In the early days, the new monoclonal antibody was derived from the immunization of mice – this is the case with the first approved monoclonal antibody, the Muromonab-CD3. Since these antibody proteins are "heterologous", they are highly immunogenic.
Therefore, when these MAB enter the human body, they will induce the body to produce antibodies against these antibodies (human anti-mouse antibodies). To know more about humanized antibodies, you can also browse https://www.bosterbio.com/featured-products.
The newly generated antibodies in these people neutralize the MAB and render it ineffective. Therefore, attempts have been made since the 1980s to increase the proportion of human-derived sequences in the antibody sequence to decrease the immunogenicity of these monoclonal antibodies.
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In accordance with this concept, "chimeric antibodies", ie antibodies consisting of a variable region of the murine antibody and a constant region of a human antibody, have been developed. This is certainly a big step forward, but it has been found that the immunogenicity of these chimeric antibodies is not low enough.
The birth of humanization technology has finally made it possible to control the immunogenicity of mouse antibodies – humanized antibodies have been combined by limiting mouse sequences in regions that determine complementarity of variable regions (antigen-antibody binding sites). Antibodies are less immunogenic.
Human-derived monoclonal antibodies use human genetic information to encode antibodies. Although there is no conclusive evidence that the immunogenicity of all human monoclonal antibodies is lower, several observations support this claim and many people prefer such antibodies.