Blood & Laboratory Values

Monoclonal Antibodies – Function & Diseases

Monoclonal Antibodies

When we talk about monoclonal antibodies , we mean proteins that are produced by a very specific cell line or cell clone. One of their specific properties is that they have only a single antigenic determinant. The production of the material used for immunization goes back to a single B lymphocyte .

What is a monoclonal antibody?

As soon as an antigen is detected by an antibody directed at it and forms a connection with it, it is referred to as an epitope. Normally, a variety of structures are present on a virus, bacteria or other pathogen surface on an epitope, so that they each react with very specific antibodies and cause a defense system in the organism. This creates a whole mixture of antibodies, including various B lymphocytes for the formation of cones, which are then activated and multiplied.

B lymphocytes are part of the white blood cells and alone are capable of binding antibodies in the body. Therefore, they make up an essential part of the immune system . They are carriers of the information for the formation of a counter-reaction and can convert into plasma cells when foreign antigens are activated , which then produce sufficient antibodies.

Monoclonal antibodies, on the other hand, are highly specific against only a single determinant of the pathogen and are therefore created from a B lymphocyte using hybridoma technology. Here, monoclonal antibodies are formed by cell fusion between lymphocytes and tumor cells , with the latter being able to divide indefinitely. This in turn makes breeding and ultimately effectiveness in drugs and antibiotics possible as soon as human monoclonal antibodies z. B. are used against infectious diseases . Such antibodies would also be helpful in the diagnosis of tumors, whereby degenerated cells can be detected via a changed surface.

Pharmacological action

In order to diagnose pathogens , it is necessary to define certain characteristics of the immune system. These can be seen on the surface. As soon as an organism uses its immune system to start defense reactions, the B lymphocytes are stimulated to produce antibodies. This forms a collection of antibodies with different properties, while each division in turn forms a B cell clone whose antibodies react to a possible antigen. 

A method developed by Nobel Prize winners Cesar Milstein and Georges Köhler and published together with Niels Jerne in 1975 is used to produce monoclonal antibodies. Using the process they developed, it was possible to specifically produce a specific type of antibody, which in turn made it possible to cultivate it in the test tube, which is not only possible in any quantity, but also with very specific characteristics of the antibodies, which in turn can then be used in medications are suitable. The process makes the immune cells more robust and they can survive as a culture. Since the fusion of tumor and immune cells results in a remarkably unlimited growth rate, this cell is referred to as a hybridoma cell.

Medical Application & Use

Once abnormal B cells with a persistent ability to divide fuse with B cells that produce antibodies, monoclonal antibodies are produced that are genetically identical. Such hybridomas are structurally identical and are only designed to recognize a very specific feature, hence the term “monoclonal”.

The production in the pharmaceutical field is very difficult and is mainly tested in research on mice. Antigens are injected into the animal to trigger immunization. Of particular interest are the B lymphocytes in the spleen , which are cultured as cells and fused with myeloma cells. The latter are those degenerated lymphocytes that form tumors.

An enzyme that hybridizes nucleic acid then ensures that hybrid cells form. The fusion of the immortal tumor cells and B-cells in their antibody production brings forth the enormous amount, which are then cultivated as cell colonies by selecting different cell clones and produce one and the same antibody again and again. These can be used precisely for medical therapy, e.g. B. to diagnose carcinogens and tumors. Meanwhile, monoclonal antibodies are also used to treat transplant rejection .

Risks & side effects

The use of monoclonal antibodies has been clinically tested for several years and represents a new and growing area in pharmaceutical development. B. Passive vaccines have proven successful, such as snake venom immune sera, tetanus immunoglobulin or digitalis antioxin. 

The complex mixing and extraction of such antibodies does not take place from the blood itself, but as a molecular-biological synthesis of proteins. Only immunoglobulin G is suitable for drugs because it is Y-shaped and thus facilitates the development of antibodies.

When used in cancer therapy , monoclonal antibodies aim to cause the abnormal cells to dissolve, thereby blocking growth factor signaling pathways, including those involved in the formation of new blood vessels . If the therapy does not respond, the B cells can then be removed from the patient’s blood again by an infusion of rituximab.

In joint diseases , such as rheumatoid arthritis , the inflammatory processes are triggered and intensified by antigens, which ultimately leads to the dissolution of the bone and joint tissue. A new equilibrium is created by antibodies, which specifically intervene in the inflammatory process.

Finally, the use of monoclonal antibodies is also used in microbiological diagnostics. In this way , parasitic, bacterial or viral infections can be recognized and detected more easily, since the pathogens can label them.

Recombinant drugs are only approved for treatment when previous therapy has been unsuccessful and disease-modifying agents have become necessary. There is a risk that the treatment can lead to an increase in the number of new infections. This is because monoclonal antibodies, while recognizing specific protein structures by mimicking them, remain proteins themselves, to be administered only by infusion or injection by the doctor. Reactions that occur are side effects at the injection site, including e.g. B. Skin reactions or allergies .

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.