PBMC from a representative patient (n=3) with mild/moderate RRP were exposed to E6 or BSA for 20 hrs. prior to mixing with HLA class I and II mismatched and irradiated PBMC in a MLR at E:T ratio of 25:1. At day 6, patient's T-cells were re-challenged with PKH26 labeled PBMC from the same mismatched stimulator. Target cell death was detected using TO-PRO-3 iodide (TP3)(77, 96). Density plots (upper right quadrant = dead target cells) (upper left = live targets), and the histograms, gated on PKH26+ targets, shows a decreased number of dead target cells that incorporated TP3 with E6 exposure (5% killing), while maximum killing without E6 (data not shown) and BSA was 30%.