The main focus of my research is to generate novel cell lines for the growth of replication deficient viral vaccine vectors. Viruses used as vaccine vectors have been engineered to be replication incompetent in host cells. Therefore, these vectors must be grown in either a permissive cell line or complementing cell line. The attenuated pox virus Modified Vaccinia Ankara (MVA) grows in chicken embryo fibroblasts, however these cells contain potentially harmful endogenous retroviruses. Adenovirus vectors which are E1A- require a complementing cell line, such as 293 human embryonic cells, which express E1A proteins.
However, complementing cell lines may result in the generation of recombinant replication competent vectors. Furthermore, the generation of clinical vaccine stocks requires that all cell lines are verified and their origins traceable to ensure a product which is free from retroviruses and TSEs. For some traditionally used cell lines this is a problem. A further limitation to the growth of viral vector stocks is toxicity of the transgene.
Duck cell lines, which do not contain endogenous retroviruses, have been investigated for their ability to support growth of replication incompetent poxviruses. One approach taken to generate GMP cell lines which produce increased yields of adenovirus vectors include engineering complementing cells to express a regulatory element, which inhibits transgene expression during vector growth.
M.G. Cottingham, F. Carroll, S. J. Morris, A. V. Turner, A. M. Vaughan, M. C. Kapulu, S. Colloca, L. Siani, S. C. Gilbert and A. V. S. Hill. (2012) Preventing spontaneous genetic rearrangements in the transgene cassettes of adenovirus vectors. Biotechnology and Bioengineering http://onlinelibrary.wiley.com/doi/10.1002/bit.24342/pdf
Morris, S. J., D. C. Farley and K. N. Leppard (2010) Generation of cell lines to complement adenovirus vectors using recombination mediated cassette exchange. BMC Biotechnology 10:92
Simian adenoviruses as vaccine vectors
Morris SJ. et al, (2016), Future Virology, 11, 649 - 659
Enhancing cellular immunogenicity of MVA-vectored vaccines by utilizing the F11L endogenous promoter
Alharbi NK. et al, (2016), Vaccine, 34, 49 - 55
Laboratory-Scale Production of Replication-Deficient Adenovirus Vectored Vaccines
Morris SJ. et al, (2016), Methods in Molecular Biology, 121 - 135
The Human Adenovirus Type 5 L4 Promoter Is Negatively Regulated by TFII-I and L4-33K
Wright J. et al, (2015), Journal of Virology, 89, 7053 - 7063
Preventing spontaneous genetic rearrangements in the transgene cassettes of adenovirus vectors
Cottingham MG. et al, (2012), Biotechnology and Bioengineering, 109, 719 - 728