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Does Peroral Administration of Factor VIII Induce Oral Tolerance in Patients with Acquired Haemophilia A? Thromb Haemost 2017. [DOI: 10.1055/s-0037-1613877] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Abstract
SummaryCpG containing phosphorotioated oligonucleotides (ODN) are efficient adjuvants able to enhance macrophage and B cell activities. Their impact in the generation of coagulation and fibrinolytic factors has not been analysed.Production of coagulation and fibrinolytic proteins by human peripheral blood mononuclear cells (PBMC) treated with ODN was assessed.ODN induced in vitro generation of tissue factor (TF), thrombin and plasminogen, by PBMC. Synthesis of TF and thrombin occurred mostly in monocytes, while plasminogen was produced by both monocytic and lymphocytic cell populations. Generation of these proteins stimulated by CpG was totally blocked by cycloheximide, indicating the requirement of ongoing protein synthesis. Protein synthesis was equally pronounced at stimulation with cytosine-phosphate-guanosine (CpG)- and GpC- containing ODN, and dependend on the presence of the phosphorotioate moiety backbone in the ODN. Plasminogen, synthesized by monocytes and lymphocytes, was shown to be the primary product of ODN activation, leading subsequently to the expression of TF and thrombin generation.Our findings should be taken into consideration when assessing advantages and drawbacks of immunotherapy and gene therapy.
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Management of Electrical and Chemical Burns in Children. J Surg Res 2014. [DOI: 10.1016/j.jss.2013.11.960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Anti-staphylococcal activities of lysostaphin and LytM catalytic domain. BMC Microbiol 2012; 12:97. [PMID: 22672475 PMCID: PMC3413552 DOI: 10.1186/1471-2180-12-97] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 06/06/2012] [Indexed: 11/24/2022] Open
Abstract
Background Lysostaphin and the catalytic domain of LytM cleave pentaglycine crossbridges of Staphylococcus aureus peptidoglycan. The bacteriocin lysostaphin is secreted by Staphylococcus simulans biovar staphylolyticus and directed against the cell walls of competing S. aureus. LytM is produced by S. aureus as a latent autolysin and can be activated in vitro by the removal of an N-terminal domain and occluding region. Results We compared the efficacies of the lysostaphin and LytM catalytic domains using a newly developed model of chronic S. aureus infected eczema. Lysostaphin was effective, like in other models. In contrast, LytM was not significantly better than control. The different treatment outcomes could be correlated with in vitro properties of the proteins, including proteolytic stability, affinity to cell wall components other than peptidoglycan, and sensitivity to the ionic milieu. Conclusions Although lysostaphin and LytM cleave the same peptide bond in the peptidoglycan, the two enzymes have very different environmental requirements what is reflected in their contrasting performance in mouse eczema model.
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Identification of conserved antigens from staphylococcal and streptococcal pathogens. J Med Microbiol 2012; 61:766-779. [DOI: 10.1099/jmm.0.040915-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Identification of an intracellular M17 family leucine aminopeptidase that is required for virulence in Staphylococcus aureus. Microbes Infect 2012; 14:989-99. [PMID: 22613209 DOI: 10.1016/j.micinf.2012.04.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 04/10/2012] [Accepted: 04/23/2012] [Indexed: 12/29/2022]
Abstract
Staphylococcus aureus is a highly virulent bacterial pathogen capable of causing a variety of ailments throughout the human body. It is a major public health concern due to the continued emergence of highly pathogenic methicillin resistant strains (MRSA) both within hospitals and in the community. Virulence in S. aureus is mediated by an array of secreted and cell wall associated virulence factors, including toxins, hemolysins and proteases. In this work we identify a leucine aminopeptidase (LAP, pepZ) that strongly impacts the pathogenic abilities of S. aureus. Disruption of the pepZ gene in either Newman or USA300 resulted in a dramatic attenuation of virulence in both localized and systemic models of infection. LAP is required for survival inside human macrophages and gene expression analysis shows that pepZ expression is highest in the intracellular environment. We examine the cellular location of LAP and demonstrate that it is localized to the bacterial cytosol. These results identify for the first time an intracellular leucine aminopeptidase that influences disease causation in a Gram-positive bacterium.
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Formylated Peptides Are Important Virulence Factors in Staphylococcus aureus Arthritis in Mice. J Infect Dis 2011; 205:305-11. [DOI: 10.1093/infdis/jir713] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Tranexamic acid, an inhibitor of plasminogen activation, aggravates staphylococcal septic arthritis and sepsis. ACTA ACUST UNITED AC 2010; 42:351-8. [PMID: 20100112 DOI: 10.3109/00365540903510690] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Haemostatic balance shifts towards pro-coagulation during infection. Plasminogen, a key molecule of fibrinolysis, may play an important role in the pathogenesis of staphylococcal infections. In the present study, we assessed the impact of inhibition of plasminogen activation by tranexamic acid on the course of staphylococcal sepsis and septic arthritis in mice. We found significantly down-regulated plasmin activity and increased D-dimer levels in the blood from the mice with staphylococcal sepsis. Treatment with tranexamic acid significantly increased the severity and mortality of staphylococcal infection. In addition, tranexamic acid reduced the survival rate in a murine model for staphylococcal enterotoxin A-induced death. The aggravation of diseases by tranexamic acid was due neither to the pro-inflammatory cytokine network, nor to impairment of bacterial clearance. Modulation of fibrinolysis, either by supplement of fibrinolytic molecules (tissue plasminogen activator or plasmin) or by fibrinogen depletion, did not reduce the mortality of staphylococcal sepsis. In conclusion, we report that treatment with tranexamic acid led to distinct aggravation of staphylococcal septic arthritis and sepsis in mice, suggesting the clinical importance of fibrinolytic balance in staphylococcal infection.
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RANKL-targeted therapy inhibits bone resorption in experimental Staphylococcus aureus-induced arthritis. Bone 2010; 46:752-8. [PMID: 19879986 DOI: 10.1016/j.bone.2009.10.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Revised: 10/11/2009] [Accepted: 10/26/2009] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Bacterial arthritis causes rapidly progressing joint destruction in humans. We have shown that addition of bisphosphonates or corticosteroids to conventional antimicrobial agents decreases the activity of osteoclasts, thereby reducing bone destruction. Here we assess the effect of RANKL-targeted treatments using soluble receptor decoy and osteprotegerin (OPG) on the course and outcome of staphylococcal arthritis. METHODS Treatment was initiated 3 days after Staphylococcus aureus inoculation and included RANK-Fc, OPG-Fc, and OPG-Fc in combination with antibiotics. Control groups were treated with antibiotics, huFc, and PBS. Joints were evaluated for clinical signs of arthritis and histologically for bone and cartilage destruction. Bone mineral density (BMD) was evaluated using a peripheral quantitative computed tomography. Circulating markers of bone metabolism, inflammatory cytokines, and chemokines were analyzed in each group. RESULTS Mice treated with RANK-Fc or OPG-Fc in combination with antibiotics preserved total BMD and trabecular bone as compared to huFc or antibiotics. Treatment with RANK-Fc or OPG-Fc diminished the levels of bone resorption markers (osteocalcin, CTX-I, and TRACP5b). Neither RANK-Fc nor OPG-Fc influenced significantly the frequency and severity of arthritis. CONCLUSIONS Inhibition of RANKL signalling efficiently prevents bone loss in the mouse model of bacterial arthritis even when started in the overt phase of infection.
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Increased expression of proto-oncogene survivin predicts Joint destruction and persistent disease activity in early rheumatoid arthritis. Ann Med 2010; 42:45-54. [PMID: 20092399 DOI: 10.3109/07853890903376280] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Rheumatoid arthritis (RA) is characterized by an uncontrolled spread of destructive joint inflammation resembling malignancy. Epidemiological studies have established strong correlation between inflammation and predisposition for cancer. Here we assess the predictive role of the circulating proto-oncogene survivin for clinical and radiological outcome of early RA. PATIENTS AND METHODS Serum survivin was measured by sandwich ELISA in 651 patients with early RA (mean duration 6 months). X-rays of hands and feet were prospectively obtained at base-line and after 1, 2, and 5 years and evaluated for the presence of bone destruction by a modified Sharp method. The predictive value of survivin for radiological destruction was calculated using multivariate regression models including antibodies against cyclic citrullinated peptides (aCCP) and rheumatoid factor (RF). Remission was assessed by the EULAR (European League Against Rheumatism) criteria and by criteria proposed by Mäkinen. RESULTS At base-line, 391 patients (60%) had high levels of survivin. Radiological progression at 5 years was significantly more frequent (P= 0.001) among survivin-positive patients than among survivin-negative. Survivin positivity predicted radiological progression independently of aCCP and RF. The positive predictive value of survivin was proved both in the group of patients with and in the group without erosions at base-line. The combination of positive tests for both survivin and aCCP had the highest prediction for radiological progression (positive predictive value 0.75). Additionally, a positive test for survivin was an independent predictor of not being in remission. CONCLUSION Detection of survivin in early RA predicted joint destruction and failure of achieving remission after 5 years in patients with early RA.
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Resistin is stored in neutrophil granules being released upon challenge with inflammatory stimuli. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1894-900. [PMID: 19770005 DOI: 10.1016/j.bbamcr.2009.09.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 09/04/2009] [Accepted: 09/08/2009] [Indexed: 12/18/2022]
Abstract
We have recently shown that resistin is a key mediator of arthritis accumulating in the inflamed joints and exerting its pro-inflammatory properties independently of TNFalpha. Here we evaluate neutrophils as a cellular source of resistin. Human neutrophils were subjected to subcellular fractionation where the presence of resistin was assessed using western blot, ELISA, and mass spectrometry. Presence of resistin on the neutrophil surface was visualized by flow cytometry. More than 95% of the neutrophils in circulation and in synovial fluid express resistin on their surface. Stimulation of mature neutrophils with fMLF induced release of resistin into supernatants and increased expression of resistin on the surface. Resistin is mobilized simultaneously with lactoferrin, a protein found in specific granules, and with granule-stored CR3/CD11b. Subcellular fractionation of human neutrophils demonstrated the presence of resistin in azurophilic and in specific granules. Here we show that neutrophils have two pools of resistin, the major one exists in specific granules, and the second on their cell membrane. Release of resistin from the neutrophil granules probably serves the main source of resistin at the site of inflammation.
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Abstract
Toll-like receptors (TLRs) are a family of cellular structures activated by recognition of pathogen associated molecular sequences. The activation of TLRs triggers a variety of intracellular mechanisms aiming to protect the host from the invading microorganisms. Lipopolysaccharide (LPS) is the main ligand for TLR4. Here we show that resistin, a cystein-rich protein believed to regulate carbohydrate metabolism, competes with LPS for binding to TLR4. Binding of recombinant resistin to human myeloid and epithelial cells was assessed by flow cytometry and its co-precipitation with TLR4 was demonstrated. Antibodies against TLR4 abolished resistin binding to human leucocytes and cytokine production by peripheral blood mononuclear cells in response to resistin stimulation. In contrast, isotype-matched murine IgG or TLR2 antibodies were unable to prevent binding of resistin to the cells. Similarly, TLR4-dependent pattern of resistin binding was observed in epithelial cell line HEK293 (human epithelial kidney cell), where TLR4 transfected, but not myeloid differentiation factor 2/CD14-transfected, TLR2 transfected or HEKnull cells, responded functionally to resistin stimulation. Intracellular signalling of resistin was assessed using inhibitors of transcription factors mitogen activated protein kinases, nuclear factor-kappaB, phosphoinositide 3-kinase and siRNA targeting TLR4 and human myeloid differentiation factor 88. Results demonstrate that TLR4 serves as a receptor for the pro-inflammatory effects of resistin in human cells. This may partly explain the multifunctional role of resistin in chronic inflammation, atherosclerosis and insulin resistance.
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Dichloroacetate alleviates development of collagen II-induced arthritis in female DBA/1 mice. Arthritis Res Ther 2009; 11:R132. [PMID: 19723321 PMCID: PMC2787291 DOI: 10.1186/ar2799] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 08/12/2009] [Accepted: 09/01/2009] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Dichloroacetate (DCA) has been in clinical use for the treatment of lactacidosis and inherited mitochondrial disorders. It has potent anti-tumor effects both in vivo and in vitro, facilitating apoptosis and inhibiting proliferation. The pro-apoptotic and anti-proliferative properties of DCA prompted us to investigate the effects of this compound in arthritis. METHODS In the present study, we used DCA to treat murine collagen type II (CII)-induced arthritis (CIA), an experimental model of rheumatoid arthritis. DBA/1 mice were treated with DCA given in drinking water. RESULTS Mice treated with DCA displayed much slower onset of CIA and significantly lower severity (P < 0.0001) and much lower frequency (36% in DCA group vs. 86% in control group) of arthritis. Also, cartilage and joint destruction was significantly decreased following DCA treatment (P = 0.005). Moreover, DCA prevented arthritis-induced cortical bone mineral loss. This clinical picture was also reflected by lower levels of anti-CII antibodies in DCA-treated versus control mice, indicating that DCA affected the humoral response. In contrast, DCA had no effect on T cell- or granulocyte-mediated responses. The beneficial effect of DCA was present in female DBA/1 mice only. This was due in part to the effect of estrogen, since ovariectomized mice did not benefit from DCA treatment to the same extent as sham-operated controls (day 30, 38.7% of ovarectomized mice had arthritis vs. only 3.4% in sham-operated group). CONCLUSION Our results indicate that DCA delays the onset and alleviates the progression of CIA in an estrogen-dependent manner.
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Short- and long-term effects of anti-CD20 treatment on B cell ontogeny in bone marrow of patients with rheumatoid arthritis. Arthritis Res Ther 2009; 11:R123. [PMID: 19686595 PMCID: PMC2745807 DOI: 10.1186/ar2789] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 07/29/2009] [Accepted: 08/17/2009] [Indexed: 12/16/2022] Open
Abstract
Introduction In the present study we evaluated changes in the B cell phenotype in peripheral blood and bone marrow (BM) of patients with rheumatoid arthritis (RA) following anti-CD20 treatment using rituximab. Methods Blood and BM samples were obtained from 37 patients with RA prior to rituximab treatment. Ten of these patients were resampled 1 month following rituximab, 14 patients after 3 months and the remaining 13 patients were included in the long-term follow up. B cell populations were characterized by CD27/IgD/CD38/CD24 expression. Results One and three months following rituximab BM retained up to 30% of B cells while circulation was totally depleted of B cells. Analysis of the remaining BM B cells showed prevalence of immature and/or transitional B cells (CD38++CD24++) and CD27+IgD- memory cells, while IgD+ cells were completely depleted. A significant reduction of CD27+ cells in BM and in circulation was observed long after rituximab treatment (mean 22 months), while levels of naive B cells in BM and in circulation were increased. The levels of rheumatoid factor decline after rituximab treatment but returned to baseline levels at the time of retreatment. Conclusions Anti-CD20 treatment achieves a depletion of IgD+ B cells shortly after the treatment. At the long term follow up, a reduction of CD27+ B cells was observed in blood and BM. The prolonged inability to up-regulate CD27 may inhibit the renewal of memory B cells. This reduction of CD27+ B cells does not prevent autoantibody production suggesting that mechanisms regulating the formation of auto reactive clones are not disrupted by rituximab.
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Abstract
Microbial superantigens represent a group of molecules that is able to cause massive activation of the host immune system. Human diseases originating from superantigen-secreting bacterial agents are characterized by shock, which continues to pose major health problems. Presently, the treatment of superantigen-mediated infections is limited to the administration of antibiotics and handling of the state of shock. However, the development of multiple antibiotic-resistant, superantigen-producing bacterial strains increases the threat of these infections, and prompts researchers to better understand and treat disease states in which exposure to superantigens is at least partly responsible for the outcome. In the past decade, significant understanding has been achieved regarding the molecular mechanisms of superantigen-host interactions. Based on this understanding, a variety of promising strategies directed against superantigens have been developed. In this review, we discuss some of these strategies, as well as the potential for therapeutic applications of superantigens for the benefit of the host.
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The decrease of soluble RAGE levels in rheumatoid arthritis patients following hormone replacement therapy is associated with increased bone mineral density and diminished bone/cartilage turnover: a randomized controlled trial. Rheumatology (Oxford) 2009; 48:785-790. [PMID: 19416946 DOI: 10.1093/rheumatology/kep079] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Relationship between elevated cerebrospinal fluid levels of plasminogen activator inhibitor 1 and neuronal destruction in patients with neuropsychiatric systemic lupus erythematosus. ACTA ACUST UNITED AC 2009; 60:2094-101. [DOI: 10.1002/art.24603] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Smoking and nicotine exposure delay development of collagen-induced arthritis in mice. Arthritis Res Ther 2009; 11:R88. [PMID: 19519907 PMCID: PMC2714144 DOI: 10.1186/ar2728] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 06/08/2009] [Accepted: 06/11/2009] [Indexed: 11/24/2022] Open
Abstract
Introduction Recent epidemiologic studies have implicated smoking as an environmental risk factor for the development of rheumatoid arthritis (RA). The aim of the present study is the evaluation of the role of cigarette smoke (CS) in the pathogenesis of collagen-induced arthritis in mice. Methods DBA/1 mice exposed to CS for 16 weeks (n = 25) and mice exposed to nicotine in drinking water (n = 10) were immunized with collagen type II (CII). Severity of arthritis was evaluated clinically and morphologically and compared with control mice (n = 35). Intensity of inflammation was evaluated by serum IL-6 and TNF-α levels. Additionally, antibody response to CII (anti-CII) and citrullinated peptides (aCCP) was measured. Results Clinical evaluation of arthritis showed a delayed onset of arthritis in CS-exposed mice compared with non-smoking controls (P < 0.05). Histologic index and weight changes were comparable between the groups; however, smoking mice presented less weight loss during the acute phase of the disease and gained weight significantly faster in the recovery phase (P < 0.05). Similar results were obtained in the mice exposed to nicotine. Nicotine also showed a direct anti-inflammatory effect diminishing IL-6 production by stimulated splenocytes in vitro (P < 0.001). Additionally, smoking mice had lower levels of aCCP and anti-CII antibodies compared with non-smoking (P < 0.05). Conclusions Neither smoking nor nicotine exposure aggravates development of CII-induced arthritis in mouse model. Moreover, CS exposure was associated with a lower level of anti-CII antibodies, providing a possible explanation for a delay of arthritis onset in this group.
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Role of CTA1R7K-COL-DD as a novel therapeutic mucosal tolerance-inducing vector for treatment of collagen-induced arthritis. ACTA ACUST UNITED AC 2009; 60:1672-82. [DOI: 10.1002/art.24566] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Impact of short-term therapies with biologics on prothrombotic biomarkers in rheumatoid arthritis. Clin Exp Rheumatol 2009; 27:491-494. [PMID: 19604443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
BACKGROUND Imbalance of haemostasis in patients with rheumatoid arthritis (RA) contributes to future risk of cardiovascular diseases (CVD). Prothrombotic molecules, e.g. fibrinogen, D-dimer, and tPA are elevated in plasma of RA patients, being associated to CVD. There is no imformation about the influence of biological drugs, e.g. anti-CD20 and tumor necrosis factor (TNF) antibodies on these prothrombotic molecules. OBJECTIVE To assess whether anti-TNF and anti-CD20 therapies modify the profiles of cardiovascular risk factors in patients with RA. METHODS The expression of prothrombotic molecules in plasma was investigated in 10 RA patients before and after treatment with TNF-alpha antibodies and in another 12 RA patients before and after anti-CD20 treatment. RESULTS Both anti-TNF and anti-CD20 infusions gave rise to clear clinical improvement. However, only anti-CD20 infusion significantly (p=0.05) reduced concentration of fibrinogen (p=0.05), D-dimer (p<0.001), as well as tPA levels (p<0.01). In contrast, in TNF antibody treated patients only tPA levels were significantly decreased following the treatment (p<0.05). CONCLUSIONS Infusion of CD20 antibodies to the patients with active RA led to a clearly reduced plasma levels of predictors of CVD indicating that this treatment, apart from its anti-inflammatory properties, may reduce the risk for future CVD in RA.
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Synovial class II antigen expression and immune complex formation in rheumatoid arthritis. ACTA MEDICA SCANDINAVICA. SUPPLEMENTUM 2009; 715:85-91. [PMID: 3296677 DOI: 10.1111/j.0954-6820.1987.tb09907.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Smoking and nicotine exposure delays development of arthritis in animal model (99.24). THE JOURNAL OF IMMUNOLOGY 2009. [DOI: 10.4049/jimmunol.182.supp.99.24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Recent results of epidemiological studies indicate smoking as an environmental risk factor for development of rheumatoid arthritis (RA). The aim of this study was to evaluate the role of smoking and nicotine in the pathogenesis of arthritis using an animal model.
DBA/1 mice were exposed to cigarette smoke for 16 weeks prior to immunization with collagen type II (CII) and through the whole course of experiment. In a separate experiment DBA/1 mice were subjected to nicotine in drinking water from the day of immunization with CII until the end of experiment. Severity of arthritis was evaluated clinically and morphologically and compared to control mice. Levels of specific anti-CII antibodies as well as of autoantibodies (aCCP and RF) and cytokines were evaluated.
Clinical evaluation of arthritis showed a delayed onset of arthritis in smoking mice as compared to non-smoking (p<0.05). Histological index and weight changes were comparable between both groups, however smoking mice were gaining weight faster than non-smoking (p<0.05). Additionally, smoking mice had decreased ability to produce antibodies (aCCP and anti-CII) as compared to non-smoking (p<0.05). Similar results were obtained in the mice exposed to nicotine. Nicotine had a direct anti-inflammatory effect diminishing cytokine production by stimulated spleenocytes in vitro.
Neither smoking nor nicotine exposure aggravates development of CII-induced arthritis in mouse model.
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Immune evasion by Staphylococcus aureus conferred by iron-regulated surface determinant protein IsdH. Microbiology (Reading) 2009; 155:667-679. [DOI: 10.1099/mic.0.025684-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The ability of Staphylococcus aureus to avoid innate immune responses including neutrophil-mediated phagocytosis is crucial for the organism to cause infection. This multifactorial process involves several secreted and cell-surface-associated proteins. In this paper we report a novel mechanism of combating neutrophils that involves iron-regulated surface determinant protein H (IsdH). The IsdH protein is part of a complex that is only expressed under iron-restricted conditions in order to bind haemoglobin and extract and transport haem into the cytoplasm. A null mutant defective in expression of IsdH, and mutants expressing variants of IsdH with substitutions in residues predicted to be involved in ligand binding, were generated from S. aureus 8325-4. The IsdH-defective mutants were shown by several measures to have reduced virulence compared with the wild-type. The mutant was engulfed more rapidly by human neutrophils in the presence of serum opsonins, survived poorly in fresh whole human blood and was less virulent in a mouse model of sepsis. The protective mechanism seems to stem from an accelerated degradation of the serum opsonin C3b.
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Abstract
Proto-oncogene survivin has recently been identified as a prognostic marker distinguishing patients with destructive rheumatoid arthritis (RA). In the present material of 132 RA patients and 82 controls, the levels of survivin correlated to urokinase (uPA) (r= 0.46), a plasminogen activator over-expressed in inflamed joints and known to exhibit potent arthritogenic properties. Here we evaluate the functional relationship between these proteins using primary synovial fibroblasts and leucocytes of RA patients, human monocytic (THP-1) and fibroblast (MRC-5) cell lines. Using inhibitors of intracellular signalling, we show that uPA and survivin share common transduction pathways in synovial fibroblasts being dependent on the activity of tyrosine kinases, phosphatidylinositide 3 kinase and mitogen effector kinase. Moreover, uPA production is significantly reduced in fibroblasts if survivin synthesis has been silenced by siRNA. Importantly, silencing of survivin in fibroblasts prevented their invasive growth in knee joints of severe combined immune deficient mice. Interaction of uPA with receptor up-regulates survivin expression in leucocytes. In turn, survivin is required for the up-regulation of uPA receptor on the cell surface. These findings indicate that survivin is an essential mediator of arthritogenic properties of uPA regulating its synthesis in synovial fibroblasts and uPAR expression in leucocytes. Close correlation between survivin and uPA levels in patients with RA supports the importance of this connection for the pathogenesis of arthritis.
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The Staphylococcus aureus response to unsaturated long chain free fatty acids: survival mechanisms and virulence implications. PLoS One 2009; 4:e4344. [PMID: 19183815 PMCID: PMC2629846 DOI: 10.1371/journal.pone.0004344] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Accepted: 12/18/2008] [Indexed: 12/13/2022] Open
Abstract
Staphylococcus aureus is an important human commensal and opportunistic pathogen responsible for a wide range of infections. Long chain unsaturated free fatty acids represent a barrier to colonisation and infection by S. aureus and act as an antimicrobial component of the innate immune system where they are found on epithelial surfaces and in abscesses. Despite many contradictory reports, the precise anti-staphylococcal mode of action of free fatty acids remains undetermined. In this study, transcriptional (microarrays and qRT-PCR) and translational (proteomics) analyses were applied to ascertain the response of S. aureus to a range of free fatty acids. An increase in expression of the σB and CtsR stress response regulons was observed. This included increased expression of genes associated with staphyloxanthin synthesis, which has been linked to membrane stabilisation. Similarly, up-regulation of genes involved in capsule formation was recorded as were significant changes in the expression of genes associated with peptidoglycan synthesis and regulation. Overall, alterations were recorded predominantly in pathways involved in cellular energetics. In addition, sensitivity to linoleic acid of a range of defined (sigB, arcA, sasF, sarA, agr, crtM) and transposon-derived mutants (vraE, SAR2632) was determined. Taken together, these data indicate a common mode of action for long chain unsaturated fatty acids that involves disruption of the cell membrane, leading to interference with energy production within the bacterial cell. Contrary to data reported for other strains, the clinically important EMRSA-16 strain MRSA252 used in this study showed an increase in expression of the important virulence regulator RNAIII following all of the treatment conditions tested. An adaptive response by S. aureus of reducing cell surface hydrophobicity was also observed. Two fatty acid sensitive mutants created during this study were also shown to diplay altered pathogenesis as assessed by a murine arthritis model. Differences in the prevalence and clinical importance of S. aureus strains might partly be explained by their responses to antimicrobial fatty acids.
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Abstract
Background Cell and animal experiments have shown that β-site APP-cleaving enzyme 1 (BACE1) may be involved in myelination. Objective Here, we assess the association of cerebrospinal fluid (CSF) BACE1 activity with multiple sclerosis (MS). Methods BACE1 activity and levels of secreted amyloid precursor protein (APP) and amyloid-β (Aβ) isoforms were analyzed in CSF from 100 patients with MS and 114 neurologically healthy controls. Patients with systemic lupus erythematosus (SLE), 26 with and 41 without cerebral engagement, were also included to enable comparisons with regards to another autoimmune disease. A subset of patients with MS and controls underwent a second lumbar puncture after 10 years. Results MS patients had lower CSF BACE1 activity than controls ( P = 0.03) and patients with cerebral SLE ( P < 0.001). Patients with cerebral SLE had higher BACE1 activity than any other group ( P < 0.05 for all comparisons). BACE1 activity correlated with the different amyloid markers in all study groups. BACE1 activity decreased over 10 years in the MS group ( P = 0.039) and correlated weakly with clinical disease severity scores in an inverse manner. Conclusions These results suggest an involvement of BACE1 in the MS disease process.
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Arthritogenic dsRNA is present in synovial fluid from rheumatoid arthritis patients with an erosive disease course. Eur J Immunol 2008; 38:3237-44. [DOI: 10.1002/eji.200838362] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Salivary resistin reflects local inflammation in Sjögren's syndrome. J Rheumatol 2008; 35:2005-2011. [PMID: 18709689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE To assess the role of resistin in primary Sjögren's syndrome (pSS) and its relation to local inflammation. METHODS Blood and saliva were collected from 37 patients with pSS (duration of symptoms 12.6+/-1 yrs) and 32 healthy controls. Expression of resistin in salivary glands was visualized immunohistologically, and levels of resistin were detected by ELISA. Levels of resistin were evaluated at baseline and following oral dehydroepiandrosterone (DHEA) treatment (50 mg/day). The effect of DHEA treatment on the secretion of resistin was assessed in vitro in human leukocytes after challenge with insulin and lipopolysaccharide. RESULTS Levels of resistin in saliva were significantly higher in patients with pSS than in controls, while circulating levels of resistin were similar in both groups. Resistin was expressed in the epithelial cells of striated ducts and in the lymphocytic foci. Resistin levels in saliva were related to the intensity of inflammation in the minor salivary glands of pSS patients. No changes of the levels of resistin in blood or saliva were observed during DHEA treatment. Exposure of naive leukocytes to DHEA in vitro induced significant expression of resistin compared to nonstimulated peripheral blood mononuclear cells (p=0.031). CONCLUSION We showed that levels of resistin are upregulated locally in the salivary glands of patients with pSS; and that the levels of resistin correspond to the intensity of lymphocytic inflammation in patients with pSS. We suggest that resistin is expressed in the salivary glands of patients with pSS and may be a driving factor of local inflammation.
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Macrophage-derived proinflammatory factors contribute to the development of arthritis and myositis after infection with an arthrogenic alphavirus. J Infect Dis 2008; 197:1585-93. [PMID: 18433328 DOI: 10.1086/587841] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Alphaviruses, such as chikungunya virus and Ross River virus (RRV), are associated with outbreaks of infectious rheumatic disease in humans worldwide. Using an established mouse model of disease that mimics RRV disease in humans, we showed that macrophage-derived factors are critical in the development of striated muscle and joint tissue damage. Histologic analyses of muscle and ankle joint tissues demonstrated a substantial reduction in inflammatory infiltrates in infected mice depleted of macrophages (i.e., "macrophage-depleted mice"). Levels of the proinflammatory factors tumor necrosis factor-alpha, interferon-gamma, and macrophage chemoattractant protein-1 were also dramatically reduced in tissue samples obtained from infected macrophage-depleted mice, compared with samples obtained from infected mice without macrophage depletion. These factors were also detected in the synovial fluid of patients with RRV-induced polyarthritis. Neutralization of these factors reduced the severity of disease in mice, whereas blocking nuclear factor kappaB by treatment with sulfasalazine ameliorated RRV inflammatory disease and tissue damage. To our knowledge, these findings are the first to demonstrate that macrophage-derived products play important roles in the development of arthritis and myositis triggered by alphavirus infection.
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mgrA regulates staphylococcal virulence important for induction and progression of septic arthritis and sepsis. Microbes Infect 2008; 10:1229-35. [PMID: 18692591 DOI: 10.1016/j.micinf.2008.07.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Revised: 06/23/2008] [Accepted: 07/07/2008] [Indexed: 02/01/2023]
Abstract
Septic arthritis and sepsis are common and feared complications of staphylococcal infections, and the increasing antibiotic resistance among staphylococci urge the extended research for virulence factors involved in these diseases. Staphylcoccus aureus produces a number of virulence factors controlled by several global regulatory genes including agr and sarA. MgrA is a recently identified global regulator, belonging to the SarA subfamily, which upregulates expression of several virulence factors including capsule and sortase. In addition, MgrA has been shown to regulate antibiotic resistance and decrease bacterial autolysis. In this study we have assessed the role of mgrA gene expression on induction and progression of septic arthritis and sepsis. Mice inoculated with the mgrA mutant displayed significantly less severe arthritis and showed a significantly better weight development, than wild-type inoculated mice. Importantly, all 10 mice inoculated with the mgrA mutant survived as compared to 70% mortality in the wild-type inoculated mice (p=0.003). In addition, the mgrA mutant showed significantly less bacterial persistence in kidneys as compared to the wild-type strain. We conclude that mgrA regulates virulence factors important for establishment and progression of septic arthritis and sepsis.
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Induction of arthritis by high mobility group box chromosomal protein 1 is independent of tumour necrosis factor signalling. Arthritis Res Ther 2008; 10:R72. [PMID: 18582368 PMCID: PMC2483464 DOI: 10.1186/ar2445] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 05/29/2008] [Accepted: 06/26/2008] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION TNFalpha and high mobility group box chromosomal protein 1 (HMGB1) are two potent proinflammatory cytokines implicated as important mediators of arthritis. Increased levels of these cytokines are found in the joints of rheumatoid arthritis patients, and the cytokines trigger arthritis when applied into the joints of naïve mice. HMGB1 is actively released from immune cells in response to TNFalpha; once released, HMGB1 in turn induces production of several proinflammatory cytokines--including IL-6 and TNFalpha--by macrophages. Whether HMGB1-induced arthritis is mediated via the TNFalpha pathway, however, is unknown. The purpose of the present study was to investigate whether the arthritis-inducing effect of HMGB1 is dependent on TNFalpha expression in vivo and to assess whether TNFalpha deficiency affects a proinflammatory cytokine response to HMGB1 in vitro. METHODS TNFalpha knockout mice and backcrossed control animals on a C57Bl6 background were injected intraarticularly with 5 microg HMGB1. Joints were dissected 3 days after intraarticular injection and were evaluated histologically by scoring the frequency and severity of arthritis. For in vitro studies, mouse spleen cultures from TNFalpha knockout mice and from control mice were incubated with different doses of HMGB1, and cell culture supernatants were collected at different time points for analysis of IL-6. RESULTS Intraarticular injection of HMGB1 into healthy mouse joints resulted in an overall frequency of 32% to 39% arthritic animals. No significant differences were found with respect to the severity and incidence of synovitis between mice deficient for TNFalpha (seven out of 18 mice with arthritis) in comparison with control TNFalpha+/+ animals (six out of 19). No significant differences were detected between spleen cells from TNFalpha+/+ mice versus TNFalpha-/- mice regarding IL-6 production upon stimulation with highly purified HMGB1 after 24 hours and 48 hours. Upon stimulation with a suboptimal dose of recombinant HMGB1, however, the splenocytes from TNFalpha+/+ animals released significantly more IL-6 than cells from the knockout mice (602 +/- 112 pg/ml and 304 +/- 50 pg/ml, respectively; P < 0.05). CONCLUSION Our data show that HMGB1-triggered joint inflammation is not mediated via the TNF pathway. Combined with our previous study, we suggest that HMGB1-triggered arthritis is probably mediated through IL-1 activation.
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Single-stranded polyinosinic acid oligonucleotides trigger leukocyte production of proteins belonging to fibrinolytic and coagulation cascades. J Leukoc Biol 2008; 84:741-7. [PMID: 18562486 DOI: 10.1189/jlb.0506345] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The present study assessed the inductory effects of ds- and ssRNA on the leukocyte production of proteins belonging to fibrinolytic and coagulation cascades. Murine splenocytes were stimulated with dsRNA [polyinosinic:polycytidylic acid (polyIC)] and ssRNA sequences [polyinosinic acid (polyI), polycytidylic acid (polyC), and polyuridylic acid (polyU)]. The expression of plasminogen (Plg), tissue factor (TF), IL-6, and IFN-alpha was assessed. Intracellular transduction mechanisms activated by oligonucleotides were evaluated using specific inhibitors of signaling pathways and genetically modified mice. polyIC efficiently and dose-dependently induced the expression of Plg, IL-6, and IFN-alpha, whereas TF was not induced by polyIC. polyI was unable to trigger IFN-alpha production, and it was efficiently inducing Plg and TF. IFN-alphaR and dsRNA-dependent protein kinase signaling were not required for the polyI-induced production of Plg or TF. Neither polyU nor polyC induced the expression of Plg or TF. Importantly, the presence of U- and C-nucleotide strands in the dsRNA significantly reduced expression of Plg and TF compared with polyI alone. Exposure of splenocytes to polyI activated the NF-kappaB pathway followed by the expression of TF and IL-6. In contrast, Plg production did not require NF-kappaB, was only partly down-regulated by p38 MAPK inhibitor, and was efficiently inhibited by insulin, indicating a different mechanism for its induction. ssRNA exerts its TF-generating properties through NF-kappaB activation in an IFN-alpha-independent manner. The expression of fibrinolytic versus coagulation proteins is regulated through distinctly different transduction pathways. As fibrinolytic and coagulation cascades are important components of inflammatory homeostasis, these findings might have importance for development of new, targeted therapies.
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Fibrinogen binding sites P336 and Y338 of clumping factor A are crucial for Staphylococcus aureus virulence. PLoS One 2008; 3:e2206. [PMID: 18493318 PMCID: PMC2374910 DOI: 10.1371/journal.pone.0002206] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Accepted: 03/20/2008] [Indexed: 02/02/2023] Open
Abstract
We have earlier shown that clumping factor A (ClfA), a fibrinogen binding surface protein of Staphylococcus aureus, is an important virulence factor in septic arthritis. When two amino acids in the ClfA molecule, P336 and Y338, were changed to serine and alanine, respectively, the fibrinogen binding property was lost. ClfAP336Y338 mutants have been constructed in two virulent S. aureus strains Newman and LS-1. The aim of this study was to analyze if these two amino acids which are vital for the fibrinogen binding of ClfA are of importance for the ability of S. aureus to generate disease. Septic arthritis or sepsis were induced in mice by intravenous inoculation of bacteria. The clfAP336Y338 mutant induced significantly less arthritis than the wild type strain, both with respect to severity and frequency. The mutant infected mice developed also a much milder systemic inflammation, measured as lower mortality, weight loss, bacterial growth in kidneys and lower IL-6 levels. The data were verified with a second mutant where clfAP336 and Y338 were changed to alanine and serine respectively. When sepsis was induced by a larger bacterial inoculum, the clfAP336Y338 mutants induced significantly less septic death. Importantly, immunization with the recombinant A domain of ClfAP336SY338A mutant but not with recombinant ClfA, protected against septic death. Our data strongly suggest that the fibrinogen binding activity of ClfA is crucial for the ability of S. aureus to provoke disease manifestations, and that the vaccine potential of recombinant ClfA is improved by removing its ability to bind fibrinogen.
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Longterm clinical and immunological effects of anti-CD20 treatment in patients with refractory systemic lupus erythematosus. J Rheumatol 2008; 35:826-833. [PMID: 18398943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE To retrospectively evaluate longterm clinical and immunological effects of anti-CD20 treatment in patients with systemic lupus erythematosus (SLE) with active nephritis or autoantibody-mediated cytopenias refractory to conventional immunosuppressive treatment. METHODS Anti-CD20 treatment (rituximab) was added to the ongoing immunosuppressive treatment in 31 SLE patients with active nephritis (n = 17), thrombocytopenia (n = 10), and hemolytic anemia (n = 4) refractory to conventional therapy. Disease activity was evaluated by the SLE Disease Activity Index. The median followup time after anti-CD20 treatment was 22 months (range 1-61 mo). RESULTS Complete B cell depletion was obtained in all patients. In 11 of the 17 lupus nephritis patients complete or partial responses were achieved after 6-12 months. Eight of these patients increased their glomerular filtration rate (GFR) by > 25%. The responders were characterized by having shorter nephritis duration, a baseline GFR > 30 ml/min, and detectable circulating CD19+ B lymphocytes before B cell depletion. Anti-CD20 treatment was highly effective in patients with autoimmune thrombocytopenia, inducing a significant increase of platelet counts after 1 month (p < 0.01). Five of 10 patients achieved complete normalization of their platelet counts within 6 months. The anti-CD20 treatment was followed by a significant reduction of autoantibodies against dsDNA and platelets, in nephritic and in thrombocytopenic patients, respectively. CONCLUSION Addition of anti-CD20 treatment to conventional immunosuppressive therapy may be a beneficial strategy in refractory lupus nephritis and autoimmune cytopenias, possibly by reducing the levels of pathogenic autoantibodies.
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MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Anemia, Hemolytic/blood
- Anemia, Hemolytic/drug therapy
- Anemia, Hemolytic/immunology
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Monoclonal, Murine-Derived
- Antigens, CD20/drug effects
- Autoantibodies/blood
- B-Lymphocytes/drug effects
- B-Lymphocytes/immunology
- B-Lymphocytes/pathology
- Dose-Response Relationship, Drug
- Female
- Humans
- Immunologic Factors/pharmacology
- Immunologic Factors/therapeutic use
- Lupus Erythematosus, Systemic/blood
- Lupus Erythematosus, Systemic/drug therapy
- Lupus Erythematosus, Systemic/immunology
- Lupus Nephritis/blood
- Lupus Nephritis/drug therapy
- Lupus Nephritis/immunology
- Male
- Middle Aged
- Purpura, Thrombocytopenic, Idiopathic/blood
- Purpura, Thrombocytopenic, Idiopathic/drug therapy
- Purpura, Thrombocytopenic, Idiopathic/immunology
- Retrospective Studies
- Rituximab
- Severity of Illness Index
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Abstract
Hyperfibrinolysis is a consequence of imbalance between fibrinolytic activators and their inhibitors. Increased levels of circulating plasminogen (Plg) activators such as tissue- or urokinase-type plasminogen activators (tPA or uPA respectively) are the most common causes of hyperfibrinolysis, occasionally causing major hemorrhages. We found that staphylokinase (SAK), a well-known Plg activator of bacterial origin, inhibits Plg activation mediated by endogenous tPA and uPA. Furthermore, mixture of SAK with tPA led to a significantly reduced Plg-dependent fibrinolysis. This inhibitory effect was exerted through direct action of SAK on Plg rather than indirectly on tPA or uPA. Inhibition of Plg activation by SAK is readily abrogated by interaction of SAK with human neutrophil peptides (HNPs). Finally, we show that NH2-terminal residues of SAK are important for the inhibitory effect of SAK on tPA- and uPA-mediated Plg activation. In conclusion, SAK reduces tPA/uPA-mediated Plg activation by means of SAK.Plg complex formation, consequently downregulating tPA/uPA-induced fibrinolysis.
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Circulating survivin indicates severe course of juvenile idiopathic arthritis. Clin Exp Rheumatol 2008; 26:373-378. [PMID: 18565266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
BACKGROUND Survivin is an anti-apoptotic protein that has been recently suggested as a predictive marker of joint destruction in adult rheumatoid arthritis. We assessed the presence of extracellular survivin in patients with juvenile idiopathic arthritis (JIA). METHODS Survivin levels were assessed in the circulation of 46 patients with JIA and in the age- and gender-matched controls (n=46) having no inflammatory disease, by ELISA. Survivin levels were analyzed with respect to the onset type and the activity of the joint disease. The intensity of inflammation and cartilage turnover was measured as levels of IL-6, serum amyloid A protein (SAA), and cartilage oligomeric matrix protein (COMP), respectively. RESULTS The levels of extracellular survivin were significantly higher in JIA compared to the controls (p=0.0002). High levels of survivin (above mean + 2SD of the controls) were detected in 8/46 (17% JIA patients. High survivin expression was associated with polyarticular onset, active phase of arthritis. In contrast, survivin was neither related to the levels of IL-6, SAA, nor to COMP. CONCLUSION Circulating survivin is expressed in a significant group of patients with JIA being associated to a severe course of the disease. It may be potentially used to select children with unfavorable prognosis of JIA who are in need of active pharmacologic treatment.
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Staphylococcus aureusinfection triggers production of neutralizing, V8 protease-specific antibodies. ACTA ACUST UNITED AC 2008; 52:267-72. [DOI: 10.1111/j.1574-695x.2007.00371.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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The impact of substance P signalling on the development of experimental staphylococcal sepsis and arthritis. Scand J Immunol 2008; 67:253-9. [PMID: 18226012 DOI: 10.1111/j.1365-3083.2007.02065.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Substance P (SP), acting on the neurokinin-1 receptor (NK-1R), is a neuropeptide, involved in the inflammatory processes. It promotes vasodilatation and increases vasopermeability, thus ensuing extravasation and accumulation of leucocytes at sites of injury. The aim of this study was to assess the impact of SP signalling on the responses during staphylococcal infection and the accompanying arthritis. Three experiments were performed where NK-1R-/- mice and controls were intravenously infected with different doses of Staphylococcus aureus. Clinical assessment of arthritis was performed as well as histological analysis of bone and cartilage destruction in the joints. In addition, the impact of NK-1R mutation on bacterial load in the kidneys as well as the phagocytic capacity of blood leucocytes were studied. Mice lacking the NK-1R displayed significantly higher bacterial load in the kidneys and significantly more severe synovitis and cartilage/bone destruction than the controls when inoculated with 1.4 x 10(7) staphylococci. Infection with 3.5 x 10(8) CFU/mouse induced sepsis. Thus, 11 days after bacterial inoculation 15 of 19 mice in the NK-1R-/- group had died versus 8 of 15 in the control group. Phagocytosis test revealed that significantly fewer macrophages from NK-1R-/- mice were able to phagocytose S. aureus when compared with macrophages from congenic control mice. Blocking the biological responses to substance P via its receptor NK-1R results in a less efficient clearance of bacteria leading to more severe arthritic lesions in mice.
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The Staphylococcus aureus surface protein IsdA mediates resistance to innate defenses of human skin. Cell Host Microbe 2007; 1:199-212. [PMID: 18005699 DOI: 10.1016/j.chom.2007.04.005] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 02/09/2007] [Accepted: 04/09/2007] [Indexed: 01/27/2023]
Abstract
Resistance to human skin innate defenses is crucial for survival and carriage of Staphylococcus aureus, a common cutaneous pathogen and nasal colonizer. Free fatty acids extracted from human skin sebum possess potent antimicrobial activity against S. aureus. The mechanisms by which S. aureus overcomes this host defense during colonization remain unknown. Here, we show that S. aureus IsdA, a surface protein produced in response to the host, decreases bacterial cellular hydrophobicity rendering them resistant to bactericidal human skin fatty acids and peptides. IsdA is required for survival of S. aureus on live human skin. Reciprocally, skin fatty acids prevent the production of virulence determinants and the induction of antibiotic resistance in S. aureus and other Gram-positive pathogens. A purified human skin fatty acid was effective in treating systemic and topical infections of S. aureus suggesting that our natural defense mechanisms can be exploited to combat drug-resistant pathogens.
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Efficacy of anti-CD20 treatment in patients with rheumatoid arthritis resistant to a combination of methotrexate/anti-TNF therapy. Scand J Immunol 2007; 66:476-83. [PMID: 17850593 DOI: 10.1111/j.1365-3083.2007.01995.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Rheumatoid arthritis (RA) is characterized by chronic joint inflammation and destruction. B cells play important role in modulating immune responses in RA. In the present study we assessed the impact of the B cell targeting as a third line treatment option. Forty-six patients with established erosive RA non-responding to combination treatment with DMARDs and TNF-alpha inhibitors were treated with anti-CD20 antibodies (rituximab). Rituximab was given intravenously once weekly on four occasions. All patients continued with the previous DMARD. Patients were followed by DAS28, levels of circulating B cells, frequency of immunoglobulin-producing cells, immunoglobulins, and rheumatoid factor levels during the period of 12-58 months. Clinical improvement was achieved in 34 of 46 patients (73%) supported by a significant reduction in DAS28 (from 6.04 to 4.64, P < 0.001). Infusion of rituximab resulted in the elimination of circulating B cells in all but one patient. Within 12 months follow-up, B cells returned to circulation in 86% of patients. Fifty-three percent of the patients were successfully retreated with rituximab or re-started with anti-TNF-alpha treatment. Of the 11 non-responders, five were retreated with anti-CD20 within 2 months, four of them with success, four patients received TNF-alpha inhibitors, the remaining two patients received an additional DMARD. Most of the RA patients resistant to TNF-alpha inhibitors may be effectively treated with anti-CD20 antibodies. The treatment is well tolerated and may be used repeatedly in the same patient and potentially increase sensitivity to previously inefficient treatment modalities.
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Extracellular survivin up-regulates adhesion molecules on the surface of leukocytes changing their reactivity pattern. J Leukoc Biol 2007; 83:149-55. [PMID: 17938276 DOI: 10.1189/jlb.0507287] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Rheumatoid arthritis (RA) is an autoimmune disease with joints as a principal target of inflammation. We have shown recently that the extracellular expression of the antiapoptotic protein survivin is associated with a destructive course of RA. Here, we address the potential impact of extracellular survivin on peripheral blood leukocytes (PBL). The binding of survivin to the surface of human PBL as well as the expression of adhesion molecules were assessed by FACS. The expression of adhesion molecules on leukocytes as a function of circulating survivin was analyzed in blood of 24 patients with RA and compared with eight healthy individuals. We show that extracellular survivin expresses immunomodulatory properties. It binds to the surface of the majority of granulocytes and a significant part of lymphocytes and monocytes inducing the activation of alpha-chains of beta-integrins and their ligand ICAM-1. Survivin-induced expression of alpha-chains of beta 2-integrins is regulated by p38 MAPK and PI-3K but not by the NF-kappaB signaling pathway. Clinical relevance of our findings is supported by the in vivo association of high circulating survivin levels with an increased expression of CD11c on monocytes and granulocytes in RA patients. The results of our study demonstrate that extracellular survivin affects the phenotype of leukocytes having a possible impact on homing of inflammatory cells during arthritis.
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Characterization of IsaA and SceD, two putative lytic transglycosylases of Staphylococcus aureus. J Bacteriol 2007; 189:7316-25. [PMID: 17675373 PMCID: PMC2168438 DOI: 10.1128/jb.00734-07] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 07/19/2007] [Indexed: 11/20/2022] Open
Abstract
Bacterial cell wall peptidoglycan is a dynamic structure requiring hydrolysis to allow cell wall growth and division. Staphylococcus aureus has many known and putative peptidoglycan hydrolases, including two likely lytic transglycosylases. These two proteins, IsaA and SceD, were both found to have autolytic activity. Regulatory studies showed that the isaA and sceD genes are partially mutually compensatory and that the production of SceD is upregulated in an isaA mutant. The expression of sceD is also greatly upregulated by the presence of NaCl. Several regulators of isaA and sceD expression were identified. Inactivation of sceD resulted in impaired cell separation, as shown by light microscopy, and "clumping" of bacterial cultures. An isaA sceD mutant is attenuated for virulence, while SceD is essential for nasal colonization in cotton rats, thus demonstrating the importance of cell wall dynamics in host-pathogen interactions.
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Abstract
We have shown that human CD20(+)25(+) B cells display immunomodulatory properties. The aim of this study was to investigate if CD25(+) B cells are found within the CD27 memory B cell population, and to analyse pattern of their cytokine production. B cells isolated from healthy subjects, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) patients were analysed regarding the frequency of CD25(+) B cells within certain B cell subsets. Purified CD25(+) B cells from healthy subject were used in vitro to evaluate their production of immunomodulatory cytokines. In healthy subjects the majority (60%) of memory B cells (CD20(+)27(+)) also co-expressed CD25 while only 10-20% of the naïve B cells (CD20(+)27(-)) and plasmablasts (CD20-27(+)) expressed CD25. In RA and SLE patients, we found that 51% and 48%, respectively, co-expressed CD25 in the memory population, whereas only 11% and 9% co-expressed CD25 in the naïve B cell population. Phenotypic analysis of the CD20(+)25(+)27(+) and CD20(+)25(+)27(-) cells using CD10, CD24, CD38, CD45, CD71, CD80, CD86, CD95, CD138, BAFF-R, TACI, IgA, IgD, IgG and IgM showed that CD20(+)25(+)27(+) B cells preferentially represent highly activated, Ig class switched memory B cells. Cytokine profile analysis showed that CD25(+) B cells secreted significantly higher levels of IL-10 versus CD25(-) B cells. In contrast, TGF-beta1 secretion was similar between the CD25(+) and CD25(-) sub-populations. In conclusion, CD20(+)25(+) B cells constitute a unique subpopulation preferentially occurring among CD20(+)27(+) memory B cells. We suggest that CD25 can be used as a marker for a memory B cell subset.
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In vivo sortase A and clumping factor A mRNA expression during Staphylococcus aureus infection. Microb Pathog 2007; 44:103-10. [PMID: 17890045 DOI: 10.1016/j.micpath.2007.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 08/10/2007] [Indexed: 10/22/2022]
Abstract
The Staphylococcus aureus cell surface protein clumping factor A (ClfA) and the enzyme sortase A (SrtA), which attach surface proteins to the cell wall, have both been shown to be virulence factors in models of septic arthritis and sepsis. The mRNA levels of clfA, srtA and the putative housekeeping gene gyrase B (gyrB) in S. aureus were determined using real-time PCR during the course of sepsis/septic arthritis. Expression was measured in joints, being a target of localized infection, and in kidneys, representing a systemic compartment. In infected kidneys, the mRNA levels of clfA, srtA and gyrB were all decreasing over time, from day 3 of infection to day 14. The transcript numbers of clfA and srtA decreased faster in septic mice than in mice with a non-septic disease. The mRNA levels of clfA and gyrB in joints, though, were increasing during the course of infection. These differences suggest that the specific tissue environment is decisive for the differentiation of staphylococci. Also, there was a negative relationship between bacterial load in a tissue and the numbers of clfA, srtA and gyrB transcripts per colony-forming unit. Possibly enters the majority of bacteria a metabolically dormant steady state at high bacterial loads.
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Pathological Survivin Expression Links Viral Infections with Pathogenesis of Erosive Rheumatoid Arthritis. Scand J Immunol 2007; 66:192-8. [PMID: 17635796 DOI: 10.1111/j.1365-3083.2007.01977.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Rheumatoid arthritis (RA) is an inflammatory joint disease leading to cartilage and bone destruction. Insufficient apoptosis in the inflamed RA synovium along with accumulation of highly differentiated B- and T-lymphocytes as well as invasive growth of macrophages and fibroblasts is among the major mechanisms supporting joint destruction. We have recently shown that circulating survivin, an apoptosis inhibitor tightly bound to tumorigenesis, is an independent predictor of development and progression of joint destruction in RA. In this review we discuss the possible connectivity between viral infection, leading to interferon (IFN)-alpha production, survivin expression, and subsequent joint inflammation. The role of IFN-alpha and the involvement of IFN transcription factors and phosphoinositide-3-kinase signalling as essential modulators of arthritogenic process are discussed in the context of survivin.
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Synovial fluid expression of autoantibodies specific for RAGE relates to less erosive course of rheumatoid arthritis. Rheumatology (Oxford) 2007; 46:1367-71. [PMID: 17569744 DOI: 10.1093/rheumatology/kem141] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The receptor for advanced glycation end products (RAGE) is expressed by many cells in joints of rheumatoid arthritis (RA) patients and interacts with a variety of pro-inflammatory ligands that are enriched in inflamed joint. The RAGE-ligand interaction leads to a sustained inflammatory response. Also, secreted form of the receptor, called soluble RAGE (sRAGE), the levels of which are decreased in RA patients, modulates inflammatory responses. We sought to determine whether RA patients display increased occurrence of autoantibodies against RAGE and whether such an autoantibody production is related to disease characteristics. METHODS Matching samples of blood and synovial fluid were collected from 50 patients with RA with acute joint effusion. Blood from 43 healthy individuals and synovial fluid samples from 32 patients with non-inflammatory joint diseases were used for comparison. Anti-RAGE antibody levels were analysed using an ELISA. RESULTS RA patients displayed significantly higher blood and synovial fluid levels of anti-RAGE antibodies, both of IgG as well as of IgM class as compared with healthy controls and with patients with non-inflammatory joint diseases. Patients with seropositive RA had significantly less IgG antibodies in their synovial fluid as compared to seronegative patients. Furthermore, the presence of IgG class of anti-RAGE antibodies locally in the joint was found to be related to less aggressive, i.e. non-erosive disease. CONCLUSION These results suggest that RAGE-specific B cell response protect patients with RA from destructive course of the disease.
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GGTase-I deficiency reduces tumor formation and improves survival in mice with K-RAS-induced lung cancer. J Clin Invest 2007; 117:1294-304. [PMID: 17476360 PMCID: PMC1857236 DOI: 10.1172/jci30868] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Accepted: 01/30/2007] [Indexed: 11/17/2022] Open
Abstract
Protein geranylgeranyltransferase type I (GGTase-I) is responsible for the posttranslational lipidation of CAAX proteins such as RHOA, RAC1, and cell division cycle 42 (CDC42). Inhibition of GGTase-I has been suggested as a strategy to treat cancer and a host of other diseases. Although several GGTase-I inhibitors (GGTIs) have been synthesized, they have very different properties, and the effects of GGTIs and GGTase-I deficiency are unclear. One concern is that inhibiting GGTase-I might lead to severe toxicity. In this study, we determined the effects of GGTase-I deficiency on cell viability and K-RAS-induced cancer development in mice. Inactivating the gene for the critical beta subunit of GGTase-I eliminated GGTase-I activity, disrupted the actin cytoskeleton, reduced cell migration, and blocked the proliferation of fibroblasts expressing oncogenic K-RAS. Moreover, the absence of GGTase-I activity reduced lung tumor formation, eliminated myeloproliferative phenotypes, and increased survival of mice in which expression of oncogenic K-RAS was switched on in lung cells and myeloid cells. Interestingly, several cell types remained viable in the absence of GGTase-I, and myelopoiesis appeared to function normally. These findings suggest that inhibiting GGTase-I may be a useful strategy to treat K-RAS-induced malignancies.
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Inactivation of traP has no effect on the agr quorum-sensing system or virulence of Staphylococcus aureus. Infect Immun 2007; 75:4519-27. [PMID: 17548478 PMCID: PMC1951194 DOI: 10.1128/iai.00491-07] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The success of Staphylococcus aureus as a pathogen can largely be attributed to the plethora of genetic regulators encoded within its genome that temporally regulate its arsenal of virulence determinants throughout its virulence lifestyle. Arguably the most important of these is the two-component, quorum-sensing system agr. Over the last decade, the controversial presence of a second quorum-sensing system (the TRAP system) has been proposed, and it has been mooted to function as the master regulator of virulence in S. aureus by modulating agr. Mutants defective in TRAP are reported to be devoid of agr expression, lacking in hemolytic activity, essentially deficient in the secretion of virulence determinants, and avirulent in infection models. A number of research groups have questioned the validity of the TRAP findings in recent years; however, a thorough and independent analysis of its role in S. aureus physiology and pathogenesis has not been forthcoming. Therefore, we have undertaken such an analysis of the TRAP locus of S. aureus. We found that a traP mutant was equally hemolytic as the wild-type strain. Furthermore, transcriptional profiling found no alterations in the traP mutant in expression levels of agr or in expression levels of multiple agr-regulated genes (hla, sspA, and spa). Analysis of secreted and surface proteins of the traP mutant revealed no deviation in comparison to the parent. Finally, analysis conducted using a murine model of S. aureus septic arthritis revealed that, in contrast to an agr mutant, the traP mutant was just as virulent as the wild-type strain.
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Cystatin C binds serum amyloid A, downregulating its cytokine-generating properties. J Rheumatol 2007; 34:1293-301. [PMID: 17552057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
OBJECTIVE To assess the interaction between cystatin C (CysC) and serum amyloid A protein (SAA). METHODS Levels of CysC and SAA and antibodies against these proteins were assessed in the paired blood and synovial fluid (SF) samples of 90 patients with rheumatoid arthritis (RA). Age and sex matched individuals having normal iohexol clearance (n = 90) and SF following joint trauma (n = 40) were used as controls. In vitro experiments included assessment of interaction between CysC and SAA by ELISA and the influence of CysC on SAA functions. RESULTS A pilot screening for cystatins C, E, and F in blood and SF of patients with RA found CysC to be by far the predominant extracellular cystatin. Circulating CysC levels were significantly lower in patients with RA compared to the matched controls (0.81 +/- 0.03 vs 1.01 +/- 0.03 mg/l; p = 0.05). These low CysC levels could not be explained by the presence of anti-CysC antibodies in patients with RA. In contrast, concentrations of CysC that accumulated in the inflamed SF were significantly greater in patients with erosive RA (1.66 +/- 0.08 mg/l) compared to nonerosive RA (1.36 +/- 0.06 mg/l; p = 0.003) and controls (1.18 +/- 0.03 mg/l; p = 0.043). In vitro studies showed direct binding of CysC to SAA. CysC/SAA binding impaired proinflammatory effects of SAA, reducing its ability to trigger expression of proinflammatory cytokines. CONCLUSION Our study shows a relative deficiency of circulating CysC during systemic inflammation in RA. Physical interaction between CysC and the acute-phase protein SAA (1) provides an explanation for CysC deficiency; and (2) suggests that CysC is regulating inflammatory responses. We hypothesize that decreased systemic CysC levels predispose to accelerated atherosclerosis and development of amyloidosis in patients with RA.
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Abstract
Rheumatoid arthritis (RA) is an autoimmune disease characterized by a persistent inflammation of the synovium, leading to the erosion of articular cartilage and bone. Synovial mast cells and their effector molecule, histamine, receive increased attention as mediators of joint inflammation. The aim of our study was to analyse levels of free histamine in serum and joint fluid of RA patients and to evaluate the potential inflammatogenic properties of histamine in vivo and in vitro. Histamine levels were measured by an ELISA in synovial fluid and sera of RA patients and of healthy controls. Histamine levels were also assessed in plasma of RA patients undergoing anti-TNF-alpha treatment. In the murine part of the study, histamine was injected intra-articularly in the knee joint of mice and the joints were subsequently analysed with respect to induction of inflammation. RA patients displayed significantly lower levels of histamine in circulation (0.93 +/- 0.16 ng/ml) compared with the healthy controls (1.89 +/- 0.45 ng/ml, P < 0.001). Locally, in synovial fluid the levels of histamine were even lower (0.37 +/- 0.16 ng/ml, P < 0.0006). Long-term anti-TNF-alpha treatment significantly increased circulating levels of histamine in RA patients. Our experiments on animals show that histamine on its own neither induces inflammation in the joint cavity nor influences the course of HMGB1 and peptidoglycan-induced joint inflammation. Based on our experimental and clinical studies we suggest that histamine lacks harmful properties in RA.
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