WEV combined with NP enhanced lymphocyte mitogen activation and proliferation. The ability of lymphocytes from the control, WEV-treated and WEV+NP-treated mice to proliferate spontaneously or in response to mitogen stimulation was evaluated using CFSE assays and flow cytometry. The isolated cells were labeled with CFSE, and the labeled cells were either left unstimulated (A, control; B, WEV; and C, WEV+NP) or stimulated with mitogen (D, control; E, WEV; and F, WEV+NP). The analysis of CFSE staining was performed after gating on viable cells. The percentage of proliferating cells (CFSE-lo) is indicated for each panel. One representative experiment of the ten is shown. (G) Data from 10 different experiments are expressed as the mean percentage of proliferating cells ± SEM for the control (gray bars), WEV-treated (closed black bars) and WEV+NP-treated (hatched bars) mice. *P < 0.05, WEV-treated vs. control; #P < 0.05, WEV+NP-treated vs. control; +P < 0.05, WEV+NP-treated vs. WEV-treated groups.