Infection Alters Bone Marrow to Promote Asthma Figure 2. Characterization of AAD in bone marrow chimeras. Bone marrow from adult na¨ıve BALB/c mice was adoptively transferred into age- matched irradiated, na¨ıve mice. Eight weeks later, after bone marrow reconstitution, chimeras were subjected to Ova-induced AAD and the development of AAD was assessed. (A) Transpulmonary resistance, (B) dynamic compliance, (C) mucus secreting cell (MSCs) within 100 mM of basement membrane (BM) in the airways, and Ova-specific (D) IL-5 and (E) IL-13 release from re-stimulated MLN cell culture supernatants. Results are represented as mean 6 SEM. n = 6–8, from two independent experiments of 3–4 mice. *P,0.05 compared to non-allergic (Chimera + Sham) control. ND = not detected. doi:10.1371/journal.pone.0042588.g002 Figure 3. C. muridarum lung infection in infants, but not neonates, alters hematopoietic cells to increase Th2 cytokine release from MLN cells. BALB/c mice were infected with C. muridarum or sham inoculated (Vehicle) as neonates, infants or adults. Nine weeks after infection bone marrow was extracted and adoptively transferred into age-matched irradiated, na¨ıve mice. Eight weeks after bone marrow reconstitution, chimeras were subjected to Ova-induced AAD and the development of AAD was assessed. Ova-induced (A–C) IL-5 and (D–F) IL-13 release in MLN cell cultures from neonate, infant and adult bone marrow chimeras. Results are represented as mean 6 SEM. n = 6–8, from two independent experiments of 3–4 mice. Age-matched controls were run in parallel with every experiment. *P,0.05 compared to un-infected allergic (Vehicle Chimera + Ova) controls. doi:10.1371/journal.pone.0042588.g003 PLoS ONE | www.plosone.org 4 August 2012 | Volume 7 | Issue 8 | e42588