• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of cancer immunotherapy based on parvoviral vectors and hybrid cell vaccination

Cheong, Siew Chiat 16 February 2005 (has links)
Cancer is a worldwide health problem and despite advances in traditional treatments i.e. surgery, chemotherapy and radiotherapy, the cure rate remains disappointing for some cancers. Different novel therapeutic strategies are being developed. In this thesis two nontraditional cancer therapy approaches are studied: gene therapy using viral vectors and antitumour vaccination with dendritic cell - tumour cell (DC/TC) hybrids. We have developed a novel ELISPOT titration method for viral vectors that is based on the actual expression of the transgene in target cells. This method was developed with recombinant parvovirus MVM-IL2, but it should be adaptable for other vectors carrying expression cassettes for secreted transgene products for which antibodies are available. The ELISPOT titration method allows for faster and better quantification of transducing units present in vector stocks as opposed to titration by in situ hybridisation (annexe I). The MVMIL2 vector has shown an anti-tumour effect against melanoma in an immunocompetent mouse model (annexe IV). Previous work concerns photodynamic inactivation of adenoviral vectors for biosafety and an in vivo study in which a synergistic effect of antiangiogenesis gene therapy combined with radiotherapy could be shown (annexes V and VI). DC/TC hybrids have been proposed as cancer vaccines for their simultaneous expression of antigen presentation machinery and tumour associated antigens. Hybrids are classically generated by polyethylene glycol (PEG) or electrofusion. These methods however require special skills and equipment and cause rather high cell lethality. Fusion via the expression of viral fusogenic membrane glycoproteins (FMG), such as the vesicular stomatitis virus-G (VSV-G) (annexe III) or the Gibbon ape Leukemia Virus (GaLV) FMG, have recently been described. We have mainly focussed on the latter. Transduction of cells with GaLV-FMG proved to be a limiting step for an efficient generation of hybrids. On the other hand, constitutive expression of GaLV-FMG leads to lethal syncytia formation in human cells. Therefore we developed a novel fusion strategy for the generation of DC/TC cell hybrids that involves the use of a non-human fusogenic cell line that constitutively expresses the GaLV-FMG. With this method we were able to generate reproducible yields of DC/TC triparental hybrids. The formation of tri-parental hybrids via the fusogenic cell line is an interesting alternative to existing DC/TC fusion methods because of its simplicity and its flexibility in the choice of fusion partners, i.e. autologous or allogeneic DCs and tumour cells. Moreover, the tri-parent hybrid system offers the possibility to further enhance the immune response by the addition of transgenes that code for immuno-modulating factors to the fusogenic cell line (annexe II).
2

Development of cancer immunotherapy based on parvoviral vectors and hybrid cell vaccination

Cheong, Siew Chiat 16 February 2005 (has links)
Cancer is a worldwide health problem and despite advances in traditional treatments i.e. surgery, chemotherapy and radiotherapy, the cure rate remains disappointing for some cancers. Different novel therapeutic strategies are being developed. In this thesis two nontraditional cancer therapy approaches are studied: gene therapy using viral vectors and antitumour vaccination with dendritic cell - tumour cell (DC/TC) hybrids.<p>We have developed a novel ELISPOT titration method for viral vectors that is based on the actual expression of the transgene in target cells. This method was developed with recombinant parvovirus MVM-IL2, but it should be adaptable for other vectors carrying expression cassettes for secreted transgene products for which antibodies are available. The ELISPOT titration method allows for faster and better quantification of transducing units present in vector stocks as opposed to titration by in situ hybridisation (annexe I). The MVMIL2 vector has shown an anti-tumour effect against melanoma in an immunocompetent mouse model (annexe IV). Previous work concerns photodynamic inactivation of adenoviral vectors for biosafety and an in vivo study in which a synergistic effect of antiangiogenesis gene therapy combined with radiotherapy could be shown (annexes V and VI).<p>DC/TC hybrids have been proposed as cancer vaccines for their simultaneous expression of antigen presentation machinery and tumour associated antigens. Hybrids are classically generated by polyethylene glycol (PEG) or electrofusion. These methods however require special skills and equipment and cause rather high cell lethality. Fusion via the expression of viral fusogenic membrane glycoproteins (FMG), such as the vesicular stomatitis virus-G (VSV-G) (annexe III) or the Gibbon ape Leukemia Virus (GaLV) FMG, have recently been described. We have mainly focussed on the latter. Transduction of cells with GaLV-FMG proved to be a limiting step for an efficient generation of hybrids. On the other hand, constitutive expression of GaLV-FMG leads to lethal syncytia formation in human cells. Therefore we developed a novel fusion strategy for the generation of DC/TC cell hybrids that involves the use of a non-human fusogenic cell line that constitutively expresses the GaLV-FMG. With this method we were able to generate reproducible yields of DC/TC triparental hybrids. The formation of tri-parental hybrids via the fusogenic cell line is an interesting alternative to existing DC/TC fusion methods because of its simplicity and its flexibility in the choice of fusion partners, i.e. autologous or allogeneic DCs and tumour cells.<p>Moreover, the tri-parent hybrid system offers the possibility to further enhance the immune response by the addition of transgenes that code for immuno-modulating factors to the fusogenic cell line (annexe II). / Doctorat en sciences biomédicales / info:eu-repo/semantics/nonPublished

Page generated in 0.0984 seconds