What is a clonal deletion?

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cells of the immune system, such as t cells and B cells, have proteins on their surface that allow them to recognize foreign attackers and attack them. The areas of these proteins may vary from cell to cell, allowing them to respond to different threats. Occasionally cells A B cells that respond to proteins that are expressed by their own cells, called autoantigens, are produced. Clonal deletion is a process that allows these cells to neutralize before they relax into the body where they could potentially begin to attack healthy tissue.

t cells are produced in the bone marrow, but mature in the thymus, gland near the heart and B cells are produced in the bone marrow. Despite their different places of origin, both cell types use a similar method of clonal deletion to ensure that ripe immune cells that respond to venonigens are not released into the bloodstream. During the ripening process, these cells come into contact with a limited cell range such as macrophages and tymicdendritic cells. These cells have a number of surface proteins called antigens that are presented by immune cells, so the cells that produce a reaction can be discarded.

For the use of thymus as an example of tymic dendritic cells, they use the presentation process, allowing t cells to try to tie surface proteins to test them for clonal deletion. The immature t cells that respond to these venonigens form a protein complex with thymic cell. In the event that this protein complex is formed, it triggers the sequence of self -destruction, called apoptosis, in the cell, so it does not mature and enters the body where it could potentially initiate a harmful reaction if it encounters this protein with another cell.

The body contains many other types of other types other than cells that are seen in the thymus and bone marrow, so the clonal deletion must be responsible for the autigens with these tissues usualE does not find. The thymus does this by having tymic dendritic cells that contain surface proteins that usually occur elsewhere, for example in pancreatic tissue. Clonal deletion may then occur in immune cells that would normally respond to these pancreatic proteins, and a similar process regulates B cells in the marrow. Some diseases, such as diabetes, could be partly caused by the body failure to present the entire range of body antigens to mature immune cells, allowing these cells to hurt and attack healthy tissue.