{"id":4974,"date":"2021-07-21T09:48:21","date_gmt":"2021-07-21T00:48:21","guid":{"rendered":"https:\/\/www.emukk.com\/WP\/?p=4963"},"modified":"2021-07-21T09:56:36","modified_gmt":"2021-07-21T00:56:36","slug":"the-most-potent-neutralizing-antibody-developed-with-antibody-phage-display-from-covid-19-convalescent-patients","status":"publish","type":"post","link":"https:\/\/www.emukk.com\/WP\/en\/the-most-potent-neutralizing-antibody-developed-with-antibody-phage-display-from-covid-19-convalescent-patients\/","title":{"rendered":"The most potent neutralizing antibody developed with antibody phage display from COVID-19 convalescent patients\u00a0"},"content":{"rendered":"<p>A group from Technische Universit\u00e4t Braunschweig, Institut f\u00fcr Biochemie, Biotechnologie und Bioinformatik, Abteilung Biotechnologie, Germany, etc. has reported on the most potent neutralizing antibody developed with antibody phage display from COVID-19 convalescent patients.<br \/>\n<a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC8260561\/\">https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC8260561\/<\/a><\/p>\n<p>Antibody phage display is now widely used as in vitro technology to select human antibody fragments for the development of therapeutic antibodies against target disease.<br \/>\nIn this author&#8217;s work, immune phage display libraries from six COVID-19 convalescent patients were constructed and RBD-binding antibodies have been selected, to develop SARS-CoV-2-inhibiting and -neutralizing antibodies. <\/p>\n<p>30 antibodies were screened in a cytopathic effect (CPE)-based neutralization screening assay to select antibodies for further characterization as IgG. This assay was performed with 250 plaque-forming units (pfu)\/well SARS-CoV-2 and 1 \u03bcg\/mL (\u223c10 nM) scFv-Fc. CPE is characterized by rounding and detachment clearly visible in phase contrast microscopy upon SARS-CoV-2 infection within 4 days, while uninfected cells maintained an undisturbed confluent monolayer. The best neutralizing 19 scFv-Fc were re-cloned and produced as human IgG in 50-mL culture scales. Half-maximal effective concentration (EC50) values of binding to RBD, S1, or S1-S2 were determined. Antibodies named STE90-C11, STE90-B2-D12, STE94-F6, and STE94-H2 showed EC50 values ranging between 0.2 and 0.5 nM on all of the antigens tested. As a result, STE90-C11 antibody was selected as the most potent one.<\/p>\n<p>Excitingly, STE90-C11 was tolerant to most known RBD mutants as shown below, especially those of the mutants B.1.429\/B.1.427, B.1.526, B1.258\u0394, B.1.535, B.1.617, and B.1.1.33, which are currently emerging.<\/p>\n<p><a href=\"https:\/\/www.emukk.com\/WP\/wp-content\/uploads\/2021\/07\/STE90-C11_mAb_SARS-CoV-2.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.emukk.com\/WP\/wp-content\/uploads\/2021\/07\/STE90-C11_mAb_SARS-CoV-2-300x202.png\" alt=\"\" width=\"300\" height=\"202\" class=\"alignleft size-medium wp-image-4965\" srcset=\"https:\/\/www.emukk.com\/WP\/wp-content\/uploads\/2021\/07\/STE90-C11_mAb_SARS-CoV-2-300x202.png 300w, https:\/\/www.emukk.com\/WP\/wp-content\/uploads\/2021\/07\/STE90-C11_mAb_SARS-CoV-2-600x403.png 600w, https:\/\/www.emukk.com\/WP\/wp-content\/uploads\/2021\/07\/STE90-C11_mAb_SARS-CoV-2-768x516.png 768w, https:\/\/www.emukk.com\/WP\/wp-content\/uploads\/2021\/07\/STE90-C11_mAb_SARS-CoV-2-272x182.png 272w, https:\/\/www.emukk.com\/WP\/wp-content\/uploads\/2021\/07\/STE90-C11_mAb_SARS-CoV-2.png 824w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>To get further insight into the neutralizing mechanism of STE90-C11, a complex of STE90-C11 Fab and SARS-CoV-2 RBD was prepared and subjected to crystallization screening. X-ray diffraction images collected from the resulting crystals yielded a dataset to an overall resolution limit of 2.0 \u00c5. After solving the structure by molecular replacement, a model was built into the electron density. Roughly 60% of this binding area can be contributed to the VH segment, forming up to 10 hydrogen bonds at the same time. The remaining 40% are provided by the VL segment contributing 8 additional hydrogen bonds to stabilize the interaction. The superposition of the RBDs of the STE90-C11:SARS-CoV-2 RBD complex with a ACE2:SARS-CoV-2 RBD complex revealed that the neutralization mechanism of STE90-C11 is based on directly competing for the ACE2 binding side, as the interaction interfaces on the RBD of both molecules almost completely overlap.\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A group from Technische Universit\u00e4t Braunschweig, Institut f\u00fcr Biochemie, Biotechnologie und Bioinformatik, Ab<\/p><\/div>\n<div class=\"blog-btn\"><a href=\"https:\/\/www.emukk.com\/WP\/en\/the-most-potent-neutralizing-antibody-developed-with-antibody-phage-display-from-covid-19-convalescent-patients\/\" class=\"home-blog-btn\">\u7d9a\u304d\u3092\u8aad\u3080<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[70,7],"tags":[],"class_list":["post-4974","post","type-post","status-publish","format-standard","hentry","category-nature-en","category-technology-en"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.emukk.com\/WP\/wp-json\/wp\/v2\/posts\/4974","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.emukk.com\/WP\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.emukk.com\/WP\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.emukk.com\/WP\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.emukk.com\/WP\/wp-json\/wp\/v2\/comments?post=4974"}],"version-history":[{"count":2,"href":"https:\/\/www.emukk.com\/WP\/wp-json\/wp\/v2\/posts\/4974\/revisions"}],"predecessor-version":[{"id":4976,"href":"https:\/\/www.emukk.com\/WP\/wp-json\/wp\/v2\/posts\/4974\/revisions\/4976"}],"wp:attachment":[{"href":"https:\/\/www.emukk.com\/WP\/wp-json\/wp\/v2\/media?parent=4974"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.emukk.com\/WP\/wp-json\/wp\/v2\/categories?post=4974"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.emukk.com\/WP\/wp-json\/wp\/v2\/tags?post=4974"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}