Pathogenic strains of Bacillus anthracis produce two potent toxins, lethal toxin (LT), a metalloprotease that cleaves mitogen-activated protein kinase kinases, and oedema toxin (ET), a calcium/calmodulin-dependent adenylate cyclase. Emerging evidence indicates a role for both toxins in suppressing the initiation of both innate and adaptive immune responses, which are essential to keep the infection under control. Here we show that LT and ET inhibit chemotaxis of T-cells and macrophages by subverting signalling by both CXC and CC chemokine receptors.
View Article and Find Full Text PDFLysophosphatidylcholine rapidly paralyses the neuromuscular junction (NMJ), similarly to snake phospholipase A2 neurotoxins, implicating a lipid hemifusion-pore transition in neuroexocytosis. The mode and kinetics of NMJ paralysis of different lysophospholipids (lysoPLs) in high or low [Mg2+] was investigated. The following order of potency was found: lysophosphatidylcholine>lysophosphatidylethanolamine>lysophosphatidic acid>lysophosphatidylserine>lysophosphatidylglycerol.
View Article and Find Full Text PDFThe entry and enzymatic activity of the anthrax edema factor (EF) in different cell types was studied by monitoring EF-induced changes in intracellular cAMP with biochemical and microscopic methods. cAMP was imaged in live cells, transfected with a fluorescence resonance energy transfer biosensor based on the protein kinase A regulatory and catalytic subunits fused to CFP and YFP, respectively. The cAMP biosensor was located either in the cytosol or was membrane-bound owing to the addition of a tag determining its myristoylation/palmitoylation.
View Article and Find Full Text PDFObjective: To investigate whether rheumatoid factor isotypes and anti-cyclic citrullinated peptide (anti-CCP) antibodies are related to clinical response in patients with rheumatoid arthritis treated with tumour necrosis factor alpha (TNFalpha) inhibitors.
Methods: The study was carried out on 132 patients with advanced rheumatoid arthritis refractory to disease-modifying antirheumatic drugs. Patients were treated with infliximab (n = 63), etanercept (n = 35) or adalimumab (n = 34).
Lung fibrosis is a major cause of mortality and morbidity in systemic sclerosis (SSc). However, its pathogenesis still needs to be elucidated. We examined whether the alteration of certain proteins in bronchoalveolar lavage fluid (BALF) might have a protective or a causative role in the lung fibrogenesis process.
View Article and Find Full Text PDFIn recent years, there have been major advances in the management of rheumatoid arthritis (RA), leading to the development of tumour necrosis factor (TNF) antagonists. With these agents, it is possible to arrest joint damage and, by treating early in the disease course, to prevent joint damage. It is also now thought that early treatment can achieve clinical remission in a substantial proportion of patients.
View Article and Find Full Text PDFBotulinum toxins are metalloproteases that act inside nerve terminals and block neurotransmitter release through their cleavage of components of the exocytosis machinery. These toxins are used to treat human diseases that are characterized by hyperfunction of cholinergic terminals. Recently, evidence has accumulated that gangliosides and synaptic vesicle proteins cooperate to mediate toxin binding to the presynaptic terminal.
View Article and Find Full Text PDFThe present report is devoted to drawing up and disseminating specific recommendations for the use of anti-TNF-alpha therapies in patients with rheumatoid arthritis (RA) in Italy. The document reports and discusses the published literature concerning the criteria for inclusion, assessment of response and for withdrawal of treatment with TNF blocking agents in RA. Several specific points concerning more sensitive warnings are discussed: tuberculosis, hepatitis, lymphoma, and cardiovascular risk and induction of autoimmunity.
View Article and Find Full Text PDFSeveral species of microorganism have developed immune evasion and/or immunosuppression strategies. Bacillus anthracis secretes two toxins, edema toxin and lethal toxin, that enter the cytosol of almost every cell type, including the cells of the innate and adaptive immune systems, and subvert cell signaling. Edema toxin causes a consistent elevation of cyclic adenosine monophosphate, whereas lethal toxin cleaves most isoforms of mitogen-activated protein kinase kinases.
View Article and Find Full Text PDFPolymyalgia rheumatica (PMR) has a marked preponderance in women. The female sex has been claimed to be a risk factor for longer-course corticosteroid therapy and to be associated with more severe systemic symptoms and lower hemoglobin levels. Eighty consecutive patients affected by PMR, seen at two tertiary referral centers, were followed-up for a mean period of 14.
View Article and Find Full Text PDFPolymyalgia rheumatica (PMR) usually exhibits a good clinical response to glucocorticoid (GC) treatment, but early clinical symptoms may create some difficulties in the differential diagnosis with elderly onset rheumatoid arthritis (EORA), particularly in patients complaining of shoulder and pelvic girdle involvement at onset (PMR-like clinical onset) (EORA/PMR). Since neuroendocrine mechanisms seem to play a pathogenetic role in these clinical conditions, the aim of this study was to evaluate hormone and cytokine responsiveness to GC treatment in these patients. Cortisol (CO), dehydroepiandrosterone sulphate (DHEAS), 17-OH-progesterone (PRG), interleukin-1 receptor antagonist (IL-1Ra), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) were evaluated at base line, and 1 month after GC treatment (prednisone 10 mg/day), in 14 PMR, 11 EORA/PMR, and 13 EORA patients (mean age 73 +/- 5 years, +/- SD, mean disease duration 3 +/- 2 months, +/- SD).
View Article and Find Full Text PDFObjective: To evaluate the efficacy of switching to etanercept treatment in patients with rheumatoid arthritis who already responded to infliximab, but presented side effects.
Methods: Charts of 553 patients with rheumatoid arthritis were retrospectively reviewed to select patients who responded to the treatment with infliximab and switched to etanercept because of occurrence of adverse effects. Clinical data were gathered during 24 weeks of etanercept treatment and for the same period of infliximab treatment before infliximab was stopped.
Botulinum neurotoxins produced by anaerobic bacteria of the genus Clostridium are the most toxic proteins known, with mouse LD50 values in the 1-5 ng/kg range, and are solely responsible for the pathophysiology of botulism. These metalloproteinases enter peripheral cholinergic nerve terminals and cleave proteins of the neuroexocytosis apparatus, causing a persistent, but reversible, inhibition of neurotransmitter release. They are used in the therapy of many human syndromes caused by hyperactive nerve terminals.
View Article and Find Full Text PDFBotulinum neurotoxin (BoNT) serotype A is commonly used in the treatment of focal dystonia, but some patients are primarily or become secondarily resistant to it. Consequently, other serotypes have to be used when immuno-resistance is proven. In the literature, patients with focal dystonia have been treated with BoNT serotype F with clinical benefit but with short lasting effects.
View Article and Find Full Text PDFObjective: To determine the usefulness of plasma procalcitonin (PCT) measurement to suspect infectious etiology in febrile patients with systemic autoimmune disease.
Methods: PCT, C-Reactive protein (CRP), erythrocyte sedimentation rate (ESR) and white blood cell count (WBC) were measured in 44 consecutive inpatients with a diagnosis of systemic autoimmune disease and fever >38 masculine C. After careful microbiologic screening no obvious infection was demonstrated in 24 patients (Group A) while an infectious bacterial complication was diagnosed in 20 cases (Group B).
Background: Polymyalgia rheumatica (PMR) may create some difficulties in the differential diagnosis of elderly-onset rheumatoid arthritis (EORA) and of EORA with PMR-like onset (EORA/PMR).
Aim: To investigate possible differences between three groups of patients, with regard to serum levels of inflammatory cytokines and steroidal hormones at baseline and after 1 month of treatment with glucocorticoids (prednisone 7.5-12.
Streptococcus pneumoniae colonizes the nasopharynx of healthy human carriers, but occasionally can spread in the body causing severe diseases. The mucosa of the respiratory tract is enriched in mast cells, key players of the innate immune response. Here, we report on the interaction of various strains of S.
View Article and Find Full Text PDFNeurotoxins affecting neuroexocytosis can represent an innovative pharmacological approach to the investigation of neural mechanisms of pain. Our interest has been focused on the use of botulinum neurotoxins (BoNTs), whose peripheral effects are extensively documented, while the effects on the central nervous system are much less clear. We have investigated both peripheral (sc into the hindpaw) and central (icv) effects of two BoNTs isoforms, BoNT/A and BoNT/B, on inflammatory pain.
View Article and Find Full Text PDFSystemic sclerosis (SSc) presents a great deal of variability in the extent and severity of skin and internal organ involvement. The diagnostic and prognostic significance of autoantibodies in SSc is undisputed and the patient's autoantibody profile represents a fundamental tool for clinicians. Scleroderma is a rare condition in children.
View Article and Find Full Text PDFIn the last few years, an autoimmune hypothesis for the pathogenesis of thrombotic thrombocytopenic purpura (TTP) has been proposed often, with variable success because of inconsistent supporting data. We are now aware that at least one subgroup of TTP patients does present with pathogenic autoantibodies (i.e, anti-ADAMTS13); this group consequently is a putative candidate for a curative treatment including plasma exchange (still the cornerstone of TTP treatment), together with corticosteroids or other immunosuppressants.
View Article and Find Full Text PDFReumatismo
September 2011
The article describes the EMEA approved indications of TNFα antagonists (adalimumab, etanercept and infliximab) in the various clinical conditions and their increasing use in diseases other than those already approved. The Authors discuss their use during pregnancy, the efficacy of a second TNFα antagonist after failure or side effects development with a previous biologic agent and the different efficacy of the various agents depending on the different clinical conditions.
View Article and Find Full Text PDFThe extensive characterization of the replicative human DNA ligase I (LigI) undertaken in the last decade demonstrated that the level of this protein strongly correlates with the rate of cell proliferation. This may allow to expand the repertoire of clinical biomarkers for the analysis of cell proliferation. We have produced a new monoclonal antibody (5H5) against LigI and exploited it as cell proliferation marker in Western blotting and immunofluorescence as well as in immunohistochemistry on paraffin tissue sections.
View Article and Find Full Text PDFDevelopment of severe gastric diseases is strongly associated with those strains of Helicobacter pylori that contain the cag pathogenicity island (PAI) inserted into the chromosome. The cag PAI encodes a type IV secretion system that translocates the major disease-associated virulence protein, CagA, into the host epithelial cell. CagA then affects host signaling pathways, leading to cell elongations and inflammation.
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