Nucleic acid for preparation of humanized antibody and application of nucleic acid

Abstract

The invention provides a nucleic acid. The nucleic acid comprises a human immunoglobulin gene or fragments thereof and is characterized by further comprising a human CD79 gene sequence. By the nucleic acid, the problem of incompatibility between BCR and each of Ig alpha and Ig beta of the human immunoglobulin gene in different species is solved, and secondary modification of a humanized antibody expressed by the nucleic acid is not needed.

Description

technical field

[0001] The invention belongs to the field of biotechnology, and mainly relates to a nucleic acid molecule and its application in the preparation of humanized antibodies. Background technique

[0002] Antibodies are an important class of biomedical products, which play an important role in the prevention and treatment of human diseases. The development of therapeutic antibodies has gone through different development stages such as murine antibodies, chimeric antibodies, reshaped antibodies, resurfaced antibodies and fully humanized antibodies. Fully humanized antibody (Full Humanized Antibody) refers to an antibody that is completely identical to the protein sequence of a human antibody obtained through genetic modification or immunization of transgenic animals. Since fully humanized antibodies do not contain animal protein, they have lower side effects and better effects, and have become the main research and development direction of current and future antib...

Examples

Embodiment 1

[0042] Transfer the modified human immunoglobulin gene into mice, and then immunize mice containing human immunoglobulin genes to obtain fully humanized antibodies. The specific steps are as follows:

[0043] 1. Optimization and transformation of human immunoglobulin genes

[0044] 1) Transformation of human immunoglobulin heavy chain gene

[0045] The human CD79 gene is transferred to the YAC or BAC vector containing human Ig through homologous recombination, and the gene cluster of the human immunoglobulin heavy chain gene is constructed as follows: figure 2 Shown (the position in the black box is the sequence of the imported human CD79 gene). Including the V region, D region, J region of human immunoglobulin heavy chain genes, hIgHCμ, hIgHCδ, hIgHCγ3, hIgHCγ1, hIgHCα1, hLCR, hCD79. The internal structure of hCD79 is as follows Picture 1-1 As shown, its gene sequence is shown in SEDIDNO.1; including the coding sequence of CD79α protein peptide and CD79β protein peptide; ...

Embodiment 2

[0142] The transformed human immunoglobulin gene was transferred into a pig as a host animal (immunoglobulin gene knockout pig) to obtain the following results:

[0143] Detection of human IgG expression in pig blood: Two transgenic pigs, 205 and 206, which were positive in PCR detection, were selected to collect blood, separate serum, and detect the expression of human IgG in blood. as comparison. The antibodies identified by ELISA were: sigma(I1886) and sigma(A8792).

[0144] The result is as follows:

[0145] 4115: 0.5mg / ml

[0146] 4116: 0.1mg / ml

[0147] 4117: 0.2mg / ml

[0148] Healthy adults: 10.2mg / ml

[0149] Ordinary pig: <0.1ng / ml

[0150] The results show that the transferred gene can express human antibody heavy chain protein in pigs.

[0151] The modification scheme of the human immunoglobulin gene of the present invention is also applicable to other mammals, for example, pigs, rabbits, sheep, horses, etc. as host animals can also achieve the beneficial eff...

technical field

[0001] The invention belongs to the field of biotechnology, and mainly relates to a nucleic acid molecule and its application in the preparation of humanized antibodies. Background technique

[0002] Antibodies are an important class of biomedical products, which play an important role in the prevention and treatment of human diseases. The development of therapeutic antibodies has gone through different development stages such as murine antibodies, chimeric antibodies, reshaped antibodies, resurfaced antibodies and fully humanized antibodies. Fully humanized antibody (Full Humanized Antibody) refers to an antibody that is completely identical to the protein sequence of a human antibody obtained through genetic modification or immunization of transgenic animals. Since fully humanized antibodies do not contain animal protein, they have lower side effects and better effects, and have become the main research and development direction of current and future antib...

Examples

Embodiment 1

[0042] Transfer the modified human immunoglobulin gene into mice, and then immunize mice containing human immunoglobulin genes to obtain fully humanized antibodies. The specific steps are as follows:

[0043] 1. Optimization and transformation of human immunoglobulin genes

[0044] 1) Transformation of human immunoglobulin heavy chain gene

[0045] The human CD79 gene is transferred to the YAC or BAC vector containing human Ig through homologous recombination, and the gene cluster of the human immunoglobulin heavy chain gene is constructed as follows: figure 2 Shown (the position in the black box is the sequence of the imported human CD79 gene). Including the V region, D region, J region of human immunoglobulin heavy chain genes, hIgHCμ, hIgHCδ, hIgHCγ3, hIgHCγ1, hIgHCα1, hLCR, hCD79. The internal structure of hCD79 is as follows Picture 1-1 As shown, its gene sequence is shown in SEDIDNO.1; including the coding sequence of CD79α protein peptide and CD79β protein peptide; ...

Embodiment 2

[0142] The transformed human immunoglobulin gene was transferred into a pig as a host animal (immunoglobulin gene knockout pig) to obtain the following results:

[0143] Detection of human IgG expression in pig blood: Two transgenic pigs, 205 and 206, which were positive in PCR detection, were selected to collect blood, separate serum, and detect the expression of human IgG in blood. as comparison. The antibodies identified by ELISA were: sigma(I1886) and sigma(A8792).

[0144] The result is as follows:

[0145] 4115: 0.5mg / ml

[0146] 4116: 0.1mg / ml

[0147] 4117: 0.2mg / ml

[0148] Healthy adults: 10.2mg / ml

[0149] Ordinary pig: <0.1ng / ml

[0150] The results show that the transferred gene can express human antibody heavy chain protein in pigs.

[0151] The modification scheme of the human immunoglobulin gene of the present invention is also applicable to other mammals, for example, pigs, rabbits, sheep, horses, etc. as host animals can also achieve the beneficial eff...

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