Figure 1
VRP vector mediated NP expression and induce NP-specific antibodies in pigs. (a) BHK-21 cells infected by VSV*ΔG-NP express NP. The left plot demonstrates GFP expression only after infection with VSV*ΔG, and the right plot GFP/NP double positive cells after infection with VSV*ΔG-NP. (b) Overlay histogram of SK-6 cells infected with CSFVΔErns (blue histogram) and CSFVΔErns-NP (red histogram). (c) Kinetics of NP antibody responses induced by VRP and WIV vaccines determined by ELISA. Pigs were vaccinated with either VSV*ΔG-NP, CSFVΔErns-NP, empty vectors or WIV vaccines, and immune sera collected at different time points and tested by ELISA. Titers were determined as the highest serum dilution leading to photometric values above the detection threshold. The pigs received a booster immunization at day 28. (d) Reactivity of sera collected at day 48 after VRP vaccination with MDBK cells infected with Belzig (H1N1, homologous virus), R757/10 (H1N2, heterologous challenge virus) or mock. In the upper row, representative results for sera from the VSV VRP vector-immunized pigs, and in the lower row results from the CSFV VRP-immunized animals are shown. The blue histograms represent mock-infected cells, and is overlaid with the red histograms representing the reactivity with virus-infected cells. (e) Reactivity of all sera from VSV*ΔG-NP, CSFVΔErns-NP and empty vectors injected pigs with Belzig (H1N1)- or R757/10 (H1N2)-infected MDCK cells, determined as described in Fig. 1d. Statistical significant differences between two groups were calculated using unpaired one-way ANOVA followed by Tukey’s multiple comparisons test (***P < 0.0001; **P < 0.005; *P < 0.05).
