PAMPs including bacterial DNA, flagella, LPS, and peptidoglycan are capable of stimulating innate immune responses. Toll-like receptor 9 in the innate immune system recognizes bacterial DNA and synthetic oligodeoxynucleotides containing unmethylated CpG dinucleotides in the context of particular
Ubenimex sequences (CpG-DNA) [28]. CpG-DNA activates immune cells such as B cells, NK cells, macrophages, and dendritic cells to express a variety of genes involved in immune and inflammatory responses [22], [23], [24], [25] and [26]. Accordingly, the immunomodulatory activities of CpG-DNA have received considerable attention as potentially useful therapeutics for infectious diseases, adjuvants, and allergic diseases [29]. It was reported that CpG-DNA is capable of inducing hBD-2 expression in human respiratory epithelial
cells [20]. However, the contribution of CpG-DNA to antimicrobial action including regulation of antimicrobial peptides production in lymphocytes has yet to be characterized. In this report, we aimed to identify the induction of the defensins and the mechanism of hBD-2 production in response to CpG-DNA in human lymphocytes.