Antibody for resisting human CD79a extracellular terminal protein, coding gene and application

Abstract

The invention discloses an antibody for resisting human CD79a extracellular terminal protein, a coding gene and application. The antibody is characterized in that a human B cell lymphoma Raji cell line is used as an immunogen for immunizing mice; splenocyte is obtained and then is fused with a mouse myeloma cell to obtain a hybridoma cell; a monoclonal antibody for specifically aiming at the human CD79a extracellular terminal protein is obtained via screening; an amino acid sequence of the monoclonal antibody is obtained by sequence analysis; variable region sequence with a heavy chain and a light chain and CDR (Complementarity-Determining Region) sequences with light chains and heavy chains are obtained via analyzing; an chimeric antibody expressed via cloning can be used for effectively and specifically recognizing the human CD79a extracellular terminal protein; in addition, when the antibody acts on human B lymphocyte, the internalization rate is high; the antibody has a good prospect for preparing a targeted drug of targeted B lymphocyte and can be used for treating diseases associated with the B lymphocyte.

Description

technical field [0001] The invention relates to the field of biotechnology, in particular to an antibody against human CD79a extracellular terminal protein, an encoding gene and an application. Background technique [0002] B cell antigen recognition receptor (BCR) is the most important molecule on the surface of B cells. It consists of a mIg that recognizes and binds antigen and two CD79a / CD79b (also known as Igα / Igβ) heterodimers that transmit antigen-stimulating signals constitute. The B cell molecule CD79a / CD79b is a member of the immunoglobulin superfamily with molecular weights of 45kDa, 33kDa and 37kDa, respectively, which have extracellular, transmembrane and cytoplasmic regions. The structure of the extracellular domain belongs to IgSF, with a C2-like domain and a V-like domain, respectively, and a glutamic acid in the transmembrane domain. The negatively charged glutamate or glutamine in the transmembrane region of CD79a and CD79b and the positively charged amino...

AI Technical Summary

Problems solved by technology

[0005] Problems existing in the current antibody-targeted therapy for B lymphocyte-related diseases: In summary, many B-NHL and B lymphocytic leukemias have been successfully treated clinically through the combination chemotherapy of CD20 chimeric antibody rituximab. However, some B-cell tumors do not express CD20, and some will lose CD20 surface markers during the treatment of MabThera, which leads to problems of drug resistance and recurrence. In the immunotherapy of these tumor patients, it is necessary to find other effective drugs. Target

Therefore, it is possible that CD79a molecule is more suitable for the therapeutic target of lymphoma and autoimmune disease than CD79b molecule. It is because there is currently no effective monoclonal antibody that responds to the CD79a molecule in living cells, so far there is no literature report on the use of live cells to immunize to obtain a monoclonal antibody against the extracellular part of the CD79a molecule

Although reported in the literature (Mason DY, Cordell JL, Brown MH, Borst J, Jones M, Pulford K, Jaffe E, Ralfkiaer E, Dallenbach F, Stein H.CD79a: a novel marker for B-cell neoplasms in routinely processedtissue samples.Blood .1995; 15; 86(4):1453-9.) Using the immunogen as the computer-simulated 15-amino acid synthetic peptide-coupled thyroglobulin of the primary structure of the protein at the extracellular end of the CD79a molecule to obtain an antibody (clone number JCB117 ), but it still does not react with living B cells as detected by flow cytometry (probably because the synthetic peptide immunogen has lost the glycosylation structure of the peptide chain folding machine), and cannot carry out the immune signal transduction function of CD79a molecule and the disease Targeted therapy research, so there is no literature report on this aspect

Literature reports (Tribolet L, Cantacessi C, Pickering DA, Navarro S, Doolan DL, Trieu A, Fei H, Chao Y, Hofmann A, Gasser RB, Giacomin PR. Loukas A.Probing of a human proteome microarray with a recombinantpathogen protein reveals a novel mechanism by which hookworms suppress B-cell receptor signaling. J Infect Dis.2015; 211(3):416-25.) The recombinant vaccine Na-ASP-2 protein used in hookworms binds to CD79a, leading to the activation of lyn and pi3k in the BCR signaling pathway Transcriptional downregulation controls BCR signaling processes, leading to B cell immunodeficiency

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