阅读说明：本技术 一种抗新型冠状病毒的单克隆抗体或其衍生体 (Monoclonal antibody or derivative thereof for resisting novel coronavirus ) 是由 朱凤才 张黎 高行素 郑滨洋 郭喜玲 陈银 王祥喜 李靖欣 于 2020-05-28 设计创作，主要内容包括：本发明公开了一种抗新型冠状病毒的单克隆抗体或其衍生体,其包含抗体轻链可变区的抗原互补决定区CDR1,CDR2和CDR3分别为SEQ ID NO：5,SEQ ID NO：6及SEQ ID NO：7的氨基酸序列；抗体重链可变区的抗原互补决定区CDR1,CDR2和CDR3分别为SEQ ID NO：1,SEQ ID NO：2及SEQ ID NO：3的氨基酸序列。本发明还公开了该抗体的制备过程及该抗体重链可变区与轻链可变区氨基酸序列。(The invention discloses a monoclonal antibody or a derivative thereof for resisting novel coronavirus, which comprises an antigen complementarity determining region CDR1 of an antibody light chain variable region, wherein CDR2 and CDR3 are respectively SEQ ID NO:5, SEQ ID NO:6 and SEQ ID NO: 7; the antigen complementarity determining regions CDR1, CDR2 and CDR3 of the antibody heavy chain variable region are SEQ ID NO:1, SEQ ID NO:2 and SEQ ID NO: 3. The invention also discloses the preparation process of the antibody and the amino acid sequences of the heavy chain variable region and the light chain variable region of the antibody.)

1. A monoclonal antibody or a derivative thereof against a novel coronavirus, comprising a first variable region and a second variable region, wherein the first variable region is an antibody light chain variable region comprising the antigen complementarity determining region CDR1, CDR2 and CDR3 respectively comprising the amino acid sequences set forth in SEQ ID NOs: 5, SEQ ID NO:6 and SEQ ID NO: 7; wherein the second variable region is an antibody heavy chain variable region comprising the antigen complementarity determining regions CDR1, CDR2 and CDR3 respectively comprising seq id NO:1, SEQ id no:2 and SEQ ID NO: 3;

preferably, the first variable region is an antibody light chain variable region comprising SEQ ID NO: 8; wherein said second variable region is an antibody heavy chain variable region comprising the amino acid sequence of SEQ id no: 4.

2. The monoclonal antibody or derivative thereof according to claim 1 or 2, characterized in that it comprises the antibody light chain variable region and antibody light chain constant region, and the hinge, CH1, CH 2 and CH3 regions of the antibody heavy chain variable region and antibody heavy chain constant region;

preferably, the antibody light chain constant region is from an antibody kappa chain or an antibody lamda chain and the antibody heavy chain constant region is from a human IgG1, IgG2, IgG3 or IgG4 subtype.

3. A DNA molecule or gene encoding the monoclonal antibody or derivative thereof of claim 1 or 2; preferably, the coding sequence for the variable region of the antibody light chain thereof comprises SEQ ID NO:10, and the coding sequence of the antibody heavy chain variable region comprises SEQ ID NO:9, or a nucleotide sequence shown in the specification.

4. An expression vector comprising the DNA molecule of claim 3 and an expression control sequence operably linked to said DNA molecule.

5. A recombinant host cell transformed with the expression vector of claim 4; preferably, the recombinant host cell or progeny thereof expresses the monoclonal antibody or derivative thereof of claim 1 or 2.

6. A method of preparing the monoclonal antibody or derivative thereof of claim 1 or 2, comprising the steps of:

a) providing an expression vector comprising the DNA molecule of claim 3 and an expression control sequence operably linked to said DNA molecule;

b) transforming a host cell with the expression vector of step a);

c) culturing the host cell obtained in step b) under suitable conditions: and

d) and (3) separating and purifying the monoclonal antibody or the derivative thereof from the culture solution of the host cell.

7. A method for the detection of a novel coronavirus, or a protein thereof, for non-diagnostic purposes, comprising administering a monoclonal antibody or derivative thereof according to claim 1 or 2.

8. A composition or kit comprising the monoclonal antibody or derivative thereof of claim 1 or 2.

9. Use of the monoclonal antibody or derivative thereof according to claim 1 or 2, comprising the use of any one of:

(1) the application in preparing a novel coronavirus detection product or a diagnosis product;

(2) the application in preparing the medicine for preventing or treating the infection of the novel coronavirus;

(3) the application in the preparation of the medicine for preventing or treating the diseases infected by the novel coronavirus.

10. Use of the composition of claim 8, comprising the use of any one of:

(1) the application in preparing a novel coronavirus detection product or a diagnosis product;

(2) the application in preparing the medicine for preventing or treating the infection of the novel coronavirus;

(3) the application in the preparation of the medicine for preventing or treating the diseases infected by the novel coronavirus.

Technical Field

The invention belongs to the fields of cellular immunology and molecular biology, and relates to a monoclonal antibody or a derivative thereof for resisting novel coronavirus.

Background

The international committee for viral classification named the novel coronavirus SARS-CoV-2 and the world health organization named the pneumonia caused by infection with this virus COVID-19. The virus has strong infectivity and wide transmission path. The virus can adapt to the human environment quickly, has the transmission capability in the latent period after infection, and reports by some asymptomatic infectors that virus nucleic acid can be detected even in various animals. These factors complicate the control of the virus and no effective therapeutic drugs and vaccines are currently on the market.

SARS-CoV-2 belongs to the genus Coronavirus, is a single-stranded positive-strand RNA virus, has a size of about 30kb, has a similarity of 79% to SARS-CoV, and has a similarity of up to about 88% to a Coronavirus (CoV) isolated from Bats. SARS-CoV-2 has typical coronavirus characteristics, and the virus envelope has typical spinous processes, which are shaped like coronages. The Spike protein (Spike protein) is the most important surface membrane protein of coronavirus, determines the host range and specificity of the virus, and is an important site of host neutralizing antibody and a key target point of vaccine design.

Because specific therapeutic drugs and effective vaccines have not been developed successfully, attempts to treat critically ill patients with convalescent patient plasma have been made, and have significant effects. Due to the complex composition of plasma and plasma products, and the potential risk factors. Neutralizing antibodies to viruses, particularly fully human monoclonal antibodies, are of particular importance in viral diagnosis and therapy. Monoclonal antibodies can recognize single epitope of virus, and some monoclonal antibodies with neutralization can infect adhesion host cells in the life cycle of virus by binding to specific sites of virus, such as receptor binding site, protease cleavage site, and attachment of membrane fusion site, and can play a role in neutralization by utilizing mechanisms such as membrane fusion and surface proteolysis. Wherein the fully human monoclonal antibody obtained from convalescent patients has more potential for drug development. Firstly, because the immune system in the convalescent patient is subjected to sufficient immune response, B cells are subjected to sufficient somatic high-frequency mutation, and the affinity of the antibody is matured to the maximum extent. And secondly, because the human immune system fully-humanized antibody does not generate immune response, the humanized antibody patent medicine has higher safety. Therefore, the human antibody with high affinity and high neutralizing activity has great application value in the aspects of controlling the novel coronavirus epidemic situation and treating severe patients.

Disclosure of Invention

One of the technical problems to be solved by the present invention is to provide a monoclonal antibody or its derivatives such as antibody Fab fragment, single chain antibody, etc. against novel coronavirus.

The second technical problem to be solved by the present invention is to provide a DNA molecule or gene encoding the above antibody.

The third technical problem to be solved by the present invention is to provide a method for preparing the above antibody.

In order to solve the technical problems, the invention adopts the following technical scheme:

in a first aspect of the present invention, there is provided a monoclonal antibody against a novel coronavirus, or a derivative thereof, comprising a first variable region and a second variable region, wherein the first variable region is an antibody light chain variable region whose antigen complementarity determining region CDR1, CDR2 and CDR3 comprise SEQ ID NO:5, SEQ ID NO:6 and SEQ ID NO: 7; wherein the second variable region is an antibody heavy chain variable region having the antigen complementarity determining regions CDR1, CDR2 and CDR3 of SEQ ID NO:1, SEQ ID NO:2 and SEQ ID NO: 3;

the derivatives of the monoclonal antibody include antibody Fab fragments, single chain antibodies, bispecific antibodies (bi-specific), and the like.

As a preferred embodiment of the present invention, the first variable region is an antibody light chain variable region which is represented by SEQ id no: 8; wherein said second variable region is an antibody heavy chain variable region represented by SEQ id no: 4.

As a preferred embodiment of the present invention, it comprises the antibody light chain variable region and the human antibody light chain constant region, and the hinge region, CH1 region, CH 2 region and CH3 region of the antibody heavy chain variable region and the human antibody heavy chain constant region.

As a preferred embodiment of the present invention, the human antibody light chain constant region is derived from a human antibody kappa chain or antibody lamda chain, and the human antibody heavy chain constant region is derived from human IgG1, IgG2, IgG3 or IgG4 subtypes.

In a second aspect of the invention, there is provided a DNA molecule or gene nucleotide sequence encoding the monoclonal antibody or derivative thereof as hereinbefore described.

As a preferred embodiment of the present invention, the variable region of the antibody light chain is SEQ ID NO:10, and the variable region of the antibody heavy chain is SEQ ID NO: 9.

In addition, the invention includes sequences that specifically hybridize to any of the nucleotide sequences provided herein. The term "specifically hybridizes" refers to the ability of a nucleotide sequence to hybridize to at least 12, 15, 20, 25, 30, 35, 40, 45, 50, or 100 linked nucleotides of a sequence provided herein or of a sequence complement thereto, such that it has less than 15%, preferably less than 10%, and more preferably less than 5% background hybridization to a control nucleic acid (e.g., non-specific DNA or DNA other than the specific antibody sequence provided herein). Various hybridization conditions can be used to detect specific hybridization, and stringency is largely determined by the washing steps of the hybridization assay. In general, high temperatures and low salt concentrations produce high stringency, while low temperatures and high salt concentrations produce low stringency. Low stringency hybridization is achieved by washing at 50 ℃ in, for example, about 2.0 XSSC, and high stringency is achieved with about 0.2 XSSC at 50 ℃.

The nucleotides encoding the antibodies of the invention or derivatives thereof may contain leader or signal sequences. The leader and signal sequences may be varied and may be substituted with alternative leader sequences, and it will be understood that in certain embodiments, the antibodies of the invention contain sequences without leader sequences. Any suitable alternative preamble or signal sequence may be used.

In a third aspect of the invention, there is provided an expression vector comprising the DNA molecule/gene nucleotide sequence set forth above and expression control sequences operatively linked to the sequence.

In a fourth aspect of the invention, there is provided a recombinant host cell transformed with an expression vector as hereinbefore described.

The recombinant host cell or progeny thereof expresses the monoclonal antibody or derivative thereof as described above.

In a fifth aspect of the invention, there is provided a method of preparing a monoclonal antibody or derivative thereof as hereinbefore described, the method comprising the steps of:

a) providing an expression vector comprising the DNA molecule sequence as described above and an expression control sequence operably linked to the sequence;

b) transforming a host cell with the expression vector of step a);

c) culturing the host cell obtained in step b) under suitable conditions: and

d) and (3) separating and purifying the monoclonal antibody or the derivative thereof from the culture solution of the host cell.

In a sixth aspect of the invention, there is provided a composition comprising a monoclonal antibody or derivative thereof as hereinbefore described.

According to a particular embodiment, the composition is a pharmaceutical composition comprising an antibody or antigen-binding portion of the invention and a pharmaceutically acceptable carrier.

Pharmaceutically acceptable carriers include any solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, as long as they are physiologically compatible. Pharmaceutically acceptable carriers include, for example, water, saline, phosphate buffered saline, dextrose, glycerol, ethanol, and the like, and combinations thereof. In most cases, it is preferred to use isotonic agents, for example, sugars, polyalcohols such as mannitol or sorbitol, or sodium chloride. Pharmaceutically suitable carriers may additionally comprise relatively small amounts of auxiliary substances which increase the half-life or effectiveness of the antibody, such as wetting or emulsifying agents, preservatives or buffers.

For example, the pharmaceutical composition may be suitable for parenteral administration. Here, the antibody is preferably prepared as an injectable solution having an antibody content of 0.1-250 mg/ml. Injectable solutions can be prepared in liquid or lyophilized form in lead oxide glass vials or vials, ampoules or drug-loaded syringes. The buffer may contain L-histidine (1-50mM, preferably 5-10mM) and have a pH of 5.0-7.0, preferably 6.0. Further suitable buffers include, but are not limited to, sodium succinate, sodium citrate, sodium phosphate or potassium phosphate buffers. Sodium chloride may be used in order to adjust the tonicity of the solution to a concentration of 0-300mM (for liquid dosage forms, 150mM is preferred). For lyophilized dosage forms, a cryoprotectant such as sucrose (e.g., 0-10%, preferably 0.5-1.0%) may also be included. Other suitable cryoprotectants are trehalose and lactose. For lyophilized dosage forms, bulking agents such as mannitol (e.g., 1-10%, preferably 2-4%) may also be included. Stabilizers such as L-methionine (e.g., 51-50mM, preferably 5-10mM) may be used in liquid and lyophilized dosage forms. More suitable bulking agents are glycine and arginine. Surfactants such as polysorbate 80 (e.g. 0-0.05%, preferably 0.005-0.01%) may also be used. Further surfactants are polysorbate 20 and BRIJ surfactants.

The compositions of the present invention may have a variety of dosage forms. These dosage forms include liquid, semi-solid, and solid dosage forms, such as liquid solutions (e.g., injectable and infusible solutions), dispersions or suspensions, tablets, pills, powders, liposomes, and suppositories. The preferred dosage form depends on the type of administration desired and the therapeutic application. Typically, the compositions are preferably administered as injectable or infusible solutions, e.g., compositions similar to other antibodies used for passive immunization of humans. Preferred routes of administration are parenteral (e.g., intravenous, subcutaneous, intraperitoneal, or intramuscular). According to a preferred embodiment, the antibody is administered by intravenous infusion or injection. According to another preferred embodiment, the antibody is administered by intramuscular or subcutaneous injection.

The therapeutic compositions should generally be sterile and stable under the conditions of manufacture and storage. The compositions may be formulated as solutions, microemulsions, dispersions, liposomes or other ordered structures suitable for high concentrations of active substances. Sterile injectable solutions can be prepared by incorporating the active substance (i.e., the antibody) in the required amount in an appropriate solvent with one or a combination of the ingredients enumerated above, as required, followed by sterile filtration of the solution. Dispersions are generally prepared by incorporating the active substance into a sterile vehicle which contains a basic dispersion medium and, where appropriate, other necessary ingredients. In the case of sterile lyophilized powders for the preparation of sterile injectable solutions, vacuum drying and spray drying are the preferred methods of preparation, which yield a powder of the active ingredient and, where appropriate, further desired ingredient from a previously sterile-filtered solution thereof. The solution may be maintained suitably fluid, for example by the use of a coating such as lecithin, by maintaining the required particle size in the case of a dispersant or by the use of a surfactant. Prolonged absorption of the injectable compositions can be achieved by the additional incorporation into the compositions of agents delaying absorption, such as monostearate salts and gelatin.

Although the preferred type of administration for many therapeutic applications is subcutaneous injection, intravenous injection or infusion, the antibodies of the present invention can be administered by a variety of methods known to those skilled in the art. One skilled in the art will appreciate that the route and/or type of administration will depend on the desired result. According to particular embodiments, the active agent may be prepared with carriers that protect the active agent from rapid release, for example, sustained or controlled release formulations including implants, transdermal patches, and microencapsulated delivery systems. Biologically degradable biocompatible polymers such as ethylene glycol diacetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid can be used. Methods for preparing the above dosage forms are well known to those skilled in the art; see, e.g., Sustained and controlledRelease Drug delivery systems, J.R. Robinson, eds., Marcel Dekker, Inc., New York, 1978.

According to particular embodiments, the antibodies of the invention may be administered orally, for example in an inert diluent or in a metabolically edible carrier. The antibody (and further ingredients, if desired) may also be encapsulated in hard or soft capsules, compressed into tablets, or added directly to a food product. For oral treatment, the antibody may be mixed with an excipient and used in the form of oral tablets, buccal tablets, capsules, elixirs, suspensions, syrups, and the like. If the antibody of the invention is intended to be administered by a route other than parenteral, it may be necessary to select a coating from substances which prevent inactivation of the antibody.

In a seventh aspect of the invention, there is provided a kit comprising a monoclonal antibody or derivative thereof as hereinbefore described. The kit also includes a diagnostic agent.

The diagnostic agent includes a detectable substance, examples of which include various enzymes, prosthetic groups, fluorescent materials, luminescent materials, bioluminescent materials, radionuclides, positron emitting metals (for use in positron emission tomography), and nonradioactive paramagnetic metal ions. With respect to metal ions which can be conjugated to antibodies for use as diagnostic agents, aSee generally U.S. Pat. No. 4,741,900. suitable enzymes include horseradish peroxidase, alkaline phosphatase, β -galactosidase, or acetylcholinesterase, suitable prosthetic groups include streptavidin, avidin, and biotin, suitable fluorescent materials include umbelliferone, fluorescein isothiocyanate, rhodamine, dichlorotriazinylamine fluorescein, dansyl chloride, and phycoerythrin, suitable luminescent materials include luminol, suitable bioluminescent materials include luciferase, luciferin, and aequorin, radioactive isotopes, such as radioactive isotopes¹²⁵I、¹³¹I、¹¹¹In and⁹⁰Y、Lu¹⁷⁷bismuth, bismuth²¹³Californium²⁵²Iridium (III)¹⁹²And tungsten¹⁸⁸Rhenium¹⁸⁸、²¹¹Astatine, astatine,⁹⁹Tc。

The kits of the invention also include a label and instructions for administration.

In the eighth aspect of the invention, the application of the monoclonal antibody or the derivative thereof in preparing a novel coronavirus detection product or a novel coronavirus diagnosis product is provided.

In a ninth aspect of the present invention, there is provided the use of the monoclonal antibody or derivative thereof as described above in the preparation of a medicament for the prevention or treatment of a novel coronavirus infection.

In the tenth aspect of the present invention, there is provided the use of the monoclonal antibody or the derivative thereof as described above for the preparation of a medicament for preventing or treating diseases caused by infection with a novel coronavirus.

In an eleventh aspect of the invention, there is provided the use of a composition as hereinbefore described in the manufacture of a test product or diagnostic product for the detection of a novel coronavirus.

In a twelfth aspect of the invention, there is provided the use of a composition as hereinbefore described in the manufacture of a medicament for the prophylaxis or treatment of a novel coronavirus infection.

In a thirteenth aspect of the invention, there is provided the use of a composition as hereinbefore described in the manufacture of a medicament for the prophylaxis or treatment of a disease caused by a novel coronavirus infection.

The term "monoclonal antibody (mab)" as used herein refers to an immunoglobulin derived from a pure line of cells, having the same structural and chemical properties, and being specific for a single antigenic determinant. Monoclonal antibodies differ from conventional polyclonal antibody preparations (usually having different antibodies directed against different determinants), each monoclonal antibody being directed against a single determinant on the antigen. In addition to their specificity, monoclonal antibodies are also advantageous in that they are obtained by hybridoma or recombinant engineered cell culture, and are not contaminated with other immunoglobulins. The modifier "monoclonal" indicates the character of the antibody as being obtained from a homogeneous population of antibodies, and is not to be construed as requiring production of the antibody by any particular method.

The terms "antibody" and "immunoglobulin" as used herein are heterotetrameric proteins of about 150000 daltons having the same structural features, consisting of two identical light chains (L) and two identical heavy chains (H). Each light chain is linked to a heavy chain by one covalent disulfide bond, while the number of disulfide bonds between heavy chains varies for different immunoglobulin isotypes. Each heavy and light chain also has regularly spaced intrachain disulfide bonds. Each heavy chain has a variable domain (VH) at one end. Followed by a plurality of constant regions. Each light chain has a variable domain (VL) at one end and a constant domain at the other end; the constant region of the light chain is opposite the first constant region of the heavy chain, and the variable region of the light chain is opposite the variable region of the heavy chain. Particular amino acid residues form the interface between the variable regions of the light and heavy chains.

The term "variable" as used herein means that certain portions of the variable regions of an antibody differ in sequence, which results in the binding and specificity of each particular antibody for its particular antigen. However, the variability is not evenly distributed throughout the antibody variable region. It is concentrated in three segments in the light and heavy chain variable regions that become Complementarity Determining Regions (CDRs) or hypervariable regions.

The more conserved portions of the variable regions are called Framework Regions (FR). The variable regions of the heavy and light chains of an antibody each comprise four FR regions, which are in a substantially β -sheet configuration, connected by three CDRs which form a connecting loop, and in some cases may form part of a β -sheet structure. The CDRs in each chain are held closely together by the FR region and form the antigen-binding site of the antibody together with the CDRs of the other chain (see Ka ba t et al, NIH Pu bl. No.91-3242, Vol. 1, 647, 669 (1991)). Antibody constant regions are not directly involved in binding of an antibody to an antigen, but they exhibit different effector functions, such as participation in antibody-dependent cellular cytotoxicity (ADCC) or complement-mediated toxicity (CDC) of an antibody.

The term "expression control sequence" as used herein generally refers to a sequence involved in controlling the expression of a gene. The expression control sequences include a promoter and a termination signal operably linked to the gene of interest. The gene (DNA) sequence encoding the antibody of the present invention can be obtained by conventional means well known to those skilled in the art, such as artificial synthesis of the protein sequence according to the present disclosure or amplification by PCR. The resulting DNA fragment, which may be synthesized or amplified by PCR, may then be inserted into a suitable expression vector by a variety of methods well known in the art. The expression vector used in the present invention may be a commercially available expression vector known to those skilled in the art, such as pCDNA3.1 expression vector of Invitrogen corporation.

Suitable host cells for transformation with the host cells to which the expression vectors are administered generally include prokaryotic and eukaryotic cells. Examples of commonly used prokaryotic host cells include E.coli, Bacillus subtilis, and the like. Commonly used eukaryotic host cells include yeast cells, insect cells, mammalian cells, and the like.

After culturing the host cells transformed with the expression vector under suitable conditions (e.g., adherent or suspension culture in a cell culture flask or bioreactor in serum-free medium), the culture supernatant is harvested and then purified by conventional separation procedures or procedures well known to those skilled in the art, including protein-A affinity chromatography, ion exchange chromatography, sterile filtration, etc., to obtain the antibody of the present invention.

The purified antibody of the present invention can be dissolved in a suitable solvent such as a sterile physiological saline solution, and the solubility can be prepared to be between 0.01 and 100mg/ml, and the desired final solubility can be prepared to be between 1 and 20 mg/ml.

Drawings

FIG. 1 is a graph showing the results of detecting the specific binding of the antibody of the present invention to recombinant S-ECD using indirect ELISA;

FIG. 2 is a graph showing the results of detection of specific binding of the antibody of the present invention to recombinant S-RBD using indirect ELISA;

FIG. 3 shows an electrophoretogram of proteins for detecting binding of the antibody of the present invention to S-RBD and S-ECD using immunoprecipitation;

FIG. 4 is a graph showing the results of detecting the affinity of the antibody of the present invention to S-RBD and S-ECD using SPR assay, wherein A: FC 05; b: FC 08; c: FC 11;

FIG. 5 is a graph showing the results of measuring the neutralizing activity of the antibody of the present invention using an in vitro neutralization assay.

Detailed Description

The invention is further illustrated by the following examples. It should be understood that the examples of the present invention are for illustrative purposes and not intended to limit the present invention. Simple modifications of the invention in accordance with its spirit fall within the scope of the claimed invention.