Fig 3. Depletion of M-cells does not affect ability to survive subsequent pulmonary challenge or mount an immune response.

BALB/c mice (n = 10 per group for a & b, n = 3 per group for c & d) were treated i.p. with rat Ig or αRANKL antibody (250 μg) on days 0, 2, 4, and 6, and then, along with an untreated group of mice (indicated as ΔiglB), were vaccinated orally with ΔiglB (1000 CFU for a & b, 10⁵ CFU for c & d) on day 8. Naïve mice receiving PBS orally were used as the non-vaccinated control. (a-b) After 30 days, all animals were intranasally challenged with 45,000 CFU of LVS (~10 LD₅₀) and were monitored daily for weight changes (a) and survival (b). Representative results from 3 experiments are shown. (c-d) After a resting period of 21 days to allow for clearance of the vaccine, mice were bled to obtain sera, and then sacrificed for spleen collection. (c) ELISpots for IFN-γ, IL-2, and IL-17 were performed using single-cell splenocytes stimulated with 1 μg of UV-killed ΔiglB. Spot numbers of 3 individual spleens with triplicate, 9 for each group, are shown with mean ± standard error. Representative of 2 independent experiments. (d) ELISAs were conducted to determine serum antibody responses (total antibody, IgG1, and IgG2a) to UV-killed ΔiglB. Representative results from 3 experiments are shown. * p <0.05, *** p < 0.001.