Figure 5.

The amount of Bax bound to heavy membranes does not change before T cells die. (A) Vβ8x T cells were activated in BL6 mice with SEB. 3 d later, T cells were isolated from the animals and cultured for 7 h. Live Vβ8x T cells were isolated by cell sorting and homogenized without detergent. Homogenates were made from resting T cells and heavy membrane and cytosol fractions prepared from each homogenate, run on SDS PAGE, and Western blotted for the indicated proteins. Cell equivalents run in each lane are shown at the bottom of the panel. (B) BAK KO mice were immunized with 100 ug SEB. 3 d later, spleen and lymph node T cells were isolated from these and other unimmunized (Rest.) BAK KO mice. Half of the T cells from the immunized BAK KO mice were incubated for 5 h to bring them closer to death (Act. inc.). The other half were kept on ice (Act.). Live cells were then purified from all the samples, and heavy membrane and cytosol fractions were prepared, run on SDS PAGE, and Western blotted as described in A. Blots shown are representative of at least three independent experiments.