Production of SARS-CoV-2 N Protein-Specific Monoclonal Antibody and Its Application in an ELISA-Based Detection System and Targeting the Interaction Between the Spike C-Terminal Domain and N Protein

• Published in: Frontiers in microbiology Vol. 12; p. 726231
• Main Authors: Kim, Dongbum, Kim, Jinsoo, Park, Sangkyu, Kim, Minyoung, Baek, Kyeongbin, Kang, Mijeong, Choi, Jun-Kyu, Maharjan, Sony, Akauliya, Madhav, Lee, Younghee, Kwon, Hyung-Joo
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 07.12.2021
• Subjects: anti-SARS-CoV-2 N antibody; bait and prey; Microbiology; N protein; SARS-CoV-2; spike protein; virus detection; anti-SARS-CoV-2 N antibody; SARS-CoV-2; bait and prey; virus detection; N protein; spike protein; ELISA
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2021.726231

SARS-CoV-2 infections continue to spread quickly by human-to-human transmission around the world. Therefore, developing methods to rapidly detect SARS-CoV-2 with high sensitivity are still urgently needed. We produced a monoclonal antibody that specifically detects the N protein of SARS-CoV-2 and recognizes N protein in cell lysates of SARS-CoV-2-infected Vero cells but not in cell lysates of MERS-CoV- or HCoV-OC43-infected Vero cells. This antibody recognized N protein in SARS-CoV-2 clades S, GR, and GH and recognized N protein in all the SARS-CoV-2 clades to ∼300 pfu. Previously, we reported that the coronavirus N protein interacts with the C-terminal domain of the spike protein (Spike CD). In this study, we developed an ELISA-based "bait and prey" system to confirm the interaction between SARS-CoV-2 Spike CD and N protein using recombinant fusion proteins. Furthermore, this system can be modified to quantitatively detect SARS-CoV-2 in culture media of infected cells by monitoring the interaction between the recombinant Spike CD fusion protein and the viral N protein, which is captured by the N protein-specific antibody. Therefore, we conclude that our N protein-specific monoclonal antibody and our ELISA-based bait and prey system could be used to diagnose SARS-CoV-2 infections.