Clonal Selection Theory

Clonal selection theory is the theory in immunology explaining how the immune system generates a specific antibody response to a previously unencountered pathogen, proposing that the body already contains a vast, pre-existing diversity of lymphocytes, each bearing a distinct receptor, and that binding to a matching antigen triggers that particular cell to proliferate into a clone of identical cells producing the same antibody. Australian immunologist Frank Macfarlane Burnet formulated the theory in 1957, building on earlier selective ideas from Niels Jerne, and Burnet shared the 1960 Nobel Prize in Physiology or Medicine for related work on acquired immunological tolerance. The theory replaced earlier instructive models, which had proposed that antigens themselves shaped antibody structure, and it remains the accepted framework for understanding adaptive immunity.