Re: What are the organelles that are unique to T-Cells?and what are their jobs?

Hello Tim,
To the best of my knowledge, there are no organelles (structures inside the 
cell) that are unique to T cells. 

T cells do have some unique (or mostly unique) functions. For example, 
cytolytic T cells (called CTL) make up most of the cells in the body that are 
capable of lysing (rupturing) other cells. These cells capable of killing other 
cells (which also include natural killer cells) store their toxins in secretory 
vesicles when they are activated and preparing to actually kill other cells. 
These secretory vesicles are little membrane enclosures inside the cells 
that contain anything the cell is secreting or storing for future secretion. In 
general, the function of CTL is to find virally infected cells and kill them 
before they can produce new virus by releasing these toxins (mostly 
perforin, which is a protein that will make holes in the target cell). 

However, secretory vesicles are by no means unique to T cells. For 
example, neurons keep a large store of neurotransmittors in vesicles at the 
cell membrane for release to propogate nerve signals to the next nerve. 
Some endocrine cells keep the hormones that they secrete in vesicles for 
ready use. Many other cell types have this capability to release the 
contents of prepared secretory vessicles very quickly after a signal and 
almost all cells have the capability to secrete particular proteins right after 
they are synthesized.

Jeff Dorfman
jdorfman@nih.gov