Expression and regulation of novel human β-defensins in gingival keratinocytes

This study evaluated the expression and regulation of β-defensins DEFB-104 and the recently identified DEFB-105-14 in gingival keratinocytes. Keratinocytes from healthy subjects were exposed to cytokines, Escherichia coli lipopolysaccharide or Candida species. Total RNA was extracted and defensin expression analyzed by reverse transcription-polymerase chain reaction. Three patterns of expression were seen: no expression, constitutive expression and inducible expression. Constitutive mRNA expression was evident for DEFB-104, 107, 109, 111, and 112. DEFB-108 and 114 were induced by interleukin (IL)-1β and Candida species. For DEFB-108 expression, synergism was observed when IL-1β was combined with tumor necrosis factor-α or interferon-γ. Downregulation of DEFB-109 occurred following treatment with Candida albicans. These findings suggest a role for multiple β-defensins in response to oral infection. Further investigation is needed to better understand their function, both in terms of antimicrobial activities and contributions to innate and acquired immunity.