Figure 3: A mouse model of RV-induced asthma exacerbation. (a) Mature mice were sensitized with ovalbumin (OVA) and alum given intraperitoneally. This was followed by intranasal challenge with additional ovalbumin. One day after the last OVA challenge, animals were infected with RV1B, a minor group virus capable of infecting mouse cells. (b) Ovalbumin and RV1B have synergistic effects of airways responsiveness. Airways responsiveness was assessed by measuring changes in respiratory system resistance in response to increasing doses of nebulized methacholine. Respiratory system resistance was measured in anesthetized and endotracheally intubated mice using a computerized ventilator (Scireq, Montreal, Quebec, Canada).