CN-121991952-A - Artificial 5' untranslated region for improving mRNA translation efficiency, construct and application thereof

Abstract

The invention provides an artificial 5 'untranslated region for improving mRNA translation efficiency, a construct and application thereof, wherein the artificial 5' untranslated region is an isolated nucleic acid molecule which comprises a nucleotide sequence shown as SEQ ID NO. 1 or a variant sequence which has at least 90% identity with SEQ ID NO. 1 and can improve mRNA translation efficiency. The artificial 5 'untranslated region sequence is rationally designed, so that unfavorable secondary structures and inhibitory elements are remarkably eliminated, an almost ideal linear channel is created for ribosome scanning, the antigen expression efficiency is improved, the artificial 5' untranslated region sequence can be flexibly combined with an antigen coding region as a standardized modularized element, the excellent universality and the platform value are shown, the uncontrollable regulation risk hidden by a natural sequence is fundamentally avoided due to the characteristic of complete artificial synthesis, and the inherent safety of mRNA products is remarkably improved.

Inventors

• XING PEIDONG
• Xie Manni
• SHEN SHUO
• ZHANG JIAYOU
• ZHANG ZHEGANG
• LIU BO
• YUE YANG
• ZHANG QINGMEI

Assignees

• 武汉生物制品研究所有限责任公司

Dates

Publication Date

20260508

Application Date

20251218

Claims (10)

1. 1. An artificial 5 'untranslated region that increases the efficiency of mRNA translation, wherein the artificial 5' untranslated region is an isolated nucleic acid molecule comprising a nucleotide sequence that is depicted as SEQ ID No. 1, or a variant sequence that has at least 90% identity to SEQ ID No. 1 and that is capable of increasing the efficiency of mRNA translation.
2. 2. The artificial 5' untranslated region of claim 1, wherein the nucleic acid molecule is a DNA molecule or an RNA molecule.
3. 3. An mRNA molecule comprising, in order from the 5 'end to the 3' end: A 5' cap structure; the artificial 5' untranslated region of claim 1 or 2; an open reading frame encoding a protein of interest; 3' untranslated region, and Poly (a) tail.
4. 4. The mRNA molecule of claim 3, wherein the 3' untranslated region is derived from a globin gene.
5. 5. A DNA construct comprising a nucleotide sequence encoding the mRNA molecule of claim 3 or 4.
6. 6. The DNA construct of claim 5, wherein the DNA construct is a plasmid, a linear DNA fragment, or a viral vector.
7. 7. A pharmaceutical composition comprising the mRNA molecule of claim 3 or 4, or the DNA construct of claim 5 or 6.
8. 8. The pharmaceutical composition of claim 7, wherein the pharmaceutical composition is a vaccine.
9. 9. Use of an artificial 5' untranslated region according to claim 1 or 2, an mRNA molecule according to claim 3 or 4, or a DNA construct according to claim 5 or 6 in the manufacture of a medicament for the prevention and/or treatment of a disease.
10. 10. The use according to claim 9, wherein the disease is an infectious disease or a tumor.

Description

Artificial 5' untranslated region for improving mRNA translation efficiency, construct and application thereof Technical Field The invention relates to the technical field of biological medicine, in particular to an artificial 5' untranslated region for improving mRNA translation efficiency, a construct and application thereof. Background With the development of biomedical technology, messenger ribonucleic acid (mRNA) vaccines are used as third-generation vaccine platforms, and have great potential in the fields of infectious disease prevention and control, tumor immunotherapy and the like. Compared with the traditional vaccine, the mRNA vaccine has the remarkable advantages of short research and development period, high production efficiency and good safety, and can excite humoral immunity and cellular immunity at the same time. However, the rapid development of this field also exposes a core technical bottleneck, namely the significant differences in potency (efficacy) of mRNA vaccines developed by different platforms, one of the core reasons being the design of the mRNA molecules themselves, in particular their translation efficiency. Therefore, optimizing the mRNA molecular skeleton and increasing the expression level of antigen proteins has become a key to improving the efficacy of mRNA vaccines. The function of an mRNA molecule depends on its efficient translation within a host cell to produce the antigen protein of interest. A typical mature mRNA molecule comprises several key cis-acting elements, a5 'end cap structure, a 5' untranslated region, an open reading frame encoding an antigen, a3 'untranslated region, and a 3' terminal poly (A) tail. Wherein the 5' untranslated region is a critical region that regulates translation initiation of an mRNA. The mechanism of action is that after the ribosomal small subunit recognizes the 5 'cap structure, it scans along the 5' untranslated region to find the start codon, thus initiating the translation process. Sequence characteristics of the 5' untranslated region, such as length, nucleotide composition, complexity of secondary structure, etc., profoundly affect the efficiency of ribosome scanning and accuracy of translation initiation. An ideal 5' untranslated region should have the characteristics of a simple secondary structure, avoiding the formation of a stable stem-loop structure that prevents ribosome scanning, no upstream initiation codon, preventing false translation initiation, and inclusion of motifs that are compatible with host cell translation mechanisms to recruit translational initiation factors with high efficiency. Currently, common mRNA vaccine designs in the art typically directly borrow the 5 'untranslated region of the human endogenous gene, with the most widely used being the 5' untranslated region of the human α -globin or β -globin gene. For example, COVID-19 mRNA vaccine (e.g., comirnaty) which has been marketed in bulk, uses the 5' untranslated region of human α -globin. While these natural 5' untranslated regions are capable of mediating basic protein translation, they are not designed to maximize antigen expression in vaccine applications as a product of natural evolution, and thus have the following inherent drawbacks and limitations: 1. The translation efficiency is suboptimal and the sequence of the native 5' untranslated region is not rationally designed to maximize translation efficiency. They may contain potentially inhibitory sequence elements or form stable secondary structures that are detrimental to ribosome scanning, thus limiting the expression levels of antigenic proteins, constituting a ceiling of mRNA vaccine efficacy. 2. Some natural 5' untranslated regions function well when expressing their native proteins, but their efficiency may be significantly reduced by context-dependent effects when used to drive expression of antigen proteins of different sources, of diverse structures, lacking universality and stability as platform technology. 3. Potential safety risks some natural 5' untranslated regions may contain regulatory elements that are not yet defined, which may interact unpredictably with specific factors within the cell, potentially affecting mRNA stability and even eliciting unwanted natural immune responses, increasing the safety risk of the vaccine. Thus, there is a strong need in the art for a completely new, artificially designed 5 'untranslated region sequence that overcomes the aforementioned drawbacks of the native 5' untranslated region, driving the advancement of mRNA vaccine technology. Disclosure of Invention Based on the expression, the invention aims to overcome the defects of the prior art and solve the technical problems that the prior mRNA vaccine depends on a natural 5' untranslated region, so that the antigen translation efficiency is bottleneck, the universality is poor and the potential risk exists. The technical scheme for solving the technical problems is as follows: In a first aspect,