Strain-specific phenotypes of airway inflammation and bronchial hyperresponsiveness induced by epicutaneous allergen sensitization in BALB/c and C57BL/6 mice

Background: Allergen sensitization through a disrupted skin barrier appears to play a prominent role in the development of atopic diseases, including allergic asthma. The role of the genetic background in immunological and physiological phenotypes induced by epicutaneous sensitization is undetermined. Methods: BALB/c and C57BL/6 mice were sensitized either epicutaneously by patch application of ovalbumin (OVA) or systemically by intraperitoneal injection of OVA with alum before exposure to aerosolized OVA. The concentrations of OVA-specific immunoglobulin in serum and cytokines in bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunosorbent assay. The severity of airway inflammation was evaluated by cell counts in BALF, and bronchial responsiveness to methacholine was measured by the flexiVent system. Results: The production of OVA-specific IgG1 and IgE was greater in the epicutaneously sensitized BALB/c than C57BL/6 mice. In contrast, both eosinophilic airway inflammation and bronchial responsiveness to methacholine were more prominent in the C57BL/6 than in the BALB/c mice. The concentrations of interleukin-4 increased significantly in the BALF from C57BL/6 mice only. No between-strain differences were observed after intraperitoneal sensitization. Conclusions: The C57BL/6 mouse is a more appropriate model than the BALB/c mouse to study the relationship between skin barrier dysfunction and the pathogenesis of allergic asthma.