keyword
MENU ▼
Read by QxMD icon Read
search

Superantigen

keyword
https://www.readbyqxmd.com/read/28934904/clonal-deletion-of-t-cell-repertoires-with-specific-t-cell-receptor-v%C3%AE-chains-by-two-endogenous-superantigens-in-nc-nga-mice
#1
Kozo Ohkusu-Tsukada, Teruyo Tsukada, Kimimasa Takahashi
Superantigens (SAgs) are powerful T-cell stimulatory proteins. Because an atopic dermatitis (AD) model NC/Nga mice had two endogenous SAgs, namely minor lymphocyte-stimulating locus-1(a) (Mls-1(a)) and mouse mammary tumor virus (MMTV)(SHN), SAg-responsive T-cells bearing Vβ5.1, Vβ6, Vβ8.1, Vβ8.2, Vβ8.3, Vβ9, and Vβ11 should be endogenously deleted. Here, we discuss that the endogenous SAgs-expression may be involved in AD-sensitivity in NC/Nga mice.
September 22, 2017: Bioscience, Biotechnology, and Biochemistry
https://www.readbyqxmd.com/read/28901485/a-novel-non%C3%A2-contact-communication-between-human-keratinocytes-and-t-cells-exosomes-derived-from-keratinocytes-support-superantigen%C3%A2-induced-proliferation-of-resting-t-cells
#2
Xiao-Wei Cai, Rong Zhu, Lei Ran, Yi-Qian Li, Ke Huang, Jing Peng, Wei He, Chun-Li Zhou, Ru-Peng Wang
It is widely accepted that keratinocytes act as non‑professional antigen‑presenting cells and support superantigen‑induced proliferation of resting T cells; however, it remains unknown whether keratinocytes function in situ with T cells via a non‑contact mechanism. The current study used a transwell co‑culture system and demonstrated, for the first time to the best of the authors' knowledge, that HaCaT cells (the human keratinocyte cell line) did induce T cell proliferation via indirect contact. The data further indicated that exosomes, small membrane vesicles that transfer antigens to recipient cells, are also involved in the superantigen‑associated immunity of keratinocytes...
September 13, 2017: Molecular Medicine Reports
https://www.readbyqxmd.com/read/28900005/shocking-superantigens-promote-establishment-of-bacterial-infection
#3
Nikolai Siemens, Anna Norrby-Teglund
No abstract text is available yet for this article.
September 12, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28892185/prevalence-comorbidities-and-mortality-of-toxic-shock-syndrome-in-united-states-children-and-adults
#4
Mark A Strom, Derek Y Hsu, Jonathan I Silverberg
Toxic Shock Syndrome (TSS) is a superantigen-mediated illness characterized by rash, hypotension and multi-organ dysfunction. The predictors of TSS and related morbidity and mortality are poorly defined. We analyzed data on 61,959,084 hospitalizations from the 2003-2012 Nationwide Inpatient Sample, a 20% stratified sample of US hospitalizations. ICD-9-CM coding was used to identify 4,491 hospitalizations with a diagnosis of TSS. Incidence, in-hospital mortality rate, comorbidities, length of stay and costs of care due to TSS were determined...
September 11, 2017: Microbiology and Immunology
https://www.readbyqxmd.com/read/28880920/the-staphylococcus-aureus-superantigen-selx-is-a-bifunctional-toxin-that-inhibits-neutrophil-function
#5
Stephen W Tuffs, David B A James, Jovanka Bestebroer, Amy C Richards, Mariya I Goncheva, Marie O'Shea, Bryan A Wee, Keun Seok Seo, Patrick M Schlievert, Andreas Lengeling, Jos A van Strijp, Victor J Torres, J Ross Fitzgerald
Bacterial superantigens (SAgs) cause Vβ-dependent T-cell proliferation leading to immune dysregulation associated with the pathogenesis of life-threatening infections such as toxic shock syndrome, and necrotizing pneumonia. Previously, we demonstrated that staphylococcal enterotoxin-like toxin X (SElX) from Staphylococcus aureus is a classical superantigen that exhibits T-cell activation in a Vβ-specific manner, and contributes to the pathogenesis of necrotizing pneumonia. Here, we discovered that SElX can also bind to neutrophils from human and other mammalian species and disrupt IgG-mediated phagocytosis...
September 2017: PLoS Pathogens
https://www.readbyqxmd.com/read/28880913/staphylococcal-enterotoxin-like-x-selx-is-a-unique-superantigen-with-functional-features-of-two-major-families-of-staphylococcal-virulence-factors
#6
Ries J Langley, Yi Tian Ting, Fiona Clow, Paul G Young, Fiona J Radcliff, Jeong Min Choi, Richard P Sequeira, Silva Holtfreter, Heather Baker, John D Fraser
Staphylococcus aureus is an opportunistic pathogen that produces many virulence factors. Two major families of which are the staphylococcal superantigens (SAgs) and the Staphylococcal Superantigen-Like (SSL) exoproteins. The former are immunomodulatory toxins that induce a Vβ-specific activation of T cells, while the latter are immune evasion molecules that interfere with a wide range of innate immune defences. The superantigenic properties of Staphylococcal enterotoxin-like X (SElX) have recently been established...
September 2017: PLoS Pathogens
https://www.readbyqxmd.com/read/28858870/the-tlr2-antagonist-staphylococcal-superantigen-like-protein-3-acts-as-a-virulence-factor-to-promote-bacterial-pathogenicity-in-vivo
#7
Kirsten J Koymans, Oliver Goldmann, Christofer A Q Karlsson, Wiedjai Sital, Robert Thänert, Adinda Bisschop, Manouk Vrieling, Johan Malmström, Kok P M van Kessel, Carla J C de Haas, Jos A G van Strijp, Eva Medina
Toll-like receptor (TLR) signaling is important in the initiation of immune responses and subsequent instigation of adaptive immunity. TLR2 recognizes bacterial lipoproteins and plays a central role in the host defense against bacterial infections, including those caused by Staphylococcus aureus. Many studies have demonstrated the importance of TLR2 in murine S. aureus infection. S. aureus evades TLR2 activation by secreting two proteins, staphylococcal superantigen-like protein 3 (SSL3) and 4 (SSL4). In this study, we demonstrate that antibodies against SSL3 and SSL4 are found in healthy individuals, indicating that humans are exposed to these proteins during S...
September 1, 2017: Journal of Innate Immunity
https://www.readbyqxmd.com/read/28838616/molecular-analysis-of-immunoglobulin-variable-genes-supports-a-germinal-center-experienced-normal-counterpart-in-primary-cutaneous-diffuse-large-b-cell-lymphoma-leg-type
#8
Anne Pham-Ledard, Martina Prochazkova-Carlotti, Mélanie Deveza, Marie-Pierre Laforet, Marie Beylot-Barry, Béatrice Vergier, Marie Parrens, Jean Feuillard, Jean-Philippe Merlio, Nathalie Gachard
BACKGROUND: Immunophenotype of primary cutaneous diffuse large B-cell lymphoma, leg-type (PCLBCL-LT) suggests a germinal center-experienced B lymphocyte (BCL2+ MUM1+ BCL6+/-). OBJECTIVES: As maturation history of B-cell is "imprinted" during B-cell development on the immunoglobulin gene sequence, we studied the structure and sequence of the variable part of the genes (IGHV, IGLV, IGKV), immunoglobulin surface expression and features of class switching in order to determine the PCLBCL-LT cell of origin...
July 26, 2017: Journal of Dermatological Science
https://www.readbyqxmd.com/read/28807764/staphylococcal-enterotoxin-c2-mutant-drives-t-lymphocyte-activation-through-pi3k-mtor-and-nf-%C3%A4-b-signaling-pathways
#9
Xuanhe Fu, Mingkai Xu, Songyuan Yao, Huiwen Zhang, Chenggang Zhang, Jinghai Zhang
Staphylococcal enterotoxin C2 (SEC2), a superantigen, causes rapid clonal expansion of lymphocytes and secretion of T cell growth factors, leading to a severe inflammatory response within tissues. Although previous studies have shown that ST-4, a SEC2 mutant with enhanced recognition of Vβ regions of T-cell receptors (TCRVβ), can activate an increased number of T cells and produce more cytokines than SEC2. However, the signaling mechanisms of SEC2/ST-4-mediated immune activation have not been addressed. In this study, we showed that the phosphatidylinositide-3-kinase (PI-3K) inhibitor LY294002, mammalian target of rapamycin (mTOR) inhibitor rapamycin, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) inhibitor Bay11-7085 could suppress SEC2/ST-4-induced proliferation, CD69/CD25 expression, cell-cycle progression, and IL-2 production in BALB/c mouse splenocytes...
October 15, 2017: Toxicology and Applied Pharmacology
https://www.readbyqxmd.com/read/28794279/nasopharyngeal-infection-by-streptococcus-pyogenes-requires-superantigen-responsive-v%C3%AE-specific-t-cells
#10
Joseph J Zeppa, Katherine J Kasper, Ivor Mohorovic, Delfina M Mazzuca, S M Mansour Haeryfar, John K McCormick
The globally prominent pathogen Streptococcus pyogenes secretes potent immunomodulatory proteins known as superantigens (SAgs), which engage lateral surfaces of major histocompatibility class II molecules and T-cell receptor (TCR) β-chain variable domains (Vβs). These interactions result in the activation of numerous Vβ-specific T cells, which is the defining activity of a SAg. Although streptococcal SAgs are known virulence factors in scarlet fever and toxic shock syndrome, mechanisms by how SAgs contribute to the life cycle of S...
August 9, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28742082/bacterial-deception-of-mait-cells-in-a-cloud-of-superantigen-and-cytokines
#11
REVIEW
Johan K Sandberg, Anna Norrby-Teglund, Edwin Leeansyah
The bacterium Staphylococcus aureus is an important cause of the life-threatening condition toxic shock syndrome in humans. Bacterial toxins known as superantigens (SAgs) generate this illness by acting as broad activators of a substantial fraction of all T lymphocytes, bypassing the normally highly stringent T-cell receptor antigen specificity to cause a systemic inflammatory cytokine storm in the host. In a new study, Shaler et al. found that immune cells called mucosa-associated invariant T (MAIT) cells make an unexpectedly large contribution to the SAg response in a largely T-cell receptor-independent, cytokine-driven manner...
July 2017: PLoS Biology
https://www.readbyqxmd.com/read/28736763/immunologic-effects-of-maraviroc-in-hiv-infected-patients-with-severe-cd4-lymphopenia-starting-antiretroviral-therapy-a-sub-study-of-the-cadiris-trial
#12
Pablo F Belaunzarán-Zamudio, Livio Azzoni, David H Canaday, Yanink N Caro-Vega, Brian Clagget, Mohammed S Rassool, Benigno Rodriguez, Ian Sanne, Irini Sereti, Juan G Sierra-Madero, Michael M Lederman
BACKGROUND: We aimed to describe the mechanisms of immunological recovery and the effects of blocking CCR5 in patients starting ART with advanced HIV-infection. METHODS: This was a sub-study of a 48 week double-blind, clinical trial where patients starting ART with CD4+ cell counts <100 cells/uL were randomized to receive maraviroc or a placebo. CD4+ and CD8+ cell maturation phenotypes, expression of PD-1 and CCR5, and activation indices were measured at weeks 0, 4, 12, 24, and 48...
2017: Pathogens & Immunity
https://www.readbyqxmd.com/read/28734577/characterization-of-a-pvl-negative-community-acquired-methicillin-resistant-staphylococcus-aureus-strain-of-sequence-type-88-in-china
#13
Lu Sun, Dandan Wu, Yan Chen, Qian Wang, Haiping Wang, Yunsong Yu
Sequence type 88 community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) strain SR434, isolated from an outpatient with skin and soft tissue infection, was subjected to whole genome sequencing, antimicrobial susceptibility testing, mouse skin infection model and hemolysis analysis to identify its virulence and resistance determinants. MRSA strain SR434 is resistant to clindamycin, erythromycin and fosfomycin. Four plasmids with resistance genes were identified in this strain, including a 20,658bp blaZ-carrying plasmid, a 2473bp ermC-carrying plasmid, a 2622bp fosB7-carrying plasmid (86% identity with plasmid in a ST2590 MRSA strain) and a 4817bp lnuA-carrying plasmid (99% identity with pLNU4 from bovine coagulase-nagetive Staphylococci)...
July 13, 2017: International Journal of Medical Microbiology: IJMM
https://www.readbyqxmd.com/read/28719668/epidemiology-and-distribution-of-10-superantigens-among-invasive-streptococcus-pyogenes-disease-in-germany-from-2009-to-2014
#14
Matthias Imöhl, Christina Fitzner, Stephanie Perniciaro, Mark van der Linden
A nationwide laboratory-based surveillance study of invasive S. pyogenes infections was conducted in Germany. Invasive isolates (n = 719) were obtained between 2009 and 2014. Most isolates were obtained from blood (92.1%). The proportions of isolates from cerebrospinal fluid, pleural fluid, synovial fluid and peritoneal fluid were 3.9%, 1.8%, 1.7% and 0.6%, respectively. The most common emm types were emm 1 (31.8%), emm 28 (15.4%) and emm 89 (14.5%). The most common superantigen genes (speA, speC, speG, speH, speI, speJ, speK, speL, speM, ssa) identified from S...
2017: PloS One
https://www.readbyqxmd.com/read/28715277/superantigen-staphylococcal-enterotoxin-c1-inhibits-the-growth-of-bladder-cancer
#15
Tao Liu, Lin Li, Lei Yin, Hongyuan Yu, Hongwei Jing, Yang Liu, Chuize Kong, Mingkai Xu
Superantigens can induce cell-mediated cytotoxicity preferentially against MHC II-positive target cells with large amounts of inflammatory cytokines releasing. In this study, superantigen staphylococcal enterotoxin C (SEC) 1 was investigated to evaluate its potential in bladder cancer immunotherapy in vitro and in vivo. Our results revealed that SEC1 could stimulate the proliferation of human peripheral blood mononuclear cells (PBMCs) in a dose-dependent manner, accompanied with the release of interleukin-2, interferon-γ, and tumor necrosis factor-α, and increased the population of CD4(+) T cells and CD8(+) T cells...
September 2017: Bioscience, Biotechnology, and Biochemistry
https://www.readbyqxmd.com/read/28683848/role-of-local-allergic-inflammation-and-staphylococcus-aureus-enterotoxins-in-chinese-patients-with-chronic-rhinosinusitis-with-nasal-polyps
#16
K-J Cheng, Y-Y Xu, M-L Zhou, S-H Zhou, S-Q Wang
OBJECTIVE: To investigate the role of local allergic inflammation and Staphylococcus aureus enterotoxins in chronic rhinosinusitis with nasal polyps. METHODS: This study included 36 patients with chronic rhinosinusitis with nasal polyps and 18 controls. Total immunoglobulin E, eosinophil cationic protein, staphylococcal enterotoxin types A and B specific immunoglobulin E, staphylococcal enterotoxin types A and B, and myeloperoxidase levels were determined. RESULTS: Four patients with chronic rhinosinusitis with nasal polyps had a local allergy...
August 2017: Journal of Laryngology and Otology
https://www.readbyqxmd.com/read/28680421/an-emm5-group-a-streptococcal-outbreak-among-workers-in-a-factory-manufacturing-telephone-accessories
#17
Mingliang Chen, Wenqing Wang, Lihong Tu, Yaxu Zheng, Hao Pan, Gangyi Wang, Yanxin Chen, Xi Zhang, Linying Zhu, Jian Chen, Min Chen
Ranked among the top10 infectious causes of death worldwide, group A Streptococcus (GAS) causes small- and large-scale outbreaks, depending on the trigger as transmission of a GAS strain or expansion of predominant clones. In China, GAS infections other than scarlet fever are not notifiable. In Shanghai, an epidemiological investigation was initiated after two successive severe pneumonia cases with one death in a digital factory, from where outbreaks are less widely reported. The investigation was performed using emm typing, pulsed-field gel electrophoresis (PFGE) typing, superantigen profiling, and genome analysis...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28653102/identification-of-set11-from-staphylococcus-aureus-mu50-strain-as-a-ortholog-of-ssl7-via-bioinformatic-analysis-and-determination-of-its-possible-targets-from-human-serum-using-cnbr-pull-down-assays
#18
Ying Li, Xiaobao Chen, Nan Jia, Xuan Zhang, Jianye Zang
OBJECTIVES: To identify and characterize staphylococcus exotoxin-like (SET) protein Set11 from Staphylococcus aureus Mu50 strain and its possible targets proteins from human blood/serum. RESULTS: Set11 is a member of the staphylococcal superantigen-like (SSL) proteins (also called Staphylococcus exotoxin-like (SET) proteins) family that is found in staphylococcal strain Mu50. Its structure and function, however, remain unknown. We performed bioinformatics analysis of Set11: it had 90% sequence identity to SSL7 in NCTC 8325 strain, indicating Set11 is a SSL7 ortholog...
June 26, 2017: Biotechnology Letters
https://www.readbyqxmd.com/read/28646491/sickle-cells-produce-functional-immune-modulators-and-cytotoxics
#19
Chiao-Wang Sun, Li-Chen Wu, Peter L Knopick, David S Bradley, Tim Townes, David S Terman
Sickle erythrocytes' (SSRBCs) unique physical adaptation to hypoxic conditions renders them able to home to hypoxic tumor niches in vivo, shut down tumor blood flow and induce tumoricidal responses. SSRBCs are also useful vehicles for transport of encapsulated drugs and oncolytic virus into hypoxic tumors with enhanced anti-tumor effects. In search of additional modes for arming sickle cells with cytotoxics, we turned to a lentiviral β-globin vector with optimized Locus Control Region/β-globin coding region/promoter/enhancers...
June 24, 2017: American Journal of Hematology
https://www.readbyqxmd.com/read/28642756/high-prevalence-of-macrolide-resistance-and-molecular-characterization-of-streptococcus-pyogenes-isolates-circulating-in-china-from-2009-to-2016
#20
Binghuai Lu, Yujie Fang, Yanyan Fan, Xingchun Chen, Junrui Wang, Ji Zeng, Yi Li, Zhijun Zhang, Lei Huang, Hongxia Li, Dong Li, Fengxia Zhu, Yanchao Cui, Duochun Wang
Streptococcus pyogenes, or group A Streptococcus, is a pathogen responsible for a wide range of clinical manifestations, from mild skin and soft tissue infections and pharyngitis to severe diseases. Its epidemiological characteristics should be comprehensively under surveillance for regulating the national prevention and treatment practice. Herein, a total of 140 S. pyogenes, including 38 invasive and 102 noninvasive isolates, were collected from infected patients in 10 tertiary general hospitals from 7 cities/provinces in China during the years 2009-2016...
2017: Frontiers in Microbiology
keyword
keyword
116590
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"