Ovarian cancer commonly relapses after remission and activating tumour-specific T cells with dendritic cells loaded with tumour cells is a promising approach to target residual microscopic tumours. SK-OV-3 cells expressing HER-2/neu and MUC1 ovarian antigens were killed and their immunogenicity enhanced by hypochlorous acid (HOC1) oxidation. Treatment with 60 uM HOC1 for 1 h induced necrosis in all the cells. Oxidised, but not live SK-OV-3 were engulfed by monocyte-derived DCs. Autologous T cells primed with DCs of HLA-A2+ healthy volunteers loaded with oxidised SK-OV-3 (HLA-A2") recognised oxidised SK-OV-3 and HLA-A2-restricted epitopes of MUC1 and HER-2/neu. Responses were absent with heat- or hydrochloric acid (HCl)-killed SK-OV-3, thus HOC1 oxidation and not cell death/necrosis enhanced the immunogenicity of SK-OV-3. Oxidised SK-OV-3 primed T cells did not respond to oxidised melanoma, or vice versa. Next, T cells of ovarian cancer patients in remission, whose tumours overexpressed MUC1 and/or HER-2/neu, were tested using the same model. DCs of HLA-A2+ and A2" patients pulsed with oxidised SK- OV-3 stimulated T cells specific for oxidised SK-OV-3, and HER-2/neu and MUC1 epitopes. Oxidised SK-OV-3 loaded DCs further matured with CD40 agonistic antibody or monophosphoryl lipid A, primed stronger CD4+ and CD8+ responses than immature DCs. T cells stimulated this way also recognised autologous tumour cells from ascites, demonstrating that SK-OV-3 shared significant antigenic repertoire with tumours in patients. Finally, this DC-based vaccination was tested in vivo using the B16.F10 melanoma model. B16.F10 highly expressed tyrosinase-related protein (TRP)-2, and all the cells were necrotic after 1 h treatment with 60uM HOC1. Mice immunised intravenously and not intraperitoneally or subcutaneously with bone- marrow derived DCs loaded with oxidised B16.F10, responded to TRP-2 and oxidised B16.F10. Oxidised and not heat- or HCl-killed B16.F10, primed specific T cells in vivo. DCs were required for efficient delivery for processing and presentation of oxidised B16.F10 in vivo.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:625143 |
| Date | January 2008 |
| Creators | Chiang, C. L. L. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1444144/ |
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