Method for preparing recombinant human IgE receptor protein and application of recombinant human IgE receptor protein

Abstract

The invention discloses a method for preparing recombinant human IgE receptor protein and application of the recombinant human IgE receptor protein, and belongs to the field of biological engineering and blood purification technology. Fc epsilon RI alpha-D2 with high binding force with IgE is highly expressed by means of gene recombination technology, recombinant protein is obtained by means of purification and used as a genin of an adsorbent, and the prepared adsorbent fixed onto a solid phase can be used for binding the IgE in a high-affinity manner. The method solves the problems of low safety and high cost of the prior art in the field of IgE removal by means of the blood purification technology. The method has an excellent application prospect in terms of removing excessive IgE in blood of an allergic reaction patient by means of the blood purification technology, treating allergic reaction mediated by the IgE, purifying the IgE and the like.

Description

technical field [0001] The invention belongs to the field of bioengineering, and specifically relates to the expression and preparation of a blood purification adsorbent ligand-the extracellular second region (FcεRIα-D2) of the recombinant human IgE receptor protein FcεRIα chain, and its application in the field of blood purification and antibody Applications such as purification. Background technique [0002] Allergies have an enormous prevalence, affecting more than 25% of the world's population. Among them, type I allergy (Allergic inflammation, Al), also known as immediate hypersensitivity reaction, is an immune system disease caused by IgE, such as allergic asthma, allergic urticaria, allergic rhinitis and penicillin-induced allergy. Sexual shock, etc. [0003] The mechanism of allergic reaction is that the allergen first invades the allergic body through the respiratory tract, digestive tract mucosa and skin, stimulating the body to produce specific IgE against the a...

AI Technical Summary

Problems solved by technology

The main defect that exists is: (1) the antibody of IgE is the serum polyclonal antibody that obtains by immune sheep, and the content in serum is low, purification process is complicated, so cost is high, expensive; (2) the molecular weight of IgG is big, reaches 150kDa , causing the immobilized goat anti-human IgG to fall off easily, and foreign proteins entering the patient's body will become new allergens and lead to aggravated allergic reactions. In order to reduce this risk, the author connected a human IgE as the The adsorption column of the ligand is used to absorb the falling IgG ligand, which greatly increases the application cost of the adsorbent, and the coupled IgE on the adsorbent also has the problem of falling off. Once falling off, the IgE concentration in the blood of the patient is increased. concentration

The main disadvantages of the adsorbent are: (1) the adsorbent also has a high removal rate for IgG, and the selective adsorption effect for IgE is poor; (2) the ligand lentil lectin is extracted from lentils , with a molecular weight of 46kDa, the shedding of this exogenous ligand with a larger molecular weight will still cause the patient's own immune response, hindering its application in the field of blood purification to remove IgE

In order to study the binding characteristics of IgE and its receptors, Sandomenico et al. recombined the amino acid sequence of the second extracellular region of FcεRIα at positions 84-170 into the plasmid pETMA11, and expressed the protein prokaryotically using E.coli BL21 (DE3) to obtain recombinant protein inclusion. The expression level of the body is only 5mg / L culture solution, the expression level is very low, far from meeting the production and preparation requirements (IgE-binding properties and selectivity of peptide mimics of the Fc RI binding site[J]. Molecular immunology.2009, 46 (16): 3300-3309.)

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