2024年11月23日 · 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.

During clonal selection, random mutations during clonal expansion cause the production of B cells with increased antibody-binding affinity for their antigens. The clonal selection hypothesis may explain why secondary immune responses are so effective at …

Antigen selects the B cell that has the receptor it can bind to. Antigen binding stimulates B cell to divide by mitosis. Now have millions of B cells that can bind that specific antigen. A result of B cell colonal selection. All B cells produced are identical, same receptor.

2023年8月31日 · Animation Overview: Clonal Selection and Clonal Expansion. During its development, each B-lymphocyte becomes genetically programmed, through a process called gene translocation, to make a unique antibody molecule that will function as a B-cell receptor.

The theory states that in a pre-existing group of lymphocytes (both B and T cells), a specific antigen activates (i.e. selects) only its counter-specific cell, which then induces that particular cell to multiply, producing identical clones for antibody production.

2024年10月18日 · When an antigen enters the body for the first time, the small numbers of B-lymphocytes with receptors complementary to that antigen are stimulated to divide by mitosis. This is known as clonal selection

Elegant transgenic models have shown that, for B cells, the purging of potentially dangerous anti-self B cell clones (negative selection) not only takes place in BM during their generation but also at the periphery after B cells have reached their mature state.

2024年11月23日 · Clonal selection occurs after immature lymphocytes express antigen receptors. Central tolerance is the mechanism by which newly developing T cells and B cells are rendered non-reactive to self. Both developing B cells and T cells are subject to negative selection during a short period after antigen receptors are expressed.

ediate progenitor cell is called a “clone”. The set of diverse B-cells pre exist before this selection is made and existence of these B-cell variants i. independent of the subsequent selection event. Hence clonal selection theory is anal. the blood and lymph ( he fluid in the tissues). They have a lifetime. They are released and circulat.

In clonal selection, an antigen is presented to many circulating naive Bcells and (via MHC) T cells, and the lymphocytes that match the antigen are selected to form both memory and effector clones of themselves.