Figure 4

Determination of IgA-expressing cells within the small intestine and activated B cells in the growth centre (GC) of vaccinated mice.

(a) Ileum sections were also stained with anti-IgA (red) and B220 (green) antibodies on 44 day after primer immunization and were analysed by confocal microscopy (Zeiss LSM710). Scale bar, 10 μm (400×). (b) Detection of the activated B cells in the GC of PPs. The GC B cells among B220⁺ B cells (PNA⁺ FAS⁺) in the PPs were determined by flow cytometry on day 5 after the booster immunization. The results are presented as the means ± S.E.M and were analysed by using a one-way ANOVA, assuming a Gaussian distribution followed by Dunnett’s post-test and are expressed relative to the values for PBS, NC8-pSIP409, NC8-pSIP409-NP-M1-Ctrlpep and to the H9N2 inactivated vaccine (*P < 0.05, **P < 0.01, and ***P < 0.001). The data shown represent one of the three experiments with equivalent results.