Lipid and T-cell viability

[tim]

I recently tried to recover T-lymphocytes from murine mesenteric lymph
nodes. After gently pressing organs in RPMI medium, spinning 2 mn at
3000 tr/mn, and resuspending the pellet in NaCl 0,9%, I had 100% of dead
cells. I recovered and pressed many fat tissue with the lymph nodes, so
could it have any effect on cell viability ??? (Osmotic or plasmic
membran alteration until ceramide induced apoptosis ?????????) or there
is another reason. 

Thanks for replying me.