Human β-defensin HBD3 binds to immobilized Bla g2 from the German cockroach (Blattella germanica).

Human β-defensin 3 (HBD3) is a small, well-characterized peptide in mucosal secretions with broad antimicrobial activities and diverse innate immune functions. Among these functions is the ability of HBD3 to bind to antigens. In this study, we hypothesize that HBD3 binds to the allergen Bla g2 from the German cockroach (Blattella germanica).

Defensins as anti-inflammatory compounds and mucosal adjuvants.

Human neutrophil peptide alpha-defensins and human beta-defensins are small, well-characterized peptides with broad antimicrobial activities. In mixtures with microbial antigens, defensins attenuate proinflammatory cytokine responses by dendritic cells in culture, attenuate proinflammatory cytokine responses in the nasal fluids of exposed mice and enhance antibody responses in the serum of vaccinated mice. Although the exact mechanisms are unknown, defensins first start by binding to microbial antigens and adhesins, often attenuating toxic or inflammatory-inducing capacities.

Human alpha- and beta-defensins bind to immobilized adhesins from Porphyromonas gingivalis.

Human neutrophil peptide alpha-defensins (HNPs) and human beta-defensins (HBDs) are small well-characterized peptides with broad antimicrobial activities and a diversity of innate immune functions. Although the interactions of defensins with bacteria and their membranes have been well characterized, the interactions of defensins with bacterial adhesins have not. Here we determine if HNPs and HBDs bind to the immobilized adhesins of Porphyromonas gingivalis strain 381, recombinant hemagglutinin B (rHagB) and recombinant fimbrillin A (rFimA), by surface plasmon resonance spectroscopy.

Human beta-defensin 3 binds to hemagglutinin B (rHagB), a non-fimbrial adhesin from Porphyromonas gingivalis, and attenuates a pro-inflammatory cytokine response.

Regulatory mechanisms in mucosal secretions and tissues recognize antigens and attenuate pro-inflammatory cytokine responses. Here, we asked whether human beta-defensin 3 (HBD3) serves as an upstream suppressor of cytokine signaling that binds and attenuates pro-inflammatory cytokine responses to recombinant hemagglutinin B (rHagB), a non-fimbrial adhesin from Porphyromonas gingivalis strain 381. We found that HBD3 binds to immobilized rHagB and produces a significantly higher resonance unit signal in surface plasmon resonance spectroscopic analysis, than HBD2 and HBD1 that are used as control defensins.