Objective: To investigate roles of staphylococcal enterotoxin B (SEB) in mouse asthma models
Methods: BALB/c mice were intranasally sensitized with Dermatophagoides pteronyssinus (Der p) and/or SEB to develop acute asthma models. Mice were grouped to see effects of SEB and Der p interactions during the sensitization and challenge periods. Outcomes were evaluated for methacholine airway hyperresponsiveness (AHR), lung inflammatory cells, lung cytokines, serum IgE, and in vitro Der p-stimulated splenocyte responses.
Results: Intranasal SEB exposure increased lung macrophage, lymphocyte, and neutrophilic infiltration; but SEB alone did not develop any typical asthmatic phenotypes. Effects of SEB on asthma phenotypes were the most evident when co-administered with Der p during the sensitization period, developing more AHR and lung eosinophilic inflammation on Der p challenge. Serum Der p specific IgE levels were also amplified by SEB co-sensitization. In in vitro Der p re-stimulation experiments, IL-5 and IL-13 responses were also increased in splenocytes from the mice co-sensitized by SEB and Der p.
Conclusion: The present findings indicate the roles of SEB in Der p-induced allergic asthma, particularly during the sensitization period.