Figure 3.
The MAYV/IRES attenuated vaccine strain induces stronger cellular and humoral responses in BALB/c mice. 6-week-old BALB/c mice were inoculated or not with either wt MAYV or MAYV/IRES (2 × 105 PFU/50 μL, i.pl.). (a) Mechanical hypernociception was assessed at different time points after virus inoculation, as described in figure legend 1. (b) Total and differential cell counts of inflammatory cells in the blood. (c–g) plaque assay analysis of hind paw (c) LNP (d), quadriceps muscle (e), spleen (f) and serum (g). (h,i) Anti-MAYV IgM and IgG titers of pre- and post-infection serum samples collected on day zero and every 7 days until day 49. (j) Neutrophil influx to the hind foot was measured indirectly by evaluation of MPO activity. (k) Macrophage influx to the hind foot was measured indirectly by analysis of NAG activity. (l) Shows semi-quantitative analysis (histopathological score) and representative pictures of hind paw sections of control and MAYV-infected mice, 1, 3, 7, 14 and 21 d.p.i. Results were expressed as median (c–g) or mean ± SEM (a,b and h–l) and are representative of two experiments. Original magnification: 200×. Scale bar: 100 µm. *p < 0.05 when compared to control uninfected mice (MOCK), as assessed by two-way (a, i and h), one-way ANOVA followed by Newman-Keuls post-test (b–g, j,k) or Mann-Whitney test (l).