The "clonal selection theory" has become a widely accepted model for how the immune system responds to infection and how certain types of B and T lymphocytes are selected for destruction of specific antigens invading the body. The immune system is the system of specialized cells and organs that protect an organism from outside biological influences. ... Infected (Radio Show) is also the name of an internet radio podcast hosted by Martin Sargent. ... A lymphocyte is a type of white blood cell involved in the human bodys immune system. ... An antigen is any molecule that is recognized by antibodies. ...

Early Work

In 1954, immunologist Niels Jerne put forward a theory which stated that there is already a vast array of lymphocytes in the body prior to any infection. The entrance of an antigen into the body results in only one type of lymphocyte to match it and produce a corresponding antibody to destroy it. Niels Kaj Jerne (December 23, 1911 - October 7, 1994) was a British-Danish-Swedish (English-born) immunologist. ...

This selection of only one type of lymphocyte results in it being cloned or reproduced by the body extensively to ensure there are enough antibodies produced to inhibit and prevent infection.

Further Work

Australian immunologist Sir Frank Macfarlane Burnett worked on this model, and was the first to name it "clonal selection theory." Burnett explained immunological memory as the cloning of two types of lymphocyte. One clone acts immediately to combat infection whilst the other is longer lasting, remaining in the immune system for a long time, which results in immunity to that antigen.

Theories Supported by Clonal Selection

Burnett and Sir Peter Medawar worked together on understanding immunological tolerance, a phenomena also explained by clonal selection. This is the organism’s ability to tolerate introduced cells without an immune response as long as it occurred early in the organism’s development. There are a vast number of lymphocytes occurring in the immune system ranging from cells which are tolerant of self tissue to cells which are no tolerant of self tissue. However, only cells that are tolerant to self tissue will survive the embryonic stage. If non-self tissue is introduced, the lymphocytes which develop will be the ones which included the non-self tissues as self tissue.

In 1949 Burnett proposed that under certain circumstances, tissues could be successfully transplanted into foreign recipients. This work has led to a much greater understanding of the immune system and also great advances in tissues transplantation. Burnett and Medawar shared the Nobel Prize for physiology and medicine in 1960. Sir Edward Appletons medal Photographs of Nobel Prize Medals. ... Physiology (in Greek physis = nature and logos = word) is the study of the mechanical, physical, and biochemical functions of living organisms. ... Medicine is the branch of health science and the sector of public life concerned with maintaining human health or restoring it through the treatment of disease and injury. ...

References

"Biology in Context - The Spectrum of Life" Authors, Peter Aubusson, Eileen Kennedy.