Figure 1

SLPI protein vaccination induces neutralizing SLPI-specific antibodies. A: Mouse sera collected 14 days after the second vaccination with SLPI- or OVA-protein were analyzed by ELISA for the presence of SLPI-specific antibodies, as described in Materials and Methods. IgG titers representing the average of samples from six different mice were compared. B: U937 monocytic cells were incubated with 4 μg/mL SLPI with either 40 μg/mL IgG antibodies purified from sera of SLPI-vaccinated mice or from OVA-vaccinated mice and stimulated for 2 h with 100 ng/mL LPS. The IL-8 expression was quantified by Real Time-PCR. Results are shown as mean ± standard deviation of three samples. The differences between LPS-stimulated cells and control cells, between SLPI and LPS-treated cells and just LPS treated cells, between LPS- and SLPI-treated cells and cells treated with SLPI, LPS and SLPI-IgG and between SLPI, LPS and SLPI-IgG and SLPI, LPS and OVA-IgG treated U937 cells were statistically significant at p < 0.05 (One-Way ANOVA and Holm-Sidak test)