Experimental Antiglomerular Basement Membrane GN Induced by a Peptide from Actinomyces.

BACKGROUND: Antiglomerular basement membrane (anti-GBM) disease is associated with HLA-DRB1*1501 (the major predisposing genetic factor in the disease), with α3127-148 as a nephritogenic T and B cell epitope. Although the cause of disease remains unclear, the association of infections with anti-GBM disease has been long suspected. METHODS: To investigate whether microbes might activate autoreactive T and B lymphocytes via molecular mimicry in anti-GBM disease, we used bioinformatic tools, including BLAST, SYFPEITHI, and ABCpred, for peptide searching and epitope prediction. We used sera from patients with anti-GBM disease to assess peptides recognized by antibodies, and immunized WKY rats and a humanized mouse model (HLA-DR15 transgenic mice) with each of the peptide candidates to assess pathogenicity. RESULTS: On the basis of the critical motif, the bioinformatic approach identified 36 microbial peptides that mimic human α3127-148. Circulating antibodies in sera from patients with anti-GBM recognized nine of them. One peptide, B7, derived from Actinomyces species, induced proteinuria, linear IgG deposition on the GBM, and crescent formation when injected into WKY rats. The antibodies to B7 also targeted human and rat α3127-148. B7 induced T cell activation from human α3127-148-immunized rats. T cell responses to B7 were detected in rats immunized by Actinomyces lysate proteins or recombinant proteins. We confirmed B7's pathogenicity in HLA-DR15 transgenic mice that developed kidney injury similar to that observed in α3135-145-immunized mice. CONCLUSIONS: Sera from patients with anti-GBM disease recognized microbial peptides identified through a bioinformatic approach, and a peptide from Actinomyces induced experimental anti-GBM GN by T and B cell crossreactivity. These studies demonstrate that anti-GBM disease may be initiated by immunization with a microbial peptide.

Actinomycotic osteomyelitis of a long bone in an immunocompetent adult: a case report and literature review.

BACKGROUND: Actinomycosis is a rare, chronic granulomatous disease caused by Gram-positive anaerobic bacteria that colonize the oral cavity. Cervicofacial actinomycosis is the most frequent clinical presentation of actinomycosis, but hematogenous osteomyelitis at distant sites can occur in rare instance in immunocompromised or pediatric patients, only a few cases have been reported in healthy patients. Here we described a new case of distal femur osteomyelitis caused by Actinomyces in an adult patient who was immunocompetent and had no predisposing factors. CASE PRESENTATION: A woman aged 52 years with no history of trauma presented with severe pain, swelling, and increased local heat in the proximal area of the right knee 3 weeks after she first noticed discomfort. Magnetic resonance imaging showed persistent osteomyelitis of the distal metaphysis and diaphysis of the femur with a multifocal intraosseous abscess pocket. An incision and drainage of the abscess were conducted. The tissue culture, fungus culture, acid fast bacillus (AFB) culture, AFB smear, and tuberculosis polymerase chain reaction test results were negative. A pathologic examination confirmed the presence of actinomycosis. The patient was successfully treated with intravenous penicillin G for 8 weeks followed by oral amoxicillin-clavulanate for 6 weeks with repeated surgical debridement and drainage. After a 5-year follow up, the patient had no signs of recurring infection or complications and she had full range of movement in the affected knee. CONCLUSIONS: Although rare, actinomycotic osteomyelitis can occur in healthy people. Furthermore, actinomycotic osteomyelitis is easily misdiagnosed as tuberculosis in areas with a high prevalence of tuberculosis. To detect and identify the bacteria accurately, pathologic examination should be performed as well as culture tests, because the probability for culture confirmation of actinomycosis is quite low. The initial treatment is vital to a successful outcome without ostectomy or amputation.

Smoking-related cotinine levels and host responses in chronic periodontitis.

BACKGROUND AND OBJECTIVE: Smoking has been reported to increase the risk of periodontal disease by disrupting the balance of immune responses and tissue repair processes; however, this risk varies among smokers. Cotinine levels in saliva are routinely used to measure the level of smoking, and reflect the quantity of nicotine, and other smoking-related xenobiotics that challenge host systems. This study delineated characteristics of inflammatory mediators in saliva and serum antibody responses to both periodontal pathogens and commensal bacteria in smokers as they related to cotinine levels. MATERIALS AND METHODS: This case-control study (n = 279) examined salivary inflammatory mediator responses [interleukin (IL)-1ß, IL-10, prostaglandin E2, myeloperoxidase and plasminogen activator inhibitor-1], and serum IgG antibody responses to three periodontal pathogens (Aggregatibacter actinomyce-temcomitans, Porphyromonas gingivalis, Treponema denticola) and five commensal oral microorganisms (Veillonella parvula, Streptococcus sanguis, Prevotella loescheii, Actinomyces naeslundii, Capnocytophaga ochracea). RESULTS: The patients were stratified into health (n = 30), gingivitis (n = 55) and periodontitis (n = 184); cotinine levels correlated with reported smoking habits in health, less so with gingivitis, and were not correlated in periodontitis. Of the inflammatory mediators/acute phase proteins, only IL-1ß levels were positively associated (p < 0.001) with the pack years and cotinine levels. As might be predicted, patients with periodontitis smoked more (p < 0.001) and had higher levels of cotinine. IL-1ß and antibody to A. actinomycetemcomitans, P. gingivalis and T. denticola were significantly higher in the patients with periodontitis than either patients with gingivitis or who were healthy. CONCLUSIONS: Generally, antibody to the pathogens and commensals was lower with decreased cotinine levels. Smoking exacerbated differences in both inflammatory mediators and three antibody in periodontal disease compared to healthy subjects.

Serum antibodies to periodontal bacteria as diagnostic markers of periodontitis.

BACKGROUND: Assessment of periodontal conditions in epidemiologic studies usually requires a clinical examination, which is resource-intensive. We investigated the ability of serum immunoglobulin G (IgG) antibodies to periodontal bacteria to reflect clinical periodontal status. METHODS: We used checkerboard immunoblotting to assess serum IgG levels to 19 species, including established/putative periodontal pathogens and non-pathogenic bacteria, in 5,747 dentate adults aged > or = 40 years who participated in the third National Health and Nutrition Examination Survey between 1988 and 1994. Three earlier described alternative definitions of periodontitis were used, based on specific combinations of probing depth and attachment level values. Optimized elevated titer thresholds and corresponding sensitivities and specificities were calculated for each definition. Titers significantly associated with periodontitis were identified in univariable and multivariable logistic regression models. Parsimonious models were subsequently developed using age, gender, race/ethnicity, education, smoking, and diagnosed diabetes. RESULTS: In unadjusted models, high titers to Porphyromonas gingivalis were most strongly associated with periodontitis across all definitions (odds ratio, 2.07 to 2.74; P <0.05). In parsimonious models including demographic data, smoking, and diagnosed diabetes, high P. gingivalis titers were consistently associated with periodontitis, whereas high Eubacterium nodatum titers were associated with periodontal health in two of three definitions. Receiver operating characteristic curves for the parsimonious multivariable models showed that the area under the curve ranged between 0.72 and 0.78. CONCLUSIONS: Serum IgG titers to selected periodontal species, combined with demographic and behavioral characteristics, resulted in a moderately accurate classification of periodontal status in epidemiologic studies. The external validity of these findings must be examined further.

Abdominal actinomycosis.

A 59-year-old, healthy Croatian presented with a slowly growing tumor in the left lower abdomen, which was slightly painful on compression. He complained of neither dyspepsia nor fever. There were no pathologic findings in laboratory analysis, particularly no elevation of leukocytes or C-reactive protein. MRI of the abdomen (T1w, fat saturated, and iv-contrast) shows a diffuse contrast enhancing mass of the left abdominal wall (Figure 1a, arrow) with infiltration of the peritoneal cavity (Figure 1b, arrow). Because a malignant process was suspected the patient underwent abdominal surgery and excision of the tumor. Histopathological examination showed chronic-fibrosing and granulocytic, abscess-forming inflammation with Gram- and PAS-positive bacteria, corresponding to the diagnosis of chronic actinomycosis (Figure 1c). Following surgery, the patient was treated 1 month with iv and 6 more months with oral penicillin. The patient remained well 1 year after surgery. Actinomycosis is a rare, chronic granulomatous disease, which affects most commonly the cervicofacial and abdominal area. Actinomycetes are filamentous, gram-positive, anaerobic bacteria and commensal inhabitants of the oral cavity and intestinal tract; however, they acquire pathogenicity through invasion of the breached tissue. Because of its rarity and non-specific symptoms, abdominal actinomycosis is usually diagnosed postoperatively since most patients undergo exploratory laparotomy for a suspected neoplasm.

[Granulomatous diseases and pathogenic microorganism].

Granuloma formation is a chronic inflammatory reaction where macrophage system and other inflammatory cells are involved. After some antigen exposure and processing, T cells, macrophages, epithelioid cells, and giant cell are activated, and granulomas are formed. Granuloma is considered as a defense mechanism against antigens, which stay in the organs without inactivation. Granulomas including fibroblasts extra-cellular matrix surround and isolate the antigens. Granulomas are classified to noninfectious granulomas and infectious granulomas. However recent studies revealed pathogenic microorganism are suspected to be a cause of granuloma in non-inflammatory diseases. Balance between pathogenic microorganisms and defense mechanisms of the host might be important in the special immunologic reaction. In some cases, it is hard to clearly classify infectious and noninfectious granulomas. Recently, Eishi et al. reported that latent infection of Propionibacterium acnes might be cause of sarcoidosis. Several hypersensitivity pneumonias are considered to be caused by exogenous microorganisms. The symposium was organized to know and clarify the new mechanisms of non-infectious granulomatous lung diseases and pathogenic microorganisms. This report is a summary of a symposium entitled "Granulomatous Diseases and Pathogenic Microorganism", organized in the 82nd Japanese Society for Tuberculosis (president Dr. Mitsunori Sakatani, M.D.). 1. Imaging of Granulomatous Lung Diseases: Masanori AKIRA (Department of Radiology, National Hospital Organization Kinki-chuo Chest Medical Center) High-resolution computed tomography (HRCT) is a useful tool in the evaluation of parenchymal changes in patients with a granulomatous lung disease. In sarcoidosis, the HRCT findings include small, well-defined nodules in relation to lymphatic roots, lymph node enlargement, and middle or upper lobe predominance. The appearances of subacute hypersensitivity pneumonitis include ill-defined centrilobular nodules, ground-glass opacity, and air trapping especially on expiratory CT scan. Those of Langerhans cell histiocytosis include bizarre thin-walled lung cysts, centrilobular nodules and upper lobe predominance. Each of granulomatous lung disease has some characteristic HRCT appearances, but they all are non-specific for diagnosis. HRCT is also useful for grading of parenchymal changes in granulomatous lung diseases. 2. Histopathology of granulomatous lung diseases with special reference to differential diagnosis of infectious disease: Tamiko TAKEMURA (Department of Pathology, Japanese Red Cross Medical Center) The lung is commonly involved by various granulomatous diseases of various etiology. It is difficult to pathologically differentiate these granuloumatous diseases to conduct appropriate therapy, because of morphological similarity of epithelioid cell granuloma, variable etiology, and difficulty of identification of causative agents. Granulomatous diseases generally are divided into infectious and non-infectious ones for treatment. Although infectious granulomas usually reveal necrosis and abscess, non-infectious ones occasionally also reveal necrosis. In cases with granulomas in the lung, it is necessary to explore the etiologic agents including environmental ones. 3. Sarcoidosis and Propionibacterium acnes: Yoshinobu EISHI (Department of Pathology, Tokyo Medical and Dental University) P. acnes can cause latent infection in peripheral lung tissue and the mediastinal lymph nodes and persist intracellularly in a cell-wall-deficient form. This dormant form of P. acnes can be activated endogenously under certain environmental conditions (hormones, stress, living habits, etc.) and proliferate in cells at the sites of latent infection. Granulomatous inflammation occurs in sarcoidosis patients with hypersensitivity to intracellular proliferation of the cell-wall-deficient bacteria, which can infect other cells or organs when spread via the lymphatic or blood streams. The timely use of antibiotics may not only kill the bacteria proliferating at the site of disease activity, but also prevent endogenous activation of P. acnes. If long term administration of antibiotics eradicates dormant forms of the bacteria persistent in organs, it may lead to complete remission of sarcoidosis. 4. Farmer's lung and thermophilic actinomycetes: Takashi MOURI (Pulmonary Division, Iwate Prefectural Kitakami Hospital), Kohei YAMAUCHI, Hiroshi INOUE (Third Department of Internal Medicine, Iwate Medical University, School of Medicine), Kazuki KONISHI (Morioka Tsunagi Onsen Hospital) Farmer's lung is caused by the allergic reaction to inhalation of thermophilic actinomycetes. Acute symptoms are chill, fever, cough and dyspnea. Fine crackles is characteristic. Pathologically, alveolitis with lymphocytes infiltration and epithelioid cell granuloma and Masson's body are characteristics. Bronchoalveolar lavage analysis shows elevated lymphocytes and diverse CD4/8 ratio (high in average). Isolation from the environment improves the symptoms. Sometimes patients need steroid therapy, 0.5 to 1.0 mg/kg of predonisolone. Pulse therapy can be applied for severe cases. SLX analogue can prevent lymphocytes infiltration and granuloma formation in mice model. Some of acute farmer's lung show poor long term prognosis, showing emphysematous, fine granular or small nodules in chest CT. These chronic farmer's lung might be diagnosed as IIPs. 5. Hot tub lung: Takashi OGURA (Kanagawa Cardiovascular and Respiratory Center) Hot Tub Lung (HTL) is a disorder caused by exposure to Mycobacterium avium complex (MAC) organisms contaminating hot tub water. Whether this disease represents true infection or hypersensitivity pneumonitis is contoroversial. Recent reports support the theory that this disease represents a hypersensitivity pneumonitis rather than infection. The physicians should suspect a hypersensitivity pneumonitis reaction to MAC in the investigation of patients with hypersensitivity pneumonitis of unknown cause.

Multivariate design and evaluation of a set of RGRPQ-derived innate immunity peptides.

Oral commensal Streptococcus gordonii proteolytically cleave the salivary PRP-1 polypeptide into an RGRPQ innate peptide. The Arg and Gln termini are crucial for RGRPQ-mediated ammonia production and proliferation by S. gordonii SK12 and adhesion inhibition and desorption by Actinomyces naeslundii T14V, respectively. Here we have applied (i) a multivariate approach using RGRPQ-related peptides varied at amino acids 2, 3, and 4 simultaneously and (ii) size and N- and C-terminal modifications of RGRPQ to generate structure activity information. While the N-terminal arginine motif mediated ammonia production independent of peptide size, other responses required more or less full-length peptide motifs. The motifs for adhesion inhibition and desorption were the same. The adhesion and proliferation motifs required similarly a hydrophobic/low polarity amino acid 4 but differentially a hydrophilic or hydrophobic character of amino acids 2/3, respectively; polar peptides with small/hydrophilic and hydrophilic amino acids 2 and 3, respectively, had high adhesion inhibition/desorption activity, and lipophilic peptides with large/hydrophobic amino acids 2 and 3 had high proliferation activity. Accordingly, while RIWWQ had increased proliferation but abolished adhesion/desorption activity, peptides designed with hydrophilic amino acids 2 and 3 were predicted to behave in the opposite way. Moreover, a RGRPQ mimetic for all three responses should mimic small hydrophilic, large nitrogen-containing, and hydrophobic/low polarity amino acids 2, 3, and 4, respectively. Peptides fulfilling these criteria were 1-1.6-fold improved in all three responses. Thus, both mimetics and peptides with differential proliferation and adhesion activities may be generated for evaluation in biofilm models.

[The prevalence of Actinobaculum suis in boars of breeding herds in the Omsk region (Russian Federation) by indirect immunofluorescence technique]. / Untersuchung zur Verbreitung von Actinobaculum suis unter den Ebern in den Schweinezuchtbetrieben des Gebiets Omsk (Russische Föderation) unter Verwendung der indirekten Immunofluoreszenz-Technik.

Actinobaculum suis (Corynebacterium suis, Eubacterium suis, Actinomyces suis) was detected in the preputial diverticulum of 64,8% of 162 boars investigated in 8 districts of the region Omsk (Russian Federation) by indirect immunofluorescent technique. Until yet no informations were available about the prevalence of Actinobaculum (A.) suis in swine herds of the Russian Federation. The study shows that A. suis, as a main aetiological factor of cystitis and pyelonephritis in sows, is widely spread among the boars of the region Omsk. Prevalence of A. suis was not influenced by housing conditions, age or breed of investigated boars. Indirect immunofluorescent technique for detection of A. suis provides a good method for screening investigations with high numbers of samples.

Differential cytokine induction by two types of Porphyromonas gingivalis.

The presence of Porphyromonas gingivalis with type II fimA is strongly associated with adult periodontitis. However, the importance of specific fimA types in the immune response is unknown. Two types of P. gingivalis (type I and type II) and Actinomyces naeslundii were assessed for their degree of cytokine induction in the macrophage-like human cell line U937. Real-time reverse transcriptase polymerase chain reaction was used to determine mRNA expression of 12 cytokines. Significant levels of interleukin (IL)-8 induction and a similar cytokine expression pattern were observed at 6 h postinfection for all three bacterial strains. However, type II P. gingivalis infection showed statistically higher levels of IL-1beta, IL-8, IL-12 and tumor necrosis factor-alpha mRNA induction than those of control at 24 h postinfection, whereas type I P. gingivalis and A. naeslundii showed no significant induction of these cytokines. These data suggest that compared with A. naeslundii and type I P. gingivalis, type II P. gingivalis prolongs the cytokine response. Although other factors may also be involved, the sustained cytokine response induced by type II P. gingivalis may play an important role in enhanced periodontal tissue inflammation and destruction.

Expression of MHC Class II, CD70, CD80, CD86 and pro-inflammatory cytokines is differentially regulated in oral epithelial cells following bacterial challenge.

Oral epithelium may play a regulatory role in local immune responses when interacting with bacteria. The present study was undertaken to investigate the effects of selected bacterial pathogens found in periodontal and endodontic infections on oral epithelial cells. Expression of cell surface molecules (major histocompatibility complex (MHC) Class II, CD54, CD70, CD80 and CD86) and secretion of inflammatory cytokines (interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha) in response to selected bacterial challenge were examined on an immortalized oral epithelial cell line, HOK-18A and a skin epithelial cell line, HaCaT. Actinomyces viscosus, Actinomyces israelii, Fusobacterium nucleatum lipopolysaccharide (LPS) or primary human periradicular exudate from a granuloma were co-cultured with epithelial cells for 4 or 24 h. Subsequently, cell surface expression of MHC Class II, CD54, CD70, CD80 and CD86, along with pro-inflammatory cytokine levels were determined using flow cytometry, ELISA and RT-PCR. Results indicated that the selected oral bacteria have greater effects on oral versus skin epithelial cells. F. nucleatum increased MHC Class II and CD54 (ICAM-1) cell surface expression on HOK-18A and HaCaT cells. A. israelii also had enhancing effects on the expression of CD54 and MHC Class II. A. israelii and LPS induced a 2.8-fold (P < 0.001) and 4.4-fold (P < 0.005) TNF-alpha secretion, respectively, while F. nucleatum and LPS induced a 10-fold (P < 0.0004) and 6-fold (P < 0.01) IL-1beta secretion, respectively by HOK-18A. Interestingly, CD70, CD80, and CD86 were generally decreased upon bacteria and LPS challenge on HOK-18A. The effects of increased MHC Class II and decreased CD70 were also evident with challenge of human periradicular exudate on HOK-18A. The implications of the study are unique in that oral epithelial cells may play both activating and inhibitory roles in the host immune response towards infection by oral bacteria. We introduce a concept of 'dormancy' where the differential expression of key cell surface antigens on oral epithelial cells may keep the recruited immune effector cells in a state of unresponsiveness, thus contributing to the long term quiescent period observed in many periodontal and endodontic lesions.

Streptococci and Actinomyces induce antibodies which cross react with epithelial antigens in periodontitis.

Perturbation of epithelial structure is a prominent but poorly understood feature of the immunopathological response to bacterial antigens which characterizes the destructive lesion of periodontitis. Western analysis of sera from 22 patients with periodontitis detected multiple antigens in extracts of epithelial cells whereas sera from 12 periodontally healthy subjects displayed only trace reaction with epithelial antigens. To investigate a possible relationship between the bacterial flora adjacent to diseased sites and the presence of antibodies reactive with epithelium, subgingival plaque samples were taken from deep periodontal pockets and cultured anaerobically. Gram positive bacteria containing antigens cross-reactive with epithelial cells were reproducibly isolated by probing membrane colony-lifts with affinity-isolated (epithelium-specific) antibodies and identified by 16S rDNA sequence homology as streptococci (S. mitis, S. constellatus and two S. intermedius strains) and Actinomyces (A. georgiae, and A. sp. oral clone). Conversely, when serum from patients with periodontitis was absorbed with the captured bacterial species the number of epithelial antigens recognized was specifically reduced. It was concluded that development of cross-reactive antibodies related to these organisms may contribute to perturbation of the epithelial attachment to the tooth and the progression of periodontitis. These autoreactive antibodies could also be a contributing factor in other diseases affecting epithelia.

Antibody-based diagnostic for 'refractory' periodontitis.

OBJECTIVE: About 10-15% of US adults are 'refractory' to therapy for chronic periodontitis. Recently, studies suggest that these patients have elevated lysine decarboxylase activity in the sulcular microbiota. The aim of this study was to determine whether an elevated IgG antibody response to lysine decarboxylase, alone or with antibody to other bacterial antigens and baseline clinical measurements, would predict 'refractory' patients with high accuracy. METHODS: Chronic periodontitis patients were treated using scaling and root planing (SRP) followed by maintenance SRP and 3-monthly re-examinations. If there was a loss of mean full mouth attachment or more than three sites appeared with > 2.5 mm new loss within a year, the subjects were re-treated (modified Widman flap surgery and systemically administered tetracycline). If attachment loss as above recurred, the subjects were 'refractory'. Baseline clinical measurements and specific antibody responses were used in a logistic regression model to predict 'refractory' subjects. RESULTS: Antibody to a peptide portion of lysine decarboxylase (HKL-Ab) and baseline bleeding on probing (BOP) prevalence measurements predicted attachment loss 3 months after initial therapy [pIAL = loss (0) or gain (1)]. IgG antibody contents to a purified antigen from Actinomyces spp. (A-Ab) and streptococcal d-alanyl glycerol lipoteichoic acid (S-Ab) were related in 'refractory' patients (R2 = 0.37, p < 0.01). From the regression equation, the relationship between the antibodies was defined as linear (pLA/S-Ab = 0) or non-linear pLA/S-Ab = 1). Using pLA/S-Ab, pIAL and age, a logistic regression equation was derived from 48 of the patients. Of 59 subjects, 37 had 2-4 mm attachment loss and were assigned as 'refractory' or successfully treated with 86% accuracy. CONCLUSION: HKL-Ab facilitated an accurate prediction of therapeutic outcome in subjects with moderate periodontitis.

Parotid salivary S-IgA antibodies during experimental gingivitis in smokers and non-smokers.

Persons who smoke display a less pronounced increase of gingival bleeding in the experimental gingivitis model as compared with non-smokers. The aim of the present study was to investigate whether this could partly be explained by differences in levels of parotid total secretory IgA (S-IgA) or parotid S-IgA reactive with selected oral microorganisms. Parotid saliva samples were obtained from 11 smoking and 14 non-smoking volunteers, at baseline, after 5 and 14 days of full mouth experimental gingivitis. Output levels of total S-IgA and of specific S-IgA reactive with cell extracts from Actinobacillus actinomycetemcomitans, Actinomyces naeslundii, Campylobacter rectus, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Peptostreptococcus micros, Streptococcus gordonii and Streptococcus mutans were determined in the samples by means of ELISA. Smokers and non-smokers were found to have similar output levels (microg/min) of total S-IgA, and the values did not significantly change during the experimental gingivitis trial. Parotid salivary outputs (units/min) of the bacteria-specific S-IgA at baseline and at days 5 and 14, were not different between smokers and non-smokers; no changes were observed during the experimental gingivitis trial. The present observations indicate that total S-IgA and bacteria-specific S-IgA in saliva are not main factors that can explain the less pronounced increase of gingival bleeding in the experimental gingivitis model in smokers as compared with non-smokers.

Phosphorylcholine-dependent cross-reactivity between dental plaque bacteria and oxidized low-density lipoproteins.

Antibodies reactive with phosphorylcholine (PC) are ubiquitous in human sera, but the antigens stimulating their production and their function are not clear. Previous studies have shown that a significant proportion of dental plaque bacteria contain PC as determined by reactivity with PC-specific mouse myeloma proteins and monoclonal antibodies. Additionally, serum antibody concentrations of immunoglobulin (IgG) G anti-PC are higher in sera of individuals who have experienced periodontal attachment loss than those who are periodontally healthy. These data implicate the oral microflora as a source of antigen-stimulating anti-PC responses. Recent data also indicate that antibodies with specificity for PC are elevated in ApoE-deficient mice, a model for studies of athersclerosis, and that such antibodies bound oxidized low-density lipoproteins (LDL) (oxLDL) in atherosclerotic plaques. These data prompted the hypothesis that human anti-PC could bind to both oral bacteria and human oxLDL, and that these antigens are cross-reactive. We therefore examined the ability of human anti-PC to bind to PC-bearing strains of oral bacteria using enzyme-linked immunosorbent inhibition assays and by assessment of direct binding of affinity-purified human anti-PC to PC-bearing Actinobacillus actinomycetemcomitans. Our results indicated that PC-bearing strains of Streptococcus oralis, Streptococcus sanguis, Haemophilus aphrophilus, Actinomyces naeslundii, Fusobacterium nucleatum, and A. actinomycetemcomitans, as well as a strain of Streptococcus pneumoniae, absorbed up to 80% of anti-PC IgG antibody from human sera. Furthermore, purified anti-PC bound to a PC-bearing strain of A. actinomycetemcomitans but only poorly to a PC-negative strain. OxLDL also absorbed anti-PC from human sera, and oxLDL but not LDL reacted with up to 80% of the anti-PC in human sera. Furthermore, purified anti-PC bound directly to oxLDL but not to LDL. The data indicate that PC-containing antigens on a variety of common oral bacteria are cross-reactive with neoantigens expressed in oxLDL. We propose that PC-bearing dental plaque microorganisms may induce an antibody response to PC that could influence the inflammatory response associated with atherosclerosis.

Immunohistochemical detection for Actinomyces sp. in swine tonsillar abscess and granulomatous mastitis.

The tonsils of eleven pigs and the mammary glands of a sow were used to investigate actinomycotic lesions due to Actinomyces sp. infection. At necropsy, there was no abnormality on these tonsils, on the other hand, numerous abscesses containing sulfur granules were found in the mammary. Histopathologically, the Actinomyces sp. lesions were noted as crypt abscesses in the tonsils and as pus-forming granulomas in the mammary glands. The microorganisms in both lesions were composed of bead-like cocci, bacillary cells and short, branching filaments, those cells being positive by the Gram's and Grocott's methods. Clubs were formed around the microbial clumps in these lesions. Immunohistochemically, there were cross-reactions between antibodies of Actinomyces sp. Chiba 101 (101) and swine actinomycetes of 7 species: A. bovis, A. hyovaginalis, A. israeli, A. naeslundii, A. pyogenes, A. suis) formerly Eubacterium suits) and A. viscosus. However it was possible to differentiate Actinomyces sp. 101 from them by absorption and dilution of the antiserum, then the microorganisms in the tonsillar crypt abscesses and the granulomatous mastitis were labelled with an immunoperoxidase technique using the absorbed Actinomyces sp. 101 antiserum. Thus, these immunolabelling properties are suggestive of the presence of 'A. suis' (Grässer) Franke 1973.

Regulation of uterine immune function during the estrous cycle and in response to infectious bacteria in sheep.

Uterine infections are a major reproductive problem in livestock. We conducted two experiments to investigate factors that may modulate uterine responses to infectious bacteria. In Exp. 1, ewes received intrauterine inoculations of either saline or bacteria (75 x 10(7) cfu of Actinomyces pyogenes and 35 x 10(7) cfu of Escherichia coli) on either d 0 or 7 of the estrous cycle. Vena caval samples containing uteroovarian blood were collected twice daily from 12 h before until 6 d after inoculation. Only ewes inoculated with bacteria on d 7 developed infections. Basal (4.8 vs .4 pmol), lipopolysaccharide-stimulated (14.2 vs 6.1 pmol), and concanavalin A-stimulated (65.8 vs 21.6 pmol) blastogenesis (i.e., [3H]thymidine incorporation) of vena caval lymphocytes was greater (P < or = .002) for ewes inoculated with bacteria or saline on d 0 rather than on d 7. The number (per 100 white blood cells) of lymphocytes was greater (41.3 vs 30.8, P < .001) and that of neutrophils was less (42.5 vs 51.6, P < .001) in ewes inoculated on d 0 rather than d 7. Bacteria increased (P < .05) vena caval PGF(2 alpha) but not PGE2 concentrations. In Exp. 2, two protein fractions (molecular weights of > or = 100 kDa and approximately 12.7 kDa) from chromatography of uterine flushings collected on d 0 or 7, or 18 d after ovariectomy on d 0 or 7, modulated phytohemagglutinin-stimulated blastogenesis; the heavier fraction from d 0 had a stimulatory component, but the major effects of the fractions were inhibitory. The differences in immune function and regulation between d 0 and 7 probably explain how the uterus of follicular phase ewes was able to prevent the development of an infection.

Specific inhibitors of bacterial adhesion: observations from the study of gram-positive bacteria that initiate biofilm formation on the tooth surface.

Oral surfaces are bathed in secretory antibodies and other salivary macromolecules that are potential inhibitors of specific microbial adhesion. Indigenous Gram-positive bacteria that colonize teeth, including viridans streptococci and actinomyces, may avoid inhibition of adhesion by host secretory molecules through various strategies that involve the structural design and binding properties of bacterial adhesins and receptors. Further studies to define the interactions of these molecules within the host environment may suggest novel approaches for the control of oral biofilm formation.

Recognition of immunoglobulin A1 by oral actinomyces and streptococcal lectins.

Actinomyces naeslundii and Streptococcus gordonii, oral bacteria that possess Gal/GalNAc- and sialic acid-reactive lectins, respectively, were adherent to immobilized secretory immunoglobulin A (IgA) and two IgA1 myeloma proteins but not to two IgA2 myeloma proteins. Apparently, O-linked oligosaccharides at the hinge region of the IgA1 heavy chain are receptors for lectin-mediated adhesion of these bacteria.

[Chronic obstructive bronchitis in a fodder farming setting]. / La bronchite chronique obstructive (BCO) en milieu agricole fourrager.

Respiratory disease in agricultural workers are dominated both in terms of frequency and severity by chronic obstructive long disease. In the Doubs, in dairy cereal farmers, the prevalence of chronic bronchitis in active farm workers is around 10 per cent, and 6 per cent are non-smokers. It is twice the level of the control population of non-exposed subjects. The frequency is most elevated in the men and increases both with age and with altitude. A longitudinal study of male farm workers aged more than 45 has shown that there is an abnormally rapid loss of forced expired volume in one second (FEV1). Two different studies carried out in the Doubs have revealed epidemiological, respiratory function and immunological arguments in favour of immuno-allergic mechanisms. Notably, obstructive chronic bronchitis (OCB) occurs more frequently in agricultural workers with a previous history of farmer's lung or previous sub-acute delayed symptoms in relation to exposure. On the other hand, there are no close links between OCB and the intensity of antigenic exposure (the total quantity of fodder handled). By contrast, there is a relationship between exposure to thermophillic actinomycetes (antigen of farmer's lung) and OCB. The frequency of serum precipitins is most elevated in farm workers with OCB than in asymptomatic agricultural workers. Finally, non-smokers who are suffering from OCB without evidence of farmer's lung, have a respiratory function profile and also alveolar lavage cell pattern characteristic of extrinsic allergic alveolitis after provocation tests to mouldy hay. These arguments are in favour of immuno-allergic mechanisms in the pathogenesis of chronic bronchitis in farm workers which seems to be well differentiated from chronic bronchitis due to smoking.

Inhibition of neutrophil and monocyte defensive functions by nicotine.

To learn more about the effects of smokeless tobacco on the defensive functions of neutrophils, we studied the influence of nicotine on these cells in vitro, looking at their bactericidal activity against oral pathogens, and at their ability to produce microbicidal reactive oxygen species (oxygen radicals). Exposure of human blood neutrophils to nicotine (0.01% to 0.1%) inhibited their ability to kill Actinomyces naeslundii, Actinobacillus actinomycetemcomitans, and Fusobacterium nucleatum. Although these concentrations of nicotine are high, such concentrations are relevant to phagocytes in the gingival sulcus, because smokeless tobacco contains 0.5% to 3.5% nicotine by dry weight. Nicotine had no such inhibitory effect when the killing assay was performed in an anaerobic environment, implying that nicotine preferentially affected oxygen-dependent killing mechanisms. To further investigate the effects of nicotine on production of oxygen radicals, neutrophils were primed with lipopolysaccharide and triggered with f-met-leu-phe or phorbol ester in the presence of nicotine. Nicotine inhibited production of superoxide anion (measured by reduction of cytochrome c) and hydrogen peroxide (measured by oxidation of phenol red). Nicotine inhibition of superoxide production was reversible by washing away the nicotine. By observing that nicotine inhibited the reduction of cytochrome c by reagent potassium superoxide, we determined that nicotine directly absorbed superoxide. In addition, by examining nicotine inhibition of the uptake of oxygen by neutrophils, we determined that nicotine also interfered with the production of oxygen radicals by these cells. Nicotine also inhibited production of superoxide and interleukin-1 beta by monocytes. Nicotine did not affect the viability of neutrophils and monocytes, as determined by their ability to exclude trypan blue dye. Inhibition of the aerobic antimicrobial functions of neutrophils and monocytes by nicotine may alter the microbial ecology of the oral cavity, and this might be one mechanism by which nicotine compromises the oral health of users of tobacco products.