Uridine

信使核糖核酸（mRNA）是告诉体内细胞如何制造特定蛋白的遗传物质。在一项新的研究中，来自英国剑桥大学等研究机构的研究人员发现，细胞的解码机器对治疗用 mRNA 的错误读取会在体内引起意料之外的免疫反应。他们确定了mRNA中导致这种情况发生的序列，并找到了一种防止“脱靶”免疫反应的方法，从而使未来mRNA疗法的设计更加安全。相关研究结果于2023年12月6日在线发表在Nature期刊上，论文标题为“N1-methylpseudouridylation of mRNA causes +1 ribosomal frameshifting”。论文通讯作者为剑桥大学的Anne Willis教授和James Thaventhiran博士。具体而言，他们发现，“读取”mRNA的细胞分子机器在遇到mRNA疗法中常见的化学修饰重复时会“打滑”。除了靶蛋白外，这些打滑还会导致产生“脱靶”蛋白，从而引发意外的免疫反应。这一最新的研究成果是在以往研究进展的基础上取得的，目的是确保防止未来基于 mRNA 的疗法出现任何安全问题。mRNA 疫苗被认为能改变游戏规则。它们已被用于控制 COVID-19 大流行，并已被提议用于治疗许多癌症以及未来的心血管、呼吸和免疫疾病。这种革命性的治疗方法部分得益于生物化学家Katalin Karikó和免疫学家Drew Weissman的研究。他们证实通过对 mRNA 的构成单元---碱基---进行化学修饰，合成的 mRNA 可以绕过人体的某些免疫防御系统，从而使得治疗药物进入人体细胞并发挥作用。这些作者发现，目前mRNA疗法中含有的一种名为N1-甲基假尿苷（N1-methylpseudouridine）的化学修饰碱基是造成mRNA序列“滑动”的原因。他们检测了接种辉瑞公司COVID-19 mRNA疫苗的人体内产生“脱靶”蛋白的证据。他们发现，在这项研究中，21 名接种疫苗的患者中有三分之一出现了非预期的免疫反应，但没有任何显著的不良反应，这与有关 COVID-19 疫苗的大量安全性数据相符。他们随后重新设计了 mRNA 序列：通过校正合成 mRNA 中容易出错的基因序列，避免了这些“脱靶”效应。这样就产生了预期的蛋白。这种设计修改可以很容易地应用于未来的 mRNA 疫苗，在产生预期效果的同时，防止出现危险和意外的免疫反应。Thaventhiran 博士说，“我们需要确保未来的 mRNA 疫苗是可靠的。我们展示的‘防打滑’mRNA 是对这一药物平台未来安全性的重要贡献。”Willis教授说，“这些新疗法为治疗多种疾病带来了希望。随着数十亿英镑的资金流入下一组mRNA疗法，这些疗法的设计必须避免意外的副作用。”Thaventhiran说，“我们可以从疫苗的 mRNA 中移除容易出错的代码，这样人体就能制造出我们想要的蛋白，从而产生免疫反应，而不会无意中制造出其他蛋白。未来 mRNA 药物的安全问题在于，错误靶向的免疫反应具有巨大的潜在危害，因此应始终避免脱靶免疫反应。”Willis补充说，“我们的研究既提出了对这类新型药物的担忧，也提出了解决方案，这是来自不同学科和背景的科研人员之间重要合作的成果。这些发现可以迅速付诸实施，以防止未来出现任何安全问题，并确保新的 mRNA 疗法安全有效。”图片来自Nature, 2023, doi:10.1038/s41586-023-06800-3。将合成 mRNA 用于治疗目的之所以具有吸引力，是因为它的制造成本低廉，因此可以通过让更多人获得这些药物来解决全球范围内存在的严重健康不平等问题。此外，合成 mRNA 还可以快速改变---例如，构建一种新的 COVID-19变体疫苗。在COVID-19 mRNA疫苗中，合成 mRNA 被用来使人体制造来自 SARS-CoV-2 的刺突蛋白。人体会将 mRNA 疫苗产生的病毒蛋白识别为外来蛋白，并产生保护性免疫。这种免疫力会持续存在，如果人体日后接触到这种病毒，免疫细胞就能在它引发严重疾病之前将其中和。细胞的解码机器称为核糖体。它“读取”天然和合成 mRNA 的遗传密码，从而产生蛋白。核糖体在 mRNA 上的精确定位对于制造正确的蛋白至关重要，因为核糖体每次“读取”mRNA 序列的三个碱基。这三个碱基决定了下一个加入蛋白链的氨基酸是什么。因此，即使核糖体沿着 mRNA 发生微小的移动，也会严重扭曲代码和由此产生的蛋白。当核糖体遇到 mRNA 中一串称为N1-甲基假尿苷的修饰碱基时，大约有 10% 的时间会发生偏移，从而导致 mRNA 被错误读取，产生非预期的蛋白---足以引发免疫反应。从 mRNA 中移除这些N1-甲基假尿苷可以防止“脱靶”蛋白的产生。参考资料：Thomas E. Mulroney et al. N1- methylpseudouridylation of mRNA causes +1 ribosomal frameshifting. Nature, 2023, doi:10.1038/s41586-023-06800-3.Researchers redesign future mRNA therapeutics to prevent potentially harmful immune responseshttps://medicalxpress.com/news/2023-12-redesign-future-mrna-therapeutics-potentially.html本文仅用于学术分享，转载请注明出处。若有侵权，请联系微信：bioonSir 删除或修改！

EnginZyme and Ajinomoto Bio-Pharma Services have developed a patented process to manufacture pseudouridine at industrial scale using biocatalysis in a sustainable, low-waste, patented process carried out in a cGMP* facility EnginZyme is in talks to help alleviate supply chain difficulties in low- and middle-income countries 2023 Nobel laureates discovered how pseudouridine could make mRNA suitable for vaccines STOCKHOLM--(BUSINESS WIRE)-- EnginZyme AB, a deep-tech company whose cell-free biomanufacturing technology uses the power of enzymes to create sustainable products and processes for a variety of industries, announced that it had patented a process to synthesize pseudouridine, a key ingredient in mRNA COVID-19 vaccines. EnginZyme and its CDMO partner, Ajinomoto Bio-Pharma Services, specialized in scale up and cGMP* manufacturing of small molecules and other high-value fine chemicals, said they could provide pseudouridine at a discount to buyers taking part in efforts to bolster the global supply chain of vaccine ingredients. The companies said they had already synthesized enough pseudouridine for more than half a billion doses of vaccine in a facility that is fully cGMP* compliant. The enzymatic process EnginZyme has perfected is cleaner and more efficient than the chemical synthesis methods currently used. A critical impurity, alpha-pseudouridine, which is a by-product of the chemical synthesis of beta-pseudouridine, is eliminated in EnginZyme's patented enzymatic synthesis. For more technical information, see our website. The 2023 Nobel Prize for Physiology or Medicine was awarded to Katalin Karikó and Drew Weissman, the pair who discovered that changing a chemical building block of messenger RNA – substituting pseudouridine for uridine – eliminated an inflammatory side effect that stalled development of vaccines based on mRNA. They made this discovery more than 15 years before the COVID-19 pandemic. During the COVID-19 crisis, the World Health Organization found that low- and middle-income countries were suffering from a lack of vaccine doses amid production and supply constraints, hoarding by wealthy countries, and prioritization of sales to governments that could pay the highest prices. "Not long after we discovered the process for making pseudouridine, we realized that we could produce a pure version at scale for much less than it was going for on the market," said Karim Engelmark Cassimjee, CEO of EnginZyme. "We decided the right thing to do would be to use this discovery to help make the global healthcare supply chain more resilient." He added that academic and nonprofit organizations could apply to receive free samples for research purposes. Geert Schelkens, R&D Manager at Ajinomoto Bio-Pharma Services, said: "The scale-up of a biocatalytic process and a green workup results in a drastic reduction of the compound's footprint. This achievement nicely aligns with our sustainability ambitions. This project with EnginZyme has been particularly rewarding because of its potential to improve the global supply chain for vaccine ingredients.” N1-methylpseudouridine-5’-triphosphate, which is derived from pseudouridine, helps stabilize and reduce the immunogenicity of mRNA. Messenger RNA technology made headlines through the successful COVID-19 vaccines produced by Pfizer-BioNTech and Moderna, and since then, an increasing number of early-stage therapeutics and emerging vaccines have been based on the technology. "Synthesizing pseudouridine with enzymes is so much more efficient than the chemical synthesis that is common today," said Matthew Thompson, head of enzyme development and innovation at EnginZyme. "It's a perfect example of what we are striving for: zero waste, less energy, and a cleaner result. We want to apply this across the spectrum of chemical manufacturing." *Current Good Manufacturing Practice regulations, enforced by the U.S. FDA, provide for systems that assure proper design, monitoring, and control of manufacturing processes and facilities. About EnginZyme EnginZyme is changing chemistry for good. We are enabling the shift to biomanufacturing by unlocking the power of enzymes for more cost-efficient and sustainable production of everyday products. Our patented enzyme immobilisation technology enables biomanufacturing without living organisms. It can be deployed using the same tools and techniques used in traditional chemical manufacturing, with lower costs and a much smaller environmental footprint. Based in Stockholm, EnginZyme is a growing company with a multidisciplinary team of experts in biocatalysis, organic chemistry, enzyme and process engineering, as well as AI and machine learning. This elite team is uniquely positioned to develop complete processes from techno-economic analysis all the way to industrial manufacture, incorporating a high degree of automation for safe, rapid, and reliable development. EnginZyme has been recognised as a Technology pioneer by the World Economic Forum and was selected to the Global Cleantech 100 list in 2022 and 2023. About Ajinomoto Bio-Pharma Services Ajinomoto Bio-Pharma Services is a fully integrated contract development and manufacturing organization with sites in Belgium, United States, Japan, and India, providing comprehensive development, cGMP manufacturing, and aseptic fill finish services for small and large molecule APIs and intermediates. Ajinomoto Bio-Pharma Services offers a broad range of innovative platforms and capabilities for pre-clinical and pilot programs to commercial quantities, including high potency APIs (HPAPI), biocatalysis, continuous flow manufacturing, Corynex® protein expression technology, oligonucleotide synthesis, antibody drug conjugations (ADC), and more. Ajinomoto Bio-Pharma Services is dedicated to providing a high level of quality and service to meet our client’s needs. Learn more: View source version on businesswire.com: Contacts Business development Karl Johan Tärbe karljohan@enginzyme.com Media Bogert-Magnier Communications James Connell jim@bogert-magnier.com +33 6 2152 1955 Elodie Doan Van elodie@bogert-magnier.com +33 6 8099 8881 Source: EnginZyme AB View this news release online at: