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KR-102962634-B1 - Antibody specific to the A33 surface antigen protein of vaccinia virus and an antigen-binding fragment thereof

KR102962634B1KR 102962634 B1KR102962634 B1KR 102962634B1KR-102962634-B1

Abstract

The present invention relates to an antibody or an antigen-binding fragment that specifically binds to an A33 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. The present invention selects a novel antibody and its antigen-binding fragment capable of high-efficiency intracellular expression based on mRNA while maintaining specificity and binding affinity for the A33 antigen, and directly synthesizes the antibody intracellularly using the mRNA encoding it, thereby confirming a rapid and stable therapeutic effect while minimizing immunogenicity in the body.

Inventors

  • 윤형석
  • 김창환
  • 유치호
  • 송영조
  • 최준영
  • 심은이
  • 이민훈
  • 조성훈

Assignees

  • 국방과학연구소

Dates

Publication Date
20260508
Application Date
20251110

Claims (19)

  1. As an antibody or antigen-binding fragment that specifically binds to the A33 antigen, The antibody or the antigen-binding fragment is characterized by comprising 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 sequence number 7, CDR-H2 represented by sequence number 8, CDR-H3 represented by sequence number 9, CDR-L1 represented by sequence number 10, CDR-L2 represented by sequence number 11, and CDR-L3 represented by sequence number 12; (c) CDR-H1 represented by SEQ ID NO. 13, CDR-H2 represented by SEQ ID NO. 14, CDR-H3 represented by SEQ ID NO. 15, CDR-L1 represented by SEQ ID NO. 16, CDR-L2 represented by SEQ ID NO. 17, and CDR-L3 represented by SEQ ID NO. 18; (d) CDR-H1 represented by sequence number 19, CDR-H2 represented by sequence number 20, CDR-H3 represented by sequence number 21, CDR-L1 represented by sequence number 22, CDR-L2 represented by sequence number 23 and CDR-L3 represented by sequence number 24; (e) CDR-H1 designated by sequence number 25, CDR-H2 designated by sequence number 26, CDR-H3 designated by sequence number 27, CDR-L1 designated by sequence number 28, CDR-L2 designated by sequence number 29, and CDR-L3 designated by sequence number 30; (f) CDR-H1 represented by sequence number 31, CDR-H2 represented by sequence number 32, CDR-H3 represented by sequence number 33, CDR-L1 represented by sequence number 34, CDR-L2 represented by sequence number 35 and CDR-L3 represented by sequence number 36; (g) CDR-H1 designated by sequence number 37, CDR-H2 designated by sequence number 38, CDR-H3 designated by sequence number 39, CDR-L1 designated by sequence number 40, CDR-L2 designated by sequence number 41 and CDR-L3 designated by sequence number 42; (h) CDR-H1 designated by SEQ ID NO. 43, CDR-H2 designated by SEQ ID NO. 44, CDR-H3 designated by SEQ ID NO. 45, CDR-L1 designated by SEQ ID NO. 46, CDR-L2 designated by SEQ ID NO. 47 and CDR-L3 designated by SEQ ID NO. 48; or (i) CDR-H1 designated by sequence number 49, CDR-H2 designated by sequence number 50, CDR-H3 designated by sequence number 51, CDR-L1 designated by sequence number 52, CDR-L2 designated by sequence number 53, and CDR-L3 designated by sequence number 54.
  2. In paragraph 1, The above antibody or its antigen-binding fragment comprises O.A1 comprising a heavy chain variable region represented by SEQ ID NO. 127 and a light chain variable region represented by SEQ ID NO. 128, O.B4 comprising a heavy chain variable region represented by SEQ ID NO. 129 and a light chain variable region represented by SEQ ID NO. 130, O.C2 comprising a heavy chain variable region represented by SEQ ID NO. 131 and a light chain variable region represented by SEQ ID NO. 132, O.G11 comprising a heavy chain variable region represented by SEQ ID NO. 133 and a light chain variable region represented by SEQ ID NO. 134, S.A1 comprising a heavy chain variable region represented by SEQ ID NO. 135 and a light chain variable region represented by SEQ ID NO. 136, S.B5 comprising a heavy chain variable region represented by SEQ ID NO. 137 and a light chain variable region represented by SEQ ID NO. 138, T.A1 comprising a heavy chain variable region represented by SEQ ID NO. 139 and a light chain variable region represented by SEQ ID NO. 140 , SEQ ID NO An antibody or its antigen-binding fragment characterized by being selected from the group consisting of T.B7, comprising a heavy chain variable region represented by 141 and a light chain variable region represented by SEQ ID NO. 142, and T.G12, comprising a heavy chain variable region represented by SEQ ID NO. 143 and a light chain variable region represented by SEQ ID NO. 144 .
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  12. In paragraph 1, An antibody or antigen-binding fragment that specifically binds to an A33 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.
  13. A nucleic acid encoding an antibody or its antigen-binding fragment according to any one of paragraphs 1, 2, and 12.
  14. In Paragraph 13, The nucleic acid is characterized by being in the form of mRNA.
  15. A vector containing the nucleic acid of Clause 13.
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  17. 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 12.
  18. In Paragraph 17, A pharmaceutical composition characterized by administering the above nucleic acid in the form of mRNA into the body to synthesize antibodies within cells.
  19. In Paragraph 18, A pharmaceutical composition characterized in that the mRNA is administered by binding to a carrier.

Description

Antibody specific to the A33 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 an A33 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, among the surface antigens of the vaccinia virus, the A33 protein is a transmembrane glycoprotein involved in cell-to-cell spread, expressed on the surface of vaccinia-infected cells to mediate viral transmission. For this reason, A33 is being proposed as a promising therapeutic target for vaccinia and orthopoxvirus infections. However, existing A33-targeted antibody technologies have several limitations. For example, while the humanized anti-A33 antibody (huA33) can target colorectal cancer cells, it has been reported to have problems such as high immunogenicity (anti-drug antibody response) in the body and low drug persistence (Non-patent Literature 1 and 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 made research efforts to secure an antibody capable of high-efficiency intracellular expression based on mRNA while maintaining specificity and binding affinity to the A33 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 A33 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 A33 antigen. Figure 2 shows the ELISA results for selecting specific substances for the A33 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 A33 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 of the invention, and the present invention is defined only by the scope of the claims. In addition, in describing the present invention, if it is determined that related known technologies, etc., may obscure the essence of the present invention, a detailed explanation thereof will be omitted. The present invention will be described in detail below. One aspect of the present invention for