Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322139
Title: The production, harvest and adsorptive recovery of an infectious herpes simplex virus vaccine
Author: O'Keeffe, Roderic S.
Awarding Body: Aston University
Current Institution: Aston University
Date of Award: 1999
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Abstract:
At present there is not a reliable vaccine against herpes virus. Viral protein vaccines as yet have proved unsuccessful to meet the challenge of raising an appropriate immune response. Cantab Pharmaceuticals has produced a virus vaccine that can undergo one round of replication in the recipient in order to produce a more specific immune reaction. This virus is called Disabled Infectious Single Cycle Herpes Simplex Virus (DISC HSV) which has been derived by deleting the essential gH gene from a type 2 herpes virus. This vaccine has been proven to be effective in animnl studies. Existing methods for the purification of viruses rely on laboratory techniques and for vaccine production would be on a far too small a scale. There is therefore a need for new virus purification methods to be developed in order to meet these large scale needs. An integrated process for the manufacture of a purified recombinant DISC J-ISV is described. The process involves culture of complementing Vero (CR2) cells, virus infection and manufacture, virus harvesting and subsequent downstremn processing. The identification of suitable growth parameters for the complementing cell line nnd optimal limes for both infection and harvest are addressed. Various traditional harvest methods were investigated and found not to be suitable for a scaled up process. A method of harvesting, that exploits the elution of cell associated viruses by the competitive binding of exogenous heparin to virus envelope gC proteins, is described and is shown to yield significantly less contaminated process streams than sonication or osmotic approaches that involve cell rupture (with> 1O-fold less complementing cell protein). High concentrations of salt (>0.8M NaCl) exhibit the same effect, although the high osmotic strength ruptures cells and increase the contamination of the process stream. This same heparin-gC protein affinity interaction is also shown to provide an efficient adsorptive purification procedure for herpes viruses which avoids the need to pre-treat the harvest material, apart from clarification, prior to chromatography. Subsequent column eluates provide product fractions with Cl 100- fold increase in virus titre and Iow levels of complementing cell protein and DNA (0.05 pg protein/pfu and 1.2 x 10-4 pg DNA/pfu respectively).
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.322139  DOI: Not available
Keywords: Chemical Engineering ; Applied Chemistry ; Chemical Engineering Medicine Molecular biology Cytology Genetics
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