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1.
Cristina Escoda-Ferran Esther Carrasco Miguel Caballero-Baños Cristina Miró-Julià Mario Martínez-Florensa Marta Consuegra-Fernández Vanesa G. Martínez Fu-Tong Liu Francisco Lozano 《FEBS letters》2014
CD6 is a lymphocyte glycoprotein receptor that physically associates with the antigen-specific receptor complex at the center of the immunological synapse, where it interacts with its ligand CD166/ALCAM. The present work reports the carbohydrate-dependent interaction of CD6 and CD166/ALCAM with Galectin-1 and -3, two well-known soluble mammalian lectins. Both galectins interfered with superantigen-induced T cell proliferation and cell adhesion phenomena mediated by the CD6-CD166/ALCAM pair, while CD6 expression protected cells from galectin-induced apoptosis. The results suggest that interaction of Galectin-1 and -3 with CD6 and CD166/ALCAM might modulate some relevant aspects of T cell physiology. 相似文献
2.
Fahriye Ceyda Dudak Esra Acar Soykut Murat Erman Oğuz Fatih Yaşar İsmail Hakkı Boyacı 《Journal of molecular recognition : JMR》2010,23(4):369-378
Staphylococcal enterotoxin B (SEB) is an exotoxin produced by Staphylococcus aureus and commonly associated with food poisoning. In this study, SEB‐binding peptides were identified by screening a phage displayed peptide library. The binding of peptides to SEB was tested with isothermal titration calorimetry (ITC) and of the five selected peptides, three showed affinity to SEB, with one measured to have the highest affinity constant (105 M?1). ITC revealed that the interaction of peptide ligands with SEB was driven entropically and the binding was dominated by hydrophobic interactions. Circular dichroism (CD) measurements and molecular dynamics (MD) simulations, together, give a structural insight into the interaction of peptides with SEB. While SEB binding peptides showed random coil structure before binding, after complex formation they had more ordered structures. The peptide with highest affinity to SEB showed stable conformation during MD simulation. Taken together, our approach about thermodynamic and structural characterization of peptide ligands can be used to develop aptamers, with high affinity and selectivity, for biosensor applications. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
3.
The high-density attachment of active antibodies or other recognition molecules to the capture surface is one of the fundamental processes in route to developing effective biosensors. One method applied frequently to enzymatic sensor systems has been the layer-by-layer assembly of the bioactive surface. Cui et al. [Cui, X., Pei, R., Wang, Z., Yang, F., Ma, Y., Dong, S., Yang, X., 2003. Biosens. Bioelectron. 18, 59–67] extended this concept to immunosensors, where they formed multilayers composed of avidin and biotinylated antibody and reported this construct to be a potent way to form an effective surface for surface plasmon resonance biodetection. We reexamined this concept in an effort to establish a simple method to improve the activity of polystyrene capture surfaces used in sandwich fluoroimmunoassays for the detection of the target, staphylococcal enterotoxin B (SEB). Using multilayers prepared by alternating between NeutrAvidin and either biotinylated mono or polyclonal anti-SEB antibody, we found that virtually all the SEB-binding activity was derived from the final layer added; and that additional layers provided no observable enhancement in fluoroimmunoassay signal strength. 相似文献
4.
Fooladi AA Sattari M Hassan ZM Mahdavi M Azizi T Horii A 《Biotechnology letters》2008,30(12):2061-2059
The bacterial superantigen staphylococcal enterotoxin B (SEB) is a potent inducer of cytotoxic T-cell activity and cytokine
production in vivo. We investigated the possibility of the therapeutic application of SEB in patients with fibrosarcoma. The
anti-tumor effect of SEB in mice with inoculated fibrosarcoma (WEHI-164) was examined by intravenous (IV) and intratumoral
(IT) injection and the sizes of the inoculated tumors, IFN-γ production, and CD4+/CD8+ T cell infiltration were determined.
The inoculated tumors were also examined histologically. In the mice in the IV-injected group, a significant reduction (P < 0.02) of tumor size was observed in comparison with mice in the IT-injected and control groups. Furthermore, the mice in
the IV-injected group showed significantly higher levels of IFN-γ (P < 0.009) and CD4+/CD8+ T cell infiltration when compared with the other groups (P < 0.02). A significantly higher frequency of necrosis in tumor tissues was also observed in mice in the IV-injected group
(P < 0.05). Our present findings suggest that tumor cell death is caused by increased cytotoxic T-cell activity and cytokine
levels in response to the IV injection of SEB and that SEB may be a good option for use as a novel therapy in patients with
fibrosarcoma.
An erratum to this article can be found at 相似文献
5.
Khreich N Lamourette P Boutal H Devilliers K Créminon C Volland H 《Analytical biochemistry》2008,377(2):182-188
Staphylococcus enterotoxin B (SEB) is one of several toxins produced by the gram positive bacterium Staphylococcus aureus. SEB is a major cause of food poisoning and represents a significant biological threat with regard to bioterrorism. A rapid, sensitive, and specific method is required to monitor food and water in cases of both natural and intentional contamination by this toxin. This report presents an improved immunochromatographic test (ICT) using immunoliposomes as label for the detection of SEB. For the first time in an ICT, the signal generated by the sulforhodamine B encapsulated into immunoliposomes was measured by fluorescence, allowing a 15-fold increase in sensitivity compared with that for visual detection of colored labels. The ICT was completed within 30 min, providing a limit of detection close to 20 pg/ml in buffer and showing no cross-reactivity with the other major toxin of the bacterium, Staphylococcus enterotoxin A. This sensitivity was retained when analyzing SEB spiked in various alimentary matrices, mimicking contaminated foods. Due to the use of fluorescent immunoliposomes as label, the present assay offers the inherent simplicity and speed of a dipstick assay while providing detection of low levels of SEB in real samples. 相似文献
6.
7.
Epidemiology of skeletal eroding band on the Great Barrier Reef and the role of injury in the initiation of this widespread coral disease 总被引:1,自引:0,他引:1
Skeletal eroding band (SEB), which manifests as dense aggregations of the ciliate Halofolliculina corallasia, was the first coral disease described from the Indo-Pacific. Little is known about its etiology or impact. This study describes
the distribution, prevalence and host range of SEB on a 500 km extent of the Great Barrier Reef (GBR), together with in situ
rates of progression and infection following experimental injury. SEB occurred on 90–100% of reefs surveyed (n=18) in each of 3 years, demonstrating that SEB is widely distributed and persistent. SEB had the highest prevalence of any
disease, affecting approximately 2% of 283,486 scleractinians and hydrocorals surveyed. Its host range was large, affecting
12 families and at least 82 scleractinian species, as well as the hydrocoral, Millepora. Corals in the families Pocilloporidae and Acroporidae were most susceptible, the former being up to five times more susceptible
than other families. Progressive tissue loss was recorded on 95% of Acropora muricata colonies monitored (n = 18), with rates of SEB progression averaging ∼2 mm/day. Injury experiments demonstrated that H. corallasia, the putative pathogen of SEB, readily colonised recently exposed coral skeleton in the absence of a vector, but did not
colonise intact coral tissue. Invading ciliates failed to form band-like aggregations associated with progressive tissue loss
on any of three coral species tested experimentally, suggesting that, while H. corallasia readily colonises recently exposed coral skeleton, it may not be sufficient in itself to cause tissue mortality. Interactions
with additional agents or factors, increasing ciliate virulence or lowering disease resistance of coral hosts may be required
before halofolliculinid infections become associated with tissue loss. 相似文献
8.
Tatsuo Hase Marti Jett Edward Asafo-Adjei Michael Topper 《In vitro cellular & developmental biology. Animal》1996,32(6):322-328
Summary The release of chromaffin granular content from staphylococcal enterotoxin B (SEB)-treated and-untreated PC12 cells was studied
by electron microscopy. The treatment of the cells with SEB at the concentration of 20 μg/ml caused marked increase of the
chromaffin granules that either bound to the plasma membrane by the characteristic rods, measuring 15 to 20 nm in length and
showing a tubular structure, or budded off at the free cell surface, surrounded by a layer of rod-containing cytoplasm and
enclosed by the plasma membrane. The binding between the granular and plasma membranes by the rods did not lead to membrane
fusion and exocytosis of the granular content. Many of the bound granules showed vesiculation with loss of the electron-dense
core material; at the same time, some of the binding rods contained intraluminal electron-dense material similar to the granular
core material. These findings suggested that the electron-dense material (i.e., norepinephrine) of the bound granules was
released extracellularly through channels within the rods. Although the granules were bound to the plasma membrane with equal
frequency at the free and contiguous cell surfaces, the granular budding occurred only at the free cell surface, indicating
that it occurred incidentally to some granules bound at the free cell surfaces. On the basis of the morphological observations,
it is postulated that the electron-dense material of the bound granule is selectively released extracellularly through the
rods, leaving the vesiculated granules behind in the cytoplasm. The same mode of release of the granular content was observed,
though less frequently, in the untreated control cells. No morphological evidence that indicated that the granular content
was released extracellularly by exocytosis was found in the treated and control cells. The present observations indicated
that the SEB treatment of PC12 cells stimulated the binding of chromaffin granules to the plasma membrane by the rods and
the budding of the bound granules at the free cell surface. 相似文献
9.
Using a newly developed fluorescent nanoparticle (NP) that gives rise to a high-intensity and stable fluorescent light, a sensitive antibody (Ab) microarray assay system has been developed for specific detection of bioterrorism agents, as exemplified by ricin, cholera toxin (CT), and staphylococcal enterotoxin B (SEB). The Ab microarray uses a sandwich format that consists of capture Abs, analytes (toxins), biotinylated detection Abs, and avidin-conjugated NP. In all three cases, polyclonal Abs (pAbs) displayed superiority over monoclonal antibodies (mAbs) in capturing toxins on microarray slides even when the pAbs and mAbs had similar affinity as determined by enzyme-linked immunosorbent assay (ELISA). The detection system was successfully used to detect toxins spiked in milk, apple cider, and blood samples. We were able to detect ricin at 100 pg/ml in buffer and at 1 ng/ml in spiked apple cider or milk, whereas CT and SEB were detected at 10 pg/ml in buffer and 100 pg/ml in spiked apple cider or milk. High specificities were also demonstrated in the detection of mixed toxin samples with similar sensitivities. The matrix effect of blood samples on the detection of mixed toxins seems to be minimal when the toxin concentration is at or above 100 ng/ml. The current study highlights the significant role of pAb and NP in increasing selectivity and sensitivity of toxin detection in a microarray format. 相似文献
10.
Screening and characterization of anti‐SEB peptides using a bacterial display library and microfluidic magnetic sorting
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Joshua M. Kogot Joseph M. Pennington Deborah A. Sarkes David A. Kingery Paul M. Pellegrino Dimitra N. Stratis‐Cullum 《Journal of molecular recognition : JMR》2014,27(12):739-745
Bacterial peptide display libraries enable the rapid and efficient selection of peptides that have high affinity and selectivity toward their targets. Using a 15‐mer random library on the outer surface of Escherichia coli (E.coli), high‐affinity peptides were selected against a staphylococcal enterotoxin B (SEB) protein after four rounds of biopanning. On‐cell screening analysis of affinity and specificity were measured by flow cytometry and directly compared to the synthetic peptide, off‐cell, using peptide‐ELISA. DNA sequencing of the positive clones after four rounds of microfluidic magnetic sorting (MMS) revealed a common consensus sequence of (S/T)CH(Y/F)W for the SEB‐binding peptides R338, R418, and R445. The consensus sequence in these bacterial display peptides has similar amino acid characteristics with SEB peptide sequences isolated from phage display. The Kd measured by peptide‐ELISA off‐cell was 2.4 nM for R418 and 3.0 nM for R445. The bacterial peptide display methodology using the semiautomated MMS resulted in the discovery of selective peptides with affinity for a food safety and defense threat. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Journal of Molecular Recognition published by John Wiley & Sons, Ltd. 相似文献