The production of antibodies is part of the immune response that occurs after the body identifies foreign proteins, known as an antigens. It is the characteristics and presence of antigens that are responsible for the production of antibodies. In their absence, no antibodies would be synthesized.
In animals, the production of antibodies occurs when a special type of immune cell, called a B cell, encounters an antigen. The antigen, which can be a dangerous foreign protein, such as a virus or a bacteria, or a harmless molecule, such as an allergen, is the catalyst for antibody production. An organism that does not come into contact with antigens has no reason to begin the production of antibodies.
In nature, animals come into contact with antigens frequently. The B cells attach to antigens and determine what type of antibody to create. If the organism has encountered a particular antigen in the past, it often knows how to destroy that molecule, and the production of antibodies specific to that antigen can begin right away. If, however, the organism has not yet encountered that antigen, it may take it some time to develop the proper antibodies in response. Though this process takes time, most animals are able to successfully recover from infection through the production of antibodies.
The strength of the immune response is also dictated by the antigen. An animal will often react more strongly to an antigen that is larger or to one that is significantly different from the proteins in its own body than it will to a smaller-sized antigen that is chemically similar to the organism’s own molecules. The organism will begin quick production of antibodies when unfamiliar or particularly threatening antigens are present.
Though it is possible for scientists to produce antibodies in a laboratory setting, the production of antibodies is a process that occurs within a living organism. In the laboratory, antibodies are produced within the bodies of live animal hosts. Animals that are biochemically distinct from humans, such as rabbits or sheep, are often used because they will readily synthesize antibodies to human proteins, which their bodies identify as threatening. Antigens are injected into the host animal’s bloodstream, eliciting an immune response in the host animal. Once the animals have created the antibodies, blood can be drawn from them and the antibodies can be separated out and used in various types of assay tests.
