MINIMALLY INVASIVE REPAIR OF ORTHOPAEDIC IMPLANTS USING GENE THERAPY

Optimising joint reconstruction management in arthritis and bone tumour patient

Recombinant ovine atadenovirus induces a strong and sustained T cell response against the hepatitis C virus NS3 antigen in mice

Ovine atadenovirus (OAdV) is a novel gene transfer vector with excellent in vivo gene transfer characteristics. In the present study, we have investigated the ability of an OAdV vector to mediate a T cell response to an antigen of the hepatitis C virus (HCV) in mice. Specifically, an expression cassette coding for non-structural protein 3 (NS3) of hepatitis C virus was inserted into the OAdV genome and the resulting recombinant virus (OAdV-ns3) was shown to propagate stably and to express the ns3 gene at a high level in vitro. A single injection of this non-replicating vector into BALB/c mice resulted in a strong induction of NS3-specific, IFN-γ secreting T-lymphocytes as measured by direct ex vivo ELISpot assay. The number of IFN-γ secreting lymphocytes remained nearly unaltered for a period of at least 10 weeks. The immune response was shown to depend on virus dose but a single intramuscular injection of less than 108 infectious particles of OAdV-ns3 was sufficient to induce a significant NS3-specific T cell response. Moreover, this response was not affected by prior immunisation of animals with human adenovirus type 5 (HAdV-5). The results of our study provide proof for the concept that OAdV vectors may be valuable tools for vaccination and immunotherapy even in the face of natural immunity to human adenoviruses

An Ovine Adenovirus Vector Lacks Transforming Ability in Cells That Are Transformed by AD5 E1A/B Sequences

AbstractAdenoviruses of the Mastadenovirus and Aviadenovirus genera are able to transform certain cell types and induce tumor formation in susceptible animals. For the mastadenoviruses the E1A/B sequences are largely responsible for these properties but E4 sequences may also be involved. The transforming sequences of the aviadenoviruses, which lack E1A/B and E4 homologues, have not yet been fully identified. The recent proposal for a third genus of adenoviruses, which apparently lack an E1A homologue and have weak E1B homology, prompted an examination of the transforming properties of ovine adenovirus OAV287 (OAV), the prototype member of the new group. When OAV and human adenovirus type 5 (Ad5) were used to infect primary rat embryo cells, transformed foci developed in Ad5- but not in OAV-infected cultures. Similarly, after plasmid transfection, baby rat kidney cells were transformed by Ad5 E1A/B but not by OAV sequences. When CSL503 cells, an ovine cell line that is permissive for OAV, were transfected with Ad5 E1A/B sequences, transformed foci again appeared. However, plasmids or fragments containing complete or partial OAV genome sequences did not detectably transform CSL503 cells under the same conditions. When Ad5 E1A/B sequences were incorporated into the complete OAV genome and transfected, transformed clones were again obtained, showing that the gene dosage and transfection conditions were not limiting for transformation. The provision of Ad5 E1A and OAV sequences in combination marginally increased the number of morphologically altered foci in baby rat kidney cells but failed to induce multilayered focus formation. The data suggest that OAV lacks transforming functions in the cell types examined. Additional information suggesting that OAV may have a fundamentally distinct strategy for replication compared with other Ads is discussed