<i>Actinobacillus actinomycetemcomitans</i>
            Serotype d-Specific Antigen Contains the O Antigen of Lipopolysaccharide

Lakio, Laura; Paju, Susanna; Alfthan, Georg; Tiirola, Terttu; Asikainen, Sirkka; Pussinen, Pirkko J.

doi:10.1128/iai.71.9.5005-5011.2003

Cited by 18 publications

(20 citation statements)

References 39 publications

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“…Six different serotypes (a to f) and the corresponding genetic loci have been identified for A. actinomycetemcomitans (19,22,27,44,50,54,55). Serotype b remains one of the common serotypes found in the human oral cavity (9,13,51).…”

mentioning

confidence: 99%

Glycosylation of the Collagen Adhesin EmaA ofAggregatibacter actinomycetemcomitansIs Dependent upon the Lipopolysaccharide Biosynthetic Pathway

2010

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confidence: 99%

Glycosylation of the Collagen Adhesin EmaA ofAggregatibacter actinomycetemcomitansIs Dependent upon the Lipopolysaccharide Biosynthetic Pathway

2010

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“…Bacterial LPS is a potent oxidant [54][55][56] and impairs steroidogenesis in Leydig cells via lipid peroxidation of cell membranes and oxidative cell damage [49,57]. This is relevant to the application of DHT as a marker of oxidative stress in our experimental model.…”

Section: Discussionmentioning

confidence: 97%

Osteoblastic Responses to LPS, Glucose-oxidised LDL and Minocycline: Therapeutic Targets for Periodontal and Cardiometabolic Diseases

Tilakaratne

Soory²

2012

EMI

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Objectives: To study redox responses of cultured osteoblasts, mediated by bacterial lipopolysaccharide (LPS), glucose (G), glucose-oxidised low density lipoprotein (GLDL) and minocycline (M) using radiolabelled steroid markers of redox status and wound healing. The clinical relevance of this concept in periodontitis patients with cardiometabolic risk markers is addressed. Methods: A well differentiated osteoblastic cell-line was cultured in Eagle's MEM in confluent monolayer, in 24 well multiwell plates. Radiolabelled testosterone was used as the steroid substrate. Experiments were set up with controls in the absence of agents, optimal concentrations (previously determined) of G, GLDL, LPS, M, GLDL+LPS and the latter combined with M (n = 8). At the end of a 24h incubation period, the reaction was terminated and the medium analysed for yields of the steroid metabolite 5 -dihydrotestosterone (DHT), the redox marker relevant to wound healing, the weaker androgen 4-androstenedione (4-A) and the diols. Analysis entailed thin layer chromatography and radioisotope scanning. Results: The yields of DHT showed 1.4-fold and 2.3-fold decreases in response to GLDL and LPS respectively and a 1.3-fold reduction in response to the combination, when compared with controls in the absence of agents. Minocycline stimulated the yield of DHT by 1.4-fold, and when combined with GLDL+LPS, the decreased yield was overcome and raised to 2-fold above the combination in response to the addition of minocycline (n = 8; p < 0.001), when compared with controls. The trends in the yields of 4-A and diols were inversely related to each other with increases and decreases over controls respectively, in keeping with enzymic pathways. Conclusions: Decreased yields of the oxidative stress marker DHT in response to LPS, G and GLDL were overcome in the presence of minocycline, which demonstrates its potential role as an adjunctive therapeutic agent in an environment of oxidative stress. These applications could be extrapolated to periodontal disease and co-existing cardiometabolic risk markers, in the context of its antiinflammatory and antioxidant actions relevant to healing. In this paper, recent patents relevant to adjunctive therapeutic management of periodontal disease co-existing with cardiometabolic risk markers are addressed. There have been significant advances in therapeutic interventions for overcoming oxidative stress-inducing mechanisms that are common to these disease entities.

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“…The serotype-specific determinant resides in the lipopolysaccharide O-antigen and is immunodominant Sims et al, 1991;Wilson and Schifferle, 1991;Lakio et al, 2003). Other biologically significant activities of the serotype-specific polysaccharide antigen (S-PA) may include a role in the adherence of A. actinomycetemcomitans cells to surfaces (Fujise et al, 2008).…”

Section: Introductionmentioning

confidence: 96%

Lack of Serotype Antigen in A. actinomycetemcomitans

et al. 2010

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Aggregatibacter actinomycetemcomitans is divided into 6 serotypes. Occurrence of non-serotypeable strains is known, but background reasons are unclear. We hypothesized that non-serotypeable strains represent new serotypes or have altered expression of serotype-specific polysaccharide antigen (S-PA). We first characterized 311 strains from 189 individuals using both immunoassay- and PCR-based serotyping. Next, using natural human infection and rabbit immunization approaches, we clarified whether the phenotypically non-serotypeable strains expressed S-PA. Immunoassay identified serotypes a-f among 216 strains from 159 individuals. The remaining 95 strains from 30 individuals were phenotypically non-serotypeable. Yet, all these strains were identified by PCR-typing as serotype a-, b-, c-, or f. Non-serotypeability was confirmed by Western immunoblot with respective rabbit antisera. Patient sera remained non-reactive with autologous non-serotypeable strains at the serotype-specific region. Rabbit immunization with a phenotypically non-serotypeable strain induced no antibody production against S-PA. Thus, phenotypically non-serotypeable strains did not include novel serotypes, but lacked S-PA expression.

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Actinobacillus actinomycetemcomitans Serotype d-Specific Antigen Contains the O Antigen of Lipopolysaccharide

Cited by 18 publications

References 39 publications

Glycosylation of the Collagen Adhesin EmaA ofAggregatibacter actinomycetemcomitansIs Dependent upon the Lipopolysaccharide Biosynthetic Pathway

Glycosylation of the Collagen Adhesin EmaA ofAggregatibacter actinomycetemcomitansIs Dependent upon the Lipopolysaccharide Biosynthetic Pathway

Osteoblastic Responses to LPS, Glucose-oxidised LDL and Minocycline: Therapeutic Targets for Periodontal and Cardiometabolic Diseases

Lack of Serotype Antigen in A. actinomycetemcomitans

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