Fig. 3.

Antigen cross-presentation by TLR agonist-activated host DCs contributes to antitumor immunity during combination immunotherapy. Flow cytometry was used to phenotypically assess the activation status of pDCs enriched from pools of tumor-draining lymph nodes, taken 24 h posttherapy (see “Materials and methods”). Mean fluorescence intensity (MFI) readouts were used as a measure of the level of expression of the a CD40 and b CD86 cell-surface activation markers. c When normalized to the vehicle-control group to allow comparison between independent experiments, MFI values for both CD40 (3 experiments shown) and CD86 (6 experiments shown) increased in response to TLR agonist therapy and independently of adoptive T-cell transfer. d Disruption of antigen cross-presentation in TAP-1^−/− mice negated the survival benefit of ATI with TLR agonists (*P = 0.118, relative to untreated TAP-1^−/− and P = 0.02, relative to treated wild-type C57BL/6; Log-Rank (Mantel–Cox) test)