FIG. 1.

LTK63 enhances proliferation and Th1 and Th2 responses to nasally delivered Pa. BALB/c mice were immunized twice (weeks 0 and 4) i.n. with a two-component Pa consisting of rPT and FHA with or without LTK63 (10 μg) and with or without light anesthesia (anes.). At 6 weeks, spleen cells were isolated and stimulated in vitro with PT, FHA, or killed B. pertussis. After 72 h, supernatants were removed and IFN-γ, IL-4, and IL-5 concentrations were measured by immunoassay. Proliferation was assessed after 4 days. Results are mean cytokine concentrations or counts per minute for proliferation assays on spleen cells from four or five mice per experimental group. Error bars, standard deviations. ∗ and ∗∗, P < 0.05 and P < 0.01, respectively, versus Pa alone (by Student's t test).