Abstract Background Aggregatibacter actinomycetemcomitans is an oral bacterium associated with aggressively progressing periodontitis. Extracellular release of bacterial outer membrane proteins has been suggested to mainly occur via vesicles. This study investigated the presence and conservation peptidoglycan-associated lipoprotein (AaPAL) among A. strains, immunostimulatory effect AaPAL, whether live cells this structural in free-soluble form independent Results The pal locus its gene...

In a search for novel bioactive cell surface structures of periodontal pathogens, it was found that sera from two patients with Actinobacillus actinomycetemcomitans -associated infections reacted strongly at 17 kDa on immunoblots A. outer-membrane protein (OMP) preparations. The antigen also recognized by anti-CsgA ( Escherichia coli curli major subunit) antibody. identified as peptidoglycan-associated lipoprotein (PAL; AaPAL) two-dimensional immunoblotting and subsequent sequence analysis...

The dentogingival junction is of crucial importance in periodontal host defense both structurally and functionally. Oral bacteria exert a constant challenge to the cells tissues at junction. response set up eliminate pathogens by innate adaptive mechanisms. In health, commensal mechanisms are dynamic steady state. During disease progression, dental bacterial plaque, junctional epithelium (JE), inflammatory cells, connective tissue, bone all go through series changes. tissue homeostasis...

Aggregatibacter actinomycetemcomitans is a gram-negative opportunistic oral pathogen. It frequently associated with subgingival biofilms of both chronic and aggressive periodontitis, the diseased sites periodontium exhibit increased levels proinflammatory mediator interleukin (IL)-1β. Some bacterial species can alter their physiological properties as result sensing IL-1β. We have recently shown that this cytokine localizes to cytoplasm A. in co-cultures organotypic gingival mucosa. However,...

Intrinsically disordered proteins (IDPs) do not have a well-defined and stable 3-dimensional fold. Some IDPs can function as either transient or permanent binders of other may interact with an array ligands by adopting different conformations. A novel outer membrane lipoprotein, bacterial interleukin receptor I (BilRI) the opportunistic oral pathogen Aggregatibacter actinomycetemcomitans binds key gatekeeper proinflammatory cytokine (IL)-1β. Because amino acid sequence lipoprotein resembles...

Actinobacillus actinomycetemcomitans is a Gram‐negative bacterium which has an important role in localized juvenile and progressive periodontitis. It sensitive to killing by the myeloperoxidase (MP)‐hydrogen peroxide(H 2 O )‐chloride system part of innate host defense mediated polymorphonuclear leukocytes. Since it been recently suggested that thiocyanate, instead chloride, could serve as main substrate for MP lactoperoxidase (LP) salivary peroxidase, we investigated this study effect both...

Bacterial biofilms resist host defenses and antibiotics partly because of their decreased metabolism. Some bacteria use proinflammatory cytokines, such as interleukin (IL)-1β, cues to promote biofilm formation alter virulence. Although one potential bacterial IL-1β receptor has been identified, current knowledge the sensing mechanism is limited. In chronic infection, periodontitis, Aggregatibacter actinomycetemcomitans requires tight adherence (tad)-locus form biofilms, tissue destroying...

Previous studies have shown that the peroxidase system with iodide is particularly effective against Actinobacillus actinomycetemcomitans. In present study, effects of iodide, chloride and thiocyanate in combinations lactoperoxidase (LP) myeloperoxidase (MP) on viability Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus mutans S. rattus were analysed. Bacteria incubated buffer solution containing peroxidase, substrate(s) H2O2 (all oral physiological concentrations), plated...

Various gram-negative species sequester host cytokines using outer membrane proteins or surface modulation by sulfated polysaccharides. An lipoprotein (BilRI) of the periodontal pathogen Aggregatibacter actinomycetemcomitans binds several cytokines, including interleukin (IL)-8. Because IL-8 is positively charged at physiological pH, we aimed to determine whether interacts with negatively lipopolysaccharide (LPS). Binding was investigated electrophoretic mobility shift assays and...

Naturally competent bacteria acquire DNA from their surroundings to survive in nutrient-poor environments and incorporate into genomes as new genes for improved survival. The secretin HofQ the oral pathogen Aggregatibacter actinomycetemcomitans has been associated with uptake. Cytokine sequestering is a potential virulence mechanism various may modulate both host defense bacterial physiology. objective of this study was elucidate possible connection between natural competence cytokine uptake...

Resonance assignment of intrinsically disordered proteins is remarkably challenging due to scant chemical shift dispersion arising from conformational heterogeneity. The challenge even greater if repeating segments are present in the amino acid sequence. To forward unambiguous resonance proteins, we iHACANCO, HACACON and (HACA)CONCAHA, three Hα-detected 4D experiments with Cα as an additional dimension. In addition, (HACA)CON(CA)NH (HACA)N(CA)CONH, new Hα-start, HN-detect which have two NH...

Peptidoglycan-associated lipoprotein (PAL) is a conserved pro-inflammatory outer membrane in Gram-negative bacteria. Compared to systemic pathogens, little known about the virulence properties of PAL Aggregatibacter actinomycetemcomitans (AaPAL). The aims this study were investigate cytolethality AaPAL and its ability induce cytokine production macrophages. Mouse macrophages stimulated with AaPAL, IL-1β, IL-6, TNF-α, MCP-1 was measured after 6, 24, 48 h. To which receptor employs for...

Epithelial cells express keratins, which are essential for the structural integrity and mechanical strength of cells. In junctional epithelium (JE) tooth, keratins such as K16, K18, K19, expressed, is typical non-differentiated rapidly dividing The expression K17, K4, K13 can be induced by injury, bacterial irritation, smoking, inflammation. addition, these found in sulcular JE. Our aim was to estimate changes K13, K19 gingival epithelial exposed Aggregatibacter actinomycetemcomitans. An...

Helicobacter pylori has frequently been isolated from human dental plaque, and oral spread via saliva is thought to be one of its principal modes transmission. Among other innate defence systems contains peroxidase enzymes lysozyme. The sensitivity H. physiological concentrations lactoperoxidase salivary substrate thiocyanate, different amounts hydrogen peroxide (H(2)O(2)) was investigated in buffer whole saliva. effect lysozyme also studied All tested strains, ATCC 43504(T) five clinical...