Clonal selection

Definition

Clonal selection is a fundamental principle of the adaptive immune response where specific lymphocytes are selected for and proliferate in response to an antigen. This process ensures that only lymphocytes with receptors specific to a given antigen expand and mount an immune response.

5 Must Know Facts For Your Next Test

1. Clonal selection occurs in both B cells and T cells within the adaptive immune system.
2. The process involves the activation, proliferation, and differentiation of lymphocytes specific to an encountered antigen.
3. Upon encountering their specific antigen, selected lymphocytes undergo clonal expansion to produce effector and memory cells.
4. Memory cells formed during clonal selection provide immunological memory for faster responses upon subsequent exposures to the same antigen.
5. Clonal deletion, a related process, ensures self-tolerance by eliminating lymphocytes that recognize self-antigens.

Review Questions

• What triggers the clonal selection of a lymphocyte?
• How does clonal selection contribute to immunological memory?
• What role does clonal deletion play in maintaining self-tolerance?

Related terms

Antigen: A molecule or molecular structure that can be bound by an antibody or a T cell receptor.

Lymphocyte: A type of white blood cell involved in the adaptive immune response, including B cells and T cells.

Immunological Memory: The ability of the immune system to respond more rapidly and effectively to pathogens that have been encountered previously.