Monoclonal Antibody Uses?

The immune response is an important factor in human resistance to disease. Antibodies are produced when an animal body is stimulated by an antigen. The specificity of an antibody depends on the antigenic determinants of the antigenic molecules, and various antigenic molecules have many antigenic determinants, so the antibody produced by an immunized animal is actually a mixture of many kinds of antibodies. Antibodies produced by immunized animals are actually a mixture of many antibodies. The efficiency of antibody production by this traditional method is low, the yield is limited, and the injection of animal antibodies into the human body can produce severe allergic reactions. In addition, it is extremely difficult to separate these different antibodies.

In recent years, based on the study of biofilm systems and the development of cell engineering, monoclonal antibody technology has emerged, which can be regarded as a major breakthrough in the field of immunology.

(1) The basic concept of monoclonal antibodies Antibodies are synthesized and secreted by plasma cells formed by the differentiation of B lymphocytes. Each B lymphocyte produces only one antigen receptor gene that recognizes one antigen by random rearrangement during maturation. There are millions of different B-lymphocyte cell lines in the spleens of animals, and after rearrangement B-lymphocytes with different genes synthesize different antibodies. When the body is stimulated by an antigen, the many determinants on the antigen molecule activate individual B cells with different genes. The activated B cells divide and proliferate to form effector B cells (plasma cells) and memory B cells, and a large number of plasma cell clones synthesize and secrete a large number of antibody molecules that are distributed into the blood and body fluids. If a plasma cell that makes a specialized antibody can be selected for culture, a population of cells can be obtained from a single cell that divides and proliferates to form a monoclonal clone. The monoclonal cells will synthesize antibodies against one antigenic determinant cluster, called monoclonal antibodies.

(2) The basic principle of monoclonal antibody technology To prepare monoclonal antibodies, it is necessary to obtain monoclonal B lymphocytes that can synthesize specific antibodies, but such B lymphocytes can not be grown in vitro. However, it is found that myeloma cells can grow and reproduce in vitro. By applying cell hybridization technology, myeloma cells and immune lymphocytes are combined into one, and hybrid myeloma cells are obtained. This hybrid cell inherits the characteristics of the two parental cells, it has the characteristics of B lymphocyte synthesizing specific antibody, and also has the characteristics of myeloma cells that can proliferate and survive in vitro. With this cell population derived from a single fusion cell culture and proliferation, specific monoclonal antibodies against an antigenic determinant can be prepared.

A monoclonal antibody is an antibody made from only one type of cell, corresponding to a polyclonal antibody/multistrain antibody - an antibody made from multiple types of cells.

Monoclonal antibodies are produced by fusing immune cells that can make such antibodies with cancer cells, a fusion cell that has the ability of a tumor cell to keep dividing and the ability of an immune cell to produce antibodies. The fused hybrid cells (hybrid tumors) can produce large amounts of the same antibody. When it is used in medicine, the small changes (if any) shown in recognizing the antigen help to minimize side effects.

In 1975, Swiss scientist Georges Koehler and British scientist Katharine Milstein fused antibody-producing B-lymphocytes with multiple myeloma cells to form hybrid tumor cells. These cells have the characteristics of both parents, the ability of myeloma cells to grow indefinitely and the antibody-producing function of B lymphocytes. As a result, these hybridoma cells are able to produce a large number of high-purity antibodies of a single type in cell culture. These antibodies are called "monoclonal antibodies".

Combining a monoclonal antibody with an anti-cancer drug or toxin makes a powerful antibody "bio-missile". When this antibody "missile" is injected into the bloodstream of a cancer patient, it will function like a missile, tracking and attaching itself to cancer cells in the patient's body, and then the anti-cancer drug or toxin combined with the antibody will kill and destroy the cancer cells, with little damage to normal tissue cells. This kind of antibody "missile" has the advantages of high selectivity, high hit rate on cancer cells and strong killing power, without the disadvantages of general chemical drugs that do not distinguish between good and bad cells and kill everything. Johns Hopkins Hospital of the United States applied antibody "missile" to treat advanced liver cancer patients and received amazing results. The liver cancer was significantly reduced and the survival period was prolonged, and there were no side effects. The invention of monoclonal antibody technology is a revolution in immunology, which breaks the method of producing antibodies only in the body in the past, and successfully produces antibodies in the method of cell culture in vitro, and at the same time reproduces fast, and can produce the high titer and high specificity level that can not be reached in the body. It comes from every cell, so it is very pure.

The superiority of monoclonal antibodies in the diagnosis and therapeutic prevention of diseases is very obvious with their high specificity and sensitivity compared to conventional antibodies.