{"title":"Structure-based humanization of a therapeutic antibody for multiple myeloma.","authors":"Stephen F Marino, Oliver Daumke","doi":"10.1007/s00109-024-02470-4","DOIUrl":null,"url":null,"abstract":"<p><p>The optimal efficacy of xenogeneically generated proteins intended for application in humans requires that their own antigenicity be minimized. This necessary adaptation of antibodies to a humanized version poses challenges since modifications even distant from the binding sites can greatly influence antigen recognition and this is the primary feature that must be maintained during all modifications. Current strategies often rely on grafting and/or randomization/selection to arrive at a humanized variant retaining the binding properties of the original molecule. However, in terms of speed and efficiency, rationally directed approaches can be superior, provided the requisite structural information is available. We present here a humanization procedure based on the high-resolution X-ray structure of a chimaeric IgG against a marker for multiple myeloma. Based on in silico modelling of humanizing amino acid substitutions identified from sequence alignments, we devised a straightforward cloning procedure to rapidly evaluate the proposed sequence changes. Careful inspection of the structure allowed the identification of a potentially problematic amino acid change that indeed disrupted antigen binding. Subsequent optimization of the antigen binding loop sequences resulted in substantial recovery of binding affinity lost in the completely humanized antibody. X-ray structures of the humanized and optimized variants demonstrate that the antigen binding mode is preserved, with surprisingly few direct contacts to antibody atoms. These results underline the importance of structural information for the efficient optimization of protein therapeutics. KEY MESSAGES: Structure-based humanization of an IgG against BCMA, a marker for Multiple Myeloma. Identification of problematic mutations and unexpected modification sites. Structures of the modified IgG-antigen complexes verified predictions. Provision of humanized high-affinity IgGs against BCMA for therapeutic applications.</p>","PeriodicalId":50127,"journal":{"name":"Journal of Molecular Medicine-Jmm","volume":null,"pages":null},"PeriodicalIF":4.8000,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11358308/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular Medicine-Jmm","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s00109-024-02470-4","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/7/25 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"GENETICS & HEREDITY","Score":null,"Total":0}
引用次数: 0
Abstract
The optimal efficacy of xenogeneically generated proteins intended for application in humans requires that their own antigenicity be minimized. This necessary adaptation of antibodies to a humanized version poses challenges since modifications even distant from the binding sites can greatly influence antigen recognition and this is the primary feature that must be maintained during all modifications. Current strategies often rely on grafting and/or randomization/selection to arrive at a humanized variant retaining the binding properties of the original molecule. However, in terms of speed and efficiency, rationally directed approaches can be superior, provided the requisite structural information is available. We present here a humanization procedure based on the high-resolution X-ray structure of a chimaeric IgG against a marker for multiple myeloma. Based on in silico modelling of humanizing amino acid substitutions identified from sequence alignments, we devised a straightforward cloning procedure to rapidly evaluate the proposed sequence changes. Careful inspection of the structure allowed the identification of a potentially problematic amino acid change that indeed disrupted antigen binding. Subsequent optimization of the antigen binding loop sequences resulted in substantial recovery of binding affinity lost in the completely humanized antibody. X-ray structures of the humanized and optimized variants demonstrate that the antigen binding mode is preserved, with surprisingly few direct contacts to antibody atoms. These results underline the importance of structural information for the efficient optimization of protein therapeutics. KEY MESSAGES: Structure-based humanization of an IgG against BCMA, a marker for Multiple Myeloma. Identification of problematic mutations and unexpected modification sites. Structures of the modified IgG-antigen complexes verified predictions. Provision of humanized high-affinity IgGs against BCMA for therapeutic applications.
期刊介绍:
The Journal of Molecular Medicine publishes original research articles and review articles that range from basic findings in mechanisms of disease pathogenesis to therapy. The focus includes all human diseases, including but not limited to:
Aging, angiogenesis, autoimmune diseases as well as other inflammatory diseases, cancer, cardiovascular diseases, development and differentiation, endocrinology, gastrointestinal diseases and hepatology, genetics and epigenetics, hematology, hypoxia research, immunology, infectious diseases, metabolic disorders, neuroscience of diseases, -omics based disease research, regenerative medicine, and stem cell research.
Studies solely based on cell lines will not be considered. Studies that are based on model organisms will be considered as long as they are directly relevant to human disease.