Expression of beta Defensins in the Human Middle Ear Mucosa / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: It is believed that the innate immunity plays a critical role in protecting the tubotympanum from being infected because the middle ear cavity is normally sterile despite of a paucity of immune cells. Among known antibacterial molecules, defensins have been shown to contribute significantly to innate immunity. However, it is still unclear whether or not beta defensins are expressed in human middle ear mucosa. MATERIALS AND METHOD: Immunolabeling and RT-PCR were performed with the mucosal specimen from normal subjects and otitis media patients, respectively. Expression of beta defensin 2 mRNA was compared between the control group and experimental group that was treated by inflammatory stimuli in the animal models using RT-PCR. RESULTS: beta defensin 1 was expressed in both normal and inflamed middle ear mucosa of human, but beta defensin 2 and 3 were found only in the inflamed mucosa. The expression of beta defensin 2 mRNA was up-regulated when the interleukin-1alpha (IL-1alpha) or lipopolysaccharide (LPS) was treated in the middle ear mucosa of the experimental animals. CONCLUSION: We could show that beta defensins are expressed in the human middle ear mucosa and that beta defensin 2 is up-regulated by the inflammatory stimuli, IL-1alpha or LPS.