Changes

==Cytotoxic CD8⁺==

==Cytotoxic CD8⁺==

<p>These T cells express the marker CD8 and once fully mature seek and destroy target cells (infected or cancer forming cells). When the cytotoxic T cell recognises the MHC I complex on the target cell (MHC I binds to TCR) the T cell kills that cell e.g. viral peptides associate with MHC I and the CD8⁺ T cell recognises this and binds to the cell. Only two pathways are used by cytotoxic T cells to kill cells:

<p>These T cells express the marker CD8 and once fully mature seek and destroy target cells (infected or neoplastic cells). When the cytotoxic T cell recognises the MHC I complex on the target cell (MHC I binds to TCR) the T cell kills that cell -for example with a viral infection,  viral peptides associate with MHC I and the CD8⁺ T cell recognises this and binds to the infected cell. Only two pathways are used by cytotoxic T cells to kill cells:

*One pathway uses the CD95 (death receptor) which  triggers apoptosis in the target cell (usually other T cells)

*One pathway uses the CD95 (death receptor) which  triggers apoptosis in the target cell (usually other T cells)

*The other pathway uses perforins and granzymes which form pores in the target cell membrane causing cell lysis

*The other pathway uses perforins and granzymes which form pores in the target cell membrane causing cell lysis