic genes. While current MAC systems generally rely on cis-elements exclusively from viral or genomic origin, the next generation of MACs may combine both into chimeric systems. As illustration of the genetic flexibility and technological potential of chimeric MACs, the herpes viral oriP/EBNA1 system, paradigm of a self-replicating and self-segregating episome in human cells is discussed in terms of future therapeutic applications.

Animals↗
PubMed1992

Characterization and site-directed mutagenesis of a low M(r) GTP-binding protein, ram p25, expressed in Escherichia coli.

The ram gene encodes a GTP-binding protein with a M(r) of 25,068 (Nagata, K., Satoh, T., Itoh, H., Kozasa, T., Okano, Y., Doi, T., Kaziro, Y., and Nozawa, Y. (1990) FEBS Lett. 275, 29-32). It has a putative effector domain very similar to that of yeast SEC4 protein, and shares 40% identity and 60% homology with it, respectively. In order to analyze the biochemical properties, ram cDNA was engineered and inserted into a bacterial expression vector; this allowed the production at a high level of soluble recombinant ram p25 in Escherichia coli. The purified ram p25 contained an equimolar amount of GDP. The purified protein bound approximately 1 mol of [35S]guanosine 5'-O-(thiotriphosphate) GTP gamma S)/mol of protein, with a Kd value of 120 nM. [35S]GTP gamma S binding to this protein was inhibited by GTP and GDP, but not by ATP and ADP. In the presence of 10 mM Mg2+, the dissociation of [8,5'-3H]GDP and [35S]GTP gamma S from ram p25 occurred with rates of 0.015 min-1 and 0.004 min-1, respectively, showing that the ram p25 has a higher affinity for GTP than GDP. The rate of release of Pi from [gamma-32P]GTP-bound ram p25 was calculated to be 0.011 min-1. The contribution of guanine nucleotide-binding and GTP-hydrolysis domains of the protein to its biochemical activities was investigated by site-directed mutagenesis. Substitution of Val for Gly at position 19 resulted in disappearance of [35S]GTP gamma S- and [3H]GDP-binding activity in spite of good expression of the protein. Mutations of Thr41 to Ser, Ala76 to Thr, and Asn133 to His slightly increased the rates of [35S] GTP gamma S binding and [3H]GDP dissociation, but had almost no effects on the manner of [gamma-32P]GTP hydrolysis. Replacement of Gln78 with Leu significantly increased the [3H]GDP dissociation rate (7-fold) and decreased GTP hydrolytic activity considerably.

Amino Acid Sequence↗
PubMed1991

The product of the rap2 gene, member of the ras superfamily. Biochemical characterization and site-directed mutagenesis.

The human rap2 gene encodes a 183 amino acid protein that shares 46% identity with the K-ras p21. Its cDNA was engineered and inserted into the bacterial expression vector ptac; this allowed the production of high levels of soluble recombinant protein in Escherichia coli that was purified to near homogeneity. The rap2 protein binds GTP and exhibits a low intrinsic GTPase activity (rate constant of 0.5 x 10(-2) min-1). It exchanges its bound GDP with a half-life of 18 min at 37 degrees C in the presence of 10 mM Mg2+. Under the same conditions, the dissociation of bound GTP was at least 25-fold slower showing that the rap2 protein has a much higher affinity for GTP than GDP. The contribution of individual domains of the protein to its biochemical activities was investigated by site-directed mutagenesis. Substitution of Val for Gly at position 12 results in a 2-fold decrease in the GDP dissociation rate constant and GTPase activity. Replacement of the Ser at position 17 by Asn severely impairs the GTP binding ability of the protein and points to an important role of this residue in the coordination of Mg2+. Mutation of Thr-35 to Ala results in a decreased affinity for GTP and a reduction (3-fold) of the GTPase activity. Finally, substitution of Thr-145 by Ile leads to an imperfect binding of guanyl nucleotides as exemplified by an increase in their dissociation rate constants and reduction of the GTPase activity of the protein. These properties of the normal and mutant rap2 proteins are compared with those of ras p21 carrying similar substitutions and are discussed in relation to the structural models proposed for ras p21.

Amino Acid Sequence↗
PubMedDate not supplied

A comparison of gene transfer methods in human dendritic cells.

Dendritic cells (DCs) are the most potent antigen-presenting cells (APCs) for the initiation of antigen-specific T-cell activation. DCs may be highly enriched from peripheral blood-adherent leukocytes by short-term (7-day) culture in the presence of interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor. Various methods of gene transfer were studied, including DNA/liposome complexes, electroporation, CaPO4 precipitation, and recombinant adenovirus (AdV) vectors. Low levels of expression were obtained with the physical methods tested. In contrast, AdV vectors expressing luciferase, beta-galactosidase, IL-2, and IL-7 all readily transduced human DCs. Increasing levels of gene expression were observed over a range of multiplicity of infection (MOI) of 10:1 to 10,000:1, with transduction efficiencies exceeding 95% at higher MOI. Although levels of maximal gene expression in DCs were significantly lower than those obtained using human tumor cell lines, IL-2 and IL-7 production of up to 5 x 10(2) ng/10(6) DC were achieved. These results suggest that AdV vectors are a promising vehicle for genetically engineering human DCs.

Dendritic Cells↗
PubMed1996

Molecular characterization of Hor v 9. Conservation of a T-cell epitope among group IX pollen allergens and human VCAM and CD2.

We have cloned, sequenced and expressed a recombinant group IX pollen allergen from barley (Hordeum vulgare). Hor v 9 is a polypeptide of 313 amino acids. The Hor v 9 cDNA clone was engineered into the E. coli protein expression vector pMAL and expressed as a fusion of maltose binding protein and truncated Hor v 9. Polyclonal antibodies to the fusion protein were raised in mice. Cross-reactive proteins, RNA and DNA homologues were found in many agricultural species including wheat, rye, triticale, oats, maize, sunflower and flax. The presence of group IX-like proteins in a variety of agricultural crops may represent a previously uncharacterized aeroallergenic occupational hazard. Sequence comparisons of the barley allergen, Hor v 9, with Poa p 9 and other cloned group IX pollen allergens revealed putative structural domains common to all. These include a signal peptide, two conserved immunoglobulin-like motifs, a 150 amino acid highly conserved carboxyterminal domain and a carboxyterminal transmembrane helix. This structural arrangement is also found in cell adhesion molecules. The highly conserved T-cell epitope previously characterized and mapped in group IX allergens (and present in Hor v 9) was found in several human cell adhesion molecule sequences (VCAM, NCAM and CD2). This T-cell epitope corresponded to the most highly conserved amino acid residues common to all group IX homologues sequenced to date. CD2 and VCAM are known to play a role in allergic inflammation: VCAM is involved in the recruitment of lymphocytes to sites of inflammation, and cross-linking CD2 leads to T-cell activation. We anticipate that the similar structural arrangement of group IX allergens and human cell adhesion molecules, as well as the presence of a T-cell epitope common to group IX pollen allergens and cell adhesion molecules, will have important consequences in the natural history of the atopic immune response.

Allergens↗
PubMed2002

Prospects for using genetic transformation for improved SIT and new biocontrol methods.

The genetic manipulation of non-drosophilid insect species is possible by the creation of recombinant DNA constructs that can be integrated into host genomes by several transposon-based vector systems. This technology will allow the development and testing of a variety of systems that can improve existing biological control methods, and the development of new highly efficient methods. For programs such as sterile insect technique (SIT), transgenic strains may include fluorescent protein marker genes for detection of released insects, and conditional gene expression systems that will result in male sterility and female lethality for genetic sexing. Conditional expression systems include the yeast GAL4 system and the bacterial Tet-off and Tet-on systems that can, respectively, negatively or positively regulate expression of genes for lethality or sterility depending on a dietary source of tetracycline. Importantly, strains for male sterility must also incorporate an effective system for genetic sexing, since typically, surviving females would remain fertile. Models for the use of these expression systems and associated genetic material come from studies in Drosophila and, while many of these systems should be transferable to other insects, continued research will be necessary in insects of interest to clone genes, optimize germ-line transformation, and perform vector stability studies and risk assessment for their release as transgenic strains.

Animal Identification Systems↗
PubMed2003

Viral-mediated delivery of the late-infantile neuronal ceroid lipofuscinosis gene, TPP-I to the mouse central nervous system.

Classical late-infantile neuronal ceroid lipofuscinosis (LINCL) is caused by mutations in tripeptidyl peptidase I (TPP-I), a pepstatin-insensitive lysosomal protease, resulting in neurodegeneration, acute seizures, visual and motor dysfunction. In vitro studies suggest that TPP-I is secreted from cells and subsequently taken up by neighboring cells, similar to other lysosomal enzymes. As such, TPP-I is an attractive candidate for enzyme replacement or gene therapy. In the present studies, we examined the feasibility of gene transfer into mouse brain using recombinant adenovirus (Ad), feline immunodeficiency virus (FIV) and adeno-associated virus (AAV) vectors expressing TPP-I, after single injections into the striatum or cerebellum. A dual TPP-I- and beta-galactosidase-expressing adenovirus vector (AdTTP-I/nlsbetagal) was used to distinguish transduced (beta-galactosidase positive) cells from cells that endocytosed secreted TTP-I. Ten days after striatal injection of AdTTP-I/nlsbetagal, beta-galactosidase-positive cells were concentrated around the injection site, corpus callosum, ependyma and choroid plexus. In cerebellar injections, beta-galactosidase expression was confined to the region of injection and in isolated neurons of the brainstem. Immunohistochemistry for TPP-I expression showed that TPP-I extended beyond areas of beta-galactosidase activity. Immunohistochemistry for TTP-I after FIVTTP-I and AAV5TTP-I injections demonstrated TPP-I in neurons of the striatum, hippocampus and Purkinje cells. For all three vectors, TPP-I activity in brain homogenates was 3-7-fold higher than endogenous levels in the injected hemispheres. Our results indicate the feasibility of vector-mediated gene transfer of TPP-I to the CNS as a potential therapy for LINCL.

Adenoviridae↗
PubMed2004

Herpesvirus/retrovirus chimeric vectors.

Over the years, the design of HSV-1 based vectors has developed from different types of replicative-defective and replication-conditioned recombinant viruses to plasmid based amplicon vectors. More recently hybrid or chimeric vectors have incorporated desired elements of different viruses to increase the efficacy of gene delivery in vitro and in vivo. Amongst different systems, herpesvirus/retrovirus chimeras take advantage of the features of the HSV-1 vectors to efficiently transduce large amounts of foreign genetic sequences, remaining episomal, to allow production of recombinant retrovirus vectors able to stably integrate into the cellular genome. This review will focus on three different groups of herpesvirus/retrovirus chimeric vectors aimed to: generate retrovirus particles in cells tranduced with HSV-1 amplicon vectors; express a limited set of retrovirus genes for vaccine purposes; and express herpesvirus/retrovirus chimeric proteins to study cellular targeting signal and improve their biological effect.

Animals↗