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| ===Killing Mechanism=== | | ===Killing Mechanism=== |
− | | + | The CTl killing mechanism is initiated by direct CTL-target cell contact. |
− | * The CTl killing mechanism is initiated by direct CTL-target cell contact.
| + | * The cells involved bind by antigen/[[MHC]] class I-TcR interaction. This allows the CTL's intracellular granules to be localised at the area of contact - the granules contain most of the molecules responsible for cytotoxicity. |
− | * The cells involved bind by antigen/[[MHC]] class I-TcR interaction. | + | * Direct cell contact stimulates the release of the granule contents into the area of contact between the two cells. The granules contain two groups of cytotoxic molecules. |
− | ** This results in the CTL's intracellular granules becoming localised to the area of contact.
| + | #Perforin, which is structurally related to the [[Complement|complement]] component, C9 and forms pores in the cell membrane. |
− | *** These granules contain most of the molecules responsible for cytotoxicity.
| + | #Granzymes, which are proteolytic enzymes that target cell nucleases and cause programmed cell death. |
− | * Direct cell contact stimulates the release of the granule contents into the area of contact between the two cells. | |
− | * The granules contain two groups of cytotoxic molecules.
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− | ** Perforin.
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− | *** Structurally related to the [[Complement|complement]] component, C9.
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− | *** Forms pores in the cell membrane.
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− | ** Granzymes.
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− | *** Proteolytic enzymes.
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− | *** Target cell nucleases.
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− | *** Cause programmed cell death.
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| ==T-Cell Activation== | | ==T-Cell Activation== |