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Development of Synthetic Polymeric Peptides for the Detection of Hepatitis B Surface Antigen-Specific Antibodies in Human Blood Products

PHRR211202-004117

Development of Synthetic Polymeric Peptides for the Detection of Hepatitis B Surface Antigen-Specific Antibodies in Human Blood Products

Background: Globally, hepatitis B virus (HBV) causes the most common and severe hepatitis infection which may lead to a wide spectrum of liver diseases. To prevent consequent HBV complications, vaccines were developed and were proven effective in minimizing viral hepatitis for the last two decades. Peptide-based serological assays using hepatitis B surface antigen (HBsAg) are used to diagnose infection and to detect vaccine coverage. However, despite the availability of effective vaccines, the Philippines remains hyperendemic for hepatitis B infections, especially for chronic types. To determine vaccine scope among Filipino human blood products, designed HBsAg epitopes specifically binding with hepatitis B antibodies will be explored.

Objectives: This study aims to develop polymeric synthetic peptides for the detection of antibodies against HBV in human blood products. Specifically, this study aims: (1) to design polymerizable peptides containing HBsAg B-cell epitopes; (2) to produce HBsAg polymeric peptide-based antigen; and (3) to demonstrate specific binding of designed polymeric peptides to hepatitis B antibodies in human blood products.

Methods: In this study, HBsAg candidate epitopes identified in the Immune Epitope Database and Analysis Resource database search were aligned, truncated and modified (addition of lysine and cysteine as N- and/or C-terminal residues). Shortlisted HBsAg epitopes were outsourced and received as lyophilized peptides. These outsourced peptides will be polymerized using dimethylsulfoxide or glutaraldehyde. The resulting polymerized peptide will be characterized using SDS-PAGE. Lastly, to demonstrate specific binding of monomeric and polymerized peptides with hepatitis B antibodies present in human blood products, enzyme-linked immunosorbent assay will be used, with HBsAg vaccine and commercially available anti-HBsAg as controls. Standard curves at 450 nm absorbance will be generated and ANOVA will be used for statistical analysis.

Keywords: hepatitis B virus (HBV), hepatitis B surface antigen (HBsAg), polymerized peptides, synthetic epitopes

Regime Classification Priority
2017 - 2022 Global competitiveness and innovation in health Biomedical products and engineering
Start Date Duration in Months Target Completion Date Actual Completion Date
2021-01-04 12 2022-01-04 0000-00-00

Ongoing

Institution Classification Region LTO #
University of the Philippines - Manila, College of Medicine Public Higher Education Institution - State Universities and Colleges NCR
Institution Region
DOST-PCHRD NCR
Name E-Mail Institution and Institution Address
Ara Karizza Buan agbuan@up.edu.ph UP College of Medicine Main Building, Pedro Gil Street, Taft Ave, Ermita, Manila, 1000 Metro Manila
Name E-Mail Institution and Institution Address
Ara Karizza Buan agbuan@up.edu.ph UP College of Medicine Main Building, Pedro Gil Street, Taft Ave, Ermita, Manila, 1000 Metro Manila
Name Expertise Affiliation
Fresthel Monica M. Climacosa, MD, PhD Microbiology, Chemically Programmable Immunity using Peptide-based constructs and cognate antibodies University of the Philippines - Manila, College of Public Health, Department of Microbiology
Salvador Eugenio C. Caoili, MD, PhD Synthetic peptides, Human blood products for research and development University of the Philippines - Manila, College of Medicine, Department of Biochemistry and Molecular Biology

Synthetic epitopes are designed and further mapped to illustrate multi-specific immune response against HBV infection. HBsAg has always been the focus of epitope prediction efforts for both acute and chronic HBV infection; and it contains the immunodominant “a” determinant region which is highly conserved in all HBV genotypes. Aligned with the studies exploring the combination of consensus genotype sequences and other specific peptide sequences, polymeric epitopes for immunoassay can be designed using in silico approaches. Ideally, longer epitopes have higher probability of containing the “true epitope” capable of binding to antibodies which is considered as a major contributor to the sensitivity of immunoassays; but for the purpose of creating cost-effective assays, the shortest linear epitopes demonstrating antibody binding may be targeted as capture antigens. Drawbacks from using short peptides such as inefficient coating in ELISA polystyrene plates, can be addressed through functional group modification, affinity tag concatenation or protein polymerization using mild oxidants such as glutaraldehyde. Hence, with the prevailing hyperendemicity of HBV infection in the Philippines, vaccine-titer surveillance through peptide-based immunoassays with synthetic vaccine-epitopes is deemed necessary. With these, synthetic polymeric peptides of hepatitis B surface antigen will be designed and polymerized to demonstrate specific binding with antibodies present in human blood products using enzyme-linked immunosorbent assay.

design polymerizable peptides containing HBsAg B-cell epitopes

N/A

Completed

  • Philippines

Non-clinical Studies

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