WO2021174594A1 - Anti-novel coronavirus monoclonal antibody and application thereof - Google Patents

Abstract

Provided are an anti-novel coronavirus monoclonal antibody, and a composition (such as a diagnostic agent and a therapeutic agent) containing the antibody. In addition, also provided is use of the antibody. The antibody can be applied to diagnosis, prevention and/or treatment of novel coronavirus infection and/or diseases caused by the infection (such as novel coronavirus pneumonia).

Description

A monoclonal antibody against new coronavirus and its application Technical field

The present invention relates to the field of immunology and molecular virology, especially the field of diagnosis, prevention and treatment of new coronaviruses. Specifically, the present invention relates to monoclonal antibodies against the novel coronavirus, and compositions containing the antibodies (for example, diagnostic agents and therapeutic agents). In addition, the present invention also relates to the use of the antibody. The antibody of the present invention can be used to diagnose, prevent and/or treat a novel coronavirus infection and/or diseases caused by the infection (for example, novel coronavirus pneumonia).

Background technique

[Corrected according to Rule 26 08.06.2020]
At the end of 2019, pneumonia caused by the new coronavirus 2019-nCoV has spread throughout the country and the world. As of March 3, 2020, the number of confirmed cases nationwide was 80,303, and the total number of deaths was 2,947. The total number of confirmed cases outside China (54 countries including Thailand, the United States, Germany, Australia, Iran, etc.) was 9,742, and the total number of deaths was 171. For example, it poses a major threat to the life and health of the public. At present, there are still no specific drugs for the treatment of the new coronavirus.

The new type of coronavirus 2019-nCoV is the pathogen that causes the new type of coronavirus pneumonia (COVID-19). It is a single-stranded RNA virus. It is the same as the severe acute respiratory syndrome coronavirus (SARS-CoV) and The Middle East respiratory syndrome coronavirus (MERS-CoV) that caused the outbreak in 2012 belongs to the coronavirus family. The spike protein (Spike, S protein) on the surface of the virus binds to the host cell receptor angiotensin-converting enzyme 2 (ACE2) molecule in the process of infecting the host, thereby initiating the fusion of the viral membrane with the host cell membrane, causing the host cell to be infected with the virus . The S protein is divided into two parts, S1 and S2. Studies have confirmed that the receptor binding domain (RBD) of the C-terminal (CTD) of S1 binds to ACE2 and mediates the process of membrane fusion.

So far, neutralizing antibodies have been proven to be an effective method for the treatment of viral diseases. The drugs currently on the market for the treatment and prevention of viral infections include palivizumab (Synagis) for the prevention of pediatric respiratory syncytial virus (RSV) infection, ibalizumab (Trogarzo) for the treatment of HIV infection, and rabies Rabishield for prevention after poison exposure. In addition, there are a variety of monoclonal antibodies against different viruses in different stages of clinical research (https://clinicaltrials.gov/). Antibodies work mainly in two ways. On the one hand, antibodies with neutralizing activity can block viral infection by binding to viral envelope proteins, blocking the binding of the virus to cell receptors. On the other hand, antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) can recruit immune cells and immune molecules such as macrophages or complement to eliminate free viruses and infections. Cell.

Therefore, it is necessary to develop neutralizing antibodies against the new coronavirus 2019-nCoV to provide effective means to prevent and treat the new coronavirus infection.

Summary of the invention

In the present invention, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. In addition, the laboratory procedures of cell culture, molecular genetics, nucleic acid chemistry, and immunology used herein are all routine procedures widely used in the corresponding fields. At the same time, in order to better understand the present invention, definitions and explanations of related terms are provided below.

As used herein, the term "antibody" refers to an immunoglobulin molecule usually composed of two pairs of polypeptide chains (each pair has a "light" (L) chain and a "heavy" (H) chain). Antibody light chains can be classified into kappa and lambda light chains. Heavy chains can be classified as mu, delta, gamma, alpha, or epsilon, and the isotype of the antibody is defined as IgM, IgD, IgG, IgA, and IgE, respectively. Within the light and heavy chains, the variable and constant regions are connected by a "J" region of about 12 or more amino acids, and the heavy chain also includes a "D" region of about 3 or more amino acids. Each heavy chain is composed of a heavy chain variable region (VH) and a heavy chain constant region (CH). The heavy chain constant region is composed of 3 domains (CH1, CH2, and CH3). Each light chain is composed of a light chain variable region (VL) and a light chain constant region (CL). The light chain constant region consists of a domain CL. The constant region of the antibody can mediate the binding of immunoglobulins to host tissues or factors, including various cells of the immune system (for example, effector cells) and the first component (C1q) of the classical complement system. The VH and VL regions can also be subdivided into regions with hyperdenaturation (called complementarity determining regions (CDR)), interspersed with more conservative regions called framework regions (FR). Each VH and VL is composed of 3 CDRs and 4 FRs arranged in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4 from the amino terminus to the carboxy terminus. The variable regions (VH and VL) of each heavy chain/light chain pair respectively form the antibody binding site. The allocation of amino acids to each region or domain follows Kabat Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, Md. (1987 and 1991)), or Chothia & Lesk (1987) J. Mol. Biol. 196: 901-917 ; Definition of Chothia et al. (1989) Nature 342:878-883. The term "antibody" is not limited by any specific method of producing antibodies. For example, it includes recombinant antibodies, monoclonal antibodies, and polyclonal antibodies. The antibodies may be antibodies of different isotypes, for example, IgG (e.g., IgG1, IgG2, IgG3 or IgG4 subtype), IgA1, IgA2, IgD, IgE or IgM antibodies.

As used herein, the term "antigen-binding fragment" of an antibody refers to a polypeptide comprising a fragment of a full-length antibody that retains the ability to specifically bind to the same antigen to which the full-length antibody binds, and/or competes with the full-length antibody It is also called "antigen binding part" for specific binding to antigen. See generally, Fundamental Immunology, Ch. 7 (Paul, W., ed., 2nd edition, Raven Press, NY (1989), which is incorporated herein by reference in its entirety for all purposes. Recombinant DNA technology can be used. Or through the enzymatic or chemical cleavage of intact antibodies to produce antigen-binding fragments of antibodies. In some cases, antigen-binding fragments include Fab, Fab', F(ab')2, Fd, Fv, dAb, and complementarity determining regions (CDR) Fragments, single-chain antibodies (e.g., scFv), chimeric antibodies, diabodies, and such polypeptides, which comprise at least a portion of an antibody sufficient to confer specific antigen-binding ability to the polypeptide.

In some cases, the antigen-binding fragment of the antibody is a single-chain antibody (e.g., scFv), in which the VL and VH domains pair to form a monovalent molecule by pairing a linker that enables it to be produced as a single polypeptide chain (see, e.g., Bird et al. , Science 242: 423 426 (1988) and Huston et al., Proc. Natl. Acad. Sci. USA 85: 5879 5883 (1988)). Such scFv molecules may have the general structure: NH2-VL-linker-VH-COOH or NH2-VH-linker-VL-COOH. Suitable prior art linkers consist of repeated GGGGS amino acid sequences or variants thereof. For example, a linker having an amino acid sequence (GGGGS) 4 can be used, but variants thereof can also be used (Holliger et al. (1993), Proc. Natl. Acad. Sci. USA 90: 6444-6448). Other linkers that can be used in the present invention are described by Alfthan et al. (1995), Protein Eng. 8: 725-731, Choi et al. (2001), Eur. J. Immunol. 31: 94-106, Hu et al. (1996), Cancer Res. 56: 3055-3061, Kipriyanov et al. (1999), J. Mol. Biol. 293: 41-56 and Roovers et al. (2001), Cancer Immunol.

In some cases, the antigen-binding fragments of antibodies are diabodies, ie, diabodies, in which the VH and VL domains are expressed on a single polypeptide chain, but a linker that is too short is used to allow two structures in the same chain Pairing between the domains, thereby forcing the domain to pair with the complementary domain of the other chain and creating two antigen binding sites (see, for example, Holliger P. et al., Proc. Natl. Acad. Sci. USA 90: 6444 6448 ( 1993), and Poljak RJ et al., Structure 2:1112 1123 (1994)).

Conventional techniques known to those skilled in the art (e.g., recombinant DNA technology or enzymatic or chemical fragmentation) can be used to obtain antigen-binding fragments (e.g., The above-mentioned antibody fragments), and the antigen-binding fragments of antibodies are specifically screened in the same manner as used for intact antibodies.

Herein, unless the context clearly indicates otherwise, when the term "antibody" is referred to, it includes not only intact antibodies but also antigen-binding fragments of antibodies.

As used herein, the term "monoclonal antibody" refers to an antibody or a fragment of an antibody from a group of highly homologous antibody molecules, that is, a group of identical antibodies, except for natural mutations that may occur spontaneously. Antibody molecule. The monoclonal antibody has high specificity for a single epitope on the antigen. Polyclonal antibodies are relative to monoclonal antibodies, which usually contain at least two or more different antibodies, and these different antibodies usually recognize different epitopes on the antigen. Monoclonal antibodies can usually be obtained using the hybridoma technology first reported by Kohler et al. (Nature, 256:495, 1975), but can also be obtained using recombinant DNA technology (for example, see Journal of virological methods, 2009, 158(1-2): 171-179).

As used herein, "neutralizing antibody" refers to an antibody or antibody fragment that can eliminate or significantly reduce the virulence (for example, the ability to infect cells) of the target virus.

As used herein, the term "E. coli expression system" refers to an expression system composed of E. coli (strain) and a vector, wherein E. coli (strain) is derived from a strain available on the market, such as but not limited to: GI698 , ER2566, BL21 (DE3), B834 (DE3), BLR (DE3).

As used herein, the term "vector" refers to a nucleic acid delivery vehicle into which polynucleotides can be inserted. When the vector can express the protein encoded by the inserted polynucleotide, the vector is called an expression vector. The vector can be introduced into the host cell through transformation, transduction or transfection, so that the genetic material elements it carries can be expressed in the host cell. Vectors are well known to those skilled in the art, including but not limited to: plasmids; phagemids; artificial chromosomes, such as yeast artificial chromosomes (YAC), bacterial artificial chromosomes (BAC) or artificial chromosomes (PAC) derived from P1; bacteriophages such as lambda Bacteriophage or M13 phage and animal virus etc. Animal viruses that can be used as vectors include, but are not limited to, retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpes viruses (such as herpes simplex virus), poxviruses, baculoviruses, papillomaviruses, and papillary viruses. Polyoma vacuole virus (such as SV40). A vector can contain a variety of elements that control expression, including but not limited to promoter sequences, transcription initiation sequences, enhancer sequences, selection elements, and reporter genes. In addition, the vector may also contain an origin of replication site.

As used herein, the term "host cell" refers to a cell that can be used to introduce a vector, which includes, but is not limited to, prokaryotic cells such as Escherichia coli or Bacillus subtilis, and fungal cells such as yeast cells or Aspergillus , Such as insect cells such as S2 Drosophila cells or Sf9, or animal cells such as fibroblasts, CHO cells, COS cells, NSO cells, HeLa cells, BHK cells, HEK293 cells or human cells.

As used herein, the term "specific binding" refers to a non-random binding reaction between two molecules, such as the reaction between an antibody and the antigen to which it is directed. In some embodiments, an antibody that specifically binds to a certain antigen (or an antibody that is specific to a certain antigen) means that the antibody has a concentration of less than about 10 ^-5 M, for example, less than about 10 ^-6 M, 10 ^-7 M, The affinity (KD) of 10 ^-8 M, 10 ^-9 M, or 10 ^-10 M or less binds to the antigen.

As used herein, the term "KD" refers to the dissociation equilibrium constant of a specific antibody-antigen interaction, which is used to describe the binding affinity between the antibody and the antigen. The smaller the equilibrium dissociation constant, the tighter the antibody-antigen binding, and the higher the affinity between the antibody and the antigen. Generally, the antibody (for example, the monoclonal antibody B38 of the present invention) is less than about 10 ^-5 M, such as less than about 10 ^-6 M, 10 ^-7 M, 10 ^-8 M, 10 ^-9 M, or 10 ^-10 M or The smaller dissociation equilibrium constant (KD) binds to the antigen (for example, the RBD of the new coronavirus S protein), for example, as measured in a BIACORE instrument using surface plasmon resonance (SPR).

In the present invention, amino acids are usually represented by one-letter and three-letter abbreviations well known in the art. For example, alanine can be represented by A or Ala.

As used herein, the term "neutralizing activity" refers to the ability of an antibody or antibody fragment to bind to the antigen protein on the virus, thereby preventing the virus from infecting cells and/or the maturation of the virus progeny and/or the release of the virus progeny Antibodies or antibody fragments with neutralizing activity can prevent the amplification of the virus, thereby inhibiting or eliminating the infection of the virus.

[Corrected according to Rule 26 08.06.2020]
As used herein, the terms "new coronavirus" and "2019-nCoV" refer to a type of coronavirus that was discovered in cases of viral pneumonia at the end of 2019. The two have the same meaning and can be used interchangeably.

As used herein, the terms "new coronavirus pneumonia" and "COVID-19" refer to pneumonia caused by a new coronavirus infection. The two have the same meaning and can be used interchangeably.

After a large number of experimental studies, the inventor of the present application discovered an antibody that can specifically recognize and target the S protein of the new coronavirus, especially the receptor binding domain (RBD) of the S protein, and can block the S protein. The combination of the protein's RBD and the cell receptor angiotensin-converting enzyme 2 (ACE2) shows a highly effective ability to neutralize viruses. Therefore, the antibody of the present invention is particularly suitable for diagnosing, preventing and treating novel coronavirus infection or diseases related to novel coronavirus infection (for example, novel coronavirus pneumonia).

In the first aspect of the present application, there is provided a monoclonal antibody or an antigen-binding fragment thereof, which comprises the variable heavy region (VH) complementarity determining region of the amino acid sequence shown in SEQ ID NO: 1-3, respectively 1-3 (CDR1-3); and/or, the amino acid sequence of the light chain variable region (VL) complementarity determining region 1-3 (CDR1-3) shown in SEQ ID NO: 4-6, respectively.

In some preferred embodiments, the monoclonal antibody includes a heavy chain variable region (VH) as shown in SEQ ID NO:7.

In some preferred embodiments, the monoclonal antibody includes a light chain variable region (VL) as shown in SEQ ID NO: 8.

In some preferred embodiments, the monoclonal antibody comprises: the amino acid sequence is shown in SEQ ID NO: 1-3, VH CDR1-3, and the amino acid sequence is shown in SEQ ID NO: 4-6, respectively VL CDR1-3.

In some preferred embodiments, the monoclonal antibody includes: VH as shown in SEQ ID NO: 7 and VL as shown in SEQ ID NO: 8.

In some preferred embodiments, the monoclonal antibody also has a leader sequence at the N-terminus of the variable region of the heavy chain. In some preferred embodiments, the leader sequence has an amino acid sequence as shown in SEQ ID NO: 11.

In some preferred embodiments, the monoclonal antibody also has a leader sequence at the N-terminus of the variable region of the light chain. In some preferred embodiments, the leader sequence has an amino acid sequence as shown in SEQ ID NO: 11.

In certain preferred embodiments, the monoclonal antibody or antigen-binding fragment thereof is selected from the group consisting of Fab, Fab', F(ab') ₂ , Fd, Fv, dAb, complementarity determining region fragments, single-chain antibodies (e.g., scFv), human antibody, chimeric antibody or bispecific or multispecific antibody.

In certain preferred embodiments, the monoclonal antibody further includes a heavy chain constant region. In some preferred embodiments, the amino acid sequence of the heavy chain constant region is shown in SEQ ID NO: 9.

In certain preferred embodiments, the monoclonal antibody further includes a light chain constant region. In some preferred embodiments, the amino acid sequence of the light chain constant region is shown in SEQ ID NO: 10.

In some preferred embodiments, the light chain of the monoclonal antibody is of κ type.

In some preferred embodiments, the monoclonal antibody or antigen-binding fragment thereof can specifically bind to the spike protein (S protein) of the novel coronavirus. In certain preferred embodiments, the monoclonal antibody or antigen-binding fragment thereof can target the receptor binding domain (RBD) of the spike protein (S protein) of the novel coronavirus. In certain preferred embodiments, the monoclonal antibody or antigen-binding fragment thereof can inhibit the receptor binding and/or membrane fusion process mediated by the receptor binding domain (RBD) of the S protein, and inhibit virus infection of cells .

In some preferred embodiments, the monoclonal antibody or antigen-binding fragment thereof has a neutralizing ability (for example, it can neutralize a novel coronavirus). In some preferred embodiments, the monoclonal antibody or antigen-binding fragment thereof can inhibit the infection or entry of the new coronavirus into host cells. Thus, the monoclonal antibody or its antigen-binding fragment can neutralize the novel coronavirus, and thereby prevent and treat the infection of the novel coronavirus.

The application also provides an isolated nucleic acid molecule, which encodes the monoclonal antibody or antigen-binding fragment thereof of the present invention. Such nucleic acid molecules are not limited to the method of their production, and can be obtained using genetic engineering recombination techniques or chemical synthesis methods.

Therefore, in another aspect, the present invention provides an isolated nucleic acid molecule comprising a nucleotide sequence capable of encoding an antibody heavy chain variable region, wherein the antibody heavy chain variable region comprises: the amino acid sequence is SEQ ID NO: 1-3 of VHCDR1-3.

In some preferred embodiments, the antibody heavy chain variable region has an amino acid sequence as shown in SEQ ID NO:7.

In some preferred embodiments, the nucleic acid molecule has a nucleotide sequence as shown in SEQ ID NO: 12.

In another aspect, the present invention provides an isolated nucleic acid molecule comprising a nucleotide sequence capable of encoding an antibody light chain variable region, wherein the antibody light chain variable region comprises: the amino acid sequence is SEQ ID NO: 4- 6 VL CDR1-3.

In certain preferred embodiments, the antibody light chain variable region has an amino acid sequence as shown in SEQ ID NO: 8.

In some preferred embodiments, the nucleic acid molecule has a nucleotide sequence as shown in SEQ ID NO: 13.

In another aspect, the present invention provides an isolated nucleic acid molecule comprising a nucleotide sequence capable of encoding a variable region of an antibody heavy chain as defined above, and a nucleotide sequence capable of encoding a variable region of an antibody light chain as defined above. Nucleotide sequence.

In some preferred embodiments, the antibody heavy chain variable region has an amino acid sequence as shown in SEQ ID NO:7. In some preferred embodiments, the nucleotide sequence capable of encoding the variable region of the antibody heavy chain has the nucleotide sequence shown in SEQ ID NO: 12.

In certain preferred embodiments, the nucleic acid molecule further comprises a nucleotide sequence encoding a leader sequence, which is located at the 5'end of the nucleotide sequence capable of encoding the variable region of the antibody heavy chain. In some preferred embodiments, the leader sequence has an amino acid sequence as shown in SEQ ID NO: 11. In some preferred embodiments, the nucleotide sequence encoding the leader sequence has the nucleotide sequence shown in SEQ ID NO: 16.

In certain preferred embodiments, the antibody light chain variable region includes the amino acid sequence shown in SEQ ID NO: 8. In some preferred embodiments, the nucleotide sequence capable of encoding the variable region of the antibody light chain has the nucleotide sequence shown in SEQ ID NO: 13.

In certain preferred embodiments, the nucleic acid molecule further comprises a nucleotide sequence encoding a leader sequence, which is located at the 5'end of the nucleotide sequence capable of encoding the variable region of the antibody light chain. In some preferred embodiments, the leader sequence has an amino acid sequence as shown in SEQ ID NO: 11. In some preferred embodiments, the nucleotide sequence encoding the leader sequence has the nucleotide sequence shown in SEQ ID NO: 16.

In certain preferred embodiments, the isolated nucleic acid molecule comprises the nucleotide sequence shown in SEQ ID NO: 12 and the nucleotide sequence shown in SEQ ID NO: 13.

In certain preferred embodiments, the isolated nucleic acid molecule comprises a first polynucleotide comprising a nucleotide sequence encoding a leader sequence and a nucleotide sequence capable of encoding the variable region of an antibody heavy chain; and, The second polynucleotide includes a nucleotide sequence encoding a leader sequence and a nucleotide sequence capable of encoding the variable region of the antibody light chain.

In certain preferred embodiments, the isolated nucleic acid molecule comprises a first polynucleotide, which comprises the nucleotide sequence shown in SEQ ID NO: 16 and the nucleoside shown in SEQ ID NO: 12 Acid sequence; and, the second polynucleotide, which comprises the nucleotide sequence shown in SEQ ID NO: 16 and the nucleotide sequence shown in SEQ ID NO: 13.

In certain preferred embodiments, the isolated nucleic acid molecule further comprises a nucleotide sequence capable of encoding the constant region of the antibody heavy chain. In some preferred embodiments, the heavy chain constant region has an amino acid sequence as shown in SEQ ID NO:9. In some preferred embodiments, the nucleotide sequence capable of encoding the constant region of the antibody heavy chain has the nucleotide sequence shown in SEQ ID NO: 14.

In certain preferred embodiments, the isolated nucleic acid molecule further comprises a nucleotide sequence capable of encoding the constant region of the antibody light chain. In some preferred embodiments, the light chain constant region has an amino acid sequence as shown in SEQ ID NO: 10. In some preferred embodiments, the nucleotide sequence capable of encoding the constant region of the antibody light chain has the nucleotide sequence shown in SEQ ID NO: 15.

In certain preferred embodiments, the isolated nucleic acid molecule comprises a first polynucleotide, which comprises a nucleotide sequence encoding a leader sequence, a nucleotide sequence capable of encoding the variable region of an antibody heavy chain, and a nucleotide sequence capable of encoding The nucleotide sequence of the constant region of the antibody heavy chain; and, the second polynucleotide comprising a nucleotide sequence encoding a leader sequence, a nucleotide sequence capable of encoding the variable region of the antibody light chain, and a nucleotide sequence capable of encoding the antibody light chain The nucleotide sequence of the constant region.

In certain preferred embodiments, the isolated nucleic acid molecule comprises a first polynucleotide, which comprises the nucleotide sequence shown in SEQ ID NO: 16, SEQ ID NO: 12 and SEQ ID NO: 14 ; And, the second polynucleotide, which comprises the nucleotide sequence shown in SEQ ID NO: 16, SEQ ID NO: 13 and SEQ ID NO: 15.

In another aspect, the present invention provides an isolated nucleic acid molecule encoding the monoclonal antibody or antigen-binding fragment thereof of the present invention as defined above.

In another aspect, the invention provides a vector comprising an isolated nucleic acid molecule as defined above. The vector of the present invention can be a cloning vector or an expression vector. In certain preferred embodiments, the vectors of the present invention are, for example, plasmids, cosmids, bacteriophages and the like.

In another aspect, there is also provided a host cell comprising the isolated nucleic acid molecule or vector of the present invention. Such host cells include, but are not limited to, prokaryotic cells such as E. coli cells, and eukaryotic cells such as yeast cells, insect cells, plant cells and animal cells (such as mammalian cells, such as mouse cells, human cells, etc.). The cells of the present invention can also be cell lines, such as 293T cells.

In another aspect, there is also provided a method for preparing the monoclonal antibody of the present invention or an antigen-binding fragment thereof, which comprises culturing the host cell of the present invention under suitable conditions, and recovering the monoclonal antibody of the present invention from the cell culture. Antibodies or antigen-binding fragments thereof.

In another aspect, the present invention provides a composition comprising the monoclonal antibody or antigen-binding fragment thereof, isolated nucleic acid molecule, vector or host cell as described above.

In another aspect, the present invention provides a kit comprising the monoclonal antibody or antigen-binding fragment thereof of the present invention. In certain preferred embodiments, the monoclonal antibody or antigen-binding fragment thereof of the present invention further includes a detectable label. In some preferred embodiments, the kit further includes a second antibody, which specifically recognizes the monoclonal antibody or antigen-binding fragment thereof of the present invention. Preferably, the second antibody further includes a detectable label. Such detectable labels are well known to those skilled in the art, and include, but are not limited to, radioisotopes, fluorescent substances, luminescent substances, colored substances, enzymes (such as horseradish peroxidase) and the like.

In another aspect, the present invention provides a method for detecting the presence or level of a novel coronavirus or its S protein or S protein RBD in a sample, which includes using the monoclonal antibody or antigen-binding fragment thereof of the present invention. In certain preferred embodiments, the monoclonal antibody or antigen-binding fragment thereof of the present invention further includes a detectable label. In another preferred embodiment, the method further includes using a second antibody carrying a detectable label to detect the monoclonal antibody or antigen-binding fragment thereof of the present invention. The method can be used for diagnostic purposes (for example, the sample is a sample from a patient), or for non-diagnostic purposes (for example, the sample is a cell sample, not a sample from a patient).

In another aspect, the present invention provides a method for diagnosing whether a subject is infected with a novel coronavirus, which comprises: using the monoclonal antibody or antigen-binding fragment thereof of the present invention to detect the RBD of the novel coronavirus or its S protein or S protein Presence in a sample from the subject. In certain preferred embodiments, the monoclonal antibody or antigen-binding fragment thereof of the present invention further includes a detectable label. In another preferred embodiment, the method further includes using a second antibody carrying a detectable label to detect the monoclonal antibody or antigen-binding fragment or anti-idiotypic antibody of the present invention.

In another aspect, there is provided the use of the monoclonal antibody or its antigen-binding fragment or anti-idiotype antibody of the present invention in the preparation of a kit for detecting the RBD of a novel coronavirus or its S protein or S protein The presence or level in the sample, or to diagnose whether the subject is infected with the new coronavirus.

In certain preferred embodiments, the sample includes, but is not limited to, excrement, oral or nasal secretions, alveolar lavage fluid, etc. from a subject (such as a mammal, preferably a human).

In some preferred embodiments, the monoclonal antibody is an antibody comprising: the amino acid sequence of the VH CDR1-3 shown in SEQ ID NO: 1-3, and/or the amino acid sequence of the VH CDR1-3 shown in SEQ ID, respectively VL CDR1-3 shown in NO: 4-6; preferably, it includes: VH shown in SEQ ID NO: 7 and/or VL shown in SEQ ID NO: 8.

The general method of using antibodies or antigen-binding fragments thereof to detect the presence or level of a target virus or antigen (for example, a novel coronavirus or its S protein or RBD of S protein) in a sample is well known to those skilled in the art. In some preferred embodiments, the detection method may use enzyme-linked immunosorbent assay (ELISA), enzyme immunoassay, chemiluminescence immunoassay, radioimmunoassay, fluorescence immunoassay, immunochromatography, competition method and similar detection methods .

In another aspect, the present invention provides a pharmaceutical composition comprising the monoclonal antibody or antigen-binding fragment thereof of the present invention, and a pharmaceutically acceptable carrier and/or excipient. In some preferred embodiments, the monoclonal antibody includes: the amino acid sequence of the VH CDR1-3 shown in SEQ ID NO: 1-3, and/or the amino acid sequence of the VH CDR1-3 shown in SEQ ID NO: 4-6, respectively Preferably, the monoclonal antibody includes: VH as shown in SEQ ID NO: 7 and/or VL as shown in SEQ ID NO: 8.

In another aspect, the present invention provides a method for neutralizing the virulence of a novel coronavirus in a sample, which comprises contacting a sample containing the novel coronavirus with the monoclonal antibody or antigen-binding fragment thereof of the present invention. Such methods can be used for therapeutic purposes, or non-therapeutic purposes (for example, the sample is a cell sample, not a patient or a sample from a patient).

In another aspect, there is provided the use of the monoclonal antibody or the antigen-binding fragment thereof of the present invention for the preparation of a medicament for neutralizing the virulence of the novel coronavirus in a sample. In another aspect, the present invention provides the monoclonal antibody or antigen-binding fragment thereof as described above, which is used to neutralize the virulence of the novel coronavirus in a sample.

In another aspect, there is provided the use of the monoclonal antibody or its antigen-binding fragment or anti-idiotype antibody of the present invention in the preparation of a pharmaceutical composition for the prevention or treatment of a novel coronavirus infection in a subject Or diseases related to novel coronavirus infection (such as novel coronavirus pneumonia). In another aspect, the present invention provides the monoclonal antibody or antigen-binding fragment thereof as described above, which is used to prevent or treat a novel coronavirus infection in a subject or a disease related to a novel coronavirus infection (such as a novel coronavirus infection). Viral pneumonia).

In another aspect, the present invention provides a method for preventing or treating a novel coronavirus infection or a novel coronavirus infection-related disease (such as novel coronavirus pneumonia) in a subject, which includes, giving a subject in need The person administers a prophylactic or therapeutically effective amount of the monoclonal antibody or antigen-binding fragment thereof of the present invention, or the pharmaceutical composition of the present invention.

In certain preferred embodiments, the subject is a mammal, such as a human.

The monoclonal antibody or antigen-binding fragment thereof of the present invention or the pharmaceutical composition of the present invention can be administered to a subject by any appropriate route of administration. Such administration routes include, but are not limited to, oral, buccal, sublingual, topical, parenteral, rectal, intrathecal, or nasal routes.

In some preferred embodiments, the monoclonal antibody is an antibody comprising: the amino acid sequence of the VH CDR1-3 shown in SEQ ID NO: 1-3, and/or the amino acid sequence of the VH CDR1-3 shown in SEQ ID, respectively VL CDR1-3 shown in NO: 4-6; preferably, it includes: VH shown in SEQ ID NO: 7 and/or VL shown in SEQ ID NO: 8.

The drugs and pharmaceutical compositions provided by the present invention can be used alone or in combination, and can also be used in combination with other pharmacologically active agents (for example, antiviral drugs, such as fapilavir, remdesivir, interferon, etc.). In certain preferred embodiments, the pharmaceutical composition further contains a pharmaceutically acceptable carrier and/or excipient.

Sequence information

The partial sequence information involved in this application is shown in Table 1 below.

Table 1. Partial sequence information

Beneficial effect

The monoclonal antibody (such as the B38 antibody) of the present application can bind to the new coronavirus S protein RBD with high affinity, and has strong neutralizing activity against the new coronavirus. For example, the affinity of the B38 antibody of the present invention to RBD is 70.1 nM, and the neutralization titer (half inhibitory concentration, IC ₅₀ ) of the novel coronavirus is 0.177 μg/mL. Therefore, the monoclonal antibody (for example, the B38 antibody) of the present application has clinical application value for preventing and treating novel coronavirus infection.

Description of the drawings

Figure 1 shows the results of molecular sieve chromatography and SDS-PAGE detection of the new coronavirus S protein RBD.

Figure 2 shows the molecular sieve chromatography results and SDS-PAGE detection results of the recombinantly expressed B38 antibody. The "-" on the gel chart indicates that DTT (non-reducing SDS-PAGE) is not added; "+" indicates that DTT (reduced SDS-PAGE).

Figure 3 shows the results of the kinetic curve of B38 antibody binding to RBD protein.

Figure 4 shows the cell surface fluorescence detected by BD FACSCanto in Example 6.

Figure 5 shows the neutralizing activity of different concentrations of B38 antibody against 2019-nCoV live virus.

Detailed ways

The invention will now be described with reference to the following examples which are intended to illustrate the invention rather than limit the invention.

Unless otherwise specified, the molecular biology experimental methods and immunoassay methods used in the present invention basically refer to J. Sambrook et al., Molecular Cloning: Laboratory Manual, 2nd Edition, Cold Spring Harbor Laboratory Press, 1989, and FMAusubel et al., Compiled Molecular Biology Experiment Guide, 3rd Edition, John Wiley & Sons, Inc., 1995; the restriction enzymes are used in accordance with the conditions recommended by the product manufacturer. If no specific conditions are indicated in the examples, it shall be carried out in accordance with the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used without the manufacturer's indication are all conventional products that can be purchased commercially. Those skilled in the art know that the embodiments describe the present invention by way of example, and are not intended to limit the scope of protection claimed by the present invention.

In order to obtain a neutralizing antibody with a protective effect, the inventors of the present application first used the S protein RBD of 2019-nCoV expressed in E. coli as the antigen, and through flow sorting, from the periphery of people who were infected with 2019-nCoV and recovered and discharged. From blood mononuclear cells (PBMCs), memory B cells that can specifically bind to the S protein RBD are screened, and then RT-PCR is performed on the single B cells obtained from the screening to obtain the sequence encoding the variable region of the antibody. Furthermore, the sequence encoding the variable region of the antibody and the constant region gene are linked to an expression vector, and expressed and purified in mammalian cells to obtain antibody B38. A series of functional tests on antibody B38 showed that antibody B38 can specifically bind to S protein RBD, block the binding of S protein RBD to ACE2, inhibit the infection of human cells by 2019-nCoV, and has anti-2019-nCoV infection. Neutralizing activity.

Example 1: Expression and purification of 2019-nCoV virus S protein RBD

Using NdeI and XhoI enzymes, the DNA fragment encoding the 2019-nCoV/2019 strain spike protein S protein RBD (the amino acid sequence of which is shown in SEQ ID NO: 17) was ligated to the pET21a vector, and the DNA fragment was in the coding region A nucleotide sequence encoding a 6*histidine tag (6*His tag) and a stop codon are also attached to the 3'end of the. The ligation product was transformed into BL21 E. coli competent cells. Then, pick a single clone, inoculate it into 40mL LB medium, culture for 6-8 hours; then transfer it to 4L LB medium, and cultivate it at 37 degrees Celsius to OD600=0.4-0.6. Subsequently, IPTG was added to the culture to a final concentration of 1 mM, and the culture was continued at 37 degrees Celsius for 4-6 hours. After the cultivation, the inclusion bodies were harvested and renatured. The refolded protein solution was concentrated and dialyzed into 20mM Tris, 150mM NaCl, pH9.0 buffer. Subsequently, the protein in the solution was purified by molecular sieve chromatography, using AKTA-purifier (GE) and superdex200 Hiload 16/60 column (GE) and buffer A (20mM Tris, 150mM NaCl, pH9.0), and During the purification process, the UV absorption value at 280nm was monitored at the same time, and the fraction containing the target protein was collected. After purification, the purity of the target protein (RBD of S protein) was identified by SDS-PAGE. The result is shown in Figure 1. The results in Figure 1 show that a high-purity RBD protein with a size of 32 kDa was obtained.

Example 2: Isolation of memory B cells that specifically recognize RBD protein

With the informed consent of those who were infected with the 2019-nCoV virus and recovered and discharged from the hospital, 10 mL of blood was collected to isolate PBMCs. The separated PBMCs were ^{incubated with a final concentration of 400 nM RBD protein (prepared in Example 1) at a density of 10 7} /mL for half an hour on ice; then washed twice with PBS, and then combined with the following antibodies (all purchased from BD) Incubation: anti-human CD3/PE-Cy5, anti-human CD16/PE-Cy5, anti-human CD235a/PE-Cy5, anti-human CD19/APC-Cy7, anti-human CD27/Pacific Blue, anti- human CD38/APC, anti-human IgG/FITC, and anti-His/PE. After incubating for half an hour on ice, the PBMCs were washed twice with PBS. Subsequently, PBMCs were sorted with FACSAria III, PE ^- Cy5 ^- APC ^- APC ^- Cy7 ⁺ Pacific Blue ⁺ FITC ⁺ PE ⁺ cells (ie, B cells) were collected, and directly collected into a 96-well plate, 1 cell/well.

Example 3: Isolation and identification of B38 antibody and construction of recombinant expression vector

Superscript III reverse transcriptase (Invitrogen) was used to perform reverse transcription on the B cells obtained in Example 2 (at 55° C. for 60 minutes), wherein the reverse transcription primers used are shown in Table 2.

Table 2. Sequence information of the reverse transcription primers used

Using the reverse transcription product as a template, the first round of PCR (PCRa) was performed with HotStar Tap Plus enzyme (QIAgen) to amplify the sequence of the antibody variable region; the primers used are shown in Table 3; the reaction conditions used As follows: 95°C, 5min; 35 cycles (95°C 30s, 55°C (heavy chain/κ chain) 30s, 72°C 90s); 72°C, 7min. Subsequently, the second round of PCR (PCRb) was performed with the amplified product as a template; the primers used are shown in Table 4; the reaction conditions used are as follows: 95°C, 5min; 35 cycles of (95°C) 30s, 58°C (heavy chain)/60°C (κ chain)/64°C (λ chain) 30s, 72°C (90s); 72°C, 7min.

The PCR products were separated by 1% agarose gel electrophoresis. The PCR product with a band size of 400-500bp was recovered and sent to a sequencing company for sequencing. The sequencing results were analyzed with NCBI online software.

Through sequence determination, the sequence of an antibody was obtained, named B38. The amino acid sequence of the heavy chain variable region of the B38 antibody is shown in SEQ ID NO: 7 (the coding gene is shown in SEQ ID NO: 12), and the amino acid sequence of the light chain variable region is shown in SEQ ID NO: 8 (coding The gene is shown in SEQ ID NO: 13). The sequence identity between the B38 antibody and germline genes is shown in Table 5-6 below.

Table 3. Primers used in the first round of PCR (PCRa)

Table 4. Primers used in the second round of PCR (PCRb)

Table 5. Comparison of B38 antibody heavy chain and germline genes

Table 6. Comparison of B38 antibody light chain and germline genes

The nucleotide sequence encoding the heavy chain/light chain variable region obtained by the analysis was connected to the corresponding nucleotide sequence encoding the heavy chain/κ chain constant region by bridging PCR, and then cloned into the expression vector pCAGGS( Purchased from Addgene) to obtain recombinant expression vectors encoding antibody heavy and light chains, respectively. The construction scheme of the construct expressing the heavy chain and the light chain is as follows:

Heavy chain coding sequence (5’-3’): CMV promoter-EcoR I restriction site-Leader sequence gene-VH gene-CH gene-Xho I restriction site;

Light chain (κ) coding sequence (5’-3’): CMV promoter-Sac I restriction site-Leader sequence gene-VL gene-CL (κ) gene-Xho I restriction site;

The amino acid sequence of the leader sequence is shown in SED ID NO: 11 (the coding gene is shown in SEQ ID NO: 16), and the amino acid sequence of CH is shown in SED ID NO: 9 (the coding gene is shown in SEQ ID NO: 14). (Shown), the amino acid sequence of CL is shown in SED ID NO: 10 (the coding gene is shown in SEQ ID NO: 15).

Example 4: Expression of B38 antibody

Culture 293T cells in DMEM containing 10% FBS. 293T cells were co-transfected with the recombinant expression vectors obtained in Example 3 encoding the antibody heavy chain and light chain respectively. After 4-6 hours of transfection, the cell culture medium was replaced with serum-free DMEM, and the culture was continued for 3 days. Collect the supernatant, add DMEM, continue the culture for 4 days, and then collect the supernatant again.

Centrifuge the collected supernatant at 5000 rpm for 30 min, then mix it with an equal volume of buffer containing 20 mM sodium phosphate (pH 7.0), then filter it with a 0.22 μm filter membrane, and then load it on a protein A prepacked column (5 mL, GE Healthcare). ). The protein bound to the pre-packed column was eluted with 10 mM glycine (pH 3.0). The eluted fraction is concentrated and then purified by molecular sieve chromatography. Subsequently, the purified target protein was detected by SDS-PAGE (reducing and non-reducing). The result is shown in Figure 2. The results in Figure 2 show that purified B38 antibody was obtained.

Example 5: Evaluation of the binding ability of B38 antibody and S protein RBD

In this embodiment, Biacore 8K (Biacore Inc.) is used to perform surface plasmon resonance analysis. Specific steps are as follows:

First, the anti-human IgG antibody is immobilized on the flow cell (Fc) of the CM5 chip by means of amino coupling. The fixed amount is controlled at around 8,000 response units (RU). Then, it binds to the purified B38 antibody by means of antibody capture. In addition, the RBD protein was diluted with a solution of 20 mM HEPES, 150 mM NaCl, pH 7.4 in successive times. Then, the serially diluted RBD protein was sequentially passed through each channel (starting with a low concentration and loaded one by one). Record the kinetic curve of the binding of the B38 antibody to the RBD protein (Figure 3), and use the BIA evaluation software 8K (Biacore, Inc.) software to calculate the kinetic constants (as shown in Table 4). The results in Figure 3 and Table 4 show that the B38 antibody can bind to the RBD of the S protein of 2019-nCoV with higher affinity.

Table 4. The binding kinetic constants of antibody and RBD protein

To	ka(1/Ms)	kd(1/s)	KD(M)
B38	3.73E+04	3.25E-02	7.01E-08

Example 6: Evaluation of the ability of B38 to block the binding of RBD to ACE2

Using XhoI and BamHI, the gene encoding hACE2 protein (Genbank accession number: NP_068576.1) was cloned into the pEGFP-N1 vector (purchased from Addgene), and the gene can be fused and expressed with the gene encoding GFP to construct a plasmid pEGFP-hACE2. The plasmid pEGFP-hACE2 was transfected into HEK293T cells. After 24h, the expression of GFP can be observed under a fluorescence microscope. Collect HEK293T-hACE2 cells. The irrelevant antibody was incubated with 200ng/mL RBD protein at a molar ratio of 10:1 for 1h at room temperature. Then, HEK293T-hACE2 cells (2x10 ⁵ /reaction) were incubated with the RBD protein (200ng/ml, carrying 6*His tag) incubated with irrelevant antibodies for 30min at room temperature. After centrifugation at 500xg for 5 min, the supernatant was removed, and the cells were washed twice with PBS. Subsequently, the cells were incubated with anti-His/APC (Miltenyi Biotec, 130-119-820) at room temperature for 30 minutes, and then washed twice with PBS, and then the fluorescence on the cell surface was detected with BD FACSCanto.

In order to detect the blocking effect of the B38 antibody, the B38 antibody purified in Example 4 was incubated with 200 ng/mL RBD protein at a molar ratio of 10:1 for 1 h at room temperature, and then incubated with HEK293T-hACE2 cells. Then, as described above, use anti-His/APC to detect the binding of RBD protein to cells. The result is shown in Figure 4. Figure 4 shows the cell surface fluorescence detected by BD FACSCanto. The results show that the number of hACE2-positive and RBD-positive cells (ie, cells with dual fluorescence) in the right frame is significantly less than that in the left frame; this indicates that the B38 antibody can effectively block the S protein RBD of 2019-nCoV Combination with HEK293T-hACE2 cells.

Example 7: Evaluation of the ability of B38 antibody to neutralize live 2019-nCoV virus

The B38 antibody purified in Example 4 was diluted from 200 μg/mL to the 12th gradient (0.098 μg/mL), and then respectively compared with the BetaCoV/Shenzhen/SZTH-003/2020 of _{half the tissue culture infectious dose (TCID 50)} The virus (obtained from Shenzhen Third People's Hospital, GISAID number: EPI_ISL_406594) was mixed and incubated at 37 degrees Celsius for 2 hours. After incubation, the virus was added to a 96-well plate pre-seeded with Vero cells, and _{cultured in a 37°C, 5% CO 2} incubator for 4 days to observe the cytopathic effect (CPE), and calculate the neutralization of the B38 antibody Titer. The result is shown in Figure 5. Figure 5 shows the neutralizing activity of different concentrations of B38 antibody against 2019-nCoV live virus. The results showed that the neutralizing titer (half inhibitory concentration, IC ₅₀ ) of the B38 antibody against the live 2019-nCoV virus was 0.177 μg/mL, which has excellent neutralizing activity.

Claims (14)

1. A monoclonal antibody or an antigen-binding fragment thereof, comprising, the amino acid sequence of the heavy chain variable region (VH) complementarity determining region 1-3 (CDR1-3) shown in SEQ ID NO: 1-3, respectively; and/ Or, the amino acid sequence of the light chain variable region (VL) complementarity determining region 1-3 (CDR1-3) shown in SEQ ID NO: 4-6, respectively;

   Preferably, the monoclonal antibody includes, as shown in SEQ ID NO: 7 heavy chain variable region (VH), and/or, as shown in SEQ ID NO: 8 light chain variable region (VL) ；

   Preferably, the monoclonal antibody comprises: the amino acid sequence of VH CDR1-3 shown in SEQ ID NO: 1-3, and the amino acid sequence of VL CDR1-3 shown in SEQ ID NO: 4-6;

   Preferably, the monoclonal antibody includes: VH as shown in SEQ ID NO: 7 and VL as shown in SEQ ID NO: 8;

   Preferably, the monoclonal antibody further has a leader sequence at the N-terminus of the heavy chain variable region, and/or, the monoclonal antibody further has a leader sequence at the N-terminus of the light chain variable region;

   Preferably, the leader sequence has an amino acid sequence as shown in SEQ ID NO: 11;

   Preferably, the monoclonal antibody or antigen-binding fragment thereof is selected from the group consisting of Fab, Fab', F(ab') ₂ , Fd, Fv, dAb, complementarity determining region fragments, single-chain antibodies (e.g., scFv), human antibodies, Chimeric antibody or bispecific or multispecific antibody;

   Preferably, the monoclonal antibody further includes a heavy chain constant region; preferably, the amino acid sequence of the heavy chain constant region is shown in SEQ ID NO: 9;

   Preferably, the monoclonal antibody further includes a light chain constant region; preferably, the amino acid sequence of the light chain constant region is shown in SEQ ID NO: 10.
2. An isolated nucleic acid molecule comprising a nucleic acid sequence capable of encoding an antibody heavy chain variable region, wherein the antibody heavy chain variable region comprises: VH CDR1-3 with an amino acid sequence of SEQ ID NO: 1-3;

   For example, the variable region of the antibody heavy chain has an amino acid sequence as shown in SEQ ID NO: 7;

   For example, the nucleic acid molecule has a nucleotide sequence as shown in SEQ ID NO: 12.
3. An isolated nucleic acid molecule comprising a nucleic acid sequence capable of encoding an antibody light chain variable region, wherein the antibody light chain variable region comprises: VL CDR1-3 with an amino acid sequence of SEQ ID NO: 4-6;

   For example, the variable region of the antibody light chain has an amino acid sequence as shown in SEQ ID NO: 8;

   For example, the nucleic acid molecule has a nucleotide sequence as shown in SEQ ID NO: 13.
4. An isolated nucleic acid molecule that encodes the monoclonal antibody of claim 1 or an antigen-binding fragment thereof.
5. A vector comprising the isolated nucleic acid molecule of any one of claims 2-4.
6. A host cell comprising the isolated nucleic acid molecule of any one of claims 2-4 or the vector of claim 5.
7. A method for preparing the monoclonal antibody or antigen-binding fragment thereof of claim 1, which comprises culturing the host cell of claim 6 under suitable conditions, and recovering the monoclonal antibody or antigen-binding fragment thereof from the cell culture.
8. A composition comprising the monoclonal antibody or antigen-binding fragment thereof of claim 1, the isolated nucleic acid molecule of any one of claims 2-4, the vector of claim 5, and the host cell of claim 6.
9. A kit comprising the monoclonal antibody or antigen-binding fragment thereof of claim 1;

   For example, the monoclonal antibody or its antigen-binding fragment or anti-idiotypic antibody also includes detectable labels, such as radioisotopes, fluorescent substances, luminescent substances, colored substances and enzymes;

   For example, the kit further includes a second antibody, which specifically recognizes the monoclonal antibody or its antigen-binding fragment or anti-idiotypic antibody; optionally, the second antibody also includes a detectable label, such as radioactive Isotopes, fluorescent substances, luminescent substances, colored substances and enzymes.
10. A method for detecting the presence or level of a novel coronavirus or its S protein or S protein RBD in a sample, which comprises using the monoclonal antibody of claim 1 or an antigen-binding fragment thereof;

    For example, the monoclonal antibody or its antigen-binding fragment or anti-idiotypic antibody also includes detectable labels, such as radioisotopes, fluorescent substances, chemiluminescent substances, colored substances and enzymes;

    For example, the method further includes the use of a second antibody carrying a detectable label (such as a radioisotope, a fluorescent substance, a luminescent substance, a colored substance, and an enzyme) to detect the monoclonal antibody or its antigen-binding fragment or anti-idiotype Antibody.
11. Use of the monoclonal antibody or antigen-binding fragment thereof of claim 1 in the preparation of a kit for detecting the presence or level of a novel coronavirus or its S protein or RBD in a sample, or To diagnose whether the subject is infected with the new coronavirus;

    Preferably, the sample is excrement, oral or nasal secretions, or alveolar lavage fluid from a subject (for example, a mammal, preferably a human).
12. A pharmaceutical composition comprising the monoclonal antibody or antigen-binding fragment thereof of claim 1, and a pharmaceutically acceptable carrier and/or excipient;

    Preferably, the pharmaceutical composition further contains other pharmaceutically active agents, such as favipiravir, remdesivir, interferon and the like.
13. A method for neutralizing the virulence of a novel coronavirus in a sample, which comprises contacting a sample containing the novel coronavirus with the monoclonal antibody or antigen-binding fragment thereof according to claim 1.
14. The use of the monoclonal antibody or antigen-binding fragment thereof of claim 1 in the preparation of a medicament for neutralizing the virulence of a novel coronavirus in a sample, or for preventing or treating a novel coronavirus infection in a subject or Diseases related to novel coronavirus infection (such as novel coronavirus pneumonia);

    Preferably, the subject is a mammal, such as a human;

    Preferably, the drug is used alone or in combination with other pharmacologically active agents (for example, favipiravir, remdesivir, interferon, etc.).

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