KR-102962633-B1 - Antibody specific to the B5 surface antigen protein of vaccinia virus and an antigen-binding fragment thereof

Abstract

The present invention relates to an antibody or an antigen-binding fragment that specifically binds to a B5 antigen. Furthermore, the present invention relates to a nucleic acid comprising mRNA encoding the antibody or the antigen-binding fragment, a vector comprising the nucleic acid, a host cell, and a pharmaceutical composition prepared therefrom. The present invention selected a novel antibody capable of high-efficiency intracellular expression based on mRNA while maintaining specificity and binding affinity for the B5 antigen, and confirmed a neutralizing immune response against vaccinia virus in the body by directly synthesizing the antibody intracellularly using the mRNA encoding it.

Inventors

• 윤형석
• 김창환
• 유치호
• 송영조
• 최준영
• 심은이
• 이민훈
• 김정균
• 문동현

Assignees

• 국방과학연구소

Dates

Publication Date

20260508

Application Date

20251110

Claims (13)

1. An antibody or antigen-binding fragment that specifically binds to a B5 antigen, wherein the antibody or antigen-binding fragment comprises any one of the following sets of CDRs: (a) CDR-H1 represented by SEQ ID NO. 1, CDR-H2 represented by SEQ ID NO. 2, CDR-H3 represented by SEQ ID NO. 3, CDR-L1 represented by SEQ ID NO. 4, CDR-L2 represented by SEQ ID NO. 5, and CDR-L3 represented by SEQ ID NO. 6; (b) CDR-H1 represented by SEQ ID NO. 7, CDR-H2 represented by SEQ ID NO. 8, CDR-H3 represented by SEQ ID NO. 9, CDR-L1 represented by SEQ ID NO. 10, CDR-L2 represented by SEQ ID NO. 11, and CDR-L3 represented by SEQ ID NO. 12; or (c) CDR-H1 represented by sequence number 13, CDR-H2 represented by sequence number 14, CDR-H3 represented by sequence number 15, CDR-L1 represented by sequence number 16, CDR-L2 represented by sequence number 17, and CDR-L3 represented by sequence number 18.
2. In paragraph 1, The antibody or its antigen-binding fragment is characterized by being selected from the group consisting of O.A3, comprising a heavy chain variable region represented by SEQ ID NO. 43 and a light chain variable region represented by SEQ ID NO. 44; O.G1, comprising a heavy chain variable region represented by SEQ ID NO. 45 and a light chain variable region represented by SEQ ID NO. 46; and S.B3, comprising a heavy chain variable region represented by SEQ ID NO. 47 and a light chain variable region represented by SEQ ID NO. 48.
3. delete
4. delete
5. delete
6. In paragraph 1, An antibody or antigen-binding fragment that specifically binds to a B5 antigen, characterized in that the antigen-binding fragment is selected from the group consisting of scFv (single-chain variable fragment), Fab, Fab', F(ab')2, and Fv.
7. A nucleic acid encoding an antibody or its antigen-binding fragment according to any one of paragraphs 1, 2 and 6.
8. In Paragraph 7, The nucleic acid is characterized by being in the form of mRNA.
9. A vector containing the nucleic acid of claim 7.
10. delete
11. A pharmaceutical composition for the prevention or treatment of vaccinia infection, characterized by comprising, as an active ingredient, an antibody or a nucleic acid encoding an antigen-binding fragment according to any one of claims 1, 2, and 6.
12. In Paragraph 11, A pharmaceutical composition characterized by administering the above nucleic acid in the form of mRNA into the body to synthesize antibodies within cells.
13. In Paragraph 12, The above mRNA is characterized by being administered by binding to a carrier. Pharmaceutical composition.

Description

Antibody specific to the B5 surface antigen protein of vaccinia virus and an antigen-binding fragment thereof The present invention relates to an antibody or an antigen-binding fragment that specifically binds to a B5 antigen. Furthermore, the present invention relates to a nucleic acid comprising mRNA encoding said antibody or the antigen-binding fragment, a vector and a host cell comprising said nucleic acid, and a pharmaceutical composition prepared therefrom. Vaccinia virus is a double-stranded DNA virus belonging to the genus Orthopoxvirus and is a representative virus that was widely used in the past as a smallpox vaccine. However, as the variola virus, which belongs to the same lineage, is classified as a biological threat, vaccinia virus and related antigens are being treated as core research subjects for biodefense, military disease control, and the development of virus detection technologies. Vaccinia virus-based live vaccines, which played a decisive role in the eradication of smallpox, are known to be the most effective preventive measure to date. However, these live vaccines carry potential risks that can cause serious side effects in patients with atopic dermatitis or immunocompromised individuals. Recently, with the persistent threat of bioterrorism involving vaccinia viruses or similar orthofoxviruses, there is an increasing need for safer and more precise treatments against vaccinia. Existing treatments primarily utilize antibody therapy based on the serum (Vaccinia Immune Globulin, VIG) of vaccinia-vaccinated individuals; however, these methods suffer from significant variations in efficacy with each production run and raise concerns regarding side effects caused by nonspecific binding. Therefore, there is an urgent need for the development of monoclonal antibodies that precisely target specific antigens, as well as stable production technologies. Meanwhile, the vaccinia virus B5 protein is present on the surface of the envelope and is known to be an antigen essential for transmission between host cells and the expression of pathogenicity. Since the B5 protein is involved in the formation of extracellular enveloped virions (EEVs), it has been recognized as one of the major targets for neutralizing antibodies; therefore, antibodies that specifically bind to it can be usefully applied to blocking viral spread, diagnostic detection systems, and the development of biodefense neutralizing antibodies. However, the previously reported vaccinia virus B5 antigen is a surface protein of enveloped viruses and has structural limitations that make complete neutralization by antibodies difficult (Non-patent Literature 1). Additionally, B5 antibodies exhibit isotype-dependent protective efficacy, and it has been reported that it is difficult to ensure the reproducibility and efficacy stability of antibodies because distinct protective effects are confirmed only in IgG of specific subtypes (Non-patent Literature 2). Therefore, existing antibody technologies targeting specific antigens have limitations in that it is difficult to simultaneously secure binding affinity and expression stability, and there is a need to develop improved antibody or mRNA-based expression platforms to overcome this. Against this backdrop, the inventors of the present invention have conducted research efforts to secure an antibody capable of high-efficiency intracellular expression based on mRNA while maintaining specificity and binding affinity to the B5 antigen, and to develop an antibody capable of improving the safety issues and non-specific binding side effects of existing live vaccines. As a result, they selected a novel antibody that specifically binds to the surface antigen protein B5 of the vaccinia virus, synthesized the antibody directly within cells using the mRNA encoding it, and confirmed the in vivo immune response to the vaccinia virus, thereby completing the present invention. Figure 1 shows the biopanning results for the B5 antigen. Figure 2 shows the ELISA results for selecting specific substances for the B5 antigen. Figure 3 is a graph showing the intracellular expression concentration of mRNA. Figure 4 is a graph showing the results of the binding ability test for the B5 antigen. Figure 5 is a graph confirming the neutralizing efficacy of selected antibodies against vaccinia virus-infected mice. Preferred embodiments according to the present invention will be described in detail below with reference to the attached drawings. The advantages and features of the present invention and the method for achieving them will become clear by referring to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited by the embodiments disclosed below but may be implemented in various different forms, and these embodiments are provided merely to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope o