Ultrasensitive Peptide-Based Electrochemical Biosensor for Universal Diagnostic of Dengue

Biosensors, Journal Year: 2025, Volume and Issue: 15(4), P. 236 - 236

Published: April 8, 2025

Dengue is a neglected disease mainly affecting tropical and subtropical countries. The diagnosis of dengue fever still problem since most it made from whole or recombinant DENV proteins, which present cross-reactions with other members the Flavivirus family. Therefore, there huge demand for new diagnostic methods that provide rapid, low-cost, easy-to-use confirmation. Thus, in this study, we developed an affordable electrochemical biosensor rapidly detecting immunoglobulin G (IgG) serological antibodies sera DENV-infected patients. An identified linear B-cell epitope (DENV/18) specific 1–4 serotypes recognized by IgG patient was selected as target molecule after microarray peptides using SPOT-synthesis methodology. After chemical synthesis, DENV/18-peptide immobilized on surface working electrode commercially available screen-printed gold (SPGE). capture DENV-specific allowed formation immunocomplex measured cyclic voltammetry (CV) differential pulse (DPV) potassium ferrocyanide/ferricyanide ([Fe(CN)6]3−/4−) probe. evaluation biosensor’s performance showed detection limit 100 µg mL−1 synthetic 1.21 ng CV 0.43 DPV human serum, sensitivity 7.21 µA 8.79 DPV. differentiation infected uninfected individuals possible even at high dilution factor reduced required sample volumes to few microliters. final device proved suitable diagnosing analyzing real serum samples, results good agreement molecular biology diagnostics. flexibility conjugate antigenic SPEs suggests technology could be adapted diagnose pathogens.

Language: Английский

Humoral Immune Response to the SARS-CoV-2 Spike Protein Receptor Binding Motif Linear Epitopes

Published: Feb. 2, 2024

Abstract: The worldwide spread of SARS-CoV-2 has led to a significant economic and social burden on global scale. Even though the pandemic concluded, there remains apprehension regarding emergence highly transmissible variants capable evading immunity induced by either vaccination or prior infection. success viral penetration is specific amino acid residues Receptor Binding Motif (RBM) involved in attachment. This region interacts with cellular receptor ACE2, triggering neutralizing antibody (nAb) response. In this study, we have evaluated immunogenicity serum from individuals who received single dose combination different vaccines against original strain mutated linear RBM. Despite modest response wild-type RBM, Omicron exhibit four mutations RBM (S477N, T478K, E484A, F486V) that result even lower titers. primary immune responses observed were directed towards IgA IgG. While nAbs typically target RBD, our investigation unveiled reduced seroreactivity within RBD's crucial subregion, deficiency may implications for generation protective nAbs. Evaluation S1WT S2WT peptides binding using microscale thermophoresis revealed higher affinity (35 nM) sequence (GSTPCNGVEGFNCYF), which includes FNCY patch. Our findings suggest not an immunodominant vaccinated individuals. Comprehending intricate dynamics humoral response, its interplay evolution, host genetics formulating effective strategies, only targeting but also anticipating potential future coronaviruses.

Language: Английский

Enhanced Assessment of Cross-Reactive Antigenic Determinants within the Spike Protein

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(15), P. 8180 - 8180

Published: July 26, 2024

Despite successful vaccination efforts, the emergence of new SARS-CoV-2 variants poses ongoing challenges to control COVID-19. Understanding humoral responses regarding infections and their impact is crucial for developing future vaccines that are effective worldwide. Here, we identified 41 immunodominant linear B-cell epitopes in its spike glycoprotein with an SPOT synthesis peptide array probed a pool serum from hospitalized COVID-19 patients. The bioinformatics showed restricted set unique compared other coronavirus family members. Potential crosstalk was also detected Dengue virus (DENV), which confirmed by screening individuals infected DENV before pandemic commercial ELISA anti-SARS-CoV-2 antibodies. A high-resolution evaluation antibody reactivity against peptides representing protein ten sequences NTD, RBD, S2 domains. Functionally, antibody-dependent enhancement (ADE) monocytes observed vitro pre-pandemic Dengue-positive sera. significant increase viral load measured controls, no detectable neutralization or considerable cell death, suggesting role entry. Cross-reactivity proteins This study highlights importance identifying specific generated during response pathogenic infection understand potential interplay previous on diseases vaccinations immunodiagnostics.

Language: Английский