Immunity system complexity: how T c ells kill (Introduction)

by David Turell , Thursday, October 14, 2021, 20:07 (917 days ago) @ David Turell

More of the mechanism unearthed:

https://medicalxpress.com/news/2021-10-mito-warriors-scientists-cell-assassins.html

"Cytotoxic T cells are specialist white blood cells that are trained by our immune system to recognize and eliminate threats—including tumor cells and cells infected with invading viruses, such as SARS-CoV-2, which causes COVID-19.

***

"'Once a T cell has found its target, it binds to it and releases its toxic cargo. But what is particularly remarkable is that they are then able to go on to kill and kill again. Only now, thanks to state-of-the-art technologies, have we been able to find out how they reload their weapons."

"Today, in a study published in Science, the team have shown that the refueling of T cells' toxic weapons is regulated by mitochondria. Mitochondria are often referred to as a cell's batteries as they provide the energy that power their function. However, in this case the mitochondria use an entirely different mechanism to ensure the killer T cells have sufficient 'ammunition' to destroy their targets.

"Professor Griffiths added: "These assassins need to replenish their toxic payload so that they can keep on killing without damaging the T cells themselves. This careful balancing act turns out to be regulated by the mitochondria in T cells, which set the pace of killing according to how quickly they themselves can manufacture proteins. This enables killer T cells to stay healthy and keep on killing under challenging conditions when a prolonged response is required."

***

"When a T cell finds an infected cell or, in the case of the film, a cancer cell, membrane protrusions rapidly explore the surface of the cell, checking for tell-tale signs that this is an uninvited guest. The T cell binds to the cancer cell and injects poisonous 'cytotoxin' proteins down special pathways called microtubules to the interface between the T cell and the cancer cell, before puncturing the surface of the cancer cell and delivering its deadly cargo." (my bold)

Comment: The bold describes that the T cell knows non-self automatically and adds 'cytotoxic proteins' to kill. These specialized cells follow instructions activated in their DNA which makes them extremely specialized cells. The new antibody produced is then added to the library for future use.