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https://www.readbyqxmd.com/read/28286804/bacterial-superantigen-toxins-induce-a-lethal-cytokine-storm-by-enhancing-b7-2-cd28-costimulatory-receptor-engagement-a-critical-immune-checkpoint
#1
Raymond Kaempfer, Andrey Popugailo, Revital Levy, Gila Arad, Dalia Hillman, Ziv Rotfogel
Formation of the costimulatory axis between the B7-2 and CD28 coreceptors is critical for T-cell activation. Superantigens, Gram-positive bacterial virulence factors, cause toxic shock and sepsis by hyperinducing inflammatory cytokines. We report a novel role for costimulatory receptors CD28 and B7-2 as obligatory receptors for superantigens, rendering them therapeutic targets. We show that by engaging not only CD28 but also its coligand B7-2 directly, superantigens potently enhance the interaction between B7-2 and CD28, inducing thereby T-cell hyperactivation...
2017: Receptors & Clinical Investigation
https://www.readbyqxmd.com/read/28274699/members-of-a-new-subgroup-of-streptococcus-anginosus-harbor-virulence-related-genes-previously-observed-in-streptococcus-pyogenes
#2
Anshu Babbar, Venkatesan Naveen Kumar, René Bergmann, Israel Barrantes, Dietmar H Pieper, Andreas Itzek, D Patric Nitsche-Schmitz
Conventionally categorized as commensals, the Streptococci of the species S. anginosus are facultative human pathogens that are difficult to diagnose and often overlooked. Furthermore, detailed investigation and diagnosis of S. anginosus infections is hampered by unexplored taxonomy and widely elusive molecular pathogenesis. To explore their pathogenic potential, S. anginosus isolates collected from patients of two geographical locations (Vellore, India and Leipzig, Germany) were subjected to multi-locus sequence analysis (MLSA)...
February 28, 2017: International Journal of Medical Microbiology: IJMM
https://www.readbyqxmd.com/read/28260936/microbiome-in-atopic-dermatitis
#3
REVIEW
Uwe Wollina
Atopic dermatitis (AD) is a common chronic inflammatory skin disease affecting ~10-20% of the general population. AD is characterized by disturbances in epidermal barrier function and hyperactive immune response. Recently, changes in the skin and intestinal microbiome have been analyzed in more detail. The available data suggest a link between disturbed skin microbiome and course of the disease. Flares of the disease are associated with an expansion of Staphylococcus aureus on lesional skin and a substantial loss of biodiversity in skin microbiome...
2017: Clinical, Cosmetic and Investigational Dermatology
https://www.readbyqxmd.com/read/28241767/multiple-sclerosis-an-example-of-pathogenic-viral-interaction
#4
REVIEW
Walter Fierz
A hypothesis is formulated on viral interaction between HHV-6A and EBV as a pathogenic mechanism in Multiple Sclerosis (MS). Evidence of molecular and genetic mechanisms suggests a link between HHV-6A infection and EBV activation in the brain of MS patients leading to intrathecal B-cell transformation. Consequent T-cell immune response against the EBV-infected cells is postulated as a pathogenic basis for inflammatory lesion formation in the brain of susceptible individuals. A further link between HHV-6A and EBV involves their induction of expression of the human endogenous retrovirus HERV-K18-encoded superantigen...
February 28, 2017: Virology Journal
https://www.readbyqxmd.com/read/28235987/staphylococcus-enterotoxin-profile-of-china-isolates-and-the-superantigenicity-of-some-novel-enterotoxins
#5
Menglu Shen, Yi Li, Linlin Zhang, Songbao Dai, Jiashun Wang, Yongqing Li, Lei Zhang, Jinhai Huang
The genus of staphylococcus widely distributes in environments and contributes to a variety of animal and human diseases. The enterotoxins (SEs) secreted by this type of pathogen have been the leading cause of bacterial toxic shock syndrome and food poisoning, and thus present a substantial concern to public health. In this study, we analyzed the superantigen profile of 122 staphylococcus strains isolated from diverse sources. When screened for the presence and prevalence of 17 known se or se-like (sel) genes, except selj, all other genes were detected in these isolates...
February 24, 2017: Archives of Microbiology
https://www.readbyqxmd.com/read/28219889/rapid-and-rigorous-il-17a-production-by-a-distinct-subpopulation-of-effector-memory-t-lymphocytes-constitutes-a-novel-mechanism-of-toxic-shock-syndrome-immunopathology
#6
Peter A Szabo, Ankur Goswami, Delfina M Mazzuca, Kyoungok Kim, David B O'Gorman, David A Hess, Ian D Welch, Howard A Young, Bhagirath Singh, John K McCormick, S M Mansour Haeryfar
Toxic shock syndrome (TSS) is caused by staphylococcal and streptococcal superantigens (SAgs) that provoke a swift hyperinflammatory response typified by a cytokine storm. The precipitous decline in the host's clinical status and the lack of targeted therapies for TSS emphasize the need to identify key players of the storm's initial wave. Using a humanized mouse model of TSS and human cells, we herein demonstrate that SAgs elicit in vitro and in vivo IL-17A responses within hours. SAg-triggered human IL-17A production was characterized by remarkably high mRNA stability for this cytokine...
April 1, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
https://www.readbyqxmd.com/read/28218671/human-scfvs-that-counteract-bioactivities-of-staphylococcus-aureus-tsst-1
#7
Thunchanok Rukkawattanakul, Nitat Sookrung, Watee Seesuay, Nattawat Onlamoon, Pornphan Diraphat, Wanpen Chaicumpa, Nitaya Indrawattana
Some Staphylococcus aureus isolates produced toxic shock syndrome toxin-1 (TSST-1) which is a pyrogenic toxin superantigen (PTSAg). The toxin activates a large fraction of peripheral blood T lymphocytes causing the cells to proliferate and release massive amounts of pro-inflammatory cytokines leading to a life-threatening multisystem disorder: toxic shock syndrome (TSS). PTSAg-mediated-T cell stimulation circumvents the conventional antigenic peptide presentation to T cell receptor (TCR) by the antigen-presenting cell (APC)...
February 17, 2017: Toxins
https://www.readbyqxmd.com/read/28205241/septic-transfusion-case-caused-by-a-platelet-pool-with-visible-clotting-due-to-contamination-with-staphylococcus-aureus
#8
Maria Loza-Correa, Yuntong Kou, Mariam Taha, Miloslav Kalab, Jennifer Ronholm, Patrick M Schlievert, Michael P Cahill, Robert Skeate, Christine Cserti-Gazdewich, Sandra Ramirez-Arcos
BACKGROUND: Contamination of platelet concentrates (PCs) with Staphylococcus aureus is one of the most significant ongoing transfusion safety risks in developed countries. CASE REPORT: This report describes a transfusion reaction in an elderly patient diagnosed with acute myeloid leukemia, transfused with a 4-day-old buffy coat PC through a central venous catheter. The transfusion was interrupted when a large fibrous clot in the PC obstructed infusion pump flow...
February 16, 2017: Transfusion
https://www.readbyqxmd.com/read/28193526/identification-of-the-blood-coagulation-factor-interacting-sequences-in-staphylococcal-superantigen-like-protein-10
#9
Saotomo Itoh, Takemasa Takii, Kikuo Onozaki, Tsutomu Tsuji, Shigeaki Hida
Staphylococcal superantigen-like proteins (SSLs) are a family of exoproteins of Staphylococcus aureus. We have shown that SSL10 binds to vitamin K-dependent coagulation factors and inhibits blood coagulation induced by recalcification of citrated plasma. SSL10 was revealed to bind to coagulation factors via their γ-carboxyglutamic acid (Gla) domain. In this study we attempted to identify the responsible sequence of SSL10 for the interaction with coagulation factors. We prepared a series of domain swap mutants between SSL10 and its paralog SSL7 that does not interact with coagulation factors, and examined their binding activity to immobilized prothrombin using ELISA-like binding assay...
March 25, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28128856/experimental-arthritis-in-the-rat-induced-by-the-superantigen-staphylococcal-enterotoxin-a-sea
#10
Kristina Gerlach, Christian Tomuschat, Rainer Finke, Martin Sebastian Staege, Christine Brütting, Jörg Brandt, Berit Jordan, René Schwesig, Angela Rosemeier, Karl-Stefan Delank, Malte Erich Kornhuber, Alexander Emmer
The pathogenesis of rheumatoid arthritis (RA) is incompletely understood. Human endogenous retroviruses (HERVs) and their superantigenic envelope protein (env) have been implicated in the pathogenesis of RA. In the present investigation the arthritogenic potential of the superantigen Staphylococcal enterotoxin A (SEA) has been investigated. In the present investigation, the bacterial superantigen Staphylococcal enterotoxin A (SEA) was injected into the right knee joint of 15 Lewis rats. Further 9 animals received saline...
January 27, 2017: Scandinavian Journal of Immunology
https://www.readbyqxmd.com/read/28123509/different-roles-of-staphylococcus-aureus-enterotoxin-in-different-subtypes-of-nasal-polyps
#11
Ke-Jia Cheng, Shen-Qing Wang, Ying-Ying Xu
Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial disease. The pathogenesis of CRSwNP remains unclear. This study was designed to investigate the role of inflammation and Staphylococcus aureus enterotoxin (SE) in this disease. The study included a total of 74 patients with CRSwNP and 6 controls. A serum Phadiatop assay was conducted to detect atopy status, and serum eosinophil cationic protein (ECP) and total immunoglobulin (Ig)E levels were determined using ELISA. SEA, SEB, total IgE, ECP and myeloperoxidase (MPO) levels in nasal tissue supernatant were measured using ELISA...
January 2017: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28122962/staphylococcus-aureus-downregulates-ip-10-production-and-prevents-th1-cell-recruitment
#12
Zhigang Li, Benoît Levast, Joaquín Madrenas
Staphylococcal superantigens cause toxic shock syndrome, which is characterized by massive T cell activation and a predominant Th1 profile of cytokine production. However, superantigen-producing Staphylococcus aureus strains are often part of the human nasal microbiome, and this carrier state has often been associated with some type 2 immune responses such as chronic sinusitis with polyps and atopic dermatitis. We have previously reported that the S. aureus cell wall downregulates the human T cell response to superantigens through a TLR2-dependent, IL-10-mediated mechanism...
January 25, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
https://www.readbyqxmd.com/read/28099884/characterization-of-human-and-staphylococcus-aureus-proteins-in-respiratory-mucosa-by-in-vivo-and-immunoproteomics
#13
Frank Schmidt, Tanja Meyer, Nandakumar Sundaramoorthy, Stephan Michalik, Kristin Surmann, Maren Depke, Vishnu Dhople, Manuela Gesell Salazar, Gabriele Holtappels, Nan Zhang, Barbara M Bröker, Claus Bachert, Uwe Völker
Staphylococcus aureus is a Gram-positive opportunistic bacterium which can be found as a commensal in the nares of about 50% of the human population. Besides asymptomatic carriage, S. aureus has also been found to colonize nasal polyps, a subform of chronic rhinosinusitis, in 60 to 100% of cases, and even reside intracellularly in nasal polyp tissue. The aim of this study was to shed light on the behavior of S. aureus in the human airways by analyzing S. aureus-specific proteins in nasal polyp tissue from patients with chronic rhinosinusitis and to characterize the immunogenic potential of the identified (mainly secreted) proteins...
January 15, 2017: Journal of Proteomics
https://www.readbyqxmd.com/read/28063655/analysis-of-home-dust-for-staphylococcus-aureus-and-staphylococcal-enterotoxin-genes-using-quantitative-pcr
#14
Shanna Ludwig, Isabel Jimenez-Bush, Emily Brigham, Sonali Bose, Gregory Diette, Meredith C McCormack, Elizabeth C Matsui, Meghan F Davis
BACKGROUND: The bacterium Staphylococcus aureus (SA) is known to induce allergic inflammatory responses, including through secreted staphylococcal enterotoxin (SE) superantigens. To quantify indoor environmental exposures to these potential allergens, which may be associated with worse asthma, we developed a method for the assessment of S. aureus and SE in home dust and applied it to a study of homes of inner-city adults with asthma. METHODS: We conducted laboratory experiments to optimize sample processing and real-time PCR methods for detection and quantification of SA (femB) and SEA-D, based on published primers...
March 1, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28035011/invariant-nkt-cells-are-pathogenic-in-the-hla-dr4-transgenic-humanized-mouse-model-of-toxic-shock-syndrome-and-can-be-targeted-to-reduce-morbidity
#15
Peter A Szabo, Patrick T Rudak, Joshua Choi, Stacey X Xu, Robert Schaub, Bhagirath Singh, John K McCormick, S M Mansour Haeryfar
During toxic shock syndrome (TSS), bacterial superantigens trigger a polyclonal T cell response leading to a potentially catastrophic 'cytokine storm'. Whether innate-like invariant natural killer T(iNKT) cells, with remarkable immunomodulatory properties, participate in TSS is unclear. Using genetic and cell depletion approaches, we generated iNKT cell-deficient, superantigen-sensitive HLA-DR4-transgenic (DR4tg) mice, which were compared with their iNKT-sufficient counterparts for responsiveness to staphylococcal enterotoxin B(SEB)...
December 29, 2016: Journal of Infectious Diseases
https://www.readbyqxmd.com/read/28033724/identification-of-virulence-genes-carried-by-bacteriophages-obtained-from-clinically-isolated-methicillin-resistant-staphylococcus-aureus
#16
Djursun Karasartova, Zeynep Burcin Cavusoglu, Buse Turegun, Murat T Ozsan, Fikret Şahin
Bacteriophages play an important role in the pathogenicity of Staphylococcus aureus (S. aureus) either by carrying accessory virulence factors or several superantigens. Despite their importance, there are not many studies showing the actual distribution of the virulence genes carried by the prophages obtained from the clinically isolated Staphylococcus. In this study, we investigated prophages obtained from methicillin-resistant S. aureus (MRSA) strains isolated from hospital- and community-associated (HA-CA) infections for the virulence factors...
December 2016: Acta Microbiologica et Immunologica Hungarica
https://www.readbyqxmd.com/read/28025135/doxorubicin-enhances-the-capacity-of-b-cells-to-activate-t-cells-in-urothelial-urinary-bladder-cancer
#17
A Ali Zirakzadeh, Johan Kinn, David Krantz, Robert Rosenblatt, Malin E Winerdal, Jin Hu, Ciputra Adijaya Hartana, Christian Lundgren, Emma Ahlén Bergman, Markus Johansson, Benny Holmström, Johan Hansson, Alexander Sidikii, Janos Vasko, Per Marits, Amir Sherif, Ola Winqvist
Cancer is currently treated by a combination of therapies, including chemotherapy which is believed to suppress the immune system. Combination of immunotherapy and chemotherapy correlates with improved survival but needs careful planning in order to achieve a synergistic effect. In this study, we have demonstrated that doxorubicin treatment of B cells resulted in increased expression of CD86 and concordantly increased CD4(+) T cell activation in the presence of superantigen, an effect that was inhibited by the addition of a CD86 blocking antibody...
December 24, 2016: Clinical Immunology: the Official Journal of the Clinical Immunology Society
https://www.readbyqxmd.com/read/28012189/vitamin-d3-derivatives-alone-or-in-combination-with-glucocorticoids-suppress-streptococcal-pyrogenic-enterotoxin-a-stimulated-proliferation-of-peripheral-blood-mononuclear-cells-in-patients-with-psoriasis
#18
Kae Usui, Yukari Okubo, Toshihiko Hirano, Ryoji Tsuboi
Bacterial colonization on skin or tonsil may influence the clinical response of patients with psoriasis to immunosuppressive drugs. However, few studies have investigated the effects of bacterial superantigens on therapy in these patients. Recently, combination therapy with topical glucocorticoids (GC) and vitamin D3 (VD3) appears to be more effective than GC or VD3 monotherapy for psoriasis. We evaluated the suppressive effects of betamethasone butyrate propionate (BBP), three VD3 derivatives (calcipotriol, maxacalcitol and tacalcitol), cyclosporin and BBP plus VD3, on concanavalin A (ConA)- or streptococcal pyrogenic enterotoxin A (SPEA)-stimulated proliferation of peripheral blood mononuclear cells (PBMC) obtained from 35 psoriasis patients...
December 24, 2016: Journal of Dermatology
https://www.readbyqxmd.com/read/27992203/sage-a-fast-computational-tool-for-linear-epitope-grafting-onto-a-foreign-protein-scaffold
#19
Riccardo Capelli, Filippo Marchetti, Guido Tiana, Giorgio Colombo
Computational design is becoming a driving force of structural vaccinology, whereby protein antigens are engineered to generate new biomolecules with optimized immunological properties. In particular, the design of new proteins that contain multiple, different epitopes can potentially provide novel highly efficient vaccine candidates. In this context, epitope grafting, which entails the transplantation of an antibody recognition motif from one protein onto a different protein scaffold (possibly containing other immunoreactive sequences) holds great promise for the realization of superantigens...
December 19, 2016: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/27991848/molecular-characteristics-of-erythromycin-resistant-streptococcus-pyogenes-strains-isolated-from-children-patients-in-tunis-tunisia
#20
Sonia Ksia, Hanen Smaoui, Manel Hraoui, Aida Bouafsoun, Ihem Boutiba-Ben Boubaker, Amel Kechrid
AIM: The aims of our study were to characterize phenotypically and genotypically erythromycin-resistant Streptococcus pyogenes or group A streptococci (ERGAS) isolates, to evaluate macrolide resistance and to analyze the association between emm types and virulence factors. Included in this study were all ERGAS strains isolated from 2000 to 2013 at the Children's hospital of Tunis. Antimicrobial susceptibility was performed according to the CA-SFM guidelines. Macrolide resistance genes were revealed by polymerase chain reaction (PCR) method...
December 19, 2016: Microbial Drug Resistance: MDR: Mechanisms, Epidemiology, and Disease
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