{"id":9756,"date":"2022-01-07T10:20:00","date_gmt":"2022-01-07T15:20:00","guid":{"rendered":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/?p=9756"},"modified":"2022-12-07T10:25:06","modified_gmt":"2022-12-07T15:25:06","slug":"journalclub2","status":"publish","type":"post","link":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/company-news\/journalclub2\/","title":{"rendered":"Journal club: Affinity maturation of neutralizing antibodies improves in vivo protection against SARS-CoV-2."},"content":{"rendered":"\n\n\n\t<div class=\"dkpdf-button-container\" style=\" text-align:right \">\n\n\t\t<a class=\"dkpdf-button\" href=\"\/secondary-antibody-resource\/wp-json\/wp\/v2\/posts\/9756?pdf=9756\" target=\"_blank\"><span class=\"dkpdf-button-icon\"><i class=\"fa fa-file-pdf-o\"><\/i><\/span> Download PDF<\/a>\n\n\t<\/div>\n\n\n\n\n\n<style>.entry p, .entry ol{font-size: 1rem;}.entry h3{color:#009fe3;margin-top:0}.entry h4{color:#009453;margin-top:1.5rem}.entry h5{color: #003a5c; font-size: 1.05rem;margin-top:1.5rem;}.entry figure{margin:32px auto;border:1px solid #ccc}.entry figure img{width:100%;display:block;margin:0 auto}.entry figcaption{font-size:.875rem;line-height:1.35rem;padding:10px;color:#222}.entry .blog-tbl{margin:1rem auto;caption-side:bottom}.entry .blog-tbl td,.entry .blog-tbl th{padding:10px 9px;border:1px solid #00172b;text-align:left}.entry .blog-tbl td{border-color:#003a5c}.entry .blog-tbl th{background-color:#00172b;color:#fff;border-left-color:#fff;border-right-color:#fff}.entry .blog-tbl th p{color:#fff}.entry .blog-tbl th:first-of-type{border-left-color:#00172b}.entry .blog-tbl th:last-of-type{border-right-color:#00172b}.entry .blog-tbl p{text-align:left;margin:0}.entry .box-note{border:2px solid #009453;padding:12px;margin:1rem 0}.entry .box-note p{margin:0;padding:0}.entry .styled-list{list-style-type:none}.entry .styled-list li{margin-top:1rem;line-height:1.6rem;font-size:1rem;}.entry .styled-list li::before{font-family:\"Font Awesome 5 Pro\";display:inline-block;content:\"\\f3c5\";-webkit-transform:rotate(-90deg);transform:rotate(-90deg);margin-left:-20px;margin-right:11px;font-size:.75rem;color:#ed7004;font-weight:600}.entry .styled-list ol li::before{display:none}.entry .styled-list li>ul li::before{font-weight:200}.entry .overview{width:-webkit-fit-content;width:-moz-fit-content;width:fit-content;padding:16px;margin:1rem auto;border:1px solid #eee}.entry .overview hr{margin-top:14px}.entry .overview-text{text-align:center;font-size:1rem;margin:0}.entry .btn-sq{color:#fff;font-size:.9rem;font-weight:600;border:2px solid rgb(237, 112, 4);padding:7px 13px;background:rgb(237, 112, 4);cursor:pointer;text-align:center;line-height:1.5rem;margin:0 auto;}.entry .btn-sq:hover{text-decoration:none;color:rgb(237, 112, 4);background:#fff;}.entry .btn-container{display:flex;width:100%;margin:1.3rem 0;}.entry .btn-container .fa-regular, .entry .btn-container .fa-duotone{margin-right:10px;}@media(max-width: 768px){.entry .btn-sq{font-size:1.05rem;}}<\/style>\n<style>.entry .ip-tbl{margin-bottom:1rem;}.entry .ip-tbl th,.entry .ip-tbl td{border: 1px solid #00172b;padding:10px 9px;text-align:left;}.entry .ip-tbl th{color:#00172b;text-align:center;}<\/style>\n<p><script src=\"https:\/\/kit.fontawesome.com\/904923013f.js\" crossorigin=\"anonymous\"><\/script><\/p>\n<style>.entry figure img{margin-top:6px;width:98%;margin-left:auto;margin-right:auto;}<\/style>\n<h2>Since the start of the COVID-19 pandemic, multiple vaccines have been developed that protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The way in which these work is still being deduced, but several studies have shown that the elicitation of neutralizing antibodies (nAbs) has a central role in combating infection. Recombinantly produced nAbs promise to supplement protection in populations that respond poorly to vaccines, including immunocompromised individuals. However, a major challenge when developing recombinant nAbs lies in overcoming viral escape mutations. By using directed evolution to engineer three previously characterized nAbs isolated from convalescent COVID-19 patients, researchers at The Scripps Research Institute in La Jolla, CA, were able to improve protection in a Syrian hamster model compared to using the parental antibodies. Their data suggest that appropriate affinity maturation of nAbs is an effective strategy to resist viral variation.<\/h2>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter wp-image-9773 size-full\" src=\"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-content\/uploads\/sneeze-hero.jpg\" alt=\"Journal club: Affinity maturation of neutralizing antibodies improves in vivo protection against SARS-CoV-2.\" width=\"700\" height=\"267\" srcset=\"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-content\/uploads\/sneeze-hero.jpg 700w, https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-content\/uploads\/sneeze-hero-300x114.jpg 300w\" sizes=\"(max-width: 700px) 100vw, 700px\" \/><\/p>\n<h4>Engineering higher affinity SARS-CoV-2 antibodies<\/h4>\n<p>One of the main ways in which SARS-CoV-2 infects airway epithelial cells is through binding via its spike proteins to angiotensin-converting enzyme 2 (ACE2), which is expressed at the epithelial cell surface. Neutralizing antibodies (nAbs) serve to block this interaction and prevent viral uptake. However, SARS-CoV-2 can escape these effects by developing spike protein mutations that disrupt nAb binding. To determine whether the protective efficacy of existing nAbs could be enhanced through engineering, Zhao <em>et al.<\/em> selected three nAbs known to impede SARS-CoV-2 binding to ACE2 (CC12.1, CC6.30 and CC6.33) and subjected them to rapid affinity maturation using a platform termed SAMPLER. Briefly, this involved synthesizing heavy chain and light chain libraries with up to three mutations per chain for display on the surface of yeast, followed by panning for high-affinity clones; the antibody sequences were then recovered, and twelve improved variants of each antibody were reformatted and expressed as IgGs for characterization.<\/p>\n<figure><img decoding=\"async\" loading=\"lazy\" width=\"2560\" height=\"1454\" class=\"wp-image-9759\" src=\"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-content\/uploads\/gr3_lrg-scaled.jpg\" alt=\"\" srcset=\"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-content\/uploads\/gr3_lrg-scaled.jpg 2560w, https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-content\/uploads\/gr3_lrg-300x170.jpg 300w, https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-content\/uploads\/gr3_lrg-1024x581.jpg 1024w, https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-content\/uploads\/gr3_lrg-1536x872.jpg 1536w, https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-content\/uploads\/gr3_lrg-2048x1163.jpg 2048w\" sizes=\"(max-width: 2560px) 100vw, 2560px\" \/><figcaption><strong>Figure 1.<\/strong> Binding affinity and neutralization potency of engineered SARS-CoV-2 nAbs.<br \/>\n(A) Enhanced and parental nAbs binding affinity against SARS-CoV-2 RBD by surface plasmon resonance. Parental nAbs are highlighted in black. eCC12.1.7, eCC6.33.3 and eCC6.30.2 are highlighted, whereas other engineered variants are colored in grey. RBD binding to antibodies via an Fc-capture, multi-cycle method. Association and dissociation rate constants were calculated through a 1:1 Langmuir binding model using the BIA evaluation software. (B) Neutralization IC50 against pseudotyped SARS-CoV-2 and SARS-CoV-1 viruses. (C\u2013E) SARS-CoV-2 pseudovirus neutralization curves of (C) parental CC12.1 and eCC12.1.7, (D) parental CC6.33 and eCC6.33.3, (E) parental CC6.30 and eCC6.30.2 in IgG and Fab molecules. Solid lines represent IgG neutralization whereas dashed lines represent Fab neutralization. Data are represented as mean \u00b1 SD. Data are representative of at least two independent experiments. (F) Summary table of nAb neutralization IC50 against pseudotyped SARS-CoV-1 and SARS-CoV2, as well as replicating SARS-CoV-2. (Figure taken from Zhao <em>et al<\/em>., 2022)<\/figcaption><\/figure>\n<hr \/>\n<h4>Evaluation of neutralizing potency<\/h4>\n<p>To assess the neutralizing potency of the affinity-matured nAbs, Zhao <em>et al.<\/em> seeded Vero E6 cells into 96 well plates and added various premixed solutions of nAbs\/SARS-CoV-2 variants of interest. The viral variants included B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.1 (Kappa), and B.1.617.2 (Delta), as well as variants featuring single point mutations in the receptor binding domain. After incubating to allow for viral transduction, the cells were fixed, permeabilized, and blocked, and a mixture of human anti-SARS-CoV-2 primary antibodies was added. A peroxidase-conjugated goat anti-human IgG secondary antibody (Jackson ImmunoResearch <a href=\"https:\/\/www.jacksonimmuno.com\/catalog\/products\/109-035-088\">109-035-088<\/a>) and a chemiluminescent HRP substrate were then used to detect viral uptake. Key findings included the observation that most engineered forms of CC12.1 were able to neutralize the gamma and beta lineages, which completely escaped the parental nAb and the discovery that an engineered form of CC6.30.2 was functional against viral strains containing the L452R and E484Q mutations, while the parental nAb was ineffective.<\/p>\n<hr \/>\n<h4>Assessment of <em>in vivo <\/em>protectivity<\/h4>\n<p>The <em>in vivo <\/em>efficacy of the engineered nAbs was evaluated using a Syrian hamster model of COVID-19 infection. 72 hours after infusing groups of animals with serially diluted doses of different nAbs, Zhao <em>et al. <\/em>administered an intranasal challenge with SARS-CoV-2 and performed a range of measurements. These included monitoring daily for weight loss as an indicator of disease, collecting sera at days 0 and 7 to evaluate antibody half-lives, and harvesting lung tissue to quantify viral titers via a plaque assay. The resultant data showed an engineered form of CC12.1 (eCC12.1.6) to exhibit a dose-dependent protective response both in terms of weight loss and lung viral titers, while the parental nAb provided no protection compared to a control group. An engineered version of CC6.33 (eCC6.33.3) was also found to be superior at controlling lung viral load compared to the original nAb.<\/p>\n<hr \/>\n<h4>Conclusion<\/h4>\n<p>The data generated at The Scripps Research Institute suggest affinity maturation to be a viable strategy for protecting against emerging viral variants. In further support of this, Zhao <em>et al. <\/em>have recently shown eCC12.1.6 to have significant neutralizing activity against the Omicron variant, a highly mutated form of SARS-CoV-2 which was first reported at the time of this study. Critically, reducing viral escape pathways using methods such as affinity maturation promises to help limit the spread of COVID-19 and may also have utility for tackling other viral diseases.<\/p>\n<hr \/>\n<h4>Featured products:<\/h4>\n<ul class=\"styled-list\">\n<li>Peroxidase AffiniPure Goat Anti-Human IgG H+L (Catalog# <a href=\"https:\/\/www.jacksonimmuno.com\/catalog\/products\/109-035-088\">109-035-088<\/a>)<\/li>\n<li>Alkaline Phosphatase AffiniPure Goat Anti-Human IgG, Fc\u03b3 fragment specific (Catalog# <a href=\"https:\/\/www.jacksonimmuno.com\/catalog\/products\/109-055-008\">109-055-008<\/a>)<\/li>\n<\/ul>\n<hr \/>\n<h4>Article reference:<\/h4>\n<ul class=\"styled-list\">\n<li>Zhao F, Keating C, Ozorowski G, <em>et al<\/em>. Engineering SARS-CoV-2 neutralizing antibodies for increased potency and reduced viral escape pathways. iScience. 2022;25(9):104914. <a href=\"https:\/\/www.cell.com\/iscience\/fulltext\/S2589-0042(22)01186-5?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2589004222011865%3Fshowall%3Dtrue\">doi:10.1016\/j.isci.2022.104914<\/a><\/li>\n<\/ul>\n<table class=\"table blogLinks aligncenter\">\n<thead>\n<tr>\n<th class=\"span6\">Learn more:<\/th>\n<th class=\"span6\">Do more:<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td class=\"span6\"><a href=\"\/technical\/products\/protocols\/multiple-labeling\">Multiple labeling using Secondary Antibodies<\/a><\/td>\n<td class=\"span6\"><a href=\"\/catalog\/1\">Whole\u00a0IgG affinity-purified antibodies<\/a><\/td>\n<\/tr>\n<tr>\n<td class=\"span6\"><a href=\"\/secondary-antibody-resource\/immuno-techniques\/direct-and-indirect-western-blotting\/\">Direct and Indirect Western blotting<\/a><\/td>\n<td class=\"span6\"><a href=\"\/catalog\/7\">Light Chain Specific\u00a0Secondary Antibodies<\/a><\/td>\n<\/tr>\n<tr>\n<td class=\"span6\"><a href=\"\/technical\/products\/antibody-selection\">Choosing your Secondary Antibody<\/a><\/td>\n<td class=\"span6\"><a href=\"\/technical\/products\/conjugate-selection\/enzymes\">Reporter enzyme conjugates<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<!-- AddThis Advanced Settings generic via filter on the_content --><!-- AddThis Share Buttons generic via filter on the_content --><!-- AddThis Related Posts generic via filter on the_content -->","protected":false},"excerpt":{"rendered":"<p>Download PDF Since the start of the COVID-19 pandemic, multiple vaccines have been developed that protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The way in which these work is still being deduced, but several studies have shown that the elicitation of neutralizing antibodies (nAbs) has a central role in combating infection. Recombinantly produced [&hellip;]<!-- AddThis Advanced Settings generic via filter on get_the_excerpt --><!-- AddThis Share Buttons generic via filter on get_the_excerpt --><!-- AddThis Related Posts generic via filter on get_the_excerpt --><\/p>\n","protected":false},"author":11,"featured_media":7168,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"content-type":""},"categories":[19,20],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/posts\/9756"}],"collection":[{"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/comments?post=9756"}],"version-history":[{"count":12,"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/posts\/9756\/revisions"}],"predecessor-version":[{"id":9776,"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/posts\/9756\/revisions\/9776"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/media\/7168"}],"wp:attachment":[{"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/media?parent=9756"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/categories?post=9756"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jacksonimmuno.com\/secondary-antibody-resource\/wp-json\/wp\/v2\/tags?post=9756"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}