Expression of human α- and β-defensins in odontogenic keratocytes and radicular cysts

Objective: To identify the location of human β-defensin-2 and human α-defensins in odontogenic keratocysts and radicular cysts. Patients and Methods: Immunohistochemical staining of tissue sections from enucleation specimens of 14 patients with odontogenic keratocysts and 19 patients with radicular cysts, and from normal oral mucosa from 2 healthy volunteers was done using mouse monoclonal antibodies against human cytokeratin 5/6 and rabbit polyclonal antibodies against human β-defensin-2. Results: Human β-defensin-2 immunoreactivity was evident in 10 of 14 odontogenic keratocysts (72%), and in 7 of 19 radicular cysts (37%). Signals for human β-defensin-2 were detected in the cytoplasm of keratinocytes in the parakeratinised and granular layers in both types of cysts. The localisation of human β-defensin-2 did not differ between cysts and normal mucosa. Human α-defensin immunoreactivity was detected in both types of cysts, but not in keratinocytes. Signals for human α-defensins were detected in the cytoplasm of neutrophils in the lamina propria. Conclusion: Many cysts generate human β-defensin-2 and human α-defensins suggesting that similar defence mechanisms utilising defensins exist in both types of cysts, as well as in normal oral mucosa.