Joint Fellowship Training Program
Mentor:
Keith Peden, Ph.D.
Co-mentor:
Andrew M. Lewis Jr. M.D.
Organizational Affiliation and Position:
Senior Investigators, Division of Viral Products (DVP) Office of Vaccines Research and Review (OVRR), Center for Biologics Evaluation and Research (CBER), FDA
Email:
keith.peden@fda.hhs.gov
Telephone:
301 827-1708
Running Title of Program:
Development of methods to assess the safety of vaccine cell substrates
Research Project Summary (if applicable):
Cell substrates are the cells upon which biologicals (which includes vaccines and gene therapy products) are produced. At present, the only cell substrates used for the manufacture of licensed virus vaccines in the US are primary cells (avian cells, monkey kidney cells), diploid cell strains (e.g., WI-38. MRC-5), and the Vero cell line (used only for the production of inactivated poliovirus vaccine in the US). The need to use neoplastic cell lines as substrates for the manufacture of vaccines has become urgent due to the fact that these types of cells are necessary to produce the new generation of virus-vectored vaccines necessary to combat HIV/AIDS, emerging infectious diseases (e.g., SARS), pandemic influenza, and potential agents of bioterroism. However, because biologicals are inevitably contaminated by cellular components, there have been concerns expressed over the use of certain types of neop lastic cells for vaccine manufacture, particularly cells that are tumorigenic or are derived from tumors. These concerns are based on the potential for the residual cellular components to transfer oncogenic elements and/or infectious agents to the vaccine recipient (Lewis et al., 2001). Understanding the process of neoplastic development and the safety issues posed by biologicals manufactured in neoplastic cells is basic to the scientific and regulatory mission of the Division of Viral Products, CBER/FDA.
Our scientific program consists of five projects. 1. Developing quantitative and sensitive animal model systems to assess the oncogenic activity of cellular oncogenes and cellular DNA containing activated oncogenes in order to understand the risks associated with the presence of DNA from neoplastic cells in vaccines; apart from its regulatory implications, this work is likely relevant to carcinogenesis in general; 2. Developing sensitive and quantitative in vitro assays to measure the infectivity of DNA; these assays will form the basis for studies that can be used to quantify the amount of reduction in DNA activity and will be used to make estimates of DNA clearance for regulatory purposes; 3. Understanding the evolution of the tumorigenic phenotypes of cells that undergo neoplastic transformation in culture and determining whether these changes raise the level of concern for biologicals manufactured in such cell substrates; 4. Developing real-time, quantitative PCR assays of defined sensitivity to detect oncogenic polyomaviruses and using these assays to screen biologicals for possible contamination with these agents; 5. Understanding the possible role that SV40 contamination of early vaccines played in establishing SV40 infection in humans and in producing the neoplastic diseases that have been attributed to such infections; these studies involve the isolation and characterization of novel strains of SV40 from poliovirus and adenovirus stocks produced in rhesus macaque kidney cells and dating from the 1950s and early 1960s, and the development of reporter virus neutralization assays for the primate polyomaviruses. Dr Peden and Dr Lewis have extensive experience with DNA and RNA viruses, molecular genetics, cell culture, and animal models for oncogenicity and/or tumorigenicity.
Proposed Project for IOTF Fellow:
The Fellow will be able to participate in one or more of the parts of the scientific program depending on the interests of the candidate.
Regulatory Activity:
The Fellow will be able to participate in one or more of the parts of the scientific program depending on the interests of the candidate.
Reference(s):
Peden, K.W.C. and Martin, M.A. (1995). Virological and molecular genetic techniques for studies of established HIV isolates. In "HIV: A Practical Approach", Ed. Jonathan Karn, IRL Press, pp 21-45.
Lewis, A. M., Alling, D. W., Banks, S. M., Soddu, S., and Cook, J. L. (1999). Evaluating virus-transformed cell tumorigenicity. J. Virological Methods 79: 41-50.
Lewis, A.M., Krause, P., and Peden, K. (2001). A defined risks approach to the regulatory assessment of the use of neoplastic cells as substrates for viral vaccine manufacture. Dev. Biologicals 106: 513-533.
Peden, K., Lewis, A.M., Jr. and Maudru, T. (2001). Application of quantitative methods for the detection of adventitious agents. Dev. Biologicals 106: 333-339.
Foley, J.F., Yu, C.-R, Solow, R., Yacobucci, M., Peden, K.W.C., and Farber, J.M. (2005). Roles for CXC chemokine ligands 10 and 11 in recruiting CD4+ T cells to HIV-1-infected monocytes-derived macropages, dendritic cells and lymph nodes. J. Immunology 174: 4892-4900.
Cantalupo, P., Doering, A., Sullivan, C.S., Pal, A., Peden, K.W.C., Lewis, A.M., and Pipas, J.M. (2005). Complete nucleotide sequence of polyomavirus SA12. J. Virology 79: 13094-13104.
Pal, A., Sirota, L., Maudru, T., Peden, K., and Lewis, A. M., Jr. (2006). Real-time, quantitative PCR for the detection of specific DNA in samples with mixed populations of polyomaviruses. J. Virological Methods, in press.
Peden, K, Sheng, L, Pal, A. and Lewis, A.M. (2005). Biological activity of residual cell-substrate DNA. Dev. Biologicals, in press.
