Anne Rackow1, Christa Ehmen1, Ronald von Possel2, Raquel Medialdea-Carrera3, David Brown4, Ana Maria Bispo de Filippis4, Patrícia Carvalho de Sequeira4, Rita Maria Ribeiro Nogueira4, Barie Halili5, Xhevat Jakupi6, Lindita Berisha5, Salih Ahmeti7, Kurtesh Sherifi8, Jonas Schmidt-Chanasit2, Herbert Schmitz2, Angela Mika1, Petra Emmerich2,9, Christina Deschermeier10. 1. Diagnostics Development Laboratory, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany. 2. Department for Virology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany. 3. National Institute for Health Research/Institute of Infections and Global Health, University of Liverpool, Health Protection Research Unit in Emerging and Zoonotic Infections, Liverpool, UK. 4. Instituto Oswaldo Cruz/Fiocruz, Laboratório de Flavivirus, Rio de Janeiro, Brazil. 5. University Clinical Center of Kosovo, Infectious Diseases Clinic, Pristhina, Kosovo. 6. Department of Microbiology, National Institute for Public Health of Kosova, Prishtina, Kosovo. 7. University of Prishtina "Hasan Prishtina," Medical Faculty and University Clinical Center of Kosovo, Infectious Diseases Clinic, Prishtina, Kosovo. 8. Faculty of Agricultural and Veterinary Medicine, University of Pristhina "Hasan Prishtina," Pristhina, Kosovo. 9. Department of Tropical Medicine and Infectious Diseases, Center of Internal Medicine II, University of Rostock, Rostock, Germany. 10. Diagnostics Development Laboratory, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; descherm@bnitm.de.
Abstract
BACKGROUND: The cellular surface molecule HsTOSO/FAIM3/HsFcμR has been identified as an IgM-specific Fc receptor expressed on lymphocytes. Here, we show that its extracellular immunoglobulin-like domain (HsFcμR-Igl) specifically binds to IgM/antigen immune complexes (ICs) and exploit this property for the development of novel detection systems for IgM antibodies directed against Crimean-Congo hemorrhagic fever virus (CCHFV) and Zika virus (ZIKV). METHODS: His-tagged HsFcμR-Igl was expressed in Escherichia coli and purified by affinity chromatography, oxidative refolding, and size-exclusion chromatography. Specific binding of HsFcμR-Igl to IgM/antigen ICs was confirmed, and 2 prototypic ELISAs for the detection of anti-CCHFV and anti-ZIKV IgM antibodies were developed. Thereby, patient sera and virus-specific recombinant antigens directly labeled with horseradish peroxidase (HRP) were coincubated on HsFcμR-Igl-coated ELISA plates. Bound ICs were quantified by measuring turnover of a chromogenic HRP substrate. RESULTS: Assay validation was performed using paired serum samples from 15 Kosovar patients with a PCR-confirmed CCHFV infection and 28 Brazilian patients with a PCR-confirmed ZIKV infection, along with a panel of a priori CCHFV/ZIKV-IgM-negative serum samples. Both ELISAs were highly reproducible. Sensitivity and specificity were comparable with or even exceeded in-house gold standard testing and commercial kits. Furthermore, latex beads coated with HsFcμR-Igl aggregated upon coincubation with an IgM-positive serum and HRP-labeled antigen but not with either component alone, revealing a potential for use of HsFcμR-Igl as a capture molecule in aggregation-based rapid tests. CONCLUSIONS: Recombinant HsFcμR-Igl is a versatile capture molecule for IgM/antigen ICs of human and animal origin and can be applied for the development of both plate- and bead-based serological tests.
BACKGROUND: The cellular surface molecule HsTOSO/FAIM3/HsFcμR has been identified as an IgM-specific Fc receptor expressed on lymphocytes. Here, we show that its extracellular immunoglobulin-like domain (HsFcμR-Igl) specifically binds to IgM/antigen immune complexes (ICs) and exploit this property for the development of novel detection systems for IgM antibodies directed against Crimean-Congo hemorrhagic fever virus (CCHFV) and Zika virus (ZIKV). METHODS: His-tagged HsFcμR-Igl was expressed in Escherichia coli and purified by affinity chromatography, oxidative refolding, and size-exclusion chromatography. Specific binding of HsFcμR-Igl to IgM/antigen ICs was confirmed, and 2 prototypic ELISAs for the detection of anti-CCHFV and anti-ZIKV IgM antibodies were developed. Thereby, patient sera and virus-specific recombinant antigens directly labeled with horseradish peroxidase (HRP) were coincubated on HsFcμR-Igl-coated ELISA plates. Bound ICs were quantified by measuring turnover of a chromogenic HRP substrate. RESULTS: Assay validation was performed using paired serum samples from 15 Kosovar patients with a PCR-confirmed CCHFV infection and 28 Brazilian patients with a PCR-confirmed ZIKVinfection, along with a panel of a priori CCHFV/ZIKV-IgM-negative serum samples. Both ELISAs were highly reproducible. Sensitivity and specificity were comparable with or even exceeded in-house gold standard testing and commercial kits. Furthermore, latex beads coated with HsFcμR-Igl aggregated upon coincubation with an IgM-positive serum and HRP-labeled antigen but not with either component alone, revealing a potential for use of HsFcμR-Igl as a capture molecule in aggregation-based rapid tests. CONCLUSIONS: Recombinant HsFcμR-Igl is a versatile capture molecule for IgM/antigen ICs of human and animal origin and can be applied for the development of both plate- and bead-based serological tests.
Authors: Christina Deschermeier; Christa Ehmen; Ronald von Possel; Carolin Murawski; Ben Rushton; John Amuasi; Nimako Sarpong; Oumou Maiga-Ascofaré; Raphael Rakotozandrindrainy; Danny Asogun; Yemisi Ighodalo; Lisa Oestereich; Sophie Duraffour; Meike Pahlmann; Petra Emmerich Journal: J Clin Microbiol Date: 2022-05-16 Impact factor: 11.677