Microglia response to allergic airway inflammation during early postnatal period in mice

We examined how allergic inflammation in early postnatal period influences microglia using a short- and long-term airway allergy model. Male mice (C57BL/6) were immunized by intraperitoneal injection with aluminum hydroxide and ovalbumin (OVA) or phosphate-buffered saline (PBS) (control) at postnatal days (P) 3, 7, and 11, followed by intranasal challenge with OVA or PBS solution twice a week until P30 or P70. Microglia from whole brain were isolated from PBS- and OVA-treated mice by gating on CD11b+CD45int cells with flowcytometry at P30 and P70 respectively. Results suggest the dysregulation of microglial genes related to synaptic pruning and clearance, aging, and corticosteroid pathway and distinction between short- and long- term allergen challenge. Microglia were isolated from PBS- and OVA- treated mice 1 day after intranasal challenge at P30 and P70. Collected microglia were pooled (4 samples per group) for analysis. Extracted RNA were subjected to RNA array assay. Gene expression of PBS (control group)- and OVA (allergy group)- treated mice at P30 and P70 were compared respectively.