Background A novel coronavirus, SARS-CoV-2, which emerged at the end of 2019 and causes COVID-19, has resulted in worldwide human infections. While genetically distinct, SARS-CoV-1, the aetiological agent responsible for an outbreak of severe acute respiratory syndrome (SARS) in 2002–2003, utilises the same host cell receptor as SARS-CoV-2 for entry: angiotensin-converting enzyme 2 (ACE2). Parts of the SARS-CoV-1 spike glycoprotein (S protein), which interacts with ACE2, appear conserved in SARS-CoV-2. Aim The cross-reactivity with SARS-CoV-2 of monoclonal antibodies (mAbs) previously generated against the S protein of SARS-CoV-1 was assessed. Methods The SARS-CoV-2 S protein sequence was aligned to those of SARS-CoV-1, Middle East respiratory syndrome (MERS) and common-cold coronaviruses. Abilities of mAbs generated against SARS-CoV-1 S protein to bind SARS-CoV-2 or its S protein were tested with SARS-CoV-2 infected cells as well as cells expressing either the full length protein or a fragment of its S2 subunit. Quantitative ELISA was also performed to compare binding of mAbs to recombinant S protein. Results An immunogenic domain in the S2 subunit of SARS-CoV-1 S protein is highly conserved in SARS-CoV-2 but not in MERS and human common-cold coronaviruses. Four murine mAbs raised against this immunogenic fragment could recognise SARS-CoV-2 S protein expressed in mammalian cell lines. In particular, mAb 1A9 was demonstrated to detect S protein in SARS-CoV-2-infected cells and is suitable for use in a sandwich ELISA format. Conclusion The cross-reactive mAbs may serve as useful tools for SARS-CoV-2 research and for the development of diagnostic assays for COVID-19.
【저자키워드】 COVID-19, SARS-CoV-2, Coronavirus disease 2019, Spike protein, cross-reactive antibodies, 【초록키워드】 ACE2, Coronaviruses, S protein, monoclonal antibody, spike glycoprotein, diagnostic, MERS, SARS-CoV-1, angiotensin-converting enzyme 2, ELISA, Novel coronavirus, cross-reactivity, Protein, outbreak, S2 subunit, sandwich ELISA, mAbs, binding, mAb, SARS-CoV-2 S protein, Middle East, cross-reactive, acute respiratory syndrome, domain, sequence, syndrome, SARS-CoV-2 research, host cell receptor, immunogenic, human infections, full length, while, mammalian cell, murine, Cell, common-cold, Result, responsible, tested, performed, detect, conserved, raised, expressed, demonstrated, interact, cause, the S protein, expressing, recombinant S protein, Ability, aligned, Part, SARS-CoV-2 infected cell, SARS-CoV-2-infected cell, 【제목키워드】 antibody, SARS-CoV-1, S2 subunit, cross-react,