CMG 2mutant and Fc fusion protein, its encoding gene and its application

Abstract

The invention discloses a CMG 2mutant and Fc fusion protein, its encoding gene and its application. The provided protein is any one of the protein in the following 1) or 2) 1) protein composed of an amino acid residue sequence of a sequence 2 in a sequence table; and 2 ) protein derived from 1) by that the amino acid residue sequence of the sequence 2 in the sequence table is subjected to one or more amino acid residue replacement andor deletion andor addition and possesses the same function. The experiment proves that the provided protein can prevent cells from attacking of anthrax toxin, can be taken as anthrax vaccine, the protein and antigen enables high affinity combination, are equivalent to a Fc fragment of the antibody, and the Fc fragment provides the biological activity of the antibody.

Description

Technical field [0001] The present invention relates to the field of biotechnology, in particular to a fusion protein of CMG2 mutant and Fc and its coding gene and application. Background technique [0002] Anthrax (Anthrax) is a type of infectious disease caused by infection with Bacillus anthracis. Bacillus anthracis is a gram-positive bacillus, and its carriers are herbivores such as horses and deer. Human anthrax infections mainly occur among herders who often come into contact with animals and workers engaged in leather work. There are three ways to cause anthrax infection: one is skin infection, which is mainly caused by the entry of anthrax spores from damaged skin. Bacillus anthracis often accumulates in the damaged skin. This type of infection can often recover without causing serious consequences. The second is gastrointestinal infection, which is often caused by eating raw meat contaminated by spores. This type of infection is often fatal and is also the main mode of...

AI Technical Summary

Problems solved by technology

[0007] Although vaccination is an effective means to prevent and treat infectious diseases caused by bacteria and viruses, it is not enough to deal with sudden infectious diseases only by vaccination. Taking the prevention and treatment of anthrax as an example, immunization with vaccines has the following deficiencies: (1) Anthrax infections generally arise from emergencies and it is difficult to predict when vaccination will be required

(3) Not all people can produce antibodies after vaccination

(4) The attenuated anthrax vaccine still has certain risks in terms of safety and cannot be widely used

(5) Vaccine alone cannot treat anthrax infection and neutralize anthrax toxin

[0009] There are three difficulties in the development of anti-anthrax toxin antibodies for clinical treatment: (1) mutations in pathogen antigens may cause the existing antibodies to lose their affinity with the antigen, making the antibodies unable to function; (2) most of the current antibodies are of mouse origin, Its humanization requires a lot of time and experimental verification

(3) What is more challenging is that since the affinity Kd of PA and its receptor CMG2 reaches 170pM, and the developed antibody should play a therapeutic role, its affinity should generally be equal to or higher than the affinity between the toxin and the receptor. Murine antibodies with this affinity are already difficult, and it is even more difficult to humanize them while maintaining high affinity

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