{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,16]],"date-time":"2026-06-16T18:53:19Z","timestamp":1781635999918,"version":"3.54.5"},"reference-count":35,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T00:00:00Z","timestamp":1770681600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T00:00:00Z","timestamp":1772668800000},"content-version":"vor","delay-in-days":23,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100004484","name":"Tehran University of Medical Sciences and Health Services","doi-asserted-by":"publisher","award":["99-1-228-47605"],"award-info":[{"award-number":["99-1-228-47605"]}],"id":[{"id":"10.13039\/501100004484","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    The ongoing antigenic evolution of SARS-CoV-2, particularly within the spike glycoprotein, threatens the long-term efficacy of spike-focused vaccines and serodiagnostics. While most authorized COVID-19 vaccines exclusively target the spike protein, growing evidence underscores multivalent strategies incorporating conserved viral antigens. Here, we employed a baculovirus expression vector system (BEVS) to co-express all four structural proteins, including spike, nucleocapsid, membrane, and envelope, in Sf9 insect cells. Surface-displayed antigens were used in a cell-based ELISA to profile IgG responses in convalescent sera. All antigens elicited detectable antibody binding, with nucleocapsid and membrane proteins provoking significantly stronger responses than spike (\n                    <jats:italic>p<\/jats:italic>\n                    \u2009&lt;\u20090.001), and envelope protein showing intermediate reactivity. Statistical analyses revealed distinct patterns of antigenic reactivity. These findings validate the utility of BEVS for multiplex antigen presentation and highlight the immunological and diagnostic value of conserved non-spike antigens. Combined, this study advocates multivalent vaccine strategies and refines serodiagnostics by leveraging broader antigenic targets to counter immune escape.\n                  <\/jats:p>","DOI":"10.1038\/s41598-026-38282-4","type":"journal-article","created":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T21:35:02Z","timestamp":1770759302000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Expanding SARS-CoV-2 antigen targets beyond spike using a baculovirus expression system"],"prefix":"10.1038","volume":"16","author":[{"given":"Adnan","family":"Asadbeigi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amirhossein","family":"Razavirad","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fatemeh","family":"Khajehahmadi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohsen","family":"Eghtedari","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Reza","family":"Shirkoohi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,2,10]]},"reference":[{"key":"38282_CR1","doi-asserted-by":"publisher","first-page":"711","DOI":"10.1007\/s13577-021-00512-4","volume":"34","author":"S Kashte","year":"2021","unstructured":"Kashte, S., Gulbake, A., El-Amin, I. I. I., Gupta, A. & S. F. & COVID-19 vaccines: rapid development, implications, challenges and future prospects. Hum. Cell. 34, 711\u2013733 (2021).","journal-title":"Hum. Cell"},{"key":"38282_CR2","doi-asserted-by":"publisher","first-page":"e122","DOI":"10.15190\/d.2021.1","volume":"9","author":"A Fortner","year":"2021","unstructured":"Fortner, A., Schumacher, D. & First COVID-19 vaccines receiving the US FDA and EMA emergency use authorization. Discoveries 9, e122 (2021).","journal-title":"Discoveries"},{"key":"38282_CR3","doi-asserted-by":"publisher","first-page":"e011879","DOI":"10.1136\/bmjgh-2023-011879","volume":"8","author":"JL Excler","year":"2023","unstructured":"Excler, J. L. et al. Factors, enablers and challenges for COVID-19 vaccine development. BMJ Glob Health. 8, e011879 (2023).","journal-title":"BMJ Glob Health"},{"key":"38282_CR4","doi-asserted-by":"publisher","first-page":"e1010870","DOI":"10.1371\/journal.ppat.1010870","volume":"19","author":"CY Wang","year":"2023","unstructured":"Wang, C. Y. et al. Toward a pan-SARS-CoV-2 vaccine targeting conserved epitopes on Spike and non-spike proteins for potent, broad and durable immune responses. PLoS Pathog. 19, e1010870 (2023).","journal-title":"PLoS Pathog"},{"key":"38282_CR5","doi-asserted-by":"publisher","first-page":"1318","DOI":"10.1001\/jama.2021.3199","volume":"325","author":"CB Creech","year":"2021","unstructured":"Creech, C. B., Walker, S. C. & Samuels, R. J. SARS-CoV-2 vaccines. JAMA 325, 1318 (2021).","journal-title":"JAMA"},{"key":"38282_CR6","doi-asserted-by":"publisher","first-page":"1263","DOI":"10.3390\/ijms26031263","volume":"26","author":"FS Alhamlan","year":"2025","unstructured":"Alhamlan, F. S. & Al-Qahtani, A. A. SARS-CoV-2 variants: genetic Insights, epidemiological Tracking, and implications for vaccine strategies. Int. J. Mol. Sci. 26, 1263 (2025).","journal-title":"Int. J. Mol. Sci."},{"key":"38282_CR7","doi-asserted-by":"publisher","first-page":"e82","DOI":"10.1016\/S1473-3099(23)00813-7","volume":"24","author":"Y Kaku","year":"2024","unstructured":"Kaku, Y. et al. Virological characteristics of the SARS-CoV-2 JN.1 variant. Lancet Infect. Dis. 24, e82 (2024).","journal-title":"Lancet Infect. Dis."},{"key":"38282_CR8","doi-asserted-by":"publisher","first-page":"152","DOI":"10.1186\/s12967-023-03996-w","volume":"21","author":"MH Abbasian","year":"2023","unstructured":"Abbasian, M. H. et al. Global landscape of SARS-CoV-2 mutations and conserved regions. J. Transl Med. 21, 152 (2023).","journal-title":"J. Transl Med."},{"key":"38282_CR9","doi-asserted-by":"publisher","first-page":"3822","DOI":"10.1021\/acsnano.0c02624","volume":"14","author":"B Udugama","year":"2020","unstructured":"Udugama, B. et al. Diagnosing COVID-19: the disease and tools for detection. ACS Nano. 14, 3822\u20133835 (2020).","journal-title":"ACS Nano"},{"key":"38282_CR10","doi-asserted-by":"crossref","unstructured":"Deng, Q. et al. High Performance of SARS-Cov-2\u00a0N Protein Antigen Chemiluminescence Immunoassay as Frontline Testing for Acute Phase COVID-19 Diagnosis: A Retrospective Cohort Study. Front Med. (Lausanne) 8, (2021).","DOI":"10.3389\/fmed.2021.676560"},{"key":"38282_CR11","doi-asserted-by":"crossref","unstructured":"Zhang, B. et al. Comparing the nucleocapsid proteins of human coronaviruses: Structure, Immunoregulation, Vaccine, and targeted drug. Front Mol. Biosci 9, (2022).","DOI":"10.3389\/fmolb.2022.761173"},{"key":"38282_CR12","doi-asserted-by":"crossref","unstructured":"Kim, D. K. et al. A Comprehensive, Flexible Collection of SARS-CoV-2 Coding Regions. G3 Genes|Genomes|Genetics 10, 3399\u20133402 (2020).","DOI":"10.1534\/g3.120.401554"},{"key":"38282_CR13","doi-asserted-by":"publisher","unstructured":"Birnboim, H. C. & [17] A rapid alkaline extraction method for the isolation of plasmid DNA. in 243\u2013255 (1983). https:\/\/doi.org\/10.1016\/0076-6879(83)00059-2","DOI":"10.1016\/0076-6879(83)00059-2"},{"key":"38282_CR14","doi-asserted-by":"publisher","first-page":"567","DOI":"10.1038\/nbt1095","volume":"23","author":"TA Kost","year":"2005","unstructured":"Kost, T. A., Condreay, J. P. & Jarvis, D. L. Baculovirus as versatile vectors for protein expression in insect and mammalian cells. Nat. Biotechnol. 23, 567\u2013575 (2005).","journal-title":"Nat. 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BMC Immunol. https:\/\/doi.org\/10.1186\/s12865-023-00583-y (2023).","journal-title":"BMC Immunol."},{"key":"38282_CR33","doi-asserted-by":"publisher","unstructured":"Hong, M. et al. Genetic engineering of baculovirus-insect cell system to improve protein production. Frontiers in Bioengineering and Biotechnology Preprint at (2022). https:\/\/doi.org\/10.3389\/fbioe.2022.994743","DOI":"10.3389\/fbioe.2022.994743"},{"key":"38282_CR34","doi-asserted-by":"publisher","DOI":"10.2174\/187220809787172669","author":"R Hitchman","year":"2009","unstructured":"Hitchman, R., Possee, R. & King, L. Baculovirus expression systems for Recombinant protein production in insect cells. Recent. Pat. Biotechnol. https:\/\/doi.org\/10.2174\/187220809787172669 (2009).","journal-title":"Recent. Pat. Biotechnol."},{"key":"38282_CR35","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-020-78425-9","author":"J Korn","year":"2020","unstructured":"Korn, J. et al. Baculovirus-free insect cell expression system for high yield antibody and antigen production. Sci. Rep. https:\/\/doi.org\/10.1038\/s41598-020-78425-9 (2020).","journal-title":"Sci. Rep."}],"container-title":["Scientific Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41598-026-38282-4","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-026-38282-4.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-026-38282-4.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,16]],"date-time":"2026-06-16T18:03:00Z","timestamp":1781632980000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41598-026-38282-4"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,10]]},"references-count":35,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,12]]}},"alternative-id":["38282"],"URL":"https:\/\/doi.org\/10.1038\/s41598-026-38282-4","relation":{},"ISSN":["2045-2322"],"issn-type":[{"value":"2045-2322","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,10]]},"assertion":[{"value":"2 October 2025","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"29 January 2026","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"10 February 2026","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors declare no competing interests.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}},{"value":"Sampling procedures were carried out in accordance with the principles of the Declaration of Helsinki. The study protocol was reviewed and approved by the Ethics Committee of Tehran University of Medical Sciences (Approval ID: IR.TUMS.VCR.REC.1399.315). Written informed consent was obtained from all participants prior to sample collection.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethical approval"}}],"article-number":"8174"}}