CN117820479A

CN117820479A - Novel nanobody against IL-17A

Info

Publication number: CN117820479A
Application number: CN202311865727.1A
Authority: CN
Inventors: 刘广洋; 刘拥军; 徐晓丹; 米一; 苗丽; 王道辉
Original assignee: Beijing Beilai Pharmaceutical Co ltd
Current assignee: Beijing Beilai Pharmaceutical Co ltd
Priority date: 2023-12-29
Filing date: 2023-12-29
Publication date: 2024-04-05

Abstract

The invention provides a novel nano antibody for resisting IL-17A. The novel nano antibody comprises two single-domain antibodies, and the amino acid sequence of the first single-domain antibody comprises HCDR1, HCDR2 and HCDR3 shown in SEQ ID NO. 1-3; and/or; an amino acid sequence having at least 80% sequence identity to the amino acid sequences shown in SEQ ID NO. 1-3; the second single domain antibody amino acid sequence comprises: HCDR4, HCDR5, HCDR6 as shown in SEQ ID nos. 4-6; and/or; an amino acid sequence having at least 80% sequence identity to the amino acid sequence shown in SEQ ID NO. 4-6. The antibody of the invention has IL-17A specificity, and the EC50 of the antibody combined with the target protein is 2.425 mug/mL; the IC50 of the antibody blocking function test is 0.7587 mug/mL, which is superior to the control antibody.

Description

Novel nanobody against IL-17A

Technical Field

The invention belongs to the field of antibodies, and particularly relates to a novel nano antibody for resisting IL-17A.

Background

Interleukin 17 (IL 17) is one of the 30 types of interleukins found, and is numbered at position 17. IL17 is secreted by CD4+ T cells, and can induce epithelial cells, endothelial cells and fibroblasts to synthesize and secrete IL-6, IL-8, G-CSF and PGE2, thereby promoting the expression of ICAM-1.

IL-17A protein was originally cloned in rodent activated hybridoma T cells, also originally called CTLA-8, and was the earliest found protein of the IL-17 family. IL-17A protein contains 177 amino acids in total, forms two pairs of antiparallel beta-sheets, and is stabilized in structure by multiple disulfide bonds. IL-17A is expressed in CD4+ T cells, and this protein induces IL-6 in fibroblasts. IL-17A is also a major vector for T-cell communication with the hematopoietic system, and in vivo overexpression can also lead to extramedullary granulocyte production. Studies have found that Th17 cell lineage commitment is independent of the traditional activation pathways of STAT4, STAT6, etc., i.e., inflammatory factors such as IL-17A and IL-6 are not identical. IL-17A plays a key role in host defense against various microbial pathogens and tissue inflammation, and therefore IL-17A has become an important target for drug discovery for the treatment of various forms of autoimmune and inflammatory diseases.

Antibodies as proteins capable of specifically binding to an antigen may be involved in neutralizing the antigen of interest, and when IL-17A protein is used as the antigen of interest, the art has often developed IL-17A antibodies to enable detection of IL-17A protein, or IL-17A-targeted diseases, autoimmune diseases or inflammatory diseases as described above, and the like, are treated with IL-17A antibodies. A pharmaceutical composition of a humanized anti-human IL-17A monoclonal antibody is disclosed, for example, in the Chinese patent application No. CN 201910935046.5. In particular, a pharmaceutical composition is provided, said pharmaceutical composition comprising: (a) an anti-human IL-17A monoclonal antibody; and (b) a pharmaceutically acceptable carrier, said pharmaceutically acceptable carrier comprising a buffer, a stabilizer, and a surfactant. The pharmaceutical composition can effectively improve the stability of the anti-human IL-17A monoclonal antibody under the conditions of pressurization (high temperature, freeze thawing, vibration and the like), acceleration and long-term refrigeration, and can improve the safety of clinical use. As further disclosed in chinese patent application No. CN202111031745.0, an antibody or antigen-binding fragment thereof that specifically binds to IL-17A, a preparation method and use thereof, compared with conventional antibodies, the anti-IL-17A antibody or antigen-binding fragment thereof (particularly nanobody and heavy chain antibody) of the present invention has significant advantages of small molecular weight, strong permeability, etc., so that it can recognize hidden epitopes that are not reachable by conventional antibodies, is easy to produce, and is suitable for assembly with other antibodies into multispecific and multivalent antibodies. The continued development of new IL-17A antibody types is an important condition for continued development in the art.

In alpaca peripheral blood there is a natural heavy chain antibody comprising only one heavy chain variable region (VHH) and two conventional CH2 and CH3 regions, the VHH structure cloned and expressed alone has structural stability comparable to the original heavy chain antibody and binding activity to antigen, which is the smallest unit known to bind the antigen of interest, also called nanobody. The IL-17A antibody with smaller molecular weight can be prepared through the thought of the nano antibody, and the serial antibodies obtained after different single-domain antibodies are connected in series still can ensure smaller molecular weight, so that the method has room for further research.

Based on the 9 single domain antibodies (filed in the alternative) screened by anti-IL-17A antibody development, further technical development is carried out, 12 single domain antibody combinations with relatively improved affinity, blocking effect and stability are obtained, and based on the relevant regulations of patent law singleness, 12 different single domain antibody combinations are respectively claimed.

The present invention is a patent application directed to one of the above 12 single domain antibody combination antibodies.

Based on the above, a genetically modified stem cell technology and a subsequent application technology have been developed, and different genetically modified stem cells and different applications are respectively claimed based on relevant regulations of the uniqueness of the patent laws.

For the convenience of understanding the technical solution of the present invention, reference is optionally made to other patent application documents of this project.

Disclosure of Invention

In order to solve the problems, the invention provides a novel nano antibody for resisting IL-17A.

It should be noted that, according to the invention, a series of single domain antibodies (nanobodies) are obtained by preparing the IL-17A recombinant antigen immune alpaca, and after performance study is performed on the series of single domain antibodies, in order to improve the performance of the single domain antibodies, some antibodies in the series are tried to be connected in series, so as to obtain serial antibodies with higher performance, and thus a series of inventive concepts are obtained.

Based on the above results, the present invention optionally provides IL-17A specific (anti-IL-17A, IL-17A resistant) tandem antibodies comprising two nanobody variable regions.

The terms "hypervariable region," "complementarity determining region," "HVR," or "CDR," as used herein, refer to regions that are hypervariable in sequence and/or form structurally defined loops ("hypervariable loops") in an antibody variable domain region. Typically, a natural four-chain antibody comprises six HVRs or CDRs: three are present in VH (H1, H2, H3) and three are present in VL (L1, L2, L3). Based on the Chothia definition rules, exemplary CDRs (LCDR 1, LCDR2, LCDR3, HCDR1, HCDR2, and HCDR 3) are located at amino acid residues L26-L32 (L1), L50-L52 (L2), L91-L96 (L3), H26-H32 (H1), H52-H56 (H2), and H96-H101 (H3) (Chothia et al, J.mol.biol.196:901-917 (1987)). Based on the Kabat definition rules, exemplary CDRs (LCDR 1, LCDR2, LCDR3, HCDR1, HCDR2, and HCDR 3) are located at amino acid residues L24-L34 (L1), L50-L56 (L2), L89-L97 (L3), H31-H35 (H1), H50-H65 (H2), and H95-H102 (H3) (Kabat et al, sequences of Proteins ofImmunological Interest, the fifth edition, public Health Service, national Institutes of Health, bethesda, MD (1991)). Based on IMGT definition rules, exemplary CDRs (LCDR 1, LCDR2, LCDR3, HCDR1, HCDR2, and HCDR 3) are located at amino acid residues L27-L32 (L1), L50-L51 (L2), L89-L97 (L3), H26-H33 (H1), H51-H56 (H2), and H93-H102 (H3) (Honjo, T. And Alt, F.W. (1995) Immunoglobulin genes.academic Press pp.3-443). It is well known to those skilled in the art that the CDRs of an antibody can be defined in a variety of ways, such as Kabat definition rules based on sequence variability, chothia definition rules based on structural loop region positions, and reference tools for humanized design of antibodies based on CDR grafting (see J Mol biol.273:927-48, 1997). It will be appreciated by those skilled in the art that unless otherwise specified, the terms "CDR" and "complementarity determining region" of a given antibody or region thereof (e.g., variable region) are to be understood as encompassing complementarity determining regions defined in any of the above known schemes as described by the present invention. Although the scope of the present invention is based on the sequences shown by IMGT definition rules, amino acid sequences corresponding to other CDR definition rules shall also fall within the scope of the present invention.

The scope of the invention is versatile and includes, but is not limited to, the following:

first aspect: an antibody, comprising:

(1) First single domain antibody:

the amino acid sequence comprises: HCDR1, HCDR2, HCDR3 as shown in SEQ ID nos. 1-3; and/or; an amino acid sequence having at least 80% sequence identity to the amino acid sequences shown in SEQ ID NO. 1-3;

(2) Second single domain antibody:

the amino acid sequence comprises HCDR4, HCDR5 and HCDR6 shown in SEQ ID NO. 4-6; and/or; an amino acid sequence having at least 80% sequence identity to the amino acid sequence shown in SEQ ID NO. 4-6.

SEQ ID NO.1：GFSFSIYS；

SEQ ID NO.2：ITKGGLK；

SEQ ID NO.3：NAGRENGY；

SEQ ID NO.4：GFSIHIYA；

SEQ ID NO.5：ITRGGVT；

SEQ ID NO.6：AGGTNGGY。

Alternatively, the amino acid sequence of the antibody comprises: an amino acid sequence obtained by at least one of addition, deletion, modification and/or substitution on the amino acid sequence shown in SEQ ID NO. 1-6.

Specifically, the amino acid sequence of the antibody comprises: amino acid sequences having a difference of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11 amino acids compared to the amino acid sequences shown in SEQ ID NO. 1-6.

In some embodiments, the substitution of one or more amino acids may be conservative substitutions of one or more amino acids. Such conservative substitutions are preferably substitutions of one amino acid in the following groups (a) to (e) with another amino acid residue in the same group: (a) small aliphatic, non-polar or weakly polar residues: ala, ser, thr, pro and Gly; (b) Polar, negatively charged residues and (uncharged) amides: asp, asn, glu and Gln; (c) polar, positively charged residues: his, arg and Lys; (d) large aliphatic, nonpolar residues: met, leu, he, val and Cys; and (e) an aromatic residue: phe, tyr and Trp.

In some specific embodiments, conservative substitutions are as follows: ala to Gly or to Ser; arg to Lys; asn to Gln or to His; asp to Glu; cys to Ser; gln to Asn; glu to Asp; gly to Ala or to Pro; his to Asn or to Gln; lie to Leu or to Val; leu to Ile or to Val; lys to Arg, to gin, or to Glu; met to Leu, to Tyr or to Ile; phe to Met, to Leu, or to Tyr; ser to Thr; thr to Ser; trp to Tyr; tyr to Trp; and/or Phe to Val, to Ile or to Leu.

In some expressions, the identical amino acid sequences may also be referred to as functional variants or mutants; in some embodiments, the functional variant is a single domain antibody variant (mutant) having the same or similar affinity or function as the first single domain antibody or the second single domain antibody, e.g., a variant (mutant) that specifically binds IL-17A and blocks IL-17A binding to its receptor.

The first or second single domain antibody may also include a heavy chain framework region for linking the heavy chain variable region, as is generally recognized in the art.

The heavy chain framework region comprises part or all of an antibody heavy chain framework region selected from human, murine, primate, or camelid sources or a variant thereof;

Preferably, the antibody heavy chain framework regions or variants thereof comprise part or all of a source selected from camelids;

more preferably, the heavy chain framework regions of the antibodies or variants thereof are comprised in part or in whole selected from alpaca sources.

Alternatively, the invention may provide an antibody comprising:

a first single domain antibody of the formula (i):

FR1-HCDR1-FR2-HCDR2-FR3-HCDR3-FR4；

(ii) a second single domain antibody, said second single domain antibody having the structure:

FR5-HCDR4-FR6-HCDR5-FR7-HCDR6-FR8；

wherein HCDR1, HCDR2 and HCDR3 are selected from the group consisting of:

amino acid sequences as shown in SEQ ID NO. 1-3; or; amino acid sequence having a 1, 2 or 3 amino acid difference compared to SEQ ID No. 1-3;

HCDR4, HCDR5 and HCDR6 are selected from:

amino acid sequence shown as SEQ ID NO. 4-6; or; amino acid sequence having a 1, 2 or 3 amino acid difference compared to SEQ ID No. 4-6;

FR1, FR2, FR3 and FR4 are selected from: amino acid sequence shown as SEQ ID NO. 7-10; or; an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% sequence identity compared to SEQ ID No. 7-10;

SEQ ID NO.7：EVQLVESGGGLVQPGGSLRLSCVAW；

SEQ ID NO.8：VNWYRQAPGKERELVAG；

SEQ ID NO.9：DYADSVKGRFTISRDNAKNAVYLRMNMLKPEDTAVYYC；

SEQ ID NO.10：WGQGTQVAVST；

FR5, FR6, FR7 and FR8 are selected from: amino acid sequences as shown in SEQ ID NO. 11-14; or; an amino acid sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% sequence identity compared to SEQ ID No. 11-14;

SEQ ID NO.11：EVQLVESGGGLVQPGGSLRLSCAAS；

SEQ ID NO.12：MGWYRQAPGKQRELVAT；

SEQ ID NO.13：

NNADSVKGRFTISRDNAKNTAYLQMNSLKPEDTAVYYCN；

SEQ ID NO.14：WGQGTQVTVSS。

The amino acid sequence difference is realized by at least one mode of adding, deleting, modifying and/or substituting on the amino acid sequences shown in SEQ ID NO. 1-3.

In some specific embodiments, the HCDR1 has an amino acid sequence shown as SEQ ID No.1, the HCDR2 has an amino acid sequence shown as SEQ ID No.2, the HCDR3 has an amino acid sequence shown as SEQ ID No.3, the HCDR4 has an amino acid sequence shown as SEQ ID No.4, the HCDR5 has an amino acid sequence shown as SEQ ID No.5, and the HCDR6 has an amino acid sequence shown as SEQ ID No. 6.

The amino acid sequences of the first single domain antibody and the second single domain antibody may be directly linked; or; indirectly connected through a linker.

As one preferred in the art, the linker is (GGGGS) n, wherein n is selected from 1, 2, 3, 4, 5 or 6; preferably, the linker is (GGGGS) ₃ 。

Specifically, the first single domain antibody and the second single domain antibody may be linked in an optional order; or; the first single domain antibody and the second single domain antibody are connected in the order from the N end to the C end; or; the first single domain antibody and the second single domain antibody are linked in order from the C-terminus to the N-terminus.

In some specific effects, the antibody is an anti-IL-17A antibody.

Preferably, the first single domain antibody comprises an amino acid sequence shown as SEQ ID NO. 15;

the second single domain antibody comprises an amino acid sequence shown as SEQ ID NO. 16.

SEQ ID NO.15：

EVQLVESGGGLVQPGGSLRLSCVAWGFSFSIYSVNWYRQAPGKERELVAGITKGGLKDYADSVKGRFTISRDNAKNAVYLRMNMLKPEDTAVYYCNAGRENGYWGQGTQVAVST。

SEQ ID NO.16：

EVQLVESGGGLVQPGGSLRLSCAASGFSIHIYAMGWYRQAPGKQRELVATITRGGVTNNADSVKGRFTISRDNAKNTAYLQMNSLKPEDTAVYYCNAGGTNGGYWGQGTQVTVSS。

In practical applications, the tandem nanobody may optionally include a range region and a CH region as required.

Preferably, the sequence of the range region is SEQ ID NO.17, and the sequence of the CH region is SEQ ID NO.18.

SEQ ID NO.17：DKTHTCP；

SEQ ID NO.18：

PCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK。

Second aspect: the present invention provides downstream products of the aforementioned antibodies.

The downstream product may be:

recombinant proteins comprising the aforementioned antibodies; the recombinant protein further comprises a biologically active protein or functional fragment thereof that facilitates expression and/or secretion, or that increases half-life in vivo; the bioactive protein or functional fragment thereof is selected from at least one of an immunoglobulin Fc domain, serum albumin, albumin binding polypeptide, prealbumin, carboxy terminal peptide, elastin-like polypeptide, his tag, GST tag, MBP tag, FLAG tag, and SUMO tag; the immunoglobulin Fc domain is derived from a human antibody, a murine antibody, a primate antibody or a camelid antibody, or a variant thereof; preferably, the immunoglobulin Fc domain is derived from a human IgG antibody, such as an IgG1 Fc, an IgG2 Fc, an IgG3 Fc or an IgG4 Fc, preferably an IgG1 Fc.

In some specific embodiments, the IgG1 Fc has the amino acid sequence shown in SEQ ID NO.19 and the encoding gene is SEQ ID NO.20.

SEQ ID NO.19：

DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK；

SEQ ID NO.20

GACAAAACTCACACATGCCCACCGTGCCCAGCACCTGAACTCCTGGGGGGACCGTCAGTCTTCCTCTTCCCCCCAAAACCCAAGGACACCCTCATGATCTCCCGGACCCCTGAGGTCACATGCGTGGTGGTGGACGTGAGCCACGAAGACCCTGAGGTCAAGTTCAACTGGTACGTGGACGGCGTGGAGGTGCATAATGCCAAGACAAAGCCGCGGGAGGAGCAGTACAACAGCACGTACCGTGTGGTCAGCGTCCTCACCGTCCTGCACCAGGACTGGCTGAATGGCAAGGAGTACAAGTGCAAGGTCTCCAACAAAGCCCTCCCAGCCCCCATCGAGAAAACCATCTCCAAAGCCAAAGGGCAGCCCCGAGAACCACAGGTGTACACCCTGCCCCCATCCCGGGAGGAGATGACCAAGAACCAGGTCAGCCTGACCTGCCTGGTCAAAGGCTTCTATCCCAGCGACATCGCCGTGGAGTGGGAGAGCAATGGGCAGCCGGAGAACAACTACAAGACCACGCCTCCCGTGCTGGACTCCGACGGCTCCTTCTTCCTCTACAGCAAGCTCACCGTGGACAAGAGCAGGTGGCAGCAGGGGAACGTCTTCTCATGCTCCGTGATGCACGAGGCTCTGCACAACCACTACACGCAGAAGAGCCTCTCCCTGTCTCCGGGTAAA。

In some embodiments, the recombinant protein may be a monomer, dimer, or multimer.

The downstream product may also be: an antibody formulation, comprising:

a1: any of the antibodies or recombinant proteins previously described; and

a2: a pharmaceutically acceptable carrier.

The pharmaceutically acceptable carrier may be a buffer, sterile water or a surfactant, which may be an ionic or nonionic agent.

The downstream product may also be: a kit comprising any of the antibodies, any recombinant protein or antibody preparation described previously;

optionally, the kit further comprises a container for loading the antibody preparation.

The downstream product may be: a drug conjugate, comprising:

b1: any of the antibodies or recombinant proteins; and

b2: a coupling moiety coupled to B1.

In some embodiments, the coupling moiety comprises a detectable label, drug, toxin, cytokine, radionuclide, or enzyme.

The downstream product may be: an isolated nucleic acid molecule encoding any of the antibodies or recombinant proteins.

In fact, as is well known to the person skilled in the art, due to the problem of codon degeneracy, in the case of defined amino acid sequences, there are numerous possibilities for their corresponding nucleic acid sequences, the preferred nucleic acid sequences mentioned above being only a preferred example and not the only possibility.

Preferably, the nucleic acid has the nucleotide sequence shown as SEQ ID NO. 21:

GAGGTGCAGCTGGTGGAGTCTGGGGGAGGCTTGGTGCAGCCTGGGGGGTCTCTGAGACTCTCCTGTGTAGCCTGGGGATTTAGCTTCAGTATCTATTCGGTGAACTGGTACCGCCAGGCTCCAGGGAAGGAGCGCGAGTTGGTCGCAGGTATTACGAAAGGTGGTCTAAAAGACTATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGACAACGCCAAGAACGCGGTGTATCTGCGAATGAACATGTTGAAACCTGAAGACACGGCCGTCTACTACTGTAATGCAGGCCGGGAGAATGGTTACTGGGGCCAGGGGACCCAGGTCGCCGTCTCTACCGGAGGCGGAGGATCTGGCGGAGGTGGAAGTGGCGGAGGCGGTTCTGAGGTGCAGCTGGTGGAGTCTGGGGGAGGCTTGGTGCAGCCGGGGGGGTCTCTGAGACTCTCCTGTGCAGCCTCTGGATTTAGTATCCACATCTATGCCATGGGCTGGTACCGCCAGGCTCCAGGGAAGCAGCGCGAGCTGGTCGCAACTATTACTAGAGGTGGTGTAACAAATAATGCAGACTCCGTGAAGGGGCGATTCACCATCTCCAGAGACAACGCCAAGAACACGGCGTATCTGCAAATGAACAGCCTGAAACCTGAGGACACGGCCGTCTATTACTGTAATGCAGGTGGGACGAACGGGGGCTACTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCAGACAAAACTCACACATGCCCACCGTGCCCAGCACCTGAACTCCTGGGGGGACCGTCAGTCTTCCTCTTCCCCCCAAAACCCAAGGACACCCTCATGATCTCCCGGACCCCTGAGGTCACATGCGTGGTGGTGGACGTGAGCCACGAAGACCCTGAGGTCAAGTTCAACTGGTACGTGGACGGCGTGGAGGTGCATAATGCCAAGACAAAGCCGCGGGAGGAGCAGTACAACAGCACGTACCGTGTGGTCAGCGTCCTCACCGTCCTGCACCAGGACTGGCTGAATGGCAAGGAGTACAAGTGCAAGGTCTCCAACAAAGCCCTCCCAGCCCCCATCGAGAAAACCATCTCCAAAGCCAAAGGGCAGCCCCGAGAACCACAGGTGTACACCCTGCCCCCATCCCGGGAGGAGATGACCAAGAACCAGGTCAGCCTGACCTGCCTGGTCAAAGGCTTCTATCCCAGCGACATCGCCGTGGAGTGGGAGAGCAATGGGCAGCCGGAGAACAACTACAAGACCACGCCTCCCGTGCTGGACTCCGACGGCTCCTTCTTCCTCTACAGCAAGCTCACCGTGGACAAGAGCAGGTGGCAGCAGGGGAACGTCTTCTCATGCTCCGTGATGCACGAGGCTCTGCACAACCACTACACGCAGAAGAGCCTCTCCCTGTCTCCGGGTAAATAA。

the downstream product may be: an expression vector comprising said nucleic acid molecule.

Preferably, the types of carriers include, but are not limited to: viral vectors or non-viral vectors.

Further preferably, the viral vector comprises at least one of a lentiviral vector, an adenovirus vector, a baculovirus vector, a retrovirus vector, a poxvirus vector, a sendai virus vector, and a herpes simplex virus vector.

Further preferably, the non-viral vector includes, but is not limited to, a eukaryotic vector or a prokaryotic vector.

The downstream product may be: a pharmaceutical composition comprising any of the antibodies, recombinant proteins, antibody preparations, drug conjugates, nucleic acid molecules, or expression vectors;

optionally, the pharmaceutical composition further comprises at least one pharmaceutically acceptable excipient.

In some embodiments, the adjuvant is selected from solvents, diluents, disintegrants, precipitation inhibitors, surfactants, glidants, binders, lubricants, dispersants, suspending agents, isotonic agents, thickening agents, emulsifiers, preservatives, stabilizers, hydration agents, emulsifying accelerators, buffers, absorbents, colorants, flavorants, sweeteners, ion exchangers, mold release agents, coating agents, flavoring agents, or antioxidants.

Third aspect: the invention provides the use of the aforementioned antibodies or downstream products.

The use is selected from at least one of the following uses:

c1: preparing a detection reagent or a kit;

c2: preparing a medicament for preventing and/or treating autoimmune diseases;

and C3: preparing medicine for preventing and/or treating cancer.

The autoimmune diseases include, but are not limited to, behcet's disease, systemic lupus erythematosus, chronic discoid lupus erythematosus, multiple sclerosis, systemic scleroderma, progressive systemic sclerosis, scleroderma, polymyositis, dermatomyositis, perinodular arteritis, aortiamatis syndrome, malignant rheumatoid arthritis, juvenile idiopathic arthritis, spondyloarthritis, mixed connective tissue disease, kalman's disease, sjogren's syndrome, adult Steve's disease, vasculitis, allergic granulomatous vasculitis, allergic vasculitis, rheumatoid vasculitis, macrovasculitis, ANCA-related vasculitis, cogan's syndrome, RS3PE syndrome, temporal arteritis, polymyositis rheumatica, fibromyalgia, antiphospholipid antibody syndrome, eosinophilic fasciitis, igG 4-related diseases, guillain Barre syndrome, myasthenia gravis chronic atrophic gastritis, autoimmune hepatitis, nonalcoholic steatohepatitis, primary biliary cirrhosis, good-pasture syndrome, acute glomerulonephritis, lupus nephritis, megaloblastic anemia, autoimmune hemolytic anemia, pernicious anemia, autoimmune neutropenia, idiopathic thrombocytopenic purpura, barcup's disease, hashimoto's disease autoimmune hypothyroidism, primary hypothyroidism, addison's disease, idiopathic Addison's disease, type I diabetes, slowly progressive type I diabetes, focal scleroderma, psoriasis, psoriatic arthritis, bullous pemphigoid, herpes gestation, linear IgA bullous dermatoses, acquired bullous epidermolysis, alopecia areata, leukoplakia, vitiligo vulgaris, psoriasis, and chronic adrenal gland hypofunction, neuromyelitis optica, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, sarcoidosis, giant cell arteritis, amyotrophic lateral sclerosis, former field disease, autoimmune optic neuropathy, idiopathic azoospermia, habitual abortion, inflammatory bowel disease, celiac disease, ankylosing spondylitis, severe asthma, chronic urticaria transplantation immunity, familial mediterranean fever, eosinophilic chronic sinusitis, dilated cardiomyopathy, systemic mastocytosis or inclusion body myositis;

Preferably, the autoimmune disease is plaque psoriasis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis or lupus nephritis.

Such cancers include, but are not limited to, basal cell carcinoma, cholangiocarcinoma, bladder carcinoma, bone cancer, breast cancer, peritoneal cancer, cervical cancer, cholangiocarcinoma, choriocarcinoma, colorectal cancer, connective tissue carcinoma, digestive system cancer, endometrial cancer, esophageal cancer, eye cancer, head and neck cancer, gastric cancer, glioblastoma, liver cancer, renal cancer, laryngeal cancer, leukemia, liver cancer, lung cancer, lymphoma, melanoma, myeloma, neuroblastoma, oral cancer, ovarian cancer, pancreatic cancer, prostate cancer, retinoblastoma, rhabdomyosarcoma, rectal cancer, respiratory system cancer, salivary gland carcinoma, sarcoma, skin cancer, squamous cell carcinoma, testicular cancer, thyroid cancer, uterine cancer, urinary system cancer, B-cell lymphoma, chronic lymphocytic leukemia, acute lymphoblastic leukemia, hairy cell leukemia, or chronic myelogenous leukemia.

Fourth aspect: the present invention provides detection methods or therapeutic methods based on the aforementioned antibodies or downstream products.

Specifically provided are: a method for in vitro detection of IL-17A in a sample for non-diagnostic purposes comprising the steps of:

D1: contacting the antibody, recombinant protein, antibody preparation or drug conjugate as described in any of the foregoing with a sample to be tested;

d2: detecting the antigen-antibody complex;

d3: and judging the result.

Specifically provided are: a method of preventing and/or treating an autoimmune disease comprising:

administering to a subject in need thereof a therapeutically effective amount of any of the antibodies, recombinant proteins, antibody preparations or drug conjugates.

Specifically provided are: a method of preventing and/or treating cancer comprising:

The mode of administration can be selected and adjusted by those skilled in the art according to the actual circumstances, such as the frequency of administration, the amount of administration, the duration of the word, etc.

The invention has the beneficial effects that:

the invention is based on a research and development thought, single domain antibodies 1-G12 and 1-F8 are obtained by screening nano antibodies obtained by immunizing alpaca, and serial antibodies are obtained on the basis of the two antibodies. The tandem antibody has IL-17A specificity, and the EC50 of the tandem antibody combined with the target protein in an affinity experiment is 2.425 mug/mL, which shows that the tandem antibody has good combining ability; the antibody blocking function experiment can block the Human IL-17A protein from activating 293F-IL-17RA-IL-17Rc-ACT 1-NFkB-Luc, and the IC50 is 0.7587 mug/mL, which is superior to the control antibody Ixekizumab (1.356 mug/mL).

Drawings

FIG. 1 shows SDS-PAGE results of tandem antibodies.

FIG. 2 shows the results of affinity detection of control antibody Ixekizumab.

FIG. 3 shows tandem antibody affinity assay results.

FIG. 4 shows the results of a control antibody Ixekizumab antibody blocking function assay.

FIG. 5 shows the results of a tandem antibody blocking function assay.

FIG. 6 shows the results of a control antibody Ixekizumab stability assay.

FIG. 7 shows the results of a tandem antibody stability assay.

Detailed Description

The present invention will be described in further detail with reference to the following examples, which are not intended to limit the present invention, but are merely illustrative of the present invention. The experimental methods used in the following examples are not specifically described, but the experimental methods in which specific conditions are not specified in the examples are generally carried out under conventional conditions, and the materials, reagents, etc. used in the following examples are commercially available unless otherwise specified.

In the present invention, "1-G12+1-F8", "G12-1-F8", "1-G12/1-F8" have the same meaning and refer to tandem antibodies.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly used in the art to which this invention belongs. For the purposes of explaining the present specification, the following definitions will apply, and terms used in the singular will also include the plural and vice versa, as appropriate.

The terms "a" and "an" as used herein include plural referents unless the context clearly dictates otherwise. For example, reference to "a cell" includes a plurality of such cells, equivalents thereof known to those skilled in the art, and so forth.

The term "about" as used herein means a range of + -20% of the numerical values thereafter. In some embodiments, the term "about" means a range of ±10% of the numerical value following that. In some embodiments, the term "about" means a range of ±5% of the numerical value following that.

The terms "include" or "comprising" as used herein mean "including but not limited to". The term is intended to be open ended to specify the presence of any stated features, elements, integers, steps, or components, but does not preclude the presence or addition of one or more other features, elements, integers, steps, components, or groups thereof. Thus, the term "comprising" includes the more limiting terms "consisting of … …" and "consisting essentially of … …". In one embodiment, the term "comprising" as used throughout the application, and in particular in the claims, may be replaced by the term "consisting of … …". The amino acid three-letter codes and one-letter codes used herein are as known to those skilled in the art, or as described in J biol. Chem,243, p3558 (1968).

The terms "optional," "any," or "any" used herein mean that the subsequently described event or circumstance may, but need not, occur, and that the description includes instances where the event or circumstance occurs or does not. For example, "optionally comprising 1 antibody heavy chain variable region" means that an antibody heavy chain variable region of a particular sequence may be, but is not required to be, present.

The term "and/or" as used herein is understood to mean any one of the selectable items or a combination of any two or more of the selectable items.

The term "single domain antibody" (sdAb) or "nanobody" as used herein has its ordinary meaning in the art and refers to an antibody fragment having a molecular weight of only 12-15kDa, which consists of a single monomeric variable antibody domain derived from a heavy chain. Such single domain antibodies (designated VHH) can be found in camelidae mammals and naturally lack the light chain. For a general description of (single) domain antibodies, reference is also made to the above-mentioned prior art and EP 0368684, ward et al (Nature 1989Oct 12;341 (6242): 544-6), holt et al Trends Biotechnol,2003,21 (11): 484-490; and WO 06/030220, WO 06/003388. The amino acid sequence and structure of a single domain antibody can be considered to consist of four framework regions or "FR", which are referred to in the art as "framework region 1" or "FR1", respectively; "frame region 2" or "FR2"; is "frame region 3" or "FR3"; "frame region 4" or "FR4"; the framework regions are separated by three complementarity determining regions or "CDRs", referred to in the art as "complementarity determining region 1" or "CDR1", respectively; "complementarity determining region 2" or "CDR2", and "complementarity determining region 3" or "CDR3". Thus, a single domain antibody can be defined as an amino acid sequence having the general structure: FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4, wherein FR1-FR4 refers to framework regions 1-4, respectively, and wherein CDR1-CDR3 refers to complementarity determining regions 1-3. In the context of the present disclosure, the amino acid residues of a single domain antibody are numbered according to the general numbering of the VH domains given by amino acid numbering International ImMunoGeneTics information system (http:// imgt. Cmes. Fr /).

The term "amino acid" as used herein refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimics that function in a manner similar to naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as modified amino acids such as hydroxyproline, gamma-carboxyglutamic acid, and O-phosphoserine. Amino acid analogs refer to compounds that have the same basic chemical structure as a naturally occurring amino acid, i.e., a carbon bound to hydrogen, a carboxyl group, an amino group, and an R group, e.g., homoserine, norleucine, methionine sulfoxide, methionine methyl sulfonium. These analogs have modified R groups (e.g., norleucine) or modified peptide backbones, but retain the same basic chemical structure as a naturally occurring amino acid. Amino acid mimetics refers to compounds that differ in structure from the general chemical structure of an amino acid, but function in a manner similar to naturally occurring amino acids.

The terms "activity", "functional activity" or "biological activity", or the terms "biological property" or "biological feature" as used herein are used interchangeably and include, but are not limited to, epitope/antigen affinity and specificity, the ability to neutralize or antagonize IL-17A activity in vivo or in vitro, IC50, in vivo stability of antibodies, and immunogenic properties of antibodies. Other identifiable biological properties or characteristics of antibodies known in the art include, for example, cross-reactivity (i.e., cross-reactivity with non-human homologs of the targeting peptide in general, or with other proteins or tissues), and the ability to maintain high levels of expression of the protein in mammalian cells. The aforementioned properties or characteristics are observed, assayed or assessed using techniques well known in the art, including but not limited to ELISA, FACS or BIACORE plasma resonance analysis, unrestricted in vitro or in vivo neutralization assays, receptor binding, cytokine or growth factor production and/or secretion, signal transduction, and immunohistochemistry of tissue sections of different origin (including human, primate or any other source).

The term "Fc" or "Fc region", "Fc domain" or "Fc fragment" as used herein refers to a polypeptide consisting of the CH2 and CH3 domains of IgA, igD and IgG, or the CH2, CH3 and CH4 domains of IgE and IgM through a hinge region. Although the breakdown of the Fc fragment is variable, the heavy chain Fc fragment of human IgG generally refers to the polypeptide from A231 to its carboxy terminus.

The term "epitope" as used herein refers to a protein determinant capable of specific binding to an antibody. Epitopes are typically composed of surface-clustered molecules, such as amino acids or sugar side chains, and typically have specific three-dimensional structural features, as well as specific charge features. Conformational and non-conformational epitopes differ in that binding to the former but not the latter is lost in the presence of denaturing solvents. Epitopes can include amino acid residues that are directly involved in binding and other amino acid residues that are not directly involved in binding, such as amino acid residues that are effectively blocked or covered by a specific antigen binding peptide (in other words, amino acid residues are within the footprint of a specific antigen binding peptide).

The term "affinity" or "binding affinity" as used herein refers to an inherent binding affinity that reflects interactions between members of a binding pair. Affinity can be measured by common methods known in the art. One specific method for measuring affinity is the ForteBio kinetic binding assay herein.

The term "antibody drug conjugate" as used herein refers to a substance obtained by linking a biologically active compound fragment to an antibody or antigen binding fragment portion thereof. The biologically active compound fragment and the targeting moiety may be linked by a linker. The linker is capable of cleaving in a specific environment (e.g., an intracellular low pH environment) or under a specific action (e.g., action of a lysosomal protease) to thereby separate the biologically active compound fragment from the targeting moiety or antibody or antigen binding fragment thereof. The linker comprises a cleavable or non-cleavable unit, such as a peptide or disulfide bond. The biologically active compound fragment is directly linked to the targeting moiety or antibody or antigen binding fragment thereof by a covalent bond that is capable of cleavage under a specific environment or action, thereby separating the biologically active compound fragment from the antibody or antigen binding fragment portion thereof.

The term "nucleic acid" or "polynucleotide" as used herein refers to deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) and polymers thereof in single or double stranded form. Unless specifically limited, the term includes nucleic acids containing known analogues of natural nucleotides that have similar binding properties to the reference nucleic acid and are metabolized in a manner similar to naturally occurring nucleotides (see, U.S. Pat. No.8278036 to Kariko et al, which discloses mRNA molecules with uridine replaced by pseudouridine, methods of synthesizing the mRNA molecules, and methods for delivering therapeutic proteins in vivo). Unless otherwise indicated, a particular nucleic acid sequence also implicitly encompasses conservatively modified variants thereof (e.g., degenerate codon substitutions), alleles, orthologs, SNPs, and complementary sequences, as well as the sequence explicitly indicated. Specifically, degenerate codon substitutions may be achieved by generating sequences in which the third position of one or more selected (or all) codons is substituted with mixed bases and/or deoxyinosine residues (Batzer, nucleic Acid Res.19:5081 (1991); ohtsuka, J.biol.chem.260:2605-2608 (1985); rossolini, mol.cell.probes 8:91-98 (1994)).

The term "isolated nucleic acid" as used herein is a nucleic acid that has been identified and isolated from a component of its natural environment. An isolated nucleic acid includes a nucleic acid molecule contained in a cell that typically contains the nucleic acid molecule, but the nucleic acid molecule is present at a chromosomal location that is extrachromosomal or different from its natural chromosomal location.

The term "construct" as used herein refers to any recombinant polynucleotide molecule (such as a plasmid, cosmid, virus, autonomously replicating polynucleotide molecule, phage, or linear or circular single-or double-stranded DNA or RNA polynucleotide molecule), derived from any source, capable of integrating with the genome or autonomously replicating, constituting a polynucleotide molecule in which one or more polynucleotide molecules have been functionally linked (i.e., operably linked). Recombinant constructs will typically comprise a polynucleotide of the invention operably linked to transcriptional initiation regulatory sequences that direct the transcription of the polynucleotide in a host cell. Both heterologous and non-heterologous (i.e., endogenous) promoters may be used to direct expression of the nucleic acids of the invention.

The term "vector" as used herein refers to any recombinant polynucleotide construct that can be used for transformation purposes (i.e., the introduction of heterologous DNA into a host cell). One type of vector is a "plasmid," which refers to a circular double-stranded DNA loop into which additional DNA segments may be ligated. Another type of vector is a viral vector, in which additional DNA segments can be ligated into the viral genome. Some vectors are capable of autonomous replication in a host cell into which they are introduced (e.g., bacterial vectors having a bacterial origin of replication and episomal mammalian vectors). Upon introduction into a host cell, other vectors (e.g., non-episomal mammalian vectors) integrate into the genome of the host cell and thereby replicate together with the host genome. In addition, certain vectors are capable of directing the expression of genes that are operably linked. Such vectors are referred to herein as "expression vectors".

The term "expression vector" as used herein refers to a nucleic acid molecule capable of replicating and expressing a gene of interest when transformed, transfected or transduced into a host cell. The expression vector contains one or more phenotypic selectable markers and an origin of replication to ensure maintenance of the vector and to provide amplification in the host if desired.

The terms "cell", "cell line" are used interchangeably herein and all such designations include progeny thereof. The term "host cell" refers to a cell that can be used to introduce a vector, and includes, but is not limited to, a prokaryotic cell such as E.coli, a fungal cell such as a yeast cell, or an animal cell such as a fibroblast, CHO cell, COS cell, NSO cell, heLa cell, BHK cell, HEK 293 cell, or human cell.

The term "pharmaceutical composition" as used herein generally refers to a formulation that exists in a form that allows for the biological activity of the active ingredient to be effective and that does not contain additional ingredients that have unacceptable toxicity to the subject to which the composition is to be administered. The composition is sterile.

The term "pharmaceutically acceptable" as used herein refers to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. As used herein, the term "pharmaceutically acceptable carrier, excipient and/or diluent" refers to a carrier that is pharmacologically and/or physiologically compatible with the subject and active ingredient, as is well known in the art (see, e.g., remington's Pharmaceutical sciences. Mediated by Gennaro AR,19th ed.Pennsylvania:Mack Publishing Company,1995). A pharmaceutically acceptable material, composition or vehicle, such as a liquid or solid filler, diluent, excipient, solvent, medium, encapsulating material, manufacturing aid or solvent encapsulating material, which is involved in maintaining the stability, solubility or activity of an antibody or antigen binding fragment thereof of the present disclosure, and includes, but is not limited to: pH modifiers, surfactants, adjuvants, ionic strength enhancers, diluents, agents to maintain osmotic pressure, agents to delay absorption, preservatives. For example, pH adjusters include, but are not limited to, phosphate buffers. Surfactants include, but are not limited to, cationic, anionic or nonionic surfactants, such as Tween-80. Ionic strength enhancers include, but are not limited to, sodium chloride. Preservatives include, but are not limited to, various antibacterial and antifungal agents, such as parabens, chlorobutanol, phenol, sorbic acid, and the like. Agents that maintain osmotic pressure include, but are not limited to, sugar, naCl, and the like. Agents that delay absorption include, but are not limited to, monostearates and gelatin. Diluents include, but are not limited to, water, aqueous buffers (e.g., buffered saline), alcohols and polyols (e.g., glycerol), and the like. Preservatives include, but are not limited to, various antibacterial and antifungal agents, such as thimerosal, 2-phenoxyethanol, parabens, chlorobutanol, phenol, sorbic acid, and the like. Stabilizers have the meaning commonly understood by those skilled in the art and are capable of stabilizing the desired activity of the active ingredient in a medicament, including but not limited to sodium glutamate, gelatin, SPGA, saccharides (e.g., sorbitol, mannitol, starch, sucrose, lactose, dextran, or glucose), amino acids (e.g., glutamic acid, glycine), proteins (e.g., dried whey, albumin or casein) or degradation products thereof (e.g., lactalbumin hydrolysate), and the like.

The term "subject" as used herein includes any human or non-human animal. The term "non-human animal" includes all vertebrates, e.g., mammals and non-mammals, such as non-human primates, sheep, dogs, cats, horses, cows, chickens, amphibians, reptiles, and the like.

The terms "therapeutically effective amount," "therapeutically effective dose," and "effective amount" as used herein refer to an amount of an anti-IL-17A antibody or antigen-binding fragment thereof of the invention that is effective to prevent or ameliorate a symptom of one or more diseases or conditions, or the development of the disease or condition, when administered to a cell, tissue, or subject, alone or in combination with other therapeutic agents. A therapeutically effective dose also refers to an amount of an antibody or antigen binding fragment thereof sufficient to result in an improvement in symptoms, e.g., to treat, cure, prevent, or ameliorate a related medical condition, or to increase the rate of treatment, cure, prevention, or amelioration of such a condition. When an active ingredient is administered to an individual, a therapeutically effective dose refers to that ingredient alone. When administered in combination, a therapeutically effective dose refers to the combined amount of the active ingredients that results in a therapeutic effect, whether administered in combination, sequentially or simultaneously. An effective amount of the therapeutic agent will result in an increase in the diagnostic criteria or parameter of at least 10%; typically at least 20%; preferably at least about 30%; more preferably at least 40%, most preferably at least 50%.

The term "EC50" as used herein refers to the half maximal effect concentration (concentration for 50%of maximal effect), i.e., the concentration that causes 50% of the maximal effect (in this context: ability to bind IL-17A).

The term "IC50" as used herein refers to a half inhibitory concentration (half maximal inhibitory concentration), i.e., a concentration that causes a 50% maximum inhibitory effect (in this context: the ability to inhibit IL-17A and its receptor IL-17RA binding).

The present invention will be described in further detail with reference to the following examples in order to make the objects, technical solutions and advantages of the present invention more apparent. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. Numerous specific details are set forth in the following description in order to provide a better understanding of the invention. The specific embodiments described herein are for purposes of illustration only and are not to be construed as limiting the invention in any way. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the present invention. Such structures and techniques are also described in a number of publications.

The reagents, materials and equipment that may be involved in the present invention are shown in Table 1.

TABLE 1 Main reagents, materials and apparatus according to the invention

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The primers used for screening and cloning VHH fragments and constructing nanobodies are designed by referring to the following documents:

Maass DR,Sepulveda J,Pernthaner A,Shoemaker CB.Alpaca(Lama pacos)as a convenient source of recombinant camelid heavy chain antibodies(VHHs).J Immunol Methods.2007；324(1-2):13-25.

Lin,J,Gu,Y,Xu,Y et al.Characterization and applications of nanobodies against Pseudomonas aeruginosa exotoxin a selected from single alpaca B cells.Biotechnol Biotechnol Equip 2020；34:1028-37.

Studies on design of singledomain antibodies by AlpacaVHH phage library and high throughput sequencing toconstruct Fab antibody purification system(http://hdl.handle.net/10232/00030916).

basic Experimental example IL-17 nanobody screening

As embodied in the invention patent of the same date of application, the invention obtains a plurality of schemes by screening antibodies by antigen immunized animals, wherein the screening comprises the following steps:

(1) Preparation of recombinant antigens

Adding a 6 XHis tag at the C end of the IL-17 antigen, performing gene synthesis after optimizing according to a prokaryotic codon, and subcloning into a pET28a vector; after being verified by Sanger sequencing, the plasmid is extracted; transforming the recombinant plasmid into BL21 competent, inducing overnight with 0.5mM IPTG, and collecting bacterial liquid for cleavage; purifying the recombinant protein using a nickel column; purity of the target protein was checked by SDS-PAGE.

BL21 is adopted to express IL-17A recombinant protein and nickel column is used for purification, SDS-PAGE is used for detecting the purity of target protein, and the purity of IL-17A antigen protein is more than 90% after being purified.

(2) Preparation of positive control antibody Ixekizumab

Ixekizumab heavy chain variable region: SEQ ID NO.22; light chain variable region SEQ ID NO.23.

SEQ ID NO.22：

QVQLVQSGAEVKKPGSSVKVSCKASGYSFTDYHIHWVRQAPGQGLEWMGVINPMYGTTDYNQRFKGRVTITADESTSTAYMELSSLRSEDTAVYYCARYDYFTGTGVYWGQGTLVTVSS；

SEQ ID NO.23：

DIVMTQTPLSLSVTPGQPASISCRSSRSLVHSRGNTYLHWYLQKPGQSPQLLIYKVSNRFIGVPDRFSGSGSGTDFTLKISRVEAEDVGVYYCSQSTHLPFTFGQGTKLEIK。

SDS-PAGE detects the purity of the positive control antibody protein >95%.

(3) The positive control antibody is used for detecting the binding capacity of the recombinant antigen, and the result shows that the positive antibody and the IL-17A antigen protein are well combined and can be used for subsequent immunization.

(4) Human IL-17A recombinant protein activity detection

The detection was performed using an IL-17A protein activated NIH-3T3 cell assay. NIH-3T3 cells were treated with the prepared recombinant IL-17A (TEST) and purchased IL-17A (Acro), respectively, and supernatants were collected after 72 hours to examine the secretion of mIL-6, and according to the examination results, IL-17A antigen protein had an activity of activating the expression of mIL-6 by NIH-3T3 cells, and IL-17A (TEST, hereinafter referred to as IL-17A recombinant protein) activity positively correlated with the concentration thereof, and was used for immunization.

(5) Construction and verification of IL-17A reporter gene cell strain

Based on the amino acid sequence information of IL-17RA (UniProtKB: Q96F 46) and IL-17RC (UniProtKB: Q8NAC 3), a lentiviral expression vector is constructed, lentivirus is packaged, 293 cells are co-infected, recombinant 293 cells which simultaneously overexpress the two receptors are screened, NFKB-Luciferase (SEQ ID NO. 24) and ACT1 gene (SEQ ID NO. 25) are further stably transformed, and an IL-17A reporter cell strain 293F-IL-17RA-IL-17Rc-ACT1-nfκB-Luc is constructed.

SEQ ID NO.24：

ATGGAAGATGCCAAAAACATTAAGAAGGGCCCAGCGCCATTCTACCCACTCGAAGACGGGACCGCCGGCGAGCAGCTGCACAAAGCCATGAAGCGC

TACGCCCTGGTGCCCGGCACCATCGCCTTTACCGACGCACATATCGAGGT

GGACATTACCTACGCCGAGTACTTCGAGATGAGCGTTCGGCTGGCAGAAG

CTATGAAGCGCTATGGGCTGAATACAAACCATCGGATCGTGGTGTGCAGC

GAGAATAGCTTGCAGTTCTTCATGCCCGTGTTGGGTGCCCTGTTCATCGGT

GTGGCTGTGGCCCCAGCTAACGACATCTACAACGAGCGCGAGCTGCTGAA

CAGCATGGGCATCAGCCAGCCCACCGTCGTATTCGTGAGCAAGAAAGGGC

TGCAAAAGATCCTCAACGTGCAAAAGAAGCTACCGATCATACAAAAGATC

ATCATCATGGATAGCAAGACCGACTACCAGGGCTTCCAAAGCATGTACAC

CTTCGTGACTTCCCATTTGCCACCCGGCTTCAACGAGTACGACTTCGTGCC

CGAGAGCTTCGACCGGGACAAAACCATCGCCCTGATCATGAACAGTAGTG

GCAGTACCGGATTGCCCAAGGGCGTAGCCCTACCGCACCGCACCGCTTGT

GTCCGATTCAGTCATGCCCGCGACCCCATCTTCGGCAACCAGATCATCCCC

GACACCGCTATCCTCAGCGTGGTGCCATTTCACCACGGCTTCGGCATGTTC

ACCACGCTGGGCTACTTGATCTGCGGCTTTCGGGTCGTGCTCATGTACCGC

TTCGAGGAGGAGCTATTCTTGCGCAGCTTGCAAGACTATAAGATTCAATC

TGCCCTGCTGGTGCCCACACTATTTAGCTTCTTCGCTAAGAGCACTCTCAT

CGACAAGTACGACCTAAGCAACTTGCACGAGATCGCCAGCGGCGGGGCG

CCGCTCAGCAAGGAGGTAGGTGAGGCCGTGGCCAAACGCTTCCACCTACC

AGGCATCCGCCAGGGCTACGGCCTGACAGAAACAACCAGCGCCATTCTGA

TCACCCCCGAAGGGGACGACAAGCCTGGCGCAGTAGGCAAGGTGGTGCC

CTTCTTCGAGGCTAAGGTGGTGGACTTGGACACCGGTAAGACACTGGGTG

TGAACCAGCGCGGCGAGCTGTGCGTCCGTGGCCCCATGATCATGAGCGGC

TACGTTAACAACCCCGAGGCTACAAACGCTCTCATCGACAAGGACGGCTG

GCTGCACAGCGGCGACATCGCCTACTGGGACGAGGACGAGCACTTCTTCA

TCGTGGACCGGCTGAAGAGCCTGATCAAATACAAGGGCTACCAGGTAGCC

CCAGCCGAACTGGAGAGCATCCTGCTGCAACACCCCAACATCTTCGACGC

CGGGGTCGCCGGCCTGCCCGACGACGATGCCGGCGAGCTGCCCGCCGCAG

TCGTCGTGCTGGAACACGGTAAAACCATGACCGAGAAGGAGATCGTGGA

CTATGTGGCCAGCCAGGTTACAACCGCCAAGAAGCTGCGCGGTGGTGTTG

TGTTCGTGGACGAGGTGCCTAAAGGACTGACCGGCAAGTTGGACGCCCGC

AAGATCCGCGAGATTCTCATTAAGGCCAAGAAGGGCGGCAAGATCGCCGTG；

SEQ ID NO.25：

ATGCCACCTCAGTTGCAGGAAACTCGGATGAATAGAAGCATCCCCGTGGAAGTGGACGAGAGCGAGCCGTACCCTAGTCAGCTGCTGAAGCCGATCCCTGAGTACTCCCCGGAAGAGGAATCCGAACCACCAGCCCCCAACATTCGCAATATGGCCCCCAATAGCTTGTCCGCACCAACAATGCTGCACAACTCTTCTGGCGACTTCTCTCAGGCCCACTCCACCCTGAAACTGGCGAATCACCAGCGGCCTGTATCCCGGCAGGTGACCTGTCTGAGAACTCAGGTGCTTGAAGACTCCGAGGACTCTTTCTGTAGGCGGCATCCAGGTTTGGGCAAGGCGTTTCCGTCCGGCTGTTCCGCGGTTTCAGAGCCCGCTTCCGAAAGTGTCGTGGGCGCCCTGCCAGCCGAGCACCAGTTCTCCTTCATGGAAAAGCGGAACCAGTGGCTGGTCAGTCAGCTGAGCGCCGCGTCACCTGATACAGGTCACGATTCCGACAAGTCTGACCAGTCTCTGCCCAATGCGTCAGCCGATAGTCTCGGGGGCTCCCAGGAGATGGTGCAGAGACCACAGCCGCACAGAAACCGGGCCGGGCTTGATCTGCCCACCATTGATACAGGCTACGATTCCCAGCCCCAGGACGTCCTTGGCATTCGCCAGCTGGAAAGGCCTCTGCCCTTGACCTCCGTGTGTTACCCCCAGGACCTGCCCCGCCCTTTGAGAAGCCGGGAGTTTCCCCAGTTTGAGCCCCAACGATACCCTGCCTGTGCTCAGATGCTGCCTCCGAACCTGAGCCCACACGCTCCCTGGAACTACCACTATCACTGTCCCGGCAGCCCCGATCACCAGGTGCCTTATGGACACGACTACCCGCGGGCTGCATACCAGCAGGTCATACAGCCTGCCTTGCCGGGTCAGCCGCTGCCCGGAGCTTCTGTGCGCGGCCTGCACCCCGTTCAGAAAGTGATCCTGAACTATCCAAGCCCATGGGACCATGAAGAGAGACCAGCCCAAAGAGATTGCTCTTTTCCTGGGTTGCCTAGACACCAAGACCAGCCTCACCACCAGCCTCCCAATCGGGCAGGCGCCCCAGGCGAAAGTCTCGAGTGCCCCGCCGAACTCAGACCACAGGTCCCTCAGCCCCCTTCCCCCGCGGCAGTACCCAGACCCCCCTCTAACCCACCCGCCCGGGGAACGCTCAAGACTTCAAATCTCCCAGAAGAGCTGCGCAAAGTGTTCATAACCTACAGCATGGACACCGCTATGGAGGTGGTTAAGTTCGTCAACTTCCTGCTGGTCAATGGGTTCCAGACTGCAATCGACATTTTTGAGGATAGAATTCGGGGAATCGACATCATCAAGTGGATGGAGAGATACCTGCGGGATAAGACAGTGATGATTATCGTGGCCATTAGTCCCAAGTACAAGCAAGATGTGGAGGGCGCAGAATCACAGTTGGACGAAGACGAGCACGGACTCCATACAAAATATATCCACAGGATGATGCAGATCGAGTTCATTAAACAAGGCTCCATGAATTTCCGCTTCATACCGGTCCTGTTTCCAAACGCAAAAAAAGAGCATGTACCCACTTGGCTCCAGAATACCCATGTCTACTCCTGGCCCAAGAACAAGAAGAATATCCTGCTGCGCTTGCTCAGAGAAGAAGAGTATGTCGCCCCTCCAAGGGGGCCCCTCCCCACACTCCAAGTAGTGCCACTT。

And adding a recombinant antigen for activation, adding a positive control antibody Ixekizumab for detection of a blocking experiment, calculating an EC50 value of the blocking experiment, and establishing a candidate antibody in vitro pharmacodynamics evaluation cell strain targeting IL-17A. FACS results found: the constructed IL-17A receptor over-expression cell strain can be combined with IL-17A, and the positive rate is more than 90%.

The IL-17A recombinant protein is adopted to activate 293F-IL-17RA-IL-17Rc-ACT 1-NFkB-Luc, and the IL-17A recombinant protein can effectively activate luciferase expression in 293F-IL17RA-IL17 Rc-NFkB-Luc reporter gene cell strain.

The positive control antibody Ixekizumab and the IL-17A recombinant protein are added into 293F-IL-17RA-IL-17Rc-ACT 1-NFkB-Luc cells together, and the positive control antibody Ixekizumab can inhibit the combination of IL17A protein and a membrane receptor thereof and inhibit the signal of intracellular NFkB and present a dose effect.

(6) Alpaca immunity

Immunization is carried out on Alpaca (Alpaca) by using the prepared recombinant antigen protein, the immunization interval is 21 days, partial peripheral blood is collected after 10 days of the last immunization, and ELISA detection is carried out on the immune effect of the separated serum.

(7) Detection of immune titers

The immunological titers of alpaca reached the requirements after 6 rounds of immunization (see tables 2-3 below).

TABLE 2 results of immunotiter assays

TABLE 3 results of immunotiter assays

(8) PBMC isolation and VHH antibody fragment cloning

PBMC were isolated, RNA was extracted and subjected to two rounds of PCR after reverse transcription, the products were recovered, and the concentration was determined.

(9) Construction and panning of Single-Domain antibody Yeast display libraries

The linear vector and the PCR product together electrically transformed the yeast competent strain.

(10) Single domain antibody yeast display library panning;

(11) After panning, yeast monoclonal was subjected to flow detection.

(12) Amplification, transient transfection and detection of the overlay PCR product, recovery of the product, transfection.

(13) ELISA selects positive clones, obtains VHH antibody sequences, performs gene synthesis, and purifies Protein A after genetic engineering expression.

Enriching positive clones; and selecting the enriched monoclonal, performing Phage ELISA identification, and performing sequencing analysis on the clone to obtain the nucleic acid and amino acid sequence information of the candidate single domain antibody. 20 monoclonals are randomly selected for sequencing analysis, the sequence difference is large, and the library diversity is good. The potential post-translational modification sites were analyzed by the In silico method against the amino acid sequence information of the CDR regions of the candidate single domain antibodies.

According to the result of the monoclonal flow detection of the yeast, positive clones combined with IL-17A-His are selected to extract genome DNA, and the antibody sequence is obtained by PCR. According to the sequencing result of the PCR product, selecting differential clone for overlap PCR amplification, adding signal peptide at the N end of VHH, adding IgG1-Fc at the C end, and transiently transfecting HEK293 cells with the PCR product; ELISA detection was performed on the expressed antibody supernatants: 100 mu L of transfection supernatant is added into a 96-well plate pre-coated by IL-17A recombinant antibody for incubation, ELISA detection is carried out by adopting HRP-Protein A as a secondary antibody, and differential clone combined with IL-17A-His antigen is screened for constructing eukaryotic expression vectors.

The constructed single domain antibody expression vector is transiently transfected into 293F cells, recombinant antibodies are affinity purified by Protein A, and SDS-PAGE experiments are carried out to detect the purity of candidate antibodies. The results show that the molecular weight and purity of the candidate antibodies are all in accordance with the expectations, and the next experiment can be carried out.

(14) ELISA detection of binding of recombinant antibodies to target proteins

(15) FACS detection of IL17A binding to reporter cell lines

(16) Single domain antibody blocking function assay

Antibodies were diluted in a gradient, IL-17A protein, 293F-IL-17RA-IL-17Rc-ACT 1-NFkB-Luc cells were added, 20. Mu.L Bright-GloTM assay reagent was added, and luciferase activity values in wells were detected using a Tecan M1000pro microplate reader.

(17) Single domain antibody epitope detection (NTA)

The ForteBio OCTET R2 system was subjected to kinetic characterization analysis.

(18) Single domain antibody epitope detection (HIS 1K)

Kinetic characterization analysis was performed using the ForteBio OCTET R2 system.

The invention further extends to the basis of the basic screening method described above. In the detection of the blocking activity of the antibody, the blocking effect of a part of single domain antibodies is weaker than that of a positive antibody Ixekizumab although the single domain antibodies can block the Human IL-17A protein from activating a downstream target protein. Thus, two of the anti-IL-17A single domain antibodies are serially combined to form a bivalent antibody to enhance its blocking effect. Specifically, the invention protects tandem antibodies constructed from 1-G12 and 1-F8.

EXAMPLE 1 preparation and purification of IL-17A specific tandem antibodies

The sequence of the 1-G12 variable region is SEQ ID NO.15, and the CDR regions are SEQ ID NO.1-3 in sequence;

the sequence of the 1-F8 variable region is SEQ ID NO.16, and the CDR regions are SEQ ID NO.4-6 in sequence.

In this example, the tandem antibody further comprises a linker (GGGGS) ₃ A range region (SEQ ID NO. 17) and a CH region (SEQ ID NO. 18).

The tandem antibody in this example is abbreviated as G12-1-F8, and its amino acid sequence is SEQ ID NO.15- (GGGGS) ₃ -SEQ ID NO.16-SEQ ID NO.17-SEQ ID NO.18, the gene sequence of which is SEQ ID NO.21.

The tandem antibody of this example can be prepared by referring to the antibody preparation method in the prior art, specifically as follows:

(1) The gene SEQ ID No.21 is synthesized and subcloned into an expression vector pcDNA3.4-hIgG1-Fc in tandem with a human IgG1 Fc segment gene sequence (SEQ ID No. 20). After the vector was verified by sequencing, the endotoxin-free plasmid was prepared using the Qiagen plasmid large-sample kit (CAT#: DP 117) for use.

(2) And taking out the LVTransm transfection reagent and the single-chain antibody expression vector from the refrigerator, thawing at room temperature, and blowing up and down by a pipetting gun to completely mix uniformly. The PBS buffer was removed and warmed to room temperature. Taking 2mL of PBS to one hole of a 6-hole plate, respectively adding 130 mug antibody expression vector, blowing up and down by a pipette to fully mix, adding 400 mug L VTransm, immediately blowing up and down by a pipette to mix uniformly, and standing for 10 minutes at room temperature to obtain the DNA/LVTransm complex.

(3) The DNA/L VTransm complex was added to 30mL of 293F cells, gently swirled and thoroughly mixed. The cells were exposed to 5% CO at 37 ℃ ₂ After culturing for 6-8 hours at 130rpm in the incubator, 50mL of fresh 293 cell culture medium was added and the cells were returned to the incubator for continued culturing.

After continuous culture for 7 days, the culture supernatant was collected by centrifugation, filtered with a 0.45 μm filter membrane, and the filtrate was transferred to a sterile centrifuge tube, and the antibody was purified using Protein A to obtain a purified antibody.

The procedure for purifying antibodies by Protein A is as follows:

1) Samples containing the target antibodies were added to the EP tube and mixed by gently inverting the tube.

2) EP tubes were mixed at room temperature or incubated on a rotator, (1-4 hours or overnight) and 100mM PMSF was added to prevent protein degradation.

3) The magnetic beads were collected using a magnetic separation rack and the supernatant was discarded. The supernatant was retained for analysis, if necessary.

4) To the EP tube, 1mL of binding/washing buffer was added and thoroughly mixed, the beads were collected using a magnetic rack and the supernatant was discarded, and the washing step was repeated three times.

5) To the EP tube, 500. Mu.L of elution buffer was added, and resuspended rapidly with pipetting or vortexing, and then incubated at room temperature (about 25 ℃) for 5 minutes either in a tumble mixer or by manually gently tumbling the EP tube.

6) Magnetic beads were collected using a magnetic separation rack and the supernatant containing the eluted antibodies was transferred to a clean EP tube.

7) Steps 1) and 2) were repeated twice.

8) To each 500. Mu.L of eluate, 1/10 of a neutralization buffer was added to neutralize the pH in order to maintain the biological activity of the antibody and avoid inactivation of the antibody. Buffer exchange can be performed by dialysis or desalting, if desired.

9) Binding/washing buffer: 1 XPBS, pH 7.0.

Elution buffer: (1) 0.1M glycine, pH 2-3; (2) 0.1M NaAc-HAc, pH 3.6.

Neutralization buffer: 1M Tris, pH 8.5.

Magnetic bead regeneration buffer: 0.1M NaOH.

SDS-PAGE results of the tandem antibodies G12-1-F8 are shown in FIG. 1.

SDS-PAGE detects the purity of the target antibody protein, and the result shows that the protein purity is >95%.

EXAMPLE 2IL-17A specific tandem antibody affinity assay

Using Ixekizumab as a positive control, synthesizing Ixekizumab heavy chain variable region (SEQ ID NO. 22) and light chain variable region (SEQ ID NO. 23) by genes, subcloning the heavy chain variable region into pcDNA3.4-hIgG4 vector (hIgG 4 amino acid sequence is SEQ ID NO. 26), and subcloning the light chain variable region into pcDNA3.4-hIgKc vector (hIgKc amino acid sequence is SEQ ID NO. 27); after verification by Sanger sequencing, the plasmid megapump kit is used for preparing the endotoxin-removing plasmid for standby. Other procedures reference example 1 was made to control antibodies with a purity >95%.

SEQ ID NO.26：

ASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGK；

SEQ ID NO.27：

RTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSF NRGEC。

ELISA detects binding of recombinant antibodies to target proteins:

coating an ELISA plate with the purified antibody to be detected (2 ug/mL), adding Biotin-IL-17A-His, diluting 7 points with a 5-fold gradient, performing ELISA detection with HRP-strepitavdin, and drawing a curve of OD450 values measured by each concentration to read EC50 values.

The results showed that the EC50 value of the control antibody Ixekizumab was 10.06 μg/mL, see figure 2; the EC50 of the tandem antibody was 2.425. Mu.g/mL, see FIG. 3.

Example 3 antibody blocking function assay

Blocking activity assays were performed using the 293F-IL-17RA-IL-17Rc-ACT 1-NFkB-Luc reporter cell line. This example detects tandem antibodies, control antibodies and single domain antibodies as described in example 2.

Ixekizumab results are shown in FIG. 4, and can block Human IL-17A protein from activating 293F-IL-17RA-IL-17Rc-ACT 1-NFkB-Luc, and the IC50 value is 1.356 mug/mL.

The results of the tandem antibodies are shown in FIG. 5, and the result is that the Human IL-17A protein can be blocked to activate 293F-IL-17RA-IL-17Rc-ACT 1-NFkB-Luc, and the IC50 is 0.7587 mug/mL. The results data for the tandem antibody are superior to the control antibody Ixekizumab.

Example 4 stability test procedure and results analysis:

the experimental process comprises the following steps: by detecting fluorescence change through a micro-differential scanning fluorescence (nanoDSF) technique, thermal denaturation and chemical denaturation of proteins can be detected under natural conditions, and the temperature (Tm) at which 50% of the proteins are in an unfolded state and the temperature (Tagg) at which aggregation begins to occur can be accurately determined; the higher the thermal denaturation Tm value and Tagg, the more stable the antibody protein.

Taking 100 mu L of antibody to be detected, centrifuging at 4 ℃ for 10min at 12000 Xg, sucking samples by using capillaries, preparing two capillaries for each sample, taking the capillaries as parallel control, sequentially placing the capillaries into corresponding clamping grooves, ensuring that the capillaries are full of the samples, and carrying out detection analysis. The temperature rising range is 20-95 ℃, the temperature rising rate is 1 ℃/min, and the detection time is 75min.

Tm is defined as the melting temperature, tonset is defined as the temperature at which unfolding begins, tagg is defined as the aggregation temperature.

The antibodies to be detected in this example are the tandem antibodies, the control antibodies, and the single domain antibodies described in example 2.

Lxekizumab results are shown in FIG. 6, wherein Tm1 is 56.10+/-0.02 ℃, tm2 is 79.84+/-0.13 ℃, tonset is 47.50 +/-0.08 ℃, tagg is 61.86+/-0.23 ℃;

the results of the tandem antibodies are shown in FIG. 7. The Tm1 is 59.15 +/-0.08 ℃, the Tm2 is 81.67+/-0.31 ℃, the Tonset is 52.61 +/-0.33 ℃, and the Tagg is 71.28 +/-0.23 ℃;

tandem antibody stability was significantly better than control antibody.

Application example 1 an antibody preparation

This example provides an antibody preparation comprising the tandem antibody prepared in example 1.

The auxiliary materials of the preparation comprise:

the buffer is selected from: acetic buffer, histidine buffer, phosphate buffer, citrate buffer, carbonate buffer or Tris; the concentration of the buffer is 3-60mM.

The stabilizer is selected from: arginine salts, sodium chloride, mannitol, sorbitol, sucrose, glycine, and trehalose; the concentration of the stabilizer is 50-400mM. The combination of sucrose and arginine hydrochloride is selected, wherein the concentration of sucrose is 50-200mM, and the concentration of arginine hydrochloride is 10-100mM.

The surfactant is selected from: polysorbate 80, polysorbate 20 and poloxamer 188.

Application example 2A kit

This example provides a kit for in vitro detection of IL-17A.

The kit is a competition ELISA kit and comprises a colloidal gold reagent strip and sample diluent.

The colloidal gold reagent strip comprises: sample pad, gold mark pad, chromatographic membrane and absorbent paper.

The gold-labeled pad is coated with the serial antibody prepared in the colloidal gold-labeled example 1;

a detection line and a quality control line are arranged on the chromatographic membrane, and the detection line is coated with an IL-17A antigen marked by colloidal gold; the quality control line is coated with the verification antibody of the tandem antibody.

When the sample is used, the sample dilution liquid is used for diluting the sample, the sample is dripped on a sample pad, when the sample contains a certain amount of IL-17A, the sample reacts with the colloidal gold labeled antibody, the detection line does not display color, and when the sample does not contain IL-17A, the colloidal gold labeled antibody reacts with the coating antigen on the detection limit, and the color is displayed, so that the detection purpose is achieved.

The kit can also be established by a double-antibody sandwich method, and the tandem antibody prepared in the embodiment 1 can be used as an enzyme-labeled antibody or a solid-phase antibody.

Application example 3 an antibody conjugate

This example provides antibody conjugates of tandem antibodies prepared in example 1.

The preparation method comprises the following steps:

(1) Reacting the tandem antibody or antigen-binding fragment thereof with a reducing agent in a buffer;

(2) Reacting the linker-payload with the thiol-bearing tandem antibody or antigen-binding fragment thereof obtained in step (1);

the mass ratio of reducing agent to tandem antibody or antigen binding fragment thereof is 1:1-5:1; preferably 1:1 to 4:1; further preferably 1:1 to 3:1; even more preferably 2:1 to 3:1.

The reducing agent is selected from tris (2-carboxyethyl) phosphine (TCEP) or a salt thereof, dithiothreitol or 2-mercaptoethanol. In some embodiments the reducing agent is tris (2-carboxyethyl) phosphine or a salt thereof, preferably tris (2-carboxyethyl) phosphine hydrochloride (tcep·hcl).

The buffer solution is selected from HEPES (4- (2-hydroxyethyl) -1-piperazine ethane sulfonic acid) buffer solution, histidine buffer solution, phosphate buffer solution, borate buffer solution or acetate buffer solution; preferably histidine buffer; further preferred is histidine-hydrochloric acid buffer; the concentration of the buffer is 1mM-30mM, such as 5mM, 10mM, 15mM, 20mM, 25mM or 30mM, preferably 20mM.

The ratio of the amount of the linker-payload to the amount of the substance of the tandem antibody or antigen binding fragment thereof is 2:1-10:1; preferably, the ratio of the amount of linker-payload to the amount of substance of the tandem antibody or antigen binding fragment thereof is 3:1-9:1; further preferred, the ratio of the amount of linker-payload to the amount of substance of the tandem antibody or antigen binding fragment thereof is 4:1-7:1; further preferably, the ratio of the amount of the linker-payload to the amount of the substance of the tandem antibody or antigen binding fragment thereof is from 5:1 to 7:1.

The solvent used to dissolve the linker-payload may be selected from aqueous acetone (e.g., 50% aqueous acetone), aqueous ethanol (e.g., 80% aqueous ethanol), aqueous methanol (e.g., 80% aqueous methanol), aqueous isopropanol (e.g., 80% aqueous isopropanol), aqueous dimethyl sulfoxide (e.g., 80% aqueous dimethyl sulfoxide), acetone, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMA), or N-methyl-2-pyrrolidone (NMP); preferably an aqueous acetone or DMSO, preferably 50% aqueous acetone.

Application example 4A pharmaceutical composition for the treatment of tumors

This example provides a pharmaceutical composition comprising the tandem antibodies prepared in the example.

The pharmaceutical composition also comprises any one or more of the following medicines:

nitrogen mustard, cyclophosphamide, ifosfamide, phenylalanine nitrogen mustard, chlorambucil, thiotepa, carmustine, lomustine, nimustine, busulfan, methotrexate, thioguanine, fluorouracil, capecitabine, deoxyfluorouridine, famoxadine, dactinomycin, mitomycin, bleomycin, pingyanmycin, doxorubicin, epirubicin, pyranamycin, mithramycin, mitoxantrone, vincristine, vindesine, vinorelbine, etoposide, teniposide, hydroxycamptothecin, topotecan, paclitaxel, dacarbazine, cisplatin, carboplatin, oxaliplatin, nedaplatin, erlotinib, cetuximab, bevacizumab, an Luoti, trastuzumab, palivizumab, katuzumab, imatinib, dulcitol You Shan, dittany Li Shan, gartuzumab, and nervogliboside Li Shan.

The pharmaceutical composition may be an antibody combination: for example, the serial antibody and palbociclib are used for treating cancer under the condition of a certain dosage ratio (such as 1:1).

The pharmaceutical composition may also be a combination of different types of drugs: such as antibodies in combination with cisplatin for the treatment of cancer.

It should be noted that the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the scope of the present invention, and those skilled in the art should substitute and improve the simple means based on the technical solution provided by the present invention.

Claims

1. An antibody comprising a first single domain antibody and a second single domain antibody, characterized in that,

(1) The first single domain antibody amino acid sequence comprises:

HCDR1, HCDR2, HCDR3 as shown in SEQ ID nos. 1-3; and/or; an amino acid sequence having at least 80% sequence identity to the amino acid sequences shown in SEQ ID NO. 1-3;

(2) The second single domain antibody amino acid sequence comprises:

HCDR4, HCDR5, HCDR6 as shown in SEQ ID nos. 4-6; and/or; an amino acid sequence having at least 80% sequence identity to the amino acid sequence shown in SEQ ID NO. 4-6;

SEQ ID NO.1 is GFSFSIYS; SEQ ID NO.2 is ITKGGLK; SEQ ID NO.3 is NAGRENGY; SEQ ID NO.4 is GFSIHIYA; SEQ ID NO.5 is ITRGGVT; SEQ ID NO.6 is AGGTNGGY.

2. The antibody of claim 1, wherein the amino acid sequence comprises: an amino acid sequence obtained by at least one of addition, deletion, modification and/or substitution on the amino acid sequence shown in SEQ ID NO. 1-6.

3. The antibody of claim 2, wherein the amino acid sequence of the antibody comprises: amino acid sequences having a difference of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11 amino acids compared to the amino acid sequences shown in SEQ ID NO. 1-6.

4. The antibody of any one of claims 1-3, wherein the first single domain antibody or the second single domain antibody further comprises at least 4 FR regions for linking heavy chain variable regions.

5. The antibody of claim 4, wherein the heavy chain framework region comprises a portion or all of an antibody heavy chain framework region selected from human, murine, primate, or camelid sources or a variant thereof;

6. An antibody, comprising:

a first single domain antibody of the formula (i):

FR1-HCDR1-FR2-HCDR2-FR3-HCDR3-FR4；

FR5-HCDR4-FR6-HCDR5-FR7-HCDR6-FR8；

wherein HCDR1, HCDR2 and HCDR3 are selected from the group consisting of:

HCDR4, HCDR5 and HCDR6 are selected from:

7. The antibody of claim 6, wherein HCDR1 has an amino acid sequence shown as SEQ ID No.1, HCDR2 has an amino acid sequence shown as SEQ ID No.2, HCDR3 has an amino acid sequence shown as SEQ ID No.3, HCDR4 has an amino acid sequence shown as SEQ ID No.4, HCDR5 has an amino acid sequence shown as SEQ ID No.5, and HCDR6 has an amino acid sequence shown as SEQ ID No. 6.

8. The antibody of any one of claims 1-7, wherein the amino acid sequences of the first single domain antibody and the second single domain antibody are directly linked; or; indirectly connected through a linker.

9. The antibody of claim 8, wherein the linker is (GGGGS) n, wherein n is selected from 1, 2, 3, 4, 5 or 6; preferably, the linker is (GGGGS) ₃ 。

10. The antibody of any one of claims 1-9, wherein the first single domain antibody and the second single domain antibody are linked in an optional order; or; the first single domain antibody and the second single domain antibody are connected in the order from the N end to the C end; or; the first single domain antibody and the second single domain antibody are linked in order from the C-terminus to the N-terminus.

11. The antibody of any one of claims 1-10, which is an anti-IL-17A antibody.

12. A recombinant protein comprising the antibody of any one of claims 1-11.

13. The recombinant protein according to claim 12, wherein said recombinant protein further comprises a biologically active protein or functional fragment thereof that facilitates expression and/or secretion, or that increases in vivo half-life.

14. The recombinant protein according to claim 13, wherein said biologically active protein or functional fragment thereof is selected from at least one of an immunoglobulin Fc domain, serum albumin, albumin binding polypeptide, prealbumin, carboxy terminal peptide, elastin-like polypeptide, his tag, GST tag, MBP tag, FLAG tag, and SUMO tag.

15. The recombinant protein according to claim 14, wherein said immunoglobulin Fc domain is derived from a human antibody, a murine antibody, a primate antibody or a camelid antibody, or a variant thereof;

preferably, the immunoglobulin Fc domain is derived from a human IgG antibody, such as an IgG1 Fc, an IgG2 Fc, an IgG3 Fc or an IgG4 Fc, preferably an IgG1 Fc.

16. An antibody preparation, comprising:

a1: the antibody of any one of claims 1-11 or the recombinant protein of any one of claims 12-15; and

a2: a pharmaceutically acceptable carrier.

17. Kit, characterized in that it comprises an antibody according to any one of claims 1 to 11, a recombinant protein according to any one of claims 12 to 15 or an antibody preparation according to claim 16;

18. A drug conjugate, comprising:

b1: the antibody of any one of claims 1-11 or the recombinant protein of any one of claims 12-15; and

b2: a coupling moiety coupled to B1.

19. An isolated nucleic acid molecule encoding the antibody of any one of claims 1-11 or the recombinant protein of any one of claims 12-15.

20. An expression vector comprising the nucleic acid molecule of claim 19.

21. A pharmaceutical composition comprising the antibody of any one of claims 1-11, the recombinant protein of any one of claims 12-15, the antibody preparation of claim 16, the drug conjugate of claim 18, the nucleic acid molecule of claim 19 or the expression vector of claim 20;

22. The antibody of any one of claims 1-11, the recombinant protein of any one of claims 12-15, the antibody preparation of claim 16, the drug conjugate of claim 18, or the pharmaceutical composition of claim 21 for at least one of the following uses:

c1: preparing a detection reagent or a kit;

c2: preparing a medicament for preventing and/or treating autoimmune diseases;

and C3: preparing medicine for preventing and/or treating cancer.

23. The use according to claim 22, characterized in that, the autoimmune disease includes Behcet's disease, systemic lupus erythematosus, chronic discoid lupus erythematosus, multiple sclerosis, systemic scleroderma, progressive systemic sclerosis, scleroderma, polymyositis, dermatomyositis, perinodular arteritis, aortitis syndrome, malignant rheumatoid arthritis, juvenile idiopathic arthritis, spondyloarthritis, mixed connective tissue disease, kasmann's disease, sjogren's syndrome, adult Steve's disease, vasculitis, allergic granulomatous vasculitis, allergic vasculitis, rheumatoid vasculitis, macrovasculitis, ANCA-related vasculitis, cogan's syndrome, RS3PE syndrome, temporal arteritis, polymyositis rheumatica, fibromyalgia, antiphospholipid antibody syndrome, eosinophilic fasciitis, igG 4-related diseases, guillain Barre syndrome myasthenia gravis, chronic atrophic gastritis, autoimmune hepatitis, nonalcoholic steatohepatitis, primary biliary cirrhosis, good-pasture syndrome, acute glomerulonephritis, lupus nephritis, megaloblastic anemia, autoimmune hemolytic anemia, pernicious anemia, autoimmune neutropenia, idiopathic thrombocytopenic purpura, bazedol's disease, crohn's disease bridge disease, autoimmune adrenocortical insufficiency, primary hypothyroidism, addison's disease, idiopathic Addison's disease, type I diabetes, slowly progressive type I diabetes, focal scleroderma, psoriasis, psoriatic arthritis, bullous pemphigoid, herpes gestation, linear IgA bullous dermatoses, acquired epidermolysis bullosa, alopecia areata, leukoplakia, vitiligo vulgaris, neuromyelitis optica, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, sarcoidosis, giant cell arteritis, amyotrophic lateral sclerosis, former field disease, autoimmune optic neuropathy, idiopathic azoospermia, habitual abortion, inflammatory bowel disease, celiac disease, ankylosing spondylitis, severe asthma, chronic urticaria, familial mediterranean fever, eosinophilic chronic sinusitis, dilated cardiomyopathy, systemic mastocytosis or inclusion body myositis;

24. The use according to claim 22 or 23, wherein the cancer comprises basal cell carcinoma, cholangiocarcinoma, bladder cancer, bone cancer, breast cancer, peritoneal cancer, cervical cancer, cholangiocarcinoma, choriocarcinoma, colorectal cancer, connective tissue cancer, cancer of the digestive system, endometrial cancer, esophageal cancer, eye cancer, head and neck cancer, gastric cancer, glioblastoma, liver cancer, renal cancer, laryngeal cancer, leukemia, liver cancer, lung cancer, lymphoma, melanoma, myeloma, neuroblastoma, oral cancer, ovarian cancer, pancreatic cancer, prostate cancer, retinoblastoma, rhabdomyosarcoma, rectal cancer, respiratory cancer, salivary gland cancer, sarcoma, skin cancer, squamous cell carcinoma, testicular cancer, thyroid cancer, uterine cancer, urinary system cancer, B-cell lymphoma, chronic lymphoblastic leukemia, acute lymphoblastic leukemia, hairy cell leukemia or chronic myelogenous leukemia.

25. A method for in vitro detection of IL-17A in a sample for non-diagnostic purposes, characterized in that the method comprises the steps of:

D1: the antibody of any one of claims 1-11, the recombinant protein of any one of claims 12-15, the antibody preparation of claim 16, or the drug conjugate of claim 18, in contact with a sample to be tested;

d2: detecting the antigen-antibody complex;

d3: and judging the result.

26. A method of preventing and/or treating an autoimmune disease, the method comprising:

administering to a subject in need thereof a therapeutically effective amount of the antibody of any one of claims 1-11, the recombinant protein of any one of claims 12-15, the antibody preparation of claim 16, or the drug conjugate of claim 18.

27. A method of preventing and/or treating cancer, the method comprising: