Since the 1980s, with the rapid development of DNA recombination technology and protein engineering technology, antibody engineering, as an important branch of biotechnology and medicine, has become an important tool for life science research and clinical applications. Antibody engineering produces antibody molecules with specific properties and functions by modifying and recombining antibody genes. These antibodies have shown great potential in disease diagnosis, treatment, and basic research. This article will start with the basic concept of antibodies and explore in depth the development history, technical principles, and application status of antibody engineering.

1、Antibody Fundamentals

1. Definition and structure of antibodies: Antibodies (Ab) are immunoglobulins (Ig) produced by the proliferation and differentiation of plasma cells from B lymphocytes or memory cells in the body under antigen stimulation, which can specifically bind to the corresponding antigen. Antibodies are mainly distributed in serum, tissue fluid, and exocrine fluid. Antibodies are composed of four polypeptide chains, including two identical light chains (L chains) and two completely different heavy chains (H chains), which are connected by disulfide bonds to form a symmetrical structure. According to the different types of heavy chains, antibodies can be divided into five categories: IgG, IgM, IgA, IgE, and IgD.

2. Function and classification of antibodies: Antibodies have multiple biological functions, including neutralizing toxins, promoting phagocytosis, activating complement, mediating ADCC (antibody dependent cell-mediated cytotoxicity), etc. According to the preparation method and source, antibodies can be divided into three categories: polyclonal antibodies, monoclonal antibodies, and genetically engineered antibodies. Polyclonal antibodies are mixed antibodies extracted from the serum of immunized animals. Although they have broad-spectrum characteristics, their specificity is poor and there are significant differences between batches; Monoclonal antibodies are prepared using hybridoma technology, which has high specificity and homogeneity, but the preparation process is complex and costly; Genetic engineering antibodies are new antibody molecules produced by modifying and recombining antibody genes through DNA recombination and protein engineering techniques, with higher specificity and controllability.

2、he Development History of Antibody Engineering

The first generation of antibodies: polyclonal antibodies: As early as the early 20th century, the effects of serum antibodies and bacterial toxins were discovered and began to be used for disease treatment. However, due to the immunogenicity and heterogeneity of polyclonal antibodies, their research and application are somewhat limited. However, polyclonal antibodies still play a certain role in the prevention and treatment of infectious diseases, as well as immunotherapy for certain diseases.

Second generation antibody: Monoclonal antibody: In 1975, German scholar Kohler and British scholar Millstein collaborated to develop hybridoma technology and successfully prepared monoclonal antibodies (McAbs). This technology combines immune animal spleen cells with myeloma cells through cell fusion, forming hybridoma cells that can secrete specific antibodies and proliferate infinitely. Monoclonal antibodies have high specificity and consistency, greatly promoting the development of basic disciplines such as immunology, genetics, microbiology, and molecular biology, providing new means for the research and development of antibody drugs.

Third generation antibodies: genetically engineered antibodies: In the 1980s, with a deeper understanding of the structure and function of immunoglobulin genes, people began to use DNA recombination and protein engineering techniques to modify and recombine antibody genes, preparing genetically engineered antibodies (GEAb). GEAb retains the specificity and primary biological activity of natural antibodies, while removing irrelevant structures, making humanization of antibodies and preparation of human antibodies possible. Genetic engineering antibodies have the advantages of small molecular weight, strong permeability, and easy modification, making them the preferred technology for antibody research and application.

3、Principles of Antibody Engineering Technology

1. Processing and modification of antibody genes: The core of antibody engineering lies in the modification and recombination of antibody genes. Through genetic engineering technology, antibody genes can undergo site directed mutagenesis, deletion, insertion, and other operations to alter the structure and function of antibodies. For example, by replacing the constant region of antibody genes, the immunogenicity of antibodies can be reduced; By altering the hypervariable region (HVR) of antibodies, the affinity and specificity of antibodies can be improved.

2. Selection of expression system: Another important step in antibody engineering is to select the expression system. Common expression systems include prokaryotic cells (such as E. coli), eukaryotic cells (such as mammalian cells, yeast cells), and plant cells. Different expression systems have their own advantages and disadvantages, such as the low cost and high yield of prokaryotic expression systems, but they may face the problem of insufficient post-translational modifications; The eukaryotic cell expression system can perform complex post-translational modifications, but the cost is high and the operation is complex.

3. Methods for modifying antibody molecules: In addition to genetic modification, antibody molecules can also be modified through cell fusion, chemical modification, and other methods. For example, through cell fusion technology, antibody gene fragments from different sources can be fused to form antibody molecules with dual or multiple specificities; Chemical modification can alter the physical and chemical properties of antibodies, such as improving their stability and solubility.

4、The current application status of antibody engineering

1. Drug development and treatment: Antibody engineering has a wide range of applications in the field of drug development. Antibody molecules modified by genetic engineering methods, such as chimeric antibodies, humanized antibodies, and fully humanized antibodies, have been successfully applied in the treatment of various diseases. For example, rituximab used to treat cancer and tocilizumab used to treat rheumatoid arthritis are outstanding representatives of genetically engineered antibodies. These antibody drugs block disease progression and promote patient recovery by specifically binding to target molecules, such as antigens or inflammatory factors on the surface of tumor cells.

2. Disease diagnosis: In the field of disease diagnosis, antibody engineering also plays an important role. By preparing antibodies targeting specific disease biomarkers, highly sensitive and specific diagnostic reagents can be developed. For example, in the early diagnosis of tumors, the use of antibodies to recognize antigens specifically expressed on the surface or inside of tumor cells, combined with techniques such as immunohistochemistry and flow cytometry, can achieve precise detection of tumor cells. In addition, antibodies are widely used for the diagnosis of infectious diseases, autoimmune diseases, and other diseases.

3. Immunological research: Antibody engineering provides a powerful tool for immunological research. By preparing antibodies targeting specific immune molecules, we can delve into the functions, regulatory mechanisms, and immunopathological processes of the immune system, as well as the occurrence and development of diseases. For example, using antibodies to block or activate specific immune signaling pathways can reveal the interactions and signaling mechanisms between immune cells; Through antibody labeling technology, the migration, distribution, and functional changes of immune cells in the body can be tracked.

Antibody engineering, as an important branch of biotechnology and medicine, has shown great potential in disease diagnosis, treatment, and basic research. With the launch of the Beacon Optofluidic System by Redbert (Beijing) Biotechnology Co., Ltd., it can save you a lot of screening time and greatly reduce production costs. The conventional use of hybridoma or phage display technology usually takes 3-6 months, but the Beacon Optofluidic System device can obtain specific antibody sequences in just 3 days. Single plasma cells can be directly isolated and detected in a 0.5nl system, from which target cells expressing specific antibodies can be screened, and their heavy and light chain mRNAs can be obtained. These mRNAs can be directly used for sequencing and optimization after reverse transcription. In the future, antibody engineering will continue to develop towards humanization, multi specificity, and precise delivery, and deeply integrate with emerging technologies to promote life science research and clinical applications to new heights.

* The above content is collected online for reference only. If the articles on this website involve copyright or other issues, please contact us promptly and we will handle them as soon as possible!