Where does clonal deletion occur?
Where does clonal deletion occur?
Clonal deletion can occur centrally during the initial differentiation of antigen-specific T cells or B cells or even later in peripheral sites. In the case of T cells, the site of T cell differentiation is the thymus (Sprent and Webb, 1995).
What is meant by clonal expansion?
Definition. The proliferation of B-lymphocytes and T-lymphocytes activated by clonal selection in order to produce a clone of identical cells. This enables the body to have sufficient numbers of antigen-specific lymphocytes to mount an effective immune response.
What is the purpose of the plasma cell?
Plasma cells are differentiated B-lymphocyte white blood cells capable of secreting immunoglobulin, or antibody. These cells play a significant role in the adaptive immune response, namely, being the main cells responsible for humoral immunity.
What causes clonal deletion?
Clonal deletion is the removal through apoptosis of B cells and T cells that have expressed receptors for self before developing into fully immunocompetent lymphocytes. This prevents recognition and destruction of self host cells, making it a type of negative selection or central tolerance.
Why is clonal selection important?
Clonality has important consequences for immunogenic memory. The clonal selection hypothesis states that an individual B cell expresses receptors specific to the distinct antigen, determined before the antibody ever encounters the antigen.
Why is clonal expansion so important?
Clonal expansion of lymphocytes is a hallmark of vertebrate adaptive immunity. A small number of precursor cells that recognize a specific antigen proliferate into expanded clones, differentiate and acquire various effector and memory phenotypes, which promote effective immune responses.
What is a clonal rootstock?
Clonal Paradox rootstocks are micro-propagated in a lab and then potted in a soilless potting medium. Because they are clones, they have the same genetic constitution. Clonal rootstocks are sold as potted unbudded rootstock or as nursery field grown rootstock, grafted or budded trees.
