ABSTRACT
The ongoing COVID-19 pandemic is a major global public health concern. Although rapid point of care testing for detecting viral antigen is important for management the outbreak, none of current antigen detection kits provide a reliable diagnosis due to the lack of a specific monoclonal antibody (mAb) against SARS-CoV-2. In our current study, we produced mAbs exclusively react with SARS-CoV-2 and exhibited no cross-reactivity with other human coronaviruses including SARS-CoV. Molecular modeling revealed that the mAbs bound to epitopes present on the exterior surface of the nucleocapsid, encompassing their scope for detecting SARS-CoV-2 in clinical samples. We further selected the optimal pair of anti-SARS-CoV-2 NP mAbs for designing ELISA and immunochromatographic assay. An integrated bioinformatics analysis revealed that our mAbs could comprehensively detect divergent strains of SARS-CoV-2. Due to the high redundancy and absence of cross-reactivity, our newly developed mAbs would be instrumental for developing reliable diagnosis kits for COVID-19.Funding: This work was supported in part by Japan Agency for Medical Research and Development (AMED, Grant number: JP19fk0108110 and JP20he0522001), and by Health Labour Sciences research grant from The Ministry of Health Labour and Welfare.Conflict of Interest: The authors have no conflicts of interest directly relevant to the content of this article. YY, SK, KS and DA is a current employee of Kanto Chemical Co., Inc.Ethical Approval: This study was approved by the Institutional Review Board of Yokohama City University (IRB No. B200800106), and the protocols used in the study were approved by the ethicscommittee.
Subject(s)
COVID-19 , Dyskinesia, Drug-InducedABSTRACT
SARS-CoV-2 neutralizing antibodies confer protective immunity against reinfection. We have developed a rapid test for screening SARS-CoV-2 neutralization antibodies using genome-free virus-like particles incorporated with a small luciferase peptide, HiBiT. Their entry into LgBiT-expressing target cells reconstitutes NanoLuc luciferase readily detected by a luminometer. This newly developed HiBiT-tagged Virus-like particle-based Neutralization Test (hiVNT) can readily quantify SARS-CoV-2 neutralizing antibodies within three hours with a high-throughput in a low biosafety setting. Moreover, the neutralizing activity obtained from hiVNT was highly consistent with that measured by the conventional neutralization test using authentic SARS-CoV-2. Furthermore, antibody responses to both viral spike and nucleocapsid proteins correlated with the neutralization activity assessed by hiVNT. Our newly-developed hiVNT could be instrumental to survey individuals for the presence of functional neutralizing antibody against SARS-CoV-2.