keyword
MENU ▼
Read by QxMD icon Read
search

Superantigen

keyword
https://www.readbyqxmd.com/read/28646491/sickle-cells-produce-functional-immune-modulators-and-cytotoxics
#1
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
#2
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
https://www.readbyqxmd.com/read/28633740/parvovirus-b19-infection-in-an-adult-presenting-with-connective-tissue-disease-like-symptoms-a-report-of-the-clinical-and-histological-findings
#3
J E Liles, S C Shalin, B A White, L B Trigg, J R Kaley
Parvovirus B19 infections in adults are usually associated with nonspecific and mild symptoms. However, cases presenting with a lupus-like syndrome have been described, leading to the hypothesis that parvovirus infection can induce connective tissue disease. Various histopathologic features of cutaneous manifestations of parvovirus have been reported, including features which overlap with those of connective tissue disease. Herein, we discuss an unusual case of Parvovirus  B19 infection in a middle-aged woman...
June 15, 2017: Dermatology Online Journal
https://www.readbyqxmd.com/read/28632753/mait-cells-launch-a-rapid-robust-and-distinct-hyperinflammatory-response-to-bacterial-superantigens-and-quickly-acquire-an-anergic-phenotype-that-impedes-their-cognate-antimicrobial-function-defining-a-novel-mechanism-of-superantigen-induced-immunopathology
#4
Christopher R Shaler, Joshua Choi, Patrick T Rudak, Arash Memarnejadian, Peter A Szabo, Mauro E Tun-Abraham, Jamie Rossjohn, Alexandra J Corbett, James McCluskey, John K McCormick, Olivier Lantz, Roberto Hernandez-Alejandro, S M Mansour Haeryfar
Superantigens (SAgs) are potent exotoxins secreted by Staphylococcus aureus and Streptococcus pyogenes. They target a large fraction of T cell pools to set in motion a "cytokine storm" with severe and sometimes life-threatening consequences typically encountered in toxic shock syndrome (TSS). Given the rapidity with which TSS develops, designing timely and truly targeted therapies for this syndrome requires identification of key mediators of the cytokine storm's initial wave. Equally important, early host responses to SAgs can be accompanied or followed by a state of immunosuppression, which in turn jeopardizes the host's ability to combat and clear infections...
June 2017: PLoS Biology
https://www.readbyqxmd.com/read/28624612/human-mast-cells-present-antigen-to-autologous-cd4-t-cells
#5
Sahar Lotfi-Emran, Brant R Ward, Quang T Le, Andrea L Pozez, Masoud H Manjili, Judith Woodfolk, Lawrence B Schwartz
BACKGROUND: Mast cells (MCs), the primary effector cell of the atopic response, participate in immune defense at host/environment interfaces, yet the mechanisms by which they interact with CD4(+)-T cells has been controversial. OBJECTIVE: We utilize in situ-matured primary human MCs and matched CD4(+)-T cells to diligently assess the ability of MCs to act as antigen-presenting cells. METHODS: We examined mature human skin-derived MCs by flow cytometry for expression of antigen-presenting molecules; for their ability to stimulate CD4(+)-T cells to express CD25 and proliferate when exposed to superantigen or to CMV antigen using matched T cells and MCs from CMV seropositive or seronegative donors; and for uptake of antigens...
June 14, 2017: Journal of Allergy and Clinical Immunology
https://www.readbyqxmd.com/read/28602067/bacterial-ball-as-an-unusual-finding-in-patients-with-chronic-rhinosinusitis
#6
Dong-Kyu Kim, Young Chan Wi, Su-Jin Shin, Youn Il Jang, Kyung Rae Kim, Seok Hyun Cho
Objectives: Pathophysiology of chronic rhinosinusitis (CRS) is very complex and has not yet been clearly understood. To date, various factors have been researched to have relations with the pathogenesis of CRS, such as superantigens and biofilms. Recently, we found an unusual pathological finding in patients with CRS, and we called this new entity as bacteria ball (or bioball). In this study, we analyze the clinical characteristics of bacteria ball occurred in CRS. Methods: This study enrolled consecutive 247 patients with CRS who underwent functional endoscopic sinus surgery from January 2015 to August 2016...
June 6, 2017: Clinical and Experimental Otorhinolaryngology
https://www.readbyqxmd.com/read/28581897/mutations-to-cysteine-residues-in-the-trypanosoma-cruzi-b-cell-superantigen-tc24-diminish-susceptibility-to-igm-mediated-hydrolysis
#7
Eric Luis Brown, Sarah Gunter, Kathryn M Jones, Christopher Seid, Heather T Essigmann, Maria Elena Bottazzi, Peter J Hotez, Bin Zhan, Ulrich Strych
B-cell superantigens (BC-SAgs) are immunoevasins that have evolved in response to innate catalytic IgM antibodies; germ-line encoded immunoglobulins present in the preimmune repertoire independent of prior antigen exposure. Catalysis is the result of a 2-step process that involves the formation of a non-covalent bond between the BC-SAg and the immunoglobulin first followed by covalent bond formation at the catalytic site resulting in target hydrolysis. Tc24 is a recently described Trypanosoma cruzi BC-SAg hypothesized to play a role in evading the humoral response early in the infection period...
June 5, 2017: Journal of Parasitology
https://www.readbyqxmd.com/read/28573424/vitamin-d-inhibits-the-staphylococcal-enterotoxin-b-induced-expression-of-tumor-necrosis-factor-in-microglial-cells
#8
Jinggui He, Xiyun Guo, Zhi-Qiang Liu, Ping-Chang Yang, Shaobo Yang
Microglial cells play a crucial role in inflammatory responses in neural tissue. Vitamin D (VitD3) deficiency is associated with the pathogenesis of inflammation. Staphylococcal enterotoxin B (SEB) is a superantigen and can initiate inflammation. This study tests a hypothesis that VitD3 deficiency upregulates the expression of tumor necrosis factor (TNF) in microglial cells. Microglial cells were isolated from the mouse brain. The microglial cells were cultured in the presence or absence of VitD3 or/and SEB...
June 1, 2017: Immunologic Research
https://www.readbyqxmd.com/read/28567041/pathogen-reactive-t-helper-cell-analysis-in-the-pig
#9
Friederike Ebner, Patrycja Schwiertz, Svenja Steinfelder, Robert Pieper, Jürgen Zentek, Nicole Schütze, Christoph G Baums, Gottfried Alber, Peter Geldhof, Susanne Hartmann
There is growing interest in studying host-pathogen interactions in human-relevant large animal models such as the pig. Despite the progress in developing immunological reagents for porcine T cell research, there is an urgent need to directly assess pathogen-specific T cells-an extremely rare population of cells, but of upmost importance in orchestrating the host immune response to a given pathogen. Here, we established that the activation marker CD154 (CD40L), known from human and mouse studies, identifies also porcine antigen-reactive CD4(+) T lymphocytes...
2017: Frontiers in Immunology
https://www.readbyqxmd.com/read/28561911/biofilm-formation-and-virulence-factor-analysis-of-staphylococcus-aureus-isolates-collected-from-ovine-mastitis
#10
Elisa Azara, Carla Longheu, Giovanna Sanna, Sebastiana Tola
AIMS: To perform a phenotypic and genotypic characterization of 258 S. aureus isolates from clinical ovine mastitis and used for the preparation of inactivated autogenous vaccines. METHODS AND RESULTS: The potential for biofilm production was determined by phenotypic test of Congo Red Agar (CRA) and by PCR for the detection of icaA/D genes. Isolates were also screened by PCR for the presence of enterotoxins (sea, seb, sec, sed and see), toxic shock syndrome toxin (tsst), leukotoxins (lukD-E, lukM and lukPV83), haemolysins (hly-β and hly-γ), autolysin (atlA) genes and encoding microbial surface components recognized adhesive matrix molecules (MSCRAMMs: clfA, clfB, fnbA, fnbB, bbp, cna, eno, fib, epbs, sdrC, sdrD and SdrE)...
May 31, 2017: Journal of Applied Microbiology
https://www.readbyqxmd.com/read/28512627/laboratory-mice-are-frequently-colonized-with-staphylococcus-aureus-and-mount-a-systemic-immune-response-note-of-caution-for-in-vivo-infection-experiments
#11
Daniel Schulz, Dorothee Grumann, Patricia Trübe, Kathleen Pritchett-Corning, Sarah Johnson, Kevin Reppschläger, Janine Gumz, Nandakumar Sundaramoorthy, Stephan Michalik, Sabine Berg, Jens van den Brandt, Richard Fister, Stefan Monecke, Benedict Uy, Frank Schmidt, Barbara M Bröker, Siouxsie Wiles, Silva Holtfreter
Whether mice are an appropriate model for S. aureus infection and vaccination studies is a matter of debate, because they are not considered as natural hosts of S. aureus. We previously identified a mouse-adapted S. aureus strain, which caused infections in laboratory mice. This raised the question whether laboratory mice are commonly colonized with S. aureus and whether this might impact on infection experiments. Publicly available health reports from commercial vendors revealed that S. aureus colonization is rather frequent, with rates as high as 21% among specific-pathogen-free mice...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28497030/fda-approved-immunosuppressants-targeting-staphylococcal-superantigens-mechanisms-and-insights
#12
REVIEW
Teresa Krakauer
Immunostimulating staphylococcal enterotoxin B (SEB) and related superantigenic toxins cause diseases in human beings and laboratory animals by hyperactivating cells of the immune system. These protein toxins bind to the major histocompatibility complex class II (MHC II) molecules and specific Vβ regions of T-cell receptors (TCRs), resulting in the stimulation of both monocytes/macrophages and T lymphocytes. The bridging of TCR with MHC II molecules by superantigens triggers intracellular signaling cascades, resulting in excessive release of proinflammatory mediators and massive polyclonal T-cell proliferation...
2017: ImmunoTargets and Therapy
https://www.readbyqxmd.com/read/28474248/a-potential-role-for-staphylococcal-and-streptococcal-superantigens-in-driving-skewing-of-tcr-v%C3%AE-subsets-in-tonsillar-hyperplasia
#13
Fiona J Radcliff, Fiona Clow, Murali Mahadevan, James Johnston, Thomas Proft, Richard G Douglas, John D Fraser
The TCR Vβ repertoire from patients with recurrent tonsillitis and/or tonsillar hyperplasia was examined to determine whether the TCR Vβ composition is suggestive of local superantigen activity and if so, whether it is associated with the presence of superantigen producing bacteria. Tonsil specimens were cultured aerobically to allow identification and isolation of the bacterial pathogens Staphylococcus aureus and Group A Streptococcus. TCR Vβ subset analysis of tonsil leucocytes was performed by flow cytometry...
May 4, 2017: Medical Microbiology and Immunology
https://www.readbyqxmd.com/read/28470343/pbmc-activation-via-the-erk-and-stat-signaling-pathways-enhances-the-anti-tumor-activity-of-staphylococcal-enterotoxin-a
#14
Xueting Liu, Liping Zeng, Zhongqiu Zhao, Jianxing He, Yang Xie, Lanyan Xiao, Shan Wang, Junyan Zhang, Zehong Zou, Ying He, Ailin Tao, Jianguo Zhang
Staphylococcal enterotoxin A (SEA) is well known as a superantigen and is highly potent in activating T lymphocytes. And it has been used clinically as an immunomodifier in the treatment of a number of tumors for years. However, the mechanism of its action remains largely unclear. In this study, SEA was found to significantly inhibit the proliferation and induce the death of human lung carcinoma A549 cells when co-cultured with human peripheral blood mononuclear cells (PBMCs). SEA could also induce the proliferation of human PBMCs and stimulate human PBMCs to release a wide range of cytokines that have broad anti-tumor activities such as IFN-γ, TNF-α, IL-2...
May 3, 2017: Molecular and Cellular Biochemistry
https://www.readbyqxmd.com/read/28469769/toxic-effects-of-seu-are-different-from-those-of-other-staphylococcal-enterotoxins
#15
Yi Li, Hui Deng, Pei-Dian Shi, Dan-Dan Xu, Li-Lin Zhang, Lei Zhang, Jin-Hai Huang
BACKGROUND/PURPOSE: Staphylococcal enterotoxins (SEs) are soluble extracellular proteins excreted by Staphylococcal bacterial strains, sharing similar structures and virulence. More than 20 genotypes of SEs have been identified, but the toxicity of some new SEs is still unclear. METHODS: In this study, we assessed the toxicity effects of six recombinant SEs (rSEA, rSEO, rSEG, rSEK, rSEU and rSEQ) on Balb/c mice by reverse transcription-polymerase chain reaction (RT-PCR)-based methods and enzyme activity detection...
2017: American Journal of Translational Research
https://www.readbyqxmd.com/read/28468970/concomitant-disruption-of-cd4-and-cd8-genes-facilitates-the-development-of-double-negative-%C3%AE-%C3%AE-tcr-peripheral-t-cells-that-respond-robustly-to-staphylococcal-superantigen
#16
Vaidehi R Chowdhary, Ashton Krogman, Ashenafi Y Tilahun, Mariam P Alexander, Chella S David, Govindarajan Rajagopalan
Mature peripheral double negative T (DNT) cells expressing αβ TCR but lacking CD4/CD8 coreceptors play protective as well as pathogenic roles. To better understand their development and functioning in vivo, we concomitantly inactivated CD4 and CD8 genes in mice with intact MHC class I and class II molecules with the hypothesis that this would enable the development of DNT cells. We also envisaged that these DNT cells could be activated by bacterial superantigens in vivo as activation of T cells by superantigens does not require CD4 and CD8 coreceptors...
June 1, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
https://www.readbyqxmd.com/read/28459299/enhanced-nasopharyngeal-infection-and-shedding-associated-with-an-epidemic-lineage-of-emm3-group-a-streptococcus
#17
Baharak Afshar, Claire E Turner, Theresa L Lamagni, Ken C Smith, Ali Al-Shahib, Anthony Underwood, Matthew T G Holden, Androulla Efstratiou, Shiranee Sriskandan
BACKGROUND: A group A Streptococcus (GAS) lineage of genotype emm3, sequence type 15 (ST15) was associated with a 6 month upsurge in invasive GAS disease in the UK. The epidemic lineage (Lineage C) had lost 2 typical emm3 prophages, Φ315.1 and Φ315.2 associated with the superantigen ssa, but gained a different prophage (ΦUK-M3.1) associated with a different superantigen, speC and a DNAse spd1. METHODS AND RESULTS: The presence of speC and spd1 in Lineage C ST15 strains enhanced both in vitro mitogenic and DNase activities over non-Lineage C ST15 strains...
May 1, 2017: Virulence
https://www.readbyqxmd.com/read/28442219/virulence-potential-of-staphylococcus-aureus-isolates-from-buruli-ulcer-patients
#18
Nana Ama Amissah, Monika A Chlebowicz, Anthony Ablordey, Caitlin S Tetteh, Isaac Prah, Tjip S van der Werf, Alex W Friedrich, Jan Maarten van Dijl, Ymkje Stienstra, John W Rossen
Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients. Previously sequenced genomes of 21 S. aureus isolates from BU patients were screened for the presence of virulence genes. The results show that all S. aureus isolates harbored on their core genomes genes for known virulence factors like α-hemolysin, and the α- and β-phenol soluble modulins...
June 2017: International Journal of Medical Microbiology: IJMM
https://www.readbyqxmd.com/read/28434738/relationships-among-superantigen-toxin-gene-profiles-genotypes-and-pathogenic-characteristics-of-staphylococcus-aureus-isolates-from-bovine-mastitis
#19
Dong Wang, Limei Zhang, Changfu Yong, Mingliang Shen, Tariq Ali, Muhammad Shahid, Kun Han, Xuezhang Zhou, Bo Han
Staphylococcus aureus is one of the major etiological agents of bovine mastitis, harboring a wide variety of staphylococcal superantigen (SAg) toxin genes. The SAg toxin genes are reported to be closely associated with the pathogenicity of the Staph. aureus causing the bovine mastitis. This study was conducted to investigate SAg toxin gene profiles and to assess the relationships among SAg toxin genes, genotypes of Staph. aureus, and their pathogenic properties. A total of 327 quarter milk samples were collected from bovine mastitis cases for isolation and identification of pathogens...
April 20, 2017: Journal of Dairy Science
https://www.readbyqxmd.com/read/28428772/molecular-characterization-of-staphylococcus-aureus-isolated-from-bovine-mastitis-and-close-human-contacts-in-south-african-dairy-herds-genetic-diversity-and-inter-species-host-transmission
#20
Tracy Schmidt, Marleen M Kock, Marthie M Ehlers
Staphylococcus aureus is one of the most common etiological agents of contagious bovine mastitis worldwide. The purpose of this study was to genetically characterize a collection of S. aureus isolates (bovine = 146, human = 12) recovered from cases of bovine mastitis and nasal swabs of close human contacts in the dairy environment. Isolates were screened for a combination of clinically significant antimicrobial and virulence gene markers whilst the molecular epidemiology of these isolates and possible inter-species host transmission was investigated using a combination of genotyping techniques...
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"