Development and application of a GuHCl-modified ELISA to measure the avidity of anti-HPV L1 VLP antibodies in vaccinated individuals

Dauner, Joseph G.; Pan, Yuanji; Hildesheim, Allan; Kemp, Troy J.; Porras, Carolina; Pinto, Lígia A.

doi:10.1016/j.mcp.2012.01.002

Cited by 39 publications

(36 citation statements)

References 39 publications

(61 reference statements)

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“…Variations on silk formulation and reconstitution media were used reconcile differences between assay values taken from fresh plasma samples and those derived from reconstituted plasma entrapped in silk. Previous studies demonstrated interferences from samples additives (such as buffers, protease inhibitors, or anticoagulants) can lead to artifacts in immunoassay results, which can be ameliorated through the use of additives such as chaotropes (31), or through alteration of sample matrix (32). Furthermore, chaotropes have been shown to destabilize drug-loaded silk micelles in solution, thus reducing shielding effects preventing the protein and drug from interacting (25).…”

Section: Resultsmentioning

confidence: 99%

Silk-based blood stabilization for diagnostics

Kluge

Kahn

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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Advanced personalized medical diagnostics depend on the availability of high-quality biological samples. These are typically biofluids, such as blood, saliva, or urine; and their collection and storage is critical to obtain reliable results. Without proper temperature regulation, protein biomarkers in particular can degrade rapidly in blood samples, an effect that ultimately compromises the quality and reliability of laboratory tests. Here, we present the use of silk fibroin as a solid matrix to encapsulate blood analytes, protecting them from thermally induced damage that could be encountered during nonrefrigerated transportation or freeze-thaw cycles. Blood samples are recovered by simple dissolution of the silk matrix in water. This process is demonstrated to be compatible with a number of immunoassays and provides enhanced sample preservation in comparison with traditional air-drying paper approaches. Additional processing can remediate interactions with conformational structures of the silk protein to further enhance blood stabilization and recovery. This approach can provide expanded utility for remote collection of blood and other biospecimens empowering new modalities of temperature-independent remote diagnostics.lood contains a variety of proteins, enzymes, lipids, metabolites, and peptides, which can be interrogated as biomarkers for health screening, monitoring, and diagnostics. The integrity of these blood components and thus the quality of information attained from their analysis is determined by the storage conditions from sampling until analysis, or the so-called pre-analytical phase (1, 2). This phase often includes time-consuming processing steps and the requirement for a continuous cold storage. Without temperature regulation, blood-derived biospecimens degrade quickly, accounting for up to 67% of all laboratory testing errors (2, 3). Further, when blood-derived materials are frozen, decreases in thermodynamic free energy and unfavorable ice crystal-protein interactions (4) can occur during subsequent thawing (5, 6), which can further compromise analyte integrity as a gold-standard methodology.As an alternative route, blood and blood derivatives can be dried via newer approaches such as isothermal vitrification (7), lyophilization (8), or on silica chips (9). Isothermal vitrification and lyophilization are inherently resource-intensive techniques and thus not suitable for field use. Silica chips are designed for enrichment of selected fractions of the low-molecular-weight serum proteome, but are not broadly protective at elevated temperature (10). An inexpensive alternative used since the 1960s are dried blood spots (DBS) (11), a paper card system which captures blood components among cellulose fibers as the water phase evaporates. These drying measures decrease sample weight by >90%, thus decreasing transport burden, and in theory can enhance long-term sample stability by decreasing water-dependent analyte degradation caused by hydrolysis and enzyme activity (12). Unfortunately, DBS stored in ...

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Section: Resultsmentioning

confidence: 99%

Silk-based blood stabilization for diagnostics

Kluge

Kahn

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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“…Avidity to the VLPs of other types (HPV-31 and HPV-45) was not performed due to problems with producing these L1 VLPs in our laboratory, and the sensitivity of the ELISA-based avidity assay may not be effective in determining the avidity of antibodies with a low neutralization titer. The method of assessing the avidity of the anti-HPV-16 antibodies was previously reported [14]. Briefly, microtiter plates were coated with HPV-16 L1 VLP, and each serum sample was assayed at a single dilution, ranging from 1/100 to 1/100000 for all samples evaluated, which yields an absorbance reading of 1.0 ± 0.5 as previously determined in an HPV-16 ELISA.…”

Section: Methodsmentioning

confidence: 99%

Kinetic and HPV infection effects on cross-type neutralizing antibody and avidity responses induced by Cervarix®

Kemp¹,

Safaeian²,

Hildesheim³

et al. 2012

Vaccine

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Background We previously demonstrated that Cervarix® elicits antibody responses against vaccine-related types for which clinical efficacy was demonstrated (HPV-31 and -45). Here, we evaluated the kinetics of neutralization titers and avidity of Cervarix®-induced antibodies up to 36 months of follow-up in unexposed and HPV infected women. Methods A subset of women who participated in the Cost Rica HPV-16/18 Vaccine Trial had pre- and post-vaccination sera tested for antibody responses to HPV-16, -18, -31, -45, and -58 using a pseudovirion-based neutralization assay, and HPV-16 antibody avidity using an HPV-16 L1 VLP (virus-like particle)-based ELISA developed in our laboratory. Results In uninfected women, neutralizing antibody titers did not reach significance until after the 3rd dose for HPV-31 (month 12, p=0.009) and HPV-45 (month 12, p=0.003), but then persisted up to month 36 (HPV-31, p=0.01; HPV-45, p=0.002). Individuals infected with HPV-16 or HPV-31 at enrollment developed a significantly higher median antibody response to the corresponding HPV type after one dose, but there was not a difference between median titers after three doses compared to the HPV negative group. Median HPV-16 antibody avidity and titer increased over time up to month 12; however, the HPV-16 avidity did not correlate well with HPV-16 neutralizing antibody titers at each time point examined, except for month 6. The median avidity levels were higher in HPV-16 infected women at month 1 (p=0.04) and lower in HPV-16 infected women at month 12 (p=0.006) compared to the HPV negative women. Conclusions The persistence of cross-neutralization titers at month 36 suggests cross-reactive antibody responses are likely to persist long-term and are not influenced by infection status at enrollment. However, the weak correlation between avidity and neutralization titers emphasizes the need for examining avidity in efficacy studies to determine if high avidity antibodies play a critical role in protection against infection.

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“…The method of assessing the avidity of the anti-HPV16 antibodies was previously reported. 19,20 We only evaluated HPV16 avidity because of the availability of particles for HPV16 for ELISA assays in our laboratory. In addition, the lower neutralization titers for the cross-related HPV types, would not allow a precise estimation for the ELISA-based avidity levels.…”

Section: Titers (Range Within Quartile) Controls N(%) Hpv58 Cases N(%mentioning

confidence: 99%

Cross-protective vaccine efficacy of the bivalent HPV vaccine against HPV31 is associated with humoral immune responses

Safaeian

Kemp

Pan

et al. 2013

Human Vaccines & Immunotherapeutics

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Development and application of a GuHCl-modified ELISA to measure the avidity of anti-HPV L1 VLP antibodies in vaccinated individuals

Cited by 39 publications

References 39 publications

Silk-based blood stabilization for diagnostics

Silk-based blood stabilization for diagnostics

Kinetic and HPV infection effects on cross-type neutralizing antibody and avidity responses induced by Cervarix®

Cross-protective vaccine efficacy of the bivalent HPV vaccine against HPV31 is associated with humoral immune responses

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