Figure 1
Allergic airway disease in mice breastfed by ovalbumin (OVA)-exposed sensitized mothers. (a) Schematic representation of the experimental protocol. Adult BALB/c female mice were sensitized or not with two injections of OVA in alum before mating. Pups from sensitized mothers were killed at birth and replaced by pups from non-sensitized mothers. Non-sensitized and sensitized mothers were then exposed or not exposed to OVA aerosols every other day from delivery until weaning. When 6- to 8-week-old, offspring were sensitized with two intraperitoneal injections of OVA in alum and challenged daily for 5 days with OVA aerosols. Mice were analyzed 1 day after the last aerosol. (b) Airway hyperreactivity (AHR). Dynamic lung resistance and compliance were monitored in mice breastfed by unexposed (filled circle) or OVA-exposed (empty circle) non-sensitized mothers, or unexposed (filled square) or OVA-exposed (empty square) sensitized mothers upon sensitization and challenge with OVA; n=6–7 mice per group in each experiment. Non-sensitized mice challenged with OVA (triangle) were used as controls; n=3 in each experiment. Data are expressed as mean±s.e.m. and are representative of one experiment out of two. **P<0.01. (c–e) OVA-sensitized and challenged mice breastfed by unexposed (empty bars) or OVA-exposed (light gray bars) non-sensitized mothers, or unexposed (dark gray bars) or OVA-exposed (black bars) sensitized mothers were analyzed for allergic airway inflammation. Non-sensitized mice challenged with OVA (hatched bars) were used as controls. Number and phenotype of cells in bronchoalveolar lavage (BAL) fluids (c), cytokine secretion by lung cells incubated or not with OVA (d), and serum levels of OVA-specific Ig (e). Data are expressed as mean±s.e.m. of seven experiments with n=6–8 mice per group in each experiment. ****P<0.0001; ***P<0.001; **P<0.01; *P<0.05; NS, P>0.05. (f) Histology of lung sections. Lungs from the indicated mice were sectioned and stained with Periodic Acid of Schiff (PAS) (upper panel) or May-Grünwald Giemsa (MGG) (lower panel). Data show representative microscopic images at a 10-fold magnification.
