Fig. 5.

Inhibition of Hsp90 inhibits cross-priming. (A) 4T1 cells were treated with the indicated doses of radicicol or DMSO for 6 h and electroporated with purified, LPS-free, soluble OVA protein. Cells were washed and irradiated with 7,500 Gray before being used to immunize OT-I recipients. Expansion of OT-I cells in the draining lymph nodes was quantified and plotted as the percentage of the total CD8⁺ population. (Inset) At the time of immunization, a portion of each immunizing population was analyzed by immunoblotting for OVA. (B) 4T1 cells were treated with the indicated doses of 17-AAG or DMSO as a control for 6 h and used for immunization as in A. (C) 4T1 cells were treated with the indicated doses of SU11652 or DMSO as a control for 6 h and used for immunization and analysis as in A. (D) 4T1 cells were electroporated with purified, LPS-free, soluble OVA and cultured for 12 h before treating with the indicated doses of radicicol or DMSO as a control for 6 h. Cells were washed and irradiated with 7,500 Gray before being used to immunize OT-I recipients. Expansion of OT-I cells in the draining lymph nodes was plotted as the percentage of the total CD8⁺ population. (E) 4T1 cells treated with 50 μM radicicol (as in A) were mixed at the indicated ratios with untreated cells and used for immunization and analysis as in A.