how do CD4 and CD8 T cells bring about destruction of pancreatic B-cells?
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how do CD4 and CD8 T cells bring about destruction of pancreatic B-cells? watch
- Thread Starter
- 09-11-2015 19:56
- 17-11-2015 00:49
CD8 cells are 'cytotoxic' i.e they kill cells directly. Cells continuously expose fragments of protein on the outside of the plasma membrane via MHC 1 molecules.
In a healthy state CD8 cells recognise the presented peptides as 'self'. Typically in a virally infected cell for example, part of protein fragments are chopped up and presented on the outside of the membrane via that MHC 1 molecule. CD8 then recognises the foreign protein and causes death of the infected cell. In some autoimmune conditions recognise 'self' as foreign and ultimately will kill healthy cells leading to necrosis.
CD4 play a role in activating B cells which go on to produce antibodies. If the antibodies recognise parts of the healthy cell in a pathophysiological condition, it will cause activation of the complement system, subsequent opsonisation of the cell and ingestion of the cell via a phagocytic cell e.g a macrophage.