Investigation of the “Antigen Hook Effect” in Lateral Flow Sandwich Immunoassay: The Case of Lumpy Skin Disease Virus Detection
Simone Cavalera,
Giulia Pezzoni,
Santina Grazioli,
Emiliana Brocchi,
Stefano Baselli,
Davide Lelli,
Barbara Colitti,
Thea Serra,
Fabio Di Nardo,
Matteo Chiarello,
Valentina Testa,
Sergio Rosati,
Claudio Baggiani,
Laura Anfossi
Affiliations
Simone Cavalera
Department of Chemistry, University of Turin, Via Pietro Giuria 7, 10137 Turin, TO, Italy
Giulia Pezzoni
Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia-Romagna, National/OIE/FAO Reference Centre for FMD and SVD, Via Antonio Bianchi 7, 25124 Brescia, BS, Italy
Santina Grazioli
Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia-Romagna, National/OIE/FAO Reference Centre for FMD and SVD, Via Antonio Bianchi 7, 25124 Brescia, BS, Italy
Emiliana Brocchi
Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia-Romagna, National/OIE/FAO Reference Centre for FMD and SVD, Via Antonio Bianchi 7, 25124 Brescia, BS, Italy
Stefano Baselli
Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia-Romagna, National/OIE/FAO Reference Centre for FMD and SVD, Via Antonio Bianchi 7, 25124 Brescia, BS, Italy
Davide Lelli
Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia-Romagna, National/OIE/FAO Reference Centre for FMD and SVD, Via Antonio Bianchi 7, 25124 Brescia, BS, Italy
Barbara Colitti
Department of Veterinary Science, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco, TO, Italy
Thea Serra
Department of Chemistry, University of Turin, Via Pietro Giuria 7, 10137 Turin, TO, Italy
Fabio Di Nardo
Department of Chemistry, University of Turin, Via Pietro Giuria 7, 10137 Turin, TO, Italy
Matteo Chiarello
Department of Chemistry, University of Turin, Via Pietro Giuria 7, 10137 Turin, TO, Italy
Valentina Testa
Department of Chemistry, University of Turin, Via Pietro Giuria 7, 10137 Turin, TO, Italy
Sergio Rosati
Department of Veterinary Science, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco, TO, Italy
Claudio Baggiani
Department of Chemistry, University of Turin, Via Pietro Giuria 7, 10137 Turin, TO, Italy
Laura Anfossi
Department of Chemistry, University of Turin, Via Pietro Giuria 7, 10137 Turin, TO, Italy
Lumpy skin disease (LSD) is an infectious disease affecting bovine with severe symptomatology. The implementation of effective control strategies to prevent infection outbreak requires rapid diagnostic tools. Two monoclonal antibodies (mAbs), targeting different epitopes of the LSDV structural protein p32, and gold nanoparticles (AuNPs) were used to set up a colorimetric sandwich-type lateral flow immunoassay (LFIA). Combinations including one or two mAbs, used either as the capture or detection reagent, were explored to investigate the hook effect due to antigen saturation by the detector antibody. The mAb-AuNP preparations were optimized by a full-factorial design of experiment to achieve maximum sensitivity. Opposite optimal conditions were selected when one Mab was used for capture and detection instead of two mAbs; thus, two rational routes for developing a highly sensitive LFIA according to Mab availability were outlined. The optimal LFIA for LSDV showed a low limit of detection (103.4 TCID50/mL), high inter- and intra-assay repeatability (CV% < 5.3%), and specificity (no cross-reaction towards 12 other viruses was observed), thus proving to be a good candidate as a useful tool for the point-of-need diagnosis of LSD.
