Research in the production of monoclonal antibodies is a key part of antibody humanization. The process of converting murine antibodies into human antibodies is called antibody humanization.
Initial monoclonal antibody used in clinical practice was mouse-derived monoclonal antibodies. However, there were limitations to using mouse-derived antibodies because of differences in human and mouse species. While murine antibodies can bind to specific target antigens and are able to bind to them, they do not activate human immune system such as complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity (CDC). Therefore, antigen-antibody reactions cannot take place normally. However, murine antibodies that enter the human body may be considered exogenous proteins. This can cause the immune system to produce specific antibodies using mouse antigens (i.e. Human anti-mouse antibody is (HAMA), and it is often cleared quickly by the human body with a very short half-life. Humanization of mouse-derived antibody has been done using recombinant DNA technology because of limitations in clinical use of mouse-derived antibodies.
Phage Display Library – Antibody Humanization Service
Antibody humanization is used for reducing the immunogenicity of animal monoclonal antibodies (mAbs) and for improving their activities in the human immune system. Our scientists have optimized the traditional algorithm of the CDRs grafting technique, a combination of the advantages of our empirical antibody humanization approaches and traditional algorithms, we can efficiently improve the stability and affinity of humanized antibodies in the body. We identify the CDRs from your hybridoma cell line or antibody sequence (parental antibody), and graft these CDRs into framework regions carefully selected from databases of hundreds of thousands of mature human antibodies. The framework regions of the human immunoglobulin are selected based on a number of factors including homology and position of key residues.
Alpha Lifetech Inc. has established a complementarity-determining region grafting platform, which is featured with randomization of a small set of framework residues using phage display technology and computer modeling. Six CDR loops that form the antigen-binding area are grafted into human framework regions. The simple grafting the CDRs from rodents into human frames does not always result in the reconstitution of the binding affinity or specificity of the original antigen. This is because the framework residues play a role in antigen binding. They either support the conformation of CDR loops or contact the antigen directly.
Alpha Lifetech Inc. has therefore developed a computer modeling technique to randomlyize certain framework residues, in addition to CDR-grafting. The grafted CDRs and the random residues are combined into a phage library. After cloning, the library is screened to identify the humanized antibodies that have the highest affinity. This allows for the preservation of epitope specificity. SDR grafting is used to reduce the immunogenicity CDR-grafted CDR-grafted antibodies. Within each CDR, there are more variable positions that are directly involved in the interaction with antigen, i.e., specificity-determining residues (SDRs), whereas there are more conserved residues that maintain the conformations of CDRs loops.
Alpha Lifetech Inc. can also provide a powerful tool, such as mouse CDRs library, to select the antigen-special antibodies directly from our pre-made phage display antibody libraries. With years of experience in constructing and expressing recombinant antibodies based on our proprietary phage display platform, the scientists in Alpha Lifetech Inc. are proud and confident to serve you with a comprehensive guarantee. Please send the antigen, and our scientists will provide a humanized antibody with guaranteed avidity.
The General Procedures of Antibody Humanization
-- Production and characterization of the reference murine antibody or selection from a pre-made antibody library and determination of its affinity constant
-- Determination of the specific murine variable region sequences
-- Structural modeling of the mAb variable regions, construct of a panel of variants to be tested and optimization of antibody affinity
-- Affinity characterization and analysis of the humanized variants followed by recombinant expression in mammalian cells, such as CHO and 293T cells
Service Features of Antibody Humanization Service
-- Advanced Algorithm for Aligning and Grafting of CDRs
-- Antibody humanization from a broad range of parental species including mouse, rat, rabbit, llama and avian
scFvs, Fabs and other antibodies humanized
-- A human antibody database and a proprietary method are used to analyze and design humanized antibodies.
-- Flexible packages to work in synergy with your team: choose the number of humanized variants you would like to design from 9 to 25 combinations of VH and VL sequences.
For more information about this project and to receive a customized proposal, please feel free to contact us at any time.