Single-domain antibody targeting human IgE, humanized single-domain antibody and application thereof

Abstract

The invention relates to the field of biology, and discloses a single-domain antibody targeting human IgE, a humanized single-domain antibody and application thereof. The single-domain antibody specifically bound with the IgE is composed of a framework region and antigen binding regions CDR1-CDR3, and the CDR1-CDR3 are respectively shown as SEQ ID NO.1-3 and SEQ ID NO.6-8. The single-domain antibody of some embodiments of the invention can specifically bind to human immune globulin IgE and a compound thereof, has low non-specific adsorption capacity to other immune globulin or other plasma proteins, stable adsorption performance, high adsorption efficiency and good regeneration performance, and provides a new treatment approach for patients with type I allergy. Compared with the traditional antibody, the antibody provided by the invention has the advantages of small molecular weight, strong stability, high tolerance, low immunogenicity, capability of keeping stability at extreme temperature and pH value, easiness in expression, high expression quantity, suitability for large-scale production, good safety performance in clinical treatment and high economic benefit.

Description

technical field [0001] The present invention relates to a single-domain antibody and its application, in particular to a single-domain antibody specifically binding to IgE protein and its application. Background technique [0002] Blood immunoadsorption therapy is a new clinical medical technology in the past 30 years. Some intractable diseases that have no obvious effect on drugs, such as atopic dermatitis, autoimmune system diseases, nephrotic syndrome, severe hepatitis, malignant tumors, etc., undergo in vitro immunoadsorption of blood Purification can often achieve better results. Blood immunoadsorption therapy technology has been widely used in many clinical fields such as liver disease, acute poisoning, blood, and urology. The development and production of immunosorbents has also become an important high-tech industry. [0003] Common clinical allergic asthma, allergic urticaria, allergic dermatitis, allergic rhinitis and anaphylactic shock caused by penicillin cause...

AI Technical Summary

Problems solved by technology

Although the preparation and coupling method of the adsorbent can couple a large number of ligands, it will also cause the problem that the ligands are easy to fall off. At the same time, the short spacer arm of the coupling will lead to a low adsorption capacity of the adsorbent.

Japanese scholar Sato H immobilized goat anti-human IgE IgG antibody to glass beads, and about 1g of solid phase carrier was coupled with 32.5mg of IgG protein to make an IgE adsorption column. Using hemoperfusion method, the amount of IgE in the blood of adult patients can be reduced from The effect of reducing 10000IU to 3000IU is very significant (Specificremoval of IgE by therapeutic immunoadsorption system[J].Tournal ofimmunological methods.1989,118(2);61-168.), the adsorbent uses IgE antibody protein as a ligand, can specifically Recognizing IgE protein, the removal effect of IgE protein is remarkable and the loss of other plasma proteins is less. Its main defect is that glass microbeads are used as a solid phase carrier to couple antibody proteins, which may easily cause the ligand to fall off, and heterologous proteins will be damaged when they enter the patient's body. Become a new allergen, leading to exacerbated allergic reactions

At the same time, the author also considers connecting an adsorption column with IgE as ligand to adsorb the shed sheep antibody. This method will undoubtedly increase the complexity of clinical treatment and increase the cost of treatment.

Domestic scholar Jia Lingyun used IgE receptor protein as a ligand and agarose gel as a solid phase carrier to make an IgE adsorbent (CN102660569A), which solved the problem of aggravated allergic reactions caused by ligand shedding, but its ligand The prokaryotic expression of Escherichia coli and the expression of insoluble inclusion bodies require protein renaturation and depyrogenation, which increases the difficulty of ligand acquisition and increases production costs, and the protein stability after renaturation is poor and difficult to store for a long time

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