Interferon-g Mediated Regulation of Antimicrobial Peptide Human Defensin 5 Expression in Urogenital Epithelial Cells

Annie Mirsoian1, Sheila S. Greene2, Omar Murillo1, Alison J. Quayle2, and Edith Porter1

1California State University Los Angeles, CA, 2Lousianna State University, New Orleans, CA



Background: Sexually transmitted diseases (STDs) are a leading cause of morbidity and infertility worldwide. Understanding immune mechanisms of the genital mucosa may lead to novel preventive and therapeutic measures. Our previous work has shown that human defensin 5 (HD5) is up regulated during Chlamydia trachomatis and Neisseria gonorrhoeae urethritis in the male. We also identified IFNg response elements upstream of the HD5 gene and we wished to explore whether IFNg and other proinflammatory cytokines can induce HD5 production in genital epithelial cells. Methods: Genital epithelial cells, including HeLa cells, were stimulated with IFNg and IL1 for 36 – 48 hours. Total RNA extracts and protein extracts were subjected to real-time-PCR probing for HD5 and GAPDH, and Western immunoblotting probing for HD5, respectively.  Result: Our preliminary data suggest a 3-fold increase in HD5 RNA expression after stimulation with IFNg Conclusion: Our data describing the upregulation of human defensin 5 reveal a novel mechanism of defensin regulation. IFNg mediated upregulation of HD5 may also occur in vivo through cross talk between IFNg producing NK cells and HD5 synthesizing mucosal epithelial cells.