First of all, make sure you put 2-ME in the medium. You also require IL-2
for continued stimulation of T cells, otherwise, they undergo apoptosis. If
you want to skew towards a Th2 phenotype, I have tried using IL-4 alone with
success, but you certainly require IL-2 otherwise. Also, you will need to
change the medium regularly depending on the density of the cells, and
supplement with IL-2 even if you don't put new antigen in.
Adrian Wu