title: Development and Characterization of an HPV Type-16 Specific Modified DNA Aptamer for the Improvement of Potency Assays.
abstract: Measuring vaccine potency is critical for vaccine release and is often accomplished using antibody-based ELISAs. Antibodies can be associated with significant drawbacks that are often overlooked including lot-to-lot variability, problems with cell-line maintenance, limited stability, high cost, and long discovery lead times. Here, we address many of these issues through the development of an aptamer, known as a slow off-rate modified DNA aptamer (SOMAmer), which targets a vaccine antigen in the human papillomavirus (HPV) vaccine Gardasil. The aptamer, termed HPV-07, was selected to bind the Type 16 virus-like-particle (VLP) formed by the self-assembling capsid protein L1. It is capable of binding with high sensitivity (EC50of 0.1 to 0.4 μg/mL depending on assay format) while strongly discriminating against other VLP types. The aptamer competes for binding with the neutralizing antibody H16.V5, indicating at least partial recognition of a neutralizing and clinically relevant epitope. This makes it a useful reagent for measuring both potency and stability. When used in an ELISA format, the aptamer displays both high precision (intermediate precision of 6.3%) and a large linear range spanning from 25% to 200% of a typical formulation. To further exploit the advantages of aptamers, a simplified mix and read assay was also developed. This assay format offers significant time and resource reductions compared to a traditional ELISA. These results show aptamers are suitable reagents for biological potency assays, and we expect that their implementation could improve upon current assay formats.
authors.affiliation: Department of Vaccine Analytical Development, MRL, Merck & Co., Inc. , West Point, Pennsylvania 19486, United States.
authors.forename: Jeremiah J
authors.identifier: 0000-0003-2120-3870
authors.initials: JJ
authors.lastname: Trausch
authors.affiliation: Department of Vaccine Analytical Development, MRL, Merck & Co., Inc. , West Point, Pennsylvania 19486, United States.
authors.forename: Mary
authors.initials: M
authors.lastname: Shank-Retzlaff
authors.affiliation: Department of Vaccine Analytical Development, MRL, Merck & Co., Inc. , West Point, Pennsylvania 19486, United States.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Verch
mesh_terms: D000937:Antigen-Antibody Reactions; D000956:Antigens, Viral / Q000276:immunology*; D052157:Aptamers, Nucleotide / Q000138:chemical synthesis / Q000737:chemistry / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D052162:Human papillomavirus 16 / Q000276:immunology*; D006801:Humans; D053918:Papillomavirus Vaccines / Q000276:immunology*
chemical_list: D000956:Antigens, Viral; D052157:Aptamers, Nucleotide; D000939:Epitopes; D053918:Papillomavirus Vaccines