Aim: To investigate the effects of human beta-defensins on the expression of genes involved in the host immune response of the dental pulp.
Methodology: Human odontoblast-like cells were cultured in Dulbecco's modified Eagle's medium. Cells were stimulated by recombinant human beta-defensins (rhBDs) up to 4 h. RNA was extracted followed by cDNA synthesis (oligo-(dT)-primer). Samples were analysed by real-time polymerase chain reaction (PCR) technology. Genes of interest were: human beta-defensin-1, -2, interleukin (IL)-6, IL-8, tumour necrosis factor-alpha, cyclooxygenase-2, leukotriene-A4-hydrolase, cytosolic phospholipase-A-2 (cPLA(2)), and dentine sialophosphoprotein. Gene expression of beta-actin served as internal standard for normalizing real-time PCR data. Two-way anova and the paired t-test were applied for comparison of the gene expression.
Results: In odontoblast-like cells rhBD-2 stimulation led to a down-regulation of the gene expression of hBD-1 (P < 0.05), whilst the mRNA expression of IL-6 (P < 0.05), IL-8 (P < 0.05) and cPLA(2) was increased in response to rhBD-2.
Conclusion: The results of the present study suggest immune regulatory functions of human beta-defensin-2 in odontoblast-like cells.