Pseudomonas Aeruginosa- and IL-1β-Mediated Induction of Human β-Defensin-2 in Keratinocytes Is Controlled by NF-κB and AP-1

Abstract

Human beta-defensin-2 (hBD-2) is an inducible epithelial peptide antibiotic involved in cutaneous defense. Expression of hBD-2 in keratinocytes is strongly induced by IL-1beta and culture supernatants of Pseudomonas aeruginosa (PA). The use of an IL-1 receptor antagonist revealed that PA-mediated induction of hBD-2 is not dependent on IL-1. Luciferase gene reporter experiments, demonstrated that a 2,338 bp promoter fragment of hBD-2 containing three putative NF-kappaB as well as one activator protein-1 (AP-1) binding site was strongly activated by IL-1beta and PA. Mutation of all NF-kappaB binding sites together with mutation of the AP-1 binding site completely abolished hBD-2 promoter activation by IL-1beta and PA. Treatment with the NF-kappaB inhibitor Helenalin as well as with the c-Jun N-terminal kinase (JNK) inhibitor SP600125 and the p38 mitogen-activated protein kinase inhibitor SB 202190 blocked hBD-2 induction by IL-1beta and PA. PD 98059, a selective inhibitor of extracellular signal-regulated kinase 1/2 demonstrated no significant influence. Transcription factor ELISAs indicated that the NF-kappaB heterodimer p50-p65 binds to all three NF-kappaB sites in the hBD-2 promoter upon stimulation of primary keratinocytes with IL-1beta and PA. We conclude that the activation of NF-kappaB (p50-p65) and AP-1 are crucial events for induction of hBD-2 in keratinocytes upon IL-1beta and PA stimulation.

Antiviral responses of human Fallopian tube epithelial cells to toll-like receptor 3 agonist poly(I:C)

“…Here we demonstrate, for the first time to the best of our knowledge, that HBD2 expression is inducible in primary FTEC upon stimulation with poly(I:C). This is significant because HBD2 is an effective antimicrobial against bacterial (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus) as well as viral (adenovirus, HSV, rhinovirus, and HIV) agents (68)(69)(70)(71)(72). In addition, it has chemotactic functions and can facilitate the recruitment of immune cells, such as memory T lymphocytes, iDC and mast cells (39).…”

IL‐12, IL‐23, and IL‐27 enhance human β‐defensin‐2 production in human keratinocytes

“…The cells were incubated with 10 ng/mL IL-1b and/ or the indicated concentrations of IL-12, IL-23, or IL-27 in highcalcium KBM for 48 h. The hBD-2 concentration of the culture supernatants was measured using ELISA (Peprotech, Rocky Hill, NJ). The IL-1b concentration of 10 ng/mL was adopted in this study because it did not reduce the viability of keratinocytes (>96% viable), it has been generally used in previous studies on in vitro hBD-2 production in keratinocytes [39], and this concentration was close to the IL-1b concentrations in supernatants from LPS-stimulated human macrophages [40] or tissue homogenates from the PMA-induced murine hyperplasia skin model for psoriasis [41]. Thus, IL-1b may exist at this concentration in skin wounds, infection, and inflammatory diseases.…”

Extracellular HIV-1 Tat Induces Human Beta-Defensin-2 Production Via NF-kappaB/AP-1 Dependent Pathways in Human B Cells

“…Human beta-defensins (hBD) such as hBD-2 have been shown to exert anti-HIV activity (Quiñones-Mateu et al, 2003;Sun et al, 2005;Weinberg et al, 2006). hBD is upregulated in various cell types in response to bacterial infection and pro-inflammatory cytokines (Tsutsumi-Ishii et al, 2000;Wehkamp et al, 2006). Previous studies have shown that HIV-1 virion can induce the expression of hBD, even in the absence of HIV-1 replication (Quiñones-Mateu et al, 2003).…”

“…NF-κB is responsible for HIV-1 Tat-induced hBD-2 expression in human B cells NF-κB signaling pathway is another pathway involved in hBD-2 (Tsutsumi-Ishii et al, 2000;Wehkamp et al, 2006). We examined HIV-1 Tat-induced NF-κB signaling cascades.…”

“…In addition to exerting direct antiviral effects against HIV-1, defensins have immune-stimulatory activity because they mediate the signals involved in adaptive immune responses (Bowdish et al, 2006). hBD is up-regulated in various cell types in response to microbial infection and pro-inflammatory cytokines (TsutsumiIshii et al, 2000;Wehkamp et al, 2006). Previous studies have shown that HIV-1 virion can induce the expression of hBD, even in the absence of HIV-1 replication (Quiñones-Mateu et al, 2003).…”