BIOM30002 Lecture Notes - Lecture 30: Clonal Deletion, Clonal Selection, Thymus
Document Summary
Immunological tolerance in the era of clonal selection. Frank macfarlane burnet"s theory of clonal selection (1950s): postulated the formation of vast number of clones able to recognise an unlimited number of potential antigens, including the generation of self-reactive clones. Concept of clonal deletion accounts for the immune system remaining tolerant of self. Experimental demonstration of clonal deletion had to wait until the mid-1980s. Lymphocytes are sensitive to tolerance induction when immature, having just completed the rearrangement of their antigen receptors (with rag). This is in the bone marrow for b cells and the thymus for t cells. Tolerance is triggered by too high affinity interaction with self in the absence of additional information. When receptor is first put on surface there is a test for binding capacity to self antigen. If it recognises self that cell is deleted. Or cell might try and rearrange receptors again.
