Development of Quantitative Assays to Evaluate the Safety of Cell Substrates and Vaccines

Principal Investigator: Keith Peden, PhD
Office / Division / Lab: OVRR / DVP / LR

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Overview

Public Health Issue: The introduction of new safe and effective vaccines against current (e.g., HIV) and emerging infectious agents (e.g., the SARS coronavirus, novel strains of influenza virus including a potential pandemic strain, agents of bioterrorism) is a critical component for public health. The manufacture of these vaccines will require the use of immortalized cells that are potentially cancer-inducing, i.e., neoplastic. [Neoplastic cells include spontaneously immortalized cells, cells immortalized by defined neoplastic events (such as oncogenes), cells that are tumorigenic or non-tumorigenic, and cells derived from tumors.] In order to support this new approach, new scientific information and tools are needed to evaluate safety concerns for vaccines produced in neoplastic cells.

Regulatory Contribution: Results from our research will resolve many of the safety concerns associated with neoplastic cell substrates, thus permitting a wider repertoire of cell substrates to be available for vaccine production. This, in turn, will facillitate the development and safe introduction of new vaccines.

Research Approach: The only way that CBER can perform an appropriate risk assessment on vaccines manufactured using neoplastic-cell substrates is to have assays to quantify the risks. Currently, these assays do not exist. Our research, in collaboration with others, is directed towards the development of new in vitro and in vivo quantitative assays to assess the risks posed by biologically active "contaminants" derived from the cell substrate in vaccines, such as residual cellular DNA and adventitious agents. These assays include: quantitative PCR assays for adventitious agents; in vitro assays for DNA infectivity; in vitro assays for other biological activities of DNA; and in vivo assays for DNA oncogenicity. With quantitative assays in place to measure the biological activities of DNA, the amount of reduction in these DNA activities using various treatments (e.g., chemicals or nuclease digestion) can be determined. Such information can be used to estimate risks/safety.

Mission Relevance and Outcomes: The knowledge gained through this research will result in new regulatory guidance and policy for the use of new cell substrates. It will allow CBER to regulate novel cell substrates and support the introduction of new, safe, and effective vaccines.

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Publications

Virology 2008 Nov 10;381(1):116-22
Identification of a neutralization epitope in the VP1 capsid protein of SV40.
Murata H, Teferedegne B, Sheng L, Lewis AM Jr, Peden K

Biologicals 2008 May;36(3):184-97
Oncogenicity of DNA in vivo: Tumor induction with expression plasmids for activated H-ras and c-myc.
Sheng L, Cai F, Zhu Y, Pal A, Athanasiou M, Orrison B, Blair DG, Hughes SH, Coffin JM, Lewis AM, Peden K

Biologicals 2008 Jan;36(1):65-72
Assessing the tumorigenic phenotype of VERO cells in adult and newborn nude mice.
Manohar M, Orrison B, Peden K, Lewis AM Jr

Virology 2008 Jan 5;370(1):63-76
Recovery of strains of the polyomavirus SV40 from rhesus monkey kidney cells dating from the 1950s to the early 1960s.
Peden K, Sheng L, Omeir R, Yacobucci M, Klutch M, Laassri M, Chumakov K, Pal A, Murata H, Lewis AM Jr

Virology 2008 Jan 20;370(2):343-51
Identification of a mutation in the SV40 capsid protein VP1 that influences plaque morphology, vacuolization, and receptor usage.
Murata H, Peden K, Lewis AM Jr

J Virol Methods 2006 Jul;135(1):32-42
Real-time, quantitative PCR assays for the detection of virus-specific DNA in samples with mixed populations of polyomaviruses.
Pal A, Sirota L, Maudru T, Peden K, Lewis AM Jr

Dev Biol 2006;123:45-53
Biological activity of residual cell-substrate DNA.
Peden K, Sheng L, Pal A, Lewis A

J Virol 2005 Oct;79(20):13094-104
Complete nucleotide sequence of polyomavirus SA12.
Cantalupo P, Doering A, Sullivan CS, Pal A, Peden KW, Lewis AM, Pipas JM

J Virol 2005 Apr;79(8):4774-81
Human Immunodeficiency Virus (HIV) gp41 Escape Mutants: Cross-Resistance to Peptide Inhibitors of HIV Fusion and Altered Receptor Activation of gp120.
Desmezieres E, Gupta N, Vassell R, He Y, Peden K, Sirota L, Yang Z, Wingfield P, Weiss CD

J Virol 2004 May 1;78(9):4541-4551
Apoptosis of Bystander T Cells Induced by Human Immunodeficiency Virus Type 1 with Increased Envelope/Receptor Affinity and Coreceptor Binding Site Exposure.
Holm GH, Zhang C, Gorry PR, Peden K, Schols D, De Clercq E, Gabuzda D