{"doi":"10.1074/jbc.ac120.014918","title":"Identification of an anti–SARS–CoV-2 receptor-binding domain–directed human monoclonal antibody from a naïve semisynthetic library","abstract":"There is a desperate need for safe and effective vaccines, therapies, and diagnostics for SARS– coronavirus 2 (CoV-2), the development of which will be aided by the discovery of potent and selective antibodies against relevant viral epitopes. Human phage display technology has revolutionized the process of identifying and optimizing antibodies, providing facile entry points for further applications. Herein, we use this technology to search for antibodies targeting the receptor-binding domain (RBD) of CoV-2. Specifically, we screened a naïve human semisynthetic phage library against RBD, leading to the identification of a high-affinity single-chain fragment variable region (scFv). The scFv was further engineered into two other antibody formats (scFv-Fc and IgG1). All three antibody formats showed high binding specificity to CoV-2 RBD and the spike antigens in different assay systems. Flow cytometry analysis demonstrated specific binding of the IgG1 format to cells expressing membrane-bound CoV-2 spike protein. Docking studies revealed that the scFv recognizes an epitope that partially overlaps with angiotensin-converting enzyme 2 (ACE2)–interacting sites on the CoV-2 RBD. Given its high specificity and affinity, we anticipate that these anti-CoV-2 antibodies will be useful as valuable reagents for accessing the antigenicity of vaccine candidates, as well as developing antibody-based therapeutics and diagnostics for CoV-2. There is a desperate need for safe and effective vaccines, therapies, and diagnostics for SARS– coronavirus 2 (CoV-2), the development of which will be aided by the discovery of potent and selective antibodies against relevant viral epitopes. Human phage display technology has revolutionized the process of identifying and optimizing antibodies, providing facile entry points for further applications. Herein, we use this technology to search for antibodies targeting the receptor-binding domain (RBD) of CoV-2. Specifically, we screened a naïve human semisynthetic phage library against RBD, leading to the identification of a high-affinity single-chain fragment variable region (scFv). The scFv was further engineered into two other antibody formats (scFv-Fc and IgG1). All three antibody formats showed high binding specificity to CoV-2 RBD and the spike antigens in different assay systems. Flow cytometry analysis demonstrated specific binding of the IgG1 format to cells expressing membrane-bound CoV-2 spike protein. Docking studies revealed that the scFv recognizes an epitope that partially overlaps with angiotensin-converting enzyme 2 (ACE2)–interacting sites on the CoV-2 RBD. Given its high specificity and affinity, we anticipate that these anti-CoV-2 antibodies will be useful as valuable reagents for accessing the antigenicity of vaccine candidates, as well as developing antibody-based therapeutics and diagnostics for CoV-2. The recently identified novel human coronavirus, referred to as severe acute respiratory syndrome (SARS)–coronavirus 2 (CoV-2), is the causative agent of the ongoing pandemic of COVID-19. After the report of first case of the CoV-2 infection in December 2019, it has spread all over the globe. To slow down the spread of COVID-19, many countries have introduced lockdown measures. However, these measures will not be enough to eradicate the coronavirus pandemic from the world, and there is an urgent requirement for some medical intervention to control the spread of infection either in the form of a vaccine or other therapeutic options such as small molecule or therapeutic antibodies. So far, no clinically approved therapeutics are available for CoV-2, and only symptomatic treatment is offered (1Felsenstein S. Herbert J.A. McNamara P.S. Hedrich C.M. COVID-19: immunology and treatment options.Clin. Immunol. 2020; 215 (32353634): 10844810.1016/j.clim.2020.108448Crossref PubMed Scopus (407) Google Scholar). One of the approaches is to look for neutralizing antibodies (NAbs) for CoV-2 either from conva","journal":"Journal of Biological Chemistry","year":2020,"id":61193,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":58,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9519,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":323256,"name":"Adarsh Kumar Chiranjivi","orcid":"0000-0003-0687-5900","position":1,"is_corresponding":false},{"id":323257,"name":"Shailendra Asthana","orcid":"0000-0002-6143-7500","position":2,"is_corresponding":false},{"id":323258,"name":"Naveen Yadav","orcid":"0000-0002-6931-6762","position":3,"is_corresponding":false},{"id":323259,"name":"Tripti Shrivastava","orcid":"0000-0001-6942-1274","position":4,"is_corresponding":false},{"id":323260,"name":"Shailendra Mani","orcid":"0000-0001-8541-8315","position":5,"is_corresponding":false},{"id":323261,"name":"Chandresh Sharma","orcid":"0000-0002-2813-302X","position":6,"is_corresponding":false},{"id":323262,"name":"Preeti Vishwakarma","orcid":"0000-0001-8530-4860","position":7,"is_corresponding":false},{"id":323263,"name":"Supratik Das","orcid":"0000-0002-7279-938X","position":8,"is_corresponding":false},{"id":324705,"name":"Kamal S. Pindari","orcid":null,"position":9,"is_corresponding":false},{"id":323264,"name":"Subrata Sinha","orcid":"0000-0002-2461-0415","position":10,"is_corresponding":false},{"id":323265,"name":"Sweety Samal","orcid":"0000-0001-7894-8756","position":11,"is_corresponding":false},{"id":323266,"name":"Shubbir Ahmed","orcid":"0000-0003-1655-6735","position":12,"is_corresponding":false},{"id":323267,"name":"Rajesh Kumar","orcid":"0000-0002-6744-0241","position":13,"is_corresponding":false},{"id":324704,"name":"Hilal Ahmad Parray","orcid":null,"position":0,"is_corresponding":true}],"reference_count":33,"raw_metadata":null,"created_at":"2026-07-18T21:09:27.985420Z","pmid":"32727845","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}