Monoclonal Antibodies — a Valuable Asset in Human History (Part One)

Abstract: Monoclonal antibody (McAb) was produced by B cell hybridoma cell line. Single antibody monoclonal antibody technology targeting only one antigenic determinant was first initiated in 1975 by Koehler of Germany and Milstein of the United Kingdom. The basic principle of McAb technology is that mouse myeloma cells can proliferate indefinitely and secrete immunoglobulins without antibody activity in vitro and in vivo, while spleen cells of immunized mice have the ability to produce antibodies, but cannot proliferate indefinitely. These two cells are fused into hybridoma cells using a fusion agent (PEG, etc.). Such hybridoma cells have the major features of the parental cells. It can not only proliferate in artificial culture, but also produce specific antibodies. Clones grown from a single cell can be selected by limiting dilution. McAb has many advantages, such as: high unity and homogeneity; high titer; immune antigen does not need to be purified, but pure antibodies can be obtained; different specificities (groups, types, strains) can be obtained; high yield, continuous production, etc. Among these advantages, especially the uniform high specificity, McAb has a very wide practical value, and has formed a very popular emerging industry in the world. Monoclonal antibody technology based on its simplicity Easy, fast, specific, and sensitive Ubiquitous application for disease diagnosis and treatment, food hygiene, etc. The field has broad application prospects.

Keywords: monoclonal antibody, preparation, application, prospects

Preparation of monoclonal antibodies

Stimulation of B lymphocytes from normal mice with specific antigens produces corresponding single specific antibodies, but such cells are difficult to culture in vitro. Myeloma cells can grow in vitro and grow faster than normal cells. But this cell does not produce antibodies. Hybridoma technology can be used to fuse these two functional cells together into a hybridoma cell that can produce both a single antibody and rapid growth in vitro. The whole process of preparation of monoclonal antibodies is mainly divided into three stages: immunization of mice; establishment of screening methods and procedures; hybridoma production. The optimal cells are finally selected by multiple screenings to secrete optimal antibodies.

Wide applications of monoclonal antibodies

u Rapid detection of agricultural and veterinary drugs

Agro-veterinary medicine is a small molecule substance, a kind of hapten, non-immunogenic, and cannot stimulate animals to produce antibodies. It must first be covalently bonded to a large molecular weight carrier (generally protein) through a certain length of carbon chain linking molecule. After coupling to prepare an artificial antigen, the animal is immunized with an artificial antigen, and the immune system of the animal is reacted to prepare a multi- or monoclonal antibody specific to the pesticide. The use of McAb technology makes it possible to prepare highly specific antibodies. Various agricultural and veterinary drug monoclonal antibodies have been prepared abroad and applied to the immunoassay of pesticides and veterinary drug residues.

u clinical diagnosis

The diseased cells can be determined by extracting the diseased tissue in the patient’s body and then reacting with the known monoclonal antibody, according to whether the reaction can occur between the two. Provide accurate directions for the later process, so as to achieve better, faster, and safer order.

u Enhance immunogenicity

Since 1984, Celis et al. have found that anti-hepatitis B virus (HBs) 1gG enhances the stimulation of HBs antigens to specific human T cell clones and induces interferon. Vaccination has certain risks, especially for newborn children, the immunity is very poor, and the immune system is immature. If the amount of vaccination is too large, it is easy to cause an accident. Adding a monoclonal antibody as an adjuvant to the vaccine reduces the amount of the drug used in the vaccination and avoids multiple vaccination and does not cause the body to better produce an immune response, thereby reducing the risk of vaccination.

u As immunosuppressant

Monoclonal antibodies have been widely used as immunosuppressive agents in anti-organ transplant rejection and in the treatment of autoimmune diseases. Rejection is very lethal in organ transplantation. The success of organ transplantation depends on whether rejection and the intensity of rejection occur. The monoclonal antibody can effectively inhibit the action of the corresponding lymphocytes, thereby inhibiting or reducing the occurrence of rejection. Acute graft-versus-host disease is a huge obstacle to allogeneic bone marrow transplantation, and the success of monoclonal antibody technology has brought good news to the treatment of organ transplantation and autoimmune diseases.

u Protein purification

The monoclonal antibody is first prepared by using the protein to be purified, and then the monoclonal antibody is immobilized on an inert solid phase substrate to prepare a chromatography column. The mixture is then poured, and when the mixture flows through the monoclonal antibody, the corresponding protein specifically binds to the monoclonal antibody, and the impurities flow away with the eluent. The protein can be purified by eluting the protein with a special eluent.

u Biological missile

The order and sequence of tumor treatment are directed to all cells in a certain part, including tumor cells and normal cells. Therefore, cancer patients kill tumor cells while receiving treatment, and also kill many normal cells, and even induce genetic mutations in normal cells, resulting in huge side effects. For example, the antigen of the tumor cells in the patient is extracted to prepare the corresponding monoclonal antibody, and then the monoclonal antibody is combined with the sequencing drug, and the sequenced drug is directed to the tumor cell and killed by the principle of specific binding of the antibody and the antigen. Death is beneficial to greatly reduce the side effects in the treatment, improve the treatment effect and reduce the cost of treatment. Through pre-clinical in vivo and in vitro experiments, as well as the preparation of allogeneic tumor models, it is confirmed that monoclonal antibodies can directly fight vascular endothelial growth factor, inhibit tumor growth, and significantly reduce the microvessel density (MVD) of tumors.

u Basic research applications

In-depth study of antigens.

Analysis of cell surface antigens and morphology.

Identification of T lymphocyte subsets in the blood.

Analysis of pathogens.

Further studies on the structure and function of antigenic antibodies.

References

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