Which cell molecules immune system recognises and eliminates the cell?

[TashiKaya]

Hi everybody.

 

I’m new here, so maybe this question has been asked before…if so, please point me to the answer.

 

So, my question is: if cell in the body is injured (not by microbe, but physically injured-for example its membrane becomes damaged and cell’s molecules discharge out), the body’s immune system recognizes damaged cell and eliminate it. How the body’s immune system recognizes damaged cell-which molecules it recognizes? Liking ATP, any others?

I hope I was clear enough

 

Please help…I need this for my investigations.

[CharonY]

I am not entirely sure what you mean, but damaged cells (as well as part of normal turnover for some tissue) are eliminated via apoptosis. There are several networks involved in the process and not just a few molecules. There are internal and external signals that initiate the process, though the external. Note however, that body injury does not necessarily cell injury. I.e. if you cut yourself you do not basically cut the membrane of cells. Rather, there is injury in the tissue which releases signaling molecules directing repair.

[TashiKaya]

Thank you CharonY for the answer. Actually, maybe I did not explain well my question.

 

So, if I "injure" the cell membrane by some physical method used in gene therapy (like electroporation), some molecules are leaking out of cell due to the damaged/permabilized membrane. For example ATP is leaking out and body’s immune system recognizes damaged cell and eliminates it (or not?). Are there any other detectable molecules, that are leaking through damaged/permabilized membrane and that immune system recognizes them and eliminates the cell?

[CharonY]

Typically not by just by random leaking. The electroporation is just a jolt if you will and if it was done correctly, results in an almost immediate seal. If it stays leaky, the accrues damage and enters the apoptotic pathway. During these steps they release signaling molecules that tells phagocytic cells to eat them. In this step it is assumed small amounts of ATP are released in a controlled manner via pannexin channels (high level release do not work) but only to attract resident resident macrophages. More specific molecules such as fractalkines or lysophophatidylcholin are assumed to play major roles (though they do not appear to function universally).

The reason for the high specificity is to ensure that the macrophages do not start to damage cells and tissue by some minor events.

To summarize, cells first detect themselves whether they are damaged beyond repair and then send out signals to be eaten.

[Function]

look up DAMPS (damage-associated molecular patterns) and PAMPS (pathogen-associated molecular patterns: recognition patterns of e.g. bacteria)

[CharonY]

It is actually slightly different as DAMPS generally leads to autophagy pathways. While there are pathways overlaps, the function and result is quite a bit different (think in terms of survival response vs cell death).

[Function]

Oops, never meant to insinuate that PAMPs and DAMPs lead to the same response