C18 MECHANISMS OF AIRWAY HYPERRESPONSIVENESS AND REMODELING: Acute, Transient Modulation Of Airway Smooth Muscle Contractility By Th2 Differentiated T-Cells

Rationale: Airway smooth muscle (ASM) is believed to be hypercontractile in asthma but data from human trachealis and main bronchi ASM tissues do not show intrinsic differences compared to control ASM. Results: Our preliminary data showed that asthmatic peripheral ASM exhibits a 28% greater maximal shortening velocity (Vmax) and an 80% greater maximal contractile stress than control. 24h incubation of trachealis muscle strips with Th2 cells showed an increase in Vmax of 25% in a control subject and 70% in a severe asthmatic as well as hypersensitivity in the MCh dose response.