CN117327181A

CN117327181A - Single-domain antibody for resisting IL-4 Ralpha, application and medicine

Info

Publication number: CN117327181A
Application number: CN202311107469.0A
Authority: CN
Inventors: 苏志鹏; 张云; 孟巾果; 王乐飞
Original assignee: Nanjing Rongjiekang Biotechnology Co ltd
Current assignee: Nanjing Rongjiekang Biotechnology Co ltd
Priority date: 2020-06-22
Filing date: 2020-06-22
Publication date: 2024-01-02
Also published as: CN114957472B; CN111690066B; CN111690066A; CN114957472A

Abstract

The invention discloses a single domain antibody for resisting IL-4 Ralpha, and application and medicament thereof, and relates to the technical field of antibodies. The amino acid sequence of the CDR1 of the single domain antibody disclosed by the invention is shown as any one of SEQ ID NO.37-53, the amino acid sequence of the CDR2 is shown as any one of SEQ ID NO.54-68, and the amino acid sequence of the CDR3 is shown as any one of SEQ ID NO. 69-85. The single domain antibody can specifically bind to IL-4Rα and can be used for preventive diagnosis and/or treatment of IL-4Rα related diseases such as autoimmune diseases.

Description

Single-domain antibody for resisting IL-4 Ralpha, application and medicine

Technical Field

The invention relates to the technical field of antibodies, in particular to a single-domain antibody for resisting IL-4 Ralpha, and application and medicaments thereof.

Background

IL-4 and IL-4Rα are ideal therapeutic targets for the treatment of human diseases associated with abnormal T-helper (Th 2) cells. The human IL-4R alpha subunit (Swiss Prot database accession number: P24394) is a type I membrane protein with a molecular weight of 140kDa, and binds human IL-4 with high affinity. IL-4/IL-4Rα complexes can dimerize IL-4Rα with CD132 or IL-13Rα 1 subunits via domains on the IL-4 molecule, thereby forming two distinct signaling molecule complexes corresponding to class I and class II receptors, respectively. In addition, the complex formed after IL-13 binds IL-13Rα1 can recruit IL-4Rα subunits and can likewise form class II receptor complexes. IL-4Rα can therefore modulate the biological activity associated with both IL-4 and IL-13 molecules (Gessner et al, immunobiology,201:285, 2000). In vitro experimental studies have shown that the activating effects of IL-4 and IL-13 have an effect on a variety of cells, including: t lymphocytes, B lymphocytes, eosinophils, megacytes, basophils, airway smooth muscle cells, lung fibroblasts and endothelial cells.

IL4Rα is not expressed at high levels on different cell types, typically 100-5000 molecules per cell (Lowenthal et al, J Immunol,140:456, 1988), such as peripheral blood T cells, monocytes, airway epithelial cells, B cells and lung fibroblasts. Type I receptors have an expression advantage on the surface of hematopoietic cells, while type II receptors are expressed on both hematopoietic and non-hematopoietic cell surfaces.

Polymorphism of IL-4Rα in the human population has been discussed (Gessner et al, immunobiology,201:285, 2000), and studies have shown that in certain populations the polymorphism of this molecule is associated with IgE levels or clinical atopy, e.g., V75R576 IL-4Rα is associated with allergic asthma and enhanced IL-4Rα function (Risma et al, J.Immunol.169 (3) 1604-1610, 2002).

Much evidence suggests that the IL-4/IL-13 pathway plays an important role in asthma pathology (for reviews see Chatilla, trends in Molecular Med,10:493, 2004) and a number of other disorders listed elsewhere herein. It is currently believed that increased secretion of IL-4 and IL-13 initiates and maintains this disease process. IL-13 is thought to be an important ligand triggering Airway Hyperresponsiveness (AHR), mucus hypersecretion, and airway remodeling, while IL-4 is thought to be a major contributor to Th2 polarization and IgE production (Wynn, annu Rev Immunol,21:425, 2003).

Evidence from animal models further supports the role of IL-4 ra in asthma. IL-4R antagonists (IL-4 mutants; C118 deletion) inhibited allergic airway eosinophilia and AHR development in functional mice induced by OVA sensitization during allergen stimulation with ovalbumin (OVA, a model allergen) (Tomkinson et al, J.Immunol.166 (9): 5792-5800, 2001). In addition, several in vivo studies demonstrated blocking the positive effects of IL-13 or IL-14 in animal models of asthma. For example, in a chronic model of OVA-induced persistent airway inflammation, therapeutic doses of anti-IL-13 monoclonal antibodies inhibited AHR, stopped progression of subepithelial fibrosis and inflammation, and restored mucus hypersecretion to basal levels (Yang et al, J.Pharmacol. Exp. Ther.313 (1): 8-15,2005). In the mouse OVA model, but when administered during immunization, inhibition of IL-4 with anti-IL-4 antibodies showed a significant reduction in eosinophil infiltration (Coyle et al Am J Resp Cell Mol Biol,13:54, 1995). In a similar model, IL-4 deficient mice had significantly fewer eosinophils in bronchoalveolar lavages and much less peribronchial inflammation following OVA stimulation (Brusselle et al, clin Exp Allergy,24:73, 1994).

For humans, clinical phase IIa studies have shown that among asthmatic patients, IL-4Rα antagonists (so-called IL-4 muteins) reduce allergen-induced delayed asthmatic responses and attenuate resting inflammatory states of the lungs of asthmatic patients (Wenzel et al, lancet,370:1422, 2007). These clinical data further strengthen the claim that IL-4 ra antagonists have clinical utility in asthma.

In addition to its role in asthma, IL-4Rα is associated with a number of other pathological conditions, such as COPD, including patient populations suffering from various degrees of chronic bronchitis, small airway diseases and emphysema. The underlying cause of COPD is still unknown. The "Netherlands hypothesis" suggests that there is a common susceptibility to COPD and asthma, and thus a similar mechanism may lead to the onset of both disorders (Slueter et al, eur Respir J,4 (4): p.479-89,1991). Zheng et al (J Clin Invest,106 (9): 1081-93, 2000) demonstrated that over-expression of IL-13 in the mouse lung caused emphysema, increased mucosal yield and inflammation, and could reflect many features of human COPD. Furthermore, as an IL-13 dependent response in a mouse model of allergic inflammation, AHR has been shown to predict lung hypofunction in smokers (Tashkin et al Am J Respir Crit Care Med,153 (6 Pt 1): 1802-11, 1996). In addition, a correlation between IL-13 promoter polymorphism and susceptibility to COPD was established (Van Der Pouw Kraan et al, genes Immun,3 (7): 436-9, 2002). Thus, it is the IL-4/IL-13 pathway, especially IL-13, that plays an important role in the pathogenesis of COPD.

IL-13 may play a role in the pathogenesis of inflammatory bowel disease. Heller et al (Heller et al, immunity,17 (5): 629-38, 2002) reported that administration of soluble IL-13Rα2 and IL-13 improved colonic inflammation in murine models of ulcerative colitis in humans. Accordingly, IL-13 expression was higher in rectal biopsies from patients with ulcerative colitis than in controls (Inoue et al Am J Gastroenterol,94 (9) JMl-6, I999).

In addition to asthma, the IL-4/IL-13 pathway is associated with other fibrotic disorders like systemic scleroderma (Hasegawa et al, J Rheumatoid 24 (2): 328-32, 1997), pulmonary fibrosis (Hancock et al, am J Respir Cell Mol Biol,18 (1): 60-5,1998), parasite-induced liver fibrosis (Fallon et al, J Immunol,164 (5) 2585-91,2000; chiaramonte et al, J Clin Invest,104 (6): 777-85,1999;Chiaramonte,Hepatology 34 (2): 273-82, 2001), and bladder fibrosis (Hauber et al, J. Cyst fiber, 2 189, 2003).

IL-4 is crucial for B cell mediated activities such as B cell proliferation, immunoglobulin secretion, and Fc epsilon R expression. Clinical applications of IL-4 ra inhibitors include, for example, use in allergy treatment to suppress IgE synthesis (including, for example, atopic dermatitis and food allergies), use in transplant therapy to prevent transplant rejection, and suppression of delayed-type allergic or contact allergic reactions.

IL-4R antagonists may also be used as adjuvants for allergy immunotherapy and as vaccine adjuvants. Antibodies to IL-4Rα have been described. Two examples are neutralizing murine anti-IL-4Rα monoclonal antibodies MaBETA 230 (clone 25463) and 16146 (clone 25463.11), provided by R & D company (R & D Systems) and Sigma company, respectively. These antibodies, belonging to the IgG2a subtype, were obtained by the mouse hybridoma method and were developed from purified recombinant human IL-4rα (baculovirus-derived) immunized mice. Two other neutralizing murine anti-IL-4 Rα antibodies, M57 and X2/45-12, were provided by BD Biosciences and ebiosciences, respectively. These are IgGl antibodies, also obtained by mouse hybridoma technology from mice immunized with recombinant soluble IL-4rα.

There remains a need in the art for anti-IL-4rα antibodies, particularly anti-IL-4rα heavy chain single domain antibodies, that are capable of binding to IL-4rα with high affinity and that are capable of blocking IL-4 binding to IL-4rα.

In view of this, the present invention has been made.

Disclosure of Invention

The invention aims to provide a single domain antibody for resisting IL-4 Ralpha, and application and medicaments thereof. The single domain antibody can specifically bind IL-4Rα, has high affinity, is easy to prepare and low in production cost, and can not generate strong immune response when being used as a medicament due to low immune heterogeneity, thus having wide application prospect.

The invention is realized in the following way:

in a first aspect, the invention provides a single domain antibody against IL-4Rα comprising the following complementarity determining regions: CDR1, CDR2, and CDR3;

wherein the amino acid sequence of CDR1 is shown in any one of SEQ ID NO.37-53, the amino acid sequence of CDR2 is shown in any one of SEQ ID NO.54-68, and the amino acid sequence of CDR3 is shown in any one of SEQ ID NO. 69-85.

The single domain antibody of the anti-IL-4Rα provided by the invention, which has CDR1, CDR2 and CDR3 which can be respectively changed or selected within the sequence ranges of SEQ ID NO.37-53, SEQ ID NO.54-68 and SEQ ID NO.69-85, can be combined with the IL-4Rα in any sequence, has good affinity, can be used for preparing and treating IL-4Rα -mediated related diseases, and can be used for preparing reagents for detecting IL-4Rα, and the single domain antibody has wide and various purposes.

In addition, the single-domain antibody provided by the invention has the advantages of simple structure, easiness in preparation and low production cost, and has a good application prospect because of low immune heterogeneity, and immune response is not easy to generate when the single-domain antibody is used as a medicament for treating IL-4Rα mediated related diseases.

It is noted that, based on the disclosure of the structure of the complementarity determining region described above, one skilled in the art will readily recognize that substitution or deletion of one or more amino acids based thereon will result in a single domain antibody mutant having substantially the same or increased binding activity or affinity for IL-4Rα, which is readily accomplished by one skilled in the art, and, based thereon, such single domain antibody mutant is also within the scope of the present invention.

Alternatively, in some embodiments of the invention, the complementarity determining regions of the single domain antibodies are as set forth in any one of the following (1) - (18):

(1): CDR1 is shown as SEQ ID NO.53, CDR2 is shown as SEQ ID NO.61, and CDR3 is shown as SEQ ID NO. 73;

(2): CDR1 is shown as SEQ ID NO.37, CDR2 is shown as SEQ ID NO.61, and CDR3 is shown as SEQ ID NO. 72;

(3): CDR1 is shown as SEQ ID NO.39, CDR2 is shown as SEQ ID NO.58, and CDR3 is shown as SEQ ID NO. 78;

(4): CDR1 is shown as SEQ ID NO.53, CDR2 is shown as SEQ ID NO.63, and CDR3 is shown as SEQ ID NO. 72;

(5): CDR1 is shown as SEQ ID NO.42, CDR2 is shown as SEQ ID NO.64, and CDR3 is shown as SEQ ID NO. 74;

(6): CDR1 is shown as SEQ ID NO.46, CDR2 is shown as SEQ ID NO.66, and CDR3 is shown as SEQ ID NO. 69;

(7): CDR1 is shown as SEQ ID NO.50, CDR2 is shown as SEQ ID NO.68, and CDR3 is shown as SEQ ID NO. 85;

(8): CDR1 is shown as SEQ ID NO.48, CDR2 is shown as SEQ ID NO.55, and CDR3 is shown as SEQ ID NO. 80;

(9): CDR1 is shown as SEQ ID NO.47, CDR2 is shown as SEQ ID NO.60, and CDR3 is shown as SEQ ID NO. 83;

(10): CDR1 is shown as SEQ ID NO.49, CDR2 is shown as SEQ ID NO.67, and CDR3 is shown as SEQ ID NO. 81;

(11): CDR1 is shown as SEQ ID NO.38, CDR2 is shown as SEQ ID NO.58, and CDR3 is shown as SEQ ID NO. 77;

(12): CDR1 is shown as SEQ ID NO.45, CDR2 is shown as SEQ ID NO.54, and CDR3 is shown as SEQ ID NO. 70;

(13): CDR1 is shown as SEQ ID NO.41, CDR2 is shown as SEQ ID NO.59, and CDR3 is shown as SEQ ID NO. 84;

(14): CDR1 is shown as SEQ ID NO.43, CDR2 is shown as SEQ ID NO.57, and CDR3 is shown as SEQ ID NO. 82;

(15): CDR1 is shown as SEQ ID NO.40, CDR2 is shown as SEQ ID NO.56, and CDR3 is shown as SEQ ID NO. 76;

(16): CDR1 is shown as SEQ ID NO.44, CDR2 is shown as SEQ ID NO.58, and CDR3 is shown as SEQ ID NO. 75;

(17): CDR1 is shown as SEQ ID NO.52, CDR2 is shown as SEQ ID NO.62, and CDR3 is shown as SEQ ID NO. 71;

(18): CDR1 is shown as SEQ ID NO.51, CDR2 is shown as SEQ ID NO.65, and CDR3 is shown as SEQ ID NO. 79.

The single domain antibody having the CDR structures as described in (1) to (18) above can specifically bind to IL-4Rα and has a high affinity, in particular, the CDR structures as described in (1), (3) and (6).

Alternatively, in some embodiments of the invention, the single domain antibody comprises the following framework regions: FR1, FR2, FR3 and FR4;

wherein the amino acid sequence of FR1 is shown as any one of SEQ ID NO. 86-97; the amino acid sequence of FR2 is shown in any one of SEQ ID NO. 98-109; the amino acid sequence of FR3 is shown in any one of SEQ ID NO. 110-127; the amino acid sequence of FR4 is shown as SEQ ID NO. 128.

It should be noted that, the function of the single domain antibody to achieve specific binding to IL-4rα mainly depends on CDR regions, and based on this, on the premise that the framework region and CDR region sequences of the single domain antibody are disclosed in the present invention, those skilled in the art easily think that, on the premise that the CDR region sequences remain unchanged or slightly changed, sequences similar to the framework region sequences disclosed in the present invention, for example, sequences with homology of 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% or more, are used as the framework region sequences of the single domain antibody, so that the obtained single domain antibody has the same or similar function as the single domain antibody described in the present invention, which is also included in the scope of the present invention.

Alternatively, in some embodiments of the invention, the framework regions FR1, FR2 and FR3 of the single domain antibody are as shown in any one of (a) - (r) below:

(a) FR1 is shown as SEQ ID NO.88, FR2 is shown as SEQ ID NO.100, and FR3 is shown as SEQ ID NO. 115;

(b) FR1 is shown as SEQ ID NO.88, FR2 is shown as SEQ ID NO.100, and FR3 is shown as SEQ ID NO. 114;

(c) FR1 is shown as SEQ ID NO.95, FR2 is shown as SEQ ID NO.102, and FR3 is shown as SEQ ID NO. 123;

(d) FR1 is shown as SEQ ID NO.86, FR2 is shown as SEQ ID NO.100, and FR3 is shown as SEQ ID NO. 117;

(e) FR1 is shown as SEQ ID NO.94, FR2 is shown as SEQ ID NO.105, and FR3 is shown as SEQ ID NO. 113;

(f) FR1 is shown as SEQ ID NO.87, FR2 is shown as SEQ ID NO.99, and FR3 is shown as SEQ ID NO. 110;

(g) FR1 is shown as SEQ ID NO.91, FR2 is shown as SEQ ID NO.109, and FR3 is shown as SEQ ID NO. 111;

(h) FR1 is shown as SEQ ID NO.87, FR2 is shown as SEQ ID NO.100, and FR3 is shown as SEQ ID NO. 119;

(i) FR1 is shown as SEQ ID NO.89, FR2 is shown as SEQ ID NO.101, and FR3 is shown as SEQ ID NO. 124;

(j) FR1 is shown as SEQ ID NO.93, FR2 is shown as SEQ ID NO.98, and FR3 is shown as SEQ ID NO. 112;

(k) FR1 is shown as SEQ ID NO.94, FR2 is shown as SEQ ID NO.106, and FR3 is shown as SEQ ID NO. 125;

(l) FR1 is shown as SEQ ID NO.92, FR2 is shown as SEQ ID NO.107, and FR3 is shown as SEQ ID NO. 127;

(m) FR1 is shown as SEQ ID NO.87, FR2 is shown as SEQ ID NO.103, and FR3 is shown as SEQ ID NO. 120;

(n) FR1 is shown as SEQ ID NO.87, FR2 is shown as SEQ ID NO.108, and FR3 is shown as SEQ ID NO. 126;

(o) FR1 is shown as SEQ ID NO.97, FR2 is shown as SEQ ID NO.105, and FR3 is shown as SEQ ID NO. 121;

(p) FR1 is shown as SEQ ID NO.90, FR2 is shown as SEQ ID NO.105, and FR3 is shown as SEQ ID NO. 122;

(q) FR1 is shown as SEQ ID NO.88, FR2 is shown as SEQ ID NO.100, and FR3 is shown as SEQ ID NO. 116;

(r) FR1 is shown as SEQ ID NO.96, FR2 is shown as SEQ ID NO.104, and FR3 is shown as SEQ ID NO. 118.

Alternatively, in some embodiments of the invention, the amino acid sequence of the single domain antibody is as set forth in any one of SEQ ID NOS.1-18.

In a second aspect, the invention provides a fusion protein comprising a functional domain capable of specifically binding IL-4Rα, said functional domain consisting of an anti-IL-4Rα single domain antibody as described above.

The single domain antibody provided by the invention can be fused with any other protein or substance to achieve different purposes, for example, can be combined with fluorescent protein, enzyme or radioactive element to achieve the purpose of easy detection, and can be fused with a drug molecule for treating IL-4 Ralpha-mediated related diseases to achieve the purpose of better treatment. The type of protein fused to the single domain antibody can be reasonably selected by a person skilled in the art according to actual needs or purposes, and no matter what type of substance is fused, the fusion belongs to the protection scope of the invention.

In a third aspect, the invention provides an anti-IL-4Rα antibody, which is a conventional antibody or a functional fragment thereof, the heavy chain variable region of which is comprised of an anti-IL-4Rα single domain antibody as defined in any one of the preceding claims.

Traditional antibodies are structurally composed of two identical heavy chains and two identical light chains, a light chain having a light chain variable region (VL) and a light chain constant region (CL); the heavy chain has a heavy chain variable region (VH) and a heavy chain constant region (CH 1, CH2, CH3 and/or CH 4). Given the disclosure of the structure of a single domain antibody capable of specifically binding to IL-4rα, one skilled in the art would readily recognize the use of a single domain antibody of the present invention to modify a conventional antibody, e.g., to apply the CDR region structure of a single domain antibody of the present invention to a conventional antibody to obtain a conventional antibody capable of specifically binding to IL-4rα, which is also within the scope of the present invention; further, it is also within the scope of the present invention that based on the structure of the conventional antibody, part of the structure thereof, such as Fab, fab ', (Fab') 2, fv, scFv or sdFv structure, etc., is specific for IL-4Rα binding.

Alternatively, in some embodiments of the invention, the functional fragment is a Fab, fab ', (Fab') 2, fv, scFv, or sdFv structure of the traditional antibody.

Use of an anti-IL-4rα single domain antibody, fusion protein as described above or an antibody as described above in the manufacture of a medicament for the treatment of a disease targeting IL-4rα.

Alternatively, in some embodiments of the invention, the disease is selected from asthma, allergic dermatitis, eczema, arthritis, herpes, chronic primary urticaria, scleroderma, hypertrophic scars, chronic obstructive pulmonary disease (chronic obstructive pulmonary disease, COPD), atopic dermatitis, idiopathic pulmonary fibrosis, kawasaki disease, sickle cell disease, graves ' disease, sjogren's syndrome, autoimmune lymphoproliferative syndrome, autoimmune hemolytic anemia, barrett's esophagus, autoimmune uveitis, tuberculosis, and renal disease.

The antibody of the invention can be used for treating IL-4Rα as a target spot to neutralize IL-4Rα so as to realize the effect of treating diseases, including but not limited to the diseases, and the treatment of other diseases also belongs to the protection scope of the invention.

In a fourth aspect, the invention provides a medicament for treating a disease comprising an anti-IL-4rα single domain antibody, a fusion protein as described above or an antibody as described above, and a pharmaceutically acceptable adjuvant.

The pharmaceutically acceptable auxiliary materials refer to pharmaceutical auxiliary materials in the pharmaceutical field, for example: diluents, fillers, binders, wetting agents, absorption promoters, surfactants, disintegrants, adsorption carriers, lubricants, and the like. In addition, other adjuvants such as flavoring agent, sweetener, etc. can be added. Namely, the auxiliary materials are one or more than two of diluents, fillers, adhesives, wetting agents, absorption promoters, surfactants, disintegrants, adsorption carriers, lubricants, flavoring agents and sweeteners.

The dosage form of the medicine provided by the invention is not strictly limited, can be prepared into various dosage forms according to the existing methods in the field of medicines, and is applied to patients needing treatment by oral administration, nasal inhalation, rectum, parenteral administration or transdermal administration and the like.

In a fifth aspect, the invention provides an isolated nucleic acid molecule encoding a single domain antibody as defined in any one of the preceding claims.

It is to be noted that, based on the present disclosure, a person skilled in the art can easily obtain polynucleotide molecules encoding the above single domain antibodies and fusion proteins by a conventional technique in the art, and based on the degeneracy of codons, the polynucleotide molecules are variable, and there are various possibilities for specific base sequences thereof, on the basis of which, regardless of how the polynucleotide molecules vary, as long as they can encode the single domain antibodies or fusion proteins of the present invention, they are within the scope of the present invention.

Alternatively, in some embodiments of the invention, the nucleotide sequence of the nucleic acid molecule is set forth in any one of SEQ ID NOS.19-36.

In a sixth aspect, the invention provides a vector comprising a nucleic acid molecule as described above.

In a seventh aspect, the invention provides a recombinant cell comprising a vector as described above.

In an eighth aspect, the invention provides a method of making a single domain antibody as defined in any one of the preceding claims, comprising: culturing the recombinant cells as described above, and separating and purifying the single domain antibody from the culture product.

It should be noted that, the preparation of the single domain antibodies, fusion proteins and antibodies of the present invention may be achieved by chemical synthesis methods, genetic engineering techniques, or other methods, and any method for preparing the single domain antibodies, fusion proteins or antibodies of the present invention falls within the scope of the present invention.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a diagram showing the analysis of the purification results of human recombinant protein IL-4Rα.

FIG. 2 assay of binding activity of self-produced IL-4Rα recombinant protein from company, wherein the offshore purchased IL-4Rα recombinant protein is control code Novo, the self-produced IL-4Rα recombinant protein is RJK, the tool antibody is Tab, and the human IgG is negative isotype control antibody.

FIG. 3 shows the enrichment after screening of a single domain antibody library against IL-4Rα recombinant protein, wherein P/N=the number of monoclonal bacteria grown after infection of TG1 bacteria by positive Kong Xi-shed phage/the number of monoclonal bacteria grown after infection of TG1 bacteria by positive Kong Xi-shed phage, which parameter increases gradually after enrichment has occurred; I/E = total phage added to positive wells per round of biopanning/total phage removed from positive Kong Xi per round of biopanning, which parameter gradually approaches 1 after enrichment has occurred, with a third round of enrichment P/N = 1000, I/E = 2.

FIG. 4 shows the result of SDS-PAGE analysis of single domain antibodies after one step of affinity chromatography on a nickel column.

FIG. 5 is a graph showing the affinity of purified single domain antibodies to IL-4Rα.

FIG. 6 is a plot of the neutralization assay of purified Fc fusion single domain nanobodies in IL-4 induced TF-1 cell proliferation assays.

FIG. 7 is a plot of the neutralization assay of purified Fc fusion single domain nanobodies in IL-13 induced TF-1 cell proliferation assays.

FIG. 8 is a graph showing affinity kinetics assay curves and curve fitting results for single domain antibodies 1H1 and 4E 9.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

The features and capabilities of the present invention are described in further detail below in connection with the examples.

Example 1

Construction of expression vector for human recombinant IL-4Rα protein

The method comprises the following steps:

(1) The coding sequence of IL-4Rα, recorded as NM-000418.3, was retrieved from NCBI and encoded to produce an amino acid sequence accession No. NP-000409.1.

(2) The amino acid sequences corresponding to NP 000409.1 were analyzed for the transmembrane region and extracellular end of the protein via TMHMM and SMART websites, respectively.

(3) The analysis result shows that the extracellular end of the IL-4Rα protein is 1-232 amino acids, wherein the 1-25 positions are signal peptides of the protein.

(4) The nucleotide sequence of amino acid 26-232 of IL-4Rα protein is cloned into the vector pcDNA3.4 by means of gene synthesis.

(5) And (3) carrying out Sanger sequencing on the constructed vector, comparing the original sequences, carrying out batch extraction on the recombinant plasmid after confirming no errors, removing endotoxin, carrying out expression and purification of target protein by transfecting suspension 293F, and carrying out SDS-PAGE and western blot analysis results of the IL-4Rα recombinant protein after purification, wherein the results are shown in figure 1.

EXAMPLE 2 determination of binding Activity of human recombinant protein

Experimental method of binding Activity referring to the method disclosed in Chinese patent application No. 202010166444.8 entitled single domain antibody capable of specifically binding to EpCAM and its application, recombinant IL-4Rα protein purchased from near shore was used as positive control recombinant protein, and human IgG was used as negative isotype control for tool antibody. The results are shown in FIG. 2, which shows that the self-produced protein developed less than the control at high concentrations, but was comparable to the tool antibody binding capacity (EC 50), the human IgG isotype control did not bind to the IL-4Rα recombinant protein purchased off-shore and produced by the company.

Example 3

Construction of a Single-Domain antibody library against IL-4Rα protein

The method comprises the following steps:

(1) 2mg of the IL-4Rα recombinant protein obtained by purification in example 1 was mixed with an equal volume of Freund's complete adjuvant, and an inner Mongolian Alexander bactrian camel was immunized once a week for a total of 7 consecutive immunizations, and the remaining six immunizations, except the first immunization, were animal immunizations with an equal volume of 1mg of IL-4Rα recombinant protein mixed with Freund's incomplete adjuvant, which were performed in order to intensively stimulate the camel to produce antibodies against IL-4Rα.

(2) After the animal immunization is finished, 100mL of camel peripheral blood lymphocytes are extracted and RNA of the cells is extracted.

(3) cDNA was synthesized using the extracted total RNA, and VHH (heavy chain antibody variable region) was amplified by a nested PCR reaction using the cDNA as a template.

(4) The pMECS vector and VHH fragment were digested separately using restriction enzymes, and the digested fragments and vector were ligated.

(5) Transforming the ligated fragments into competent cells TG1, constructing a phage display library of IL-4Rα protein and measuring the library capacity, the library capacity being about 1X 10 ⁹ 。

Example 4

Screening of Single-Domain antibodies against IL-4Rα proteins

The method comprises the following steps:

(1) 200. Mu.L of the recombinant TG1 cells of example 2 were inoculated into 2 XSTY medium for culture, during which 40. Mu.L of helper phage VCSM13 was added to infect the TG1 cells, and cultured overnight to amplify the phage, the phage was precipitated the next day with PEG/NaCl, and the amplified phage was collected by centrifugation.

(2) NaHCO diluted at 100mM pH 8.3 ₃ 500 mug of the IL-4Rα recombinant protein was coupled to an ELISA plate and left overnight at 4℃while a negative control well was established.

(3) The next day 200 μl of 3% skim milk was added and blocked at room temperature for 2h.

(4) After blocking was completed, 100. Mu.L of amplified phage library (approximately 2X 10 ¹¹ Individual phage particles), 1h at room temperature.

(5) After 1 hour of action, wash 5 times with PBS (containing 0.05% Tween-20) to wash away unbound phage.

(6) Dissociating phage specifically combined with IL-4Rα recombinant protein with trypsin with final concentration of 2.5mg/mL, infecting Escherichia coli TG1 cells in logarithmic growth phase, culturing at 37deg.C for 1h, generating and collecting phage for the next round of screening, repeating the same screening process for 1 round, and gradually enriching, wherein when enrichment multiple reaches more than 10 times, the enrichment effect is shown in figure 3.

Example 5

Specific positive clones for IL-4Rα were screened by phage enzyme-linked immunosorbent assay (ELISA).

The method comprises the following steps:

(1) Screening IL-4Rα recombinant protein for 3 rounds according to the single domain antibody screening method of example 2, wherein phage enrichment factor for IL-4Rα recombinant protein reaches more than 10 after screening, selecting 400 single colonies from positive clones obtained by screening, respectively inoculating into 96 deep well plates containing 100 μg/mL ampicillin TB medium, setting blank control, culturing at 37deg.C to logarithmic phase, adding IPTG with final concentration of 1mM, and culturing at 28deg.C overnight;

(2) Obtaining a crude extract antibody by using a permeation swelling method; the IL-4Rα recombinant proteins were released to 100mM NaHCO pH 8.3, respectively ₃ And 100 μg of IL-4Rα recombinant protein was coated in an ELISA plate at 4deg.C overnight;

(3) Transferring 100 mu L of the crude antibody extract obtained in the steps to an ELISA plate added with antigen, and incubating for 1h at room temperature;

(4) Washing the unbound antibody with PBST, adding 100 μl of Mouse anti-HA tag antibody (Mouse anti-HA antibody, thermo Fisher) diluted 1:2000, and incubating for 1h at room temperature;

(5) Unbound antibody was washed off with PBST, 100ul of Anti-Rabbit HRP conjugate (goat Anti-rabbit horseradish peroxidase labeled antibody, available from Thermo Fisher) diluted 1:20000 was added and incubated for 1h at room temperature;

(6) Washing off unbound antibody with PBST, adding horseradish peroxidase chromogenic solution, reacting at 37deg.C for 15min, adding stop solution, and reading absorption value at 450nm wavelength on an enzyme-labeled instrument;

(7) When the OD value of the sample hole is more than 5 times that of the control hole, judging that the sample hole is a positive cloning hole;

(8) The positive clone well was transferred and shaken in LB medium containing 100. Mu.g/. Mu.L ampicillin to extract plasmids and sequenced;

(9) Analyzing the gene sequence of each clone strain according to sequence comparison software Vector NTI, and regarding the strains with the same CDR1, CDR2 and CDR3 sequences as the same clone strain and the strains with different sequences as different clone strains to obtain the single domain antibody specific to the IL-4 Ralpha protein. The amino acid sequence of the antibody is FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4 structure, which forms the whole VHH. The obtained single-domain antibody recombinant plasmid can be expressed in a prokaryotic system to obtain the single-domain antibody aiming at IL-4R alpha protein.

The numbering of each single domain antibody and the amino acid sequence analysis result, i.e. the corresponding sequence identifier (SEQ ID No.), is given in table 1 below.

Table 1 examples the CDR and FR corresponding sequence identifiers (SEQ ID NO.)

Example 5

Purification and expression of specific single domain antibodies to IL-4Rα protein in E.coli host bacteria.

The method comprises the following steps:

(1) Plasmids (pMECS-VHH) of the different clones obtained by the above sequencing analysis were electrotransformed into E.coli HB2151 and plated on LB+amp+glucose-containing culture plates, which were incubated overnight at 37 ℃;

(2) Selecting single colony to inoculate in 5mL LB culture solution containing shore penicillin, shaking culture at 37 ℃ overnight;

(3) Inoculating 1mL of overnight culture strain into 330mL of TB culture solution, shake culturing at 37deg.C, adding 1M IPTG when OD600nm value reaches 0.6-0.9, shake culturing at 28deg.C overnight;

(4) Centrifuging, collecting escherichia coli, and obtaining an antibody crude extract by using a osmotic bursting method;

(5) The antibodies were purified by nickel column affinity chromatography, and the results of SDS-PAGE analysis of the purified single domain antibodies are shown in FIG. 4, in which VHH1-18 were numbered for the antibodies in Table 1, respectively.

Example 6

The Fc fusion antibody of the single domain antibody is prepared by referring to patent application No. 202010166444.8, and the preparation method is carried out by a method disclosed in Chinese patent application of the invention name of the single domain antibody capable of specifically binding to EpCAM.

Example 7

Binding dose-response curve assay for specific single domain antibodies to IL-4Rα protein.

Experimental methods referring to patent application No. 202010166444.8, the invention name is a single domain antibody capable of specifically binding to EpCAM and the method disclosed in the applied Chinese patent application, and the EC is calculated by drawing a curve ₅₀ The results are shown in FIG. 5 and Table 2 below.

Table 2 Single Domain antibodies bind to EC of IL-4Rα recombinant proteins ₅₀

Antibody numbering	1A9	1B1	1B2	1B4	1C4	1D9	1H1	2A7	2C10
										EC ₅₀ (nM)	2.724	0.850	5.816	0.404	2.686	0.103	1.132	3.060	4.150
Antibody numbering	2C9	2H2	3C11	3E10	3F9	3G10	4B3	4E9	4H11
										EC ₅₀ (nM)	26.29	2.168	1.379	1.838	1.602	5.207	1.364	2.135	16.290

It can be seen that in the binding detection of the 18 purified single-domain antibodies, the binding capacity of the two antibodies except for 4H11 and 2C9 was more than 10nM, the binding capacities of the other antibodies were all less than 10nM, and the binding capacities of the antibodies 1B4 and 1D9 were less than 1nM, which proves that the whole binding capacity of the single-domain antibodies obtained by the screening of this example was better.

Example 8

Expression and purification of Tool antibodies targeting human IL-4Rα (Tool antibody, tab), tab1 (dupilumab) sequences from IMGT, tab2 (L1012H 1031), tab3 (L1020H 1031) sequences from patent (patent number: CN 107474134).

The method comprises the following steps:

(1) The Tab sequence was delegated to universal biosystems (Anhui) Inc. for mammalian cell expression system codon optimization and cloned into pcDNA3.1 vector.

(2) After resistance selection, plasmid positive bacteria were selected for amplification and plasmids were extracted using a plasmid extraction kit (Macherey Nagel, cat# 740412.50).

(3) Mu.g of plasmid (50. Mu.g of heavy chain+50. Mu.g of light chain) was added per 100mL of cells and transiently expressed in 293F cells (medium: freeStyle 293Expression medium,Thermo,Cat#12338026+F-68, thermo, cat#24040032) using PEI.

(4) After 6-24 h of transfection 5% by volume of 10% Peptone (Sigma, cat#P0521-100G), 8% CO were added ₂ Culturing at 130rpm for about 7-8 days.

(5) The expression supernatant was collected when the cell viability was reduced to 50% and purified using a ProteinA (GE, cat#17-5438-02) gravity column.

(6) After PBS dialysis, the concentration was determined using Nanodrop, SEC to identify purity, and indirect ELISA to verify binding capacity.

(7) Tab obtained by the method has the concentration of not less than 2mg/ml and the purity of more than 94 percent, and combines EC50 with IL-4Rα (Novoprotein, cat#CS 33) and self-produced IL-4Rα recombinant protein at 0.25+/-0.05 nM.

Example 9

Proliferation of TF1 cells induced by human IL-4 and neutralizing proliferation experiments with tool antibodies.

Experimental method for proliferation of TF1 cells induced by human IL-4:

(1) Spreading TF-1 cells which are passaged 3-4 times after resuscitating into 96-well plates according to 10000 holes per well;

(2) Preparing a solution with the highest concentration of 500ng/mL of the human IL-4 protein, and carrying out 5-time gradient dilution;

(3) Adding the IL-4 solution diluted in a gradient manner into a cell culture hole according to the equal volume of a cell culture solution;

(4) After incubation for 72h, detecting the cell viability by using a luminescence method cell viability detection kit;

(5) And calculating the EC80 concentration of IL-4 induced TF-1 cell proliferation according to the detection result.

2 tool antibody (Tab) neutralization of human IL-4 induced TF1 cell proliferation assay:

(2) Different Tabs were formulated as 10. Mu.g/mL solutions and subjected to 5-fold gradient dilution;

(3) Mixing the Tab subjected to gradient dilution with IL-4 with EC80 concentration obtained in a proliferation experiment according to a ratio of 1:1 to prepare a mixed solution;

(4) Adding the mixed solution obtained in the previous step into a cell culture hole according to the equal volume of the cell culture solution;

(5) After incubation for 72h, detecting the cell viability by using a luminescence method cell viability detection kit;

(6) The EC50 concentration of Tab-neutralized IL-4-induced TF-1 cell proliferation was calculated from the results of the measurements, and the results are shown in Table 3.

TABLE 3 detection of IL-4-induced TF-1 proliferation by tool antibody (Tab)

Antibody name	Tab1	Tab2	Tab3
				EC ₅₀ (nM)	0.18	0.067	0.098

Example 10

Proliferation of TF1 cells induced by human IL-13 and neutralizing proliferation experiments with tool antibodies.

Experimental method for proliferation of TF1 cells induced by human IL-13:

(5) And calculating the EC80 concentration of IL-13 induced TF-1 cell proliferation according to the detection result.

2 tool antibody (Tab) neutralization of human IL-13 induced TF1 cell proliferation assay:

(3) Mixing the Tab subjected to gradient dilution with IL-13 with EC80 concentration obtained in a proliferation experiment according to a ratio of 1:1 to prepare a mixed solution;

(6) The EC50 concentration of Tab-neutralized IL-13 induced TF-1 cell proliferation was calculated from the results of the assay. The results are shown in Table 4.

TABLE 4 detection of IL-13-induced TF-1 proliferation by tool antibody (Tab)

Antibody name	Tab1	Tab2	Tab3
				EC ₅₀ (nM)	0.073	0.097	0.047

Example 11

Detection of IL-4 induced TF1 cell proliferation by neutralization of a single-domain antibody specific for IL-4Rα.

The method comprises the following steps:

(2) The different Tab, fc fused single domain antibodies of example 8 (from example 6) were formulated as a 10. Mu.g/mL solution and subjected to 5-fold gradient dilution;

(3) Mixing the Tab and the single-domain antibody which are subjected to gradient dilution with IL-4 with EC80 concentration obtained in a proliferation experiment according to a ratio of 1:1 to prepare a mixed solution;

(6) The EC50 concentrations of different single domain antibodies for neutralizing IL-4 to induce TF-1 cell proliferation were calculated based on the detection results, and the results are shown in FIG. 6 and Table 5 below.

TABLE 5 quantitative response curve for IL-4-induced TF-1 proliferation neutralization

Antibody name	1A9	1B1	1B2	1B4	1C4	1D9	1H1	2A7	2C10
										EC ₅₀ (nM)	0.099	0.302	0.363	0.190	0.055	0.086	0.072	0.119	28.1
Antibody name	2C9	2H2	3C11	3E10	3F9	3G10	4B3	4E9	4H11
										EC ₅₀ (nM)	2.375	0.149	0.083	0.175	0.133	0.507	0.231	0.071	16680000

It can be seen that, among the 18 antibodies, the neutralization effect of 4H11 was the worst compared to the other single domain antibodies in Table 5, the neutralization effect of 2C10 was generally good, but the neutralization effect of 2C9 was still 1nM or more, the EC50 of the remaining single domain antibodies was 1nM or less, and the neutralization effect was good, wherein the neutralization effect of the single domain antibodies 1C4, 4E9, 1H1 was ranked as top three, and the EC50 of 1C4 reached 55pM.

Example 12

Detection of IL-13-induced TF1 cell proliferation by neutralization of a single-domain antibody specific for IL-4Rα.

The method comprises the following steps:

(3) Mixing the Tab and the single-domain antibody which are subjected to gradient dilution with IL-13 with EC80 concentration obtained in a proliferation experiment according to a ratio of 1:1 to prepare a mixed solution;

(6) The EC50 concentrations of different single domain antibodies for neutralizing IL-13 to induce TF-1 cell proliferation were calculated based on the detection results, and the results are shown in FIG. 7 and Table 6 below.

TABLE 6 quantitative response curve detection results for IL-13-induced TF-1 proliferation neutralization

Antibody name	1A9	1B1	1B2	1B4	1C4	1D9	1H1	2A7	2C10
										EC ₅₀ (nM)	0.097	0.602	1.704	0.26	0.093	0.089	0.07	0.17	2.2e+10 ¹¹
Antibody name	2C9	2H2	3C11	3E10	3F9	3G10	483	4E9	4H11
										EC ₅₀ (nM)	1.17	0.166	0.072	0.27	0.149	0.487	0.135	0.077	1.1e+10 ¹¹

It can be seen that the neutralizing effect of 4H11 and 2C10 was poor, and the neutralizing effect of 2C9 and 1B2 was good, but the EC50 was still 1nM or more, and the EC50 of the other single domain antibodies was 1nM or less, among the neutralizing effects of the single domain antibodies 1H1, 3C11, and 4E9 were ranked as top three, and the EC50 of 1H1 was 70pM, among the 18 antibodies.

Example 13

In combination with the experimental results of example 11 and example 12, the single domain antibodies 1H1 and 4E9 had the best overall neutralization effect, and the two antibodies were selected for antigen-antibody affinity determination using an Octet RED96 instrument. The specific embodiment is as follows:

(1) SD buffer solution preparation: appropriate amounts of bovine serum albumin and tween 20 were dissolved in 1 x PBS (ph 7.4) such that the mass (or volume) fractions of bovine serum albumin and tween 20 were 0.1% and 0.02%, respectively.

(2) Preparing an antigen working solution: the antigen (IL-4 Rα recombinant protein) was formulated in SD buffer at 10 μg/mL.

(3) Preparing an antibody working solution: the antibody was first prepared with SD buffer to 100nM, then diluted with a 2-fold gradient, setting a total of 5 concentration gradients, and setting a zero concentration.

(4) The system comprises: opening the Data acquisition software in the Octet 96 and a matched computer, taking a proper amount of 75% ethanol by using mirror wiping paper to clean the bottom surface and the side surface of the acquisition probe, and preheating the instrument for more than 15 minutes.

(5) Sensor prewetting: the Sensor is placed in SD buffer solution for soaking for more than 10 minutes before the experiment starts for later use.

(6) The binding and dissociation times are shown in table 7:

table 7 step of starting up

Experimental procedure	Time(s)	Sample of
			Baseline1	60	SD
Loading	300	Antigens
			Baseline2	60	SD
Association	300	Antibodies to
			Dissociation	300	SD

(7) And (5) closing the instrument and the computer after the analysis is finished.

(8) Data analysis: KD, ka, kd, full R was calculated in DataAnalysis software ² Constant of equal correlation, the results are shown in FIG. 8 and Table 8

TABLE 8 cloning of 1H1 and 4E9 affinity kinetic data summary table

Clone name	KD(M)	Ka(1/Ms)	Kd(1/s)
				1H1	1.41E-11	5.32E+05	7.50E-06
4E9	2.39E-10	5.56E+05	1.33E-04

According to the prior document (patent CN 107474134), it is shown that Tab2 and Tab3 have affinities of 1.04×10, respectively ^-10 M and 1.83×10 ^-10 M, the affinity of the single domain antibody 1H1 obtained in the embodiment of the invention is obviously better than that of a control antibody and is 1.41 multiplied by 10 ^-11 While 4E9 was substantially equivalent to the control antibody.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A single domain antibody against IL-4 ra, comprising the following complementarity determining regions: CDR1, CDR2, and CDR3;

the complementarity determining regions of the single domain antibody are as follows:

CDR1 is shown as SEQ ID NO.38, CDR2 is shown as SEQ ID NO.58, and CDR3 is shown as SEQ ID NO. 77; or,

CDR1 is shown as SEQ ID NO.47, CDR2 is shown as SEQ ID NO.60, and CDR3 is shown as SEQ ID NO. 83.

2. The anti-IL-4 ra single domain antibody of claim 1, wherein the single domain antibody comprises the following framework regions: FR1, FR2, FR3 and FR4;

the amino acid sequence of FR4 is shown as SEQ ID NO. 128; the framework regions FR1, FR2 and FR3 of the single domain antibody are shown below:

FR1 is shown as SEQ ID NO.94, FR2 is shown as SEQ ID NO.106, and FR3 is shown as SEQ ID NO. 125; or,

FR1 is shown as SEQ ID NO.89, FR2 is shown as SEQ ID NO.101, and FR3 is shown as SEQ ID NO. 124.

3. The anti-IL-4rα single domain antibody of claim 2, wherein the amino acid sequence of the single domain antibody is as set forth in seq id No.11 or 9.

4. A fusion protein comprising a functional domain capable of specifically binding IL-4rα, said functional domain consisting of the anti-IL-4rα single domain antibody of any one of claims 1-3.

5. An anti-IL-4rα antibody, wherein the antibody is a traditional antibody or a functional fragment thereof, and the heavy chain variable region of the antibody consists of the anti-IL-4rα single domain antibody of any one of claims 1-3;

preferably, the functional fragment is a Fab, fab ', (Fab') 2, fv, scFv or sdFv structure of the conventional antibody.

6. Use of the anti-IL-4rα single domain antibody of any one of claims 1-3, the fusion protein of claim 4 or the antibody of claim 5 in the manufacture of a medicament for targeting IL-4rα for the treatment of a disease.

7. The use according to claim 6, wherein the disease is selected from asthma, allergic dermatitis, eczema, arthritis, herpes, chronic primary urticaria, scleroderma, hypertrophic scars, chronic obstructive pulmonary disease, atopic dermatitis, idiopathic pulmonary fibrosis, kawasaki disease, sickle cell disease, graves ' disease, sjogren's syndrome, autoimmune lymphoproliferative syndrome, autoimmune hemolytic anemia, barrett's esophagus, autoimmune uveitis, tuberculosis and kidney disease.

8. A medicament for the treatment of a disease, characterized in that it comprises an anti-IL-4rα single domain antibody as defined in any one of claims 1 to 3, a fusion protein as defined in claim 4 or an antibody as defined in claim 5, and a pharmaceutically acceptable adjuvant.

9. An isolated nucleic acid molecule encoding the single domain antibody of any one of claims 1-3;

preferably, the nucleotide sequence of the nucleic acid molecule is shown in SEQ ID NO.29 or 27.

10. A vector comprising the nucleic acid molecule of claim 9.

11. A recombinant cell comprising the vector of claim 10.

12. A method of making a single domain antibody according to any one of claims 1-3, comprising: culturing the recombinant cell of claim 11, and isolating and purifying the single domain antibody from the culture product.