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91.
92.
Solórzano C Bouquelet S Pereyra MA Blanco-Favela F Slomianny MC Chavez R Lascurain R Zenteno E Agundis C 《Glycoconjugate journal》2006,23(7-8):591-598
Neutrophils participate in host protection and central to this process is the regulation of oxidative mechanisms. We purified
by affinity chromatography the receptor for the GlcNAc-specific WGA from CD14+ CD16+ cell lysates (WGAr). The receptor is
a 141 kDa glycoprotein constituted by two subunits of 78 and 63 kDa. It is mainly composed of Ser, Asx, and Gly, and, in a
minor proportion, His, Cys, and Pro. Its glycan portion contains GlcNAc, Gal, and Man; NeuAc and GalNAc were identified in
a minor proportion. The amino acid sequence of the WGA receptor was predicted from tryptic peptides by MALDI-TOF, both subunits
showed homology with cytokeratin type II (26 and 29% for the 78 and 63 kDa subunits, respectively); the 78 kDa subunit showed
also homology with the human transferrin receptor (24%). Antibodies against WGAr induce higher oxidative burst than WGA, determined
by NBT reduction; however, this effect was inhibited (p < 0.05) with GlcNAc suggesting that WGAr participates as mediator in signal transduction in neutrophils. 相似文献
93.
Labarthe MC Halanek N Birchall L Russell N Desel C Todryk S Peters MJ Lucas A Falkenberg FW Dalgleish AG Whelan M Ward SJ 《Cancer immunology, immunotherapy : CII》2006,55(3):277-288
Allogeneic whole tumour cell vaccines are inherently practical compared with autologous vaccines. Cell lines are derived from
allogeneic tumour, grown in bulk and then administered as a vaccine to the patient, following irradiation, which not only
prevents any replication but also enhances antigen presentation. Protection is believed to occur through the presentation
of antigens shared between the syngeneic and allogeneic tumours. Although cytokine-transfected tumour whole cell vaccines
have been used clinically, little data is available comparing the effects of immunomodulatory cytokine-transfection directly
on the same cells when used as both an allogeneic and autologous vaccine. To address this, weakly immunogenic B16-F10 (H-2b) murine melanoma was transfected to secrete either GM-CSF, IL-4 or IL-7. Prophylactic vaccination of both syngeneic C57/BL6
(H-2b) (B6) and allogeneic C3H/Hej (H-2k) (C3H) mice showed the effects of transfected cytokine varied between models. Both GM-CSF and IL-7 significantly (P<0.05) increased the levels of protection within syngeneic B6 mice, but had a diminished effect (P>0.05) within C3H allogeneic mice. Allogeneic B16-F10 cells and syngeneic K1735 cells generated CTL against K1735 suggesting
cross-reactive immunity. Using cells labeled with fluorescent dye we demonstrate that irradiated vaccines, of either syngeneic
or allogeneic origin, appear to generate potent immune responses and fragments of either vaccine remain at the injection site
for up to 9 days. This study shows that protection can be enhanced in vivo by using transfected cytokine, but suggests that
irradiated whole cell vaccines, of either tissue-type, are rapidly processed. This leads to the conclusion that the cytokine
effects are transient and thus transfection with cytokine may be of limited long-term use in situ. 相似文献
94.
For this study, an in-depth review of the classification of Lactococcus lactis phages was performed. Reference phages as well as unclassified phages from international collections were analyzed by stringent DNA-DNA hybridization studies, electron microscopy observations, and sequence analyses. A new classification scheme for lactococcal phages is proposed that reduces the current 12 groups to 8. However, two new phages (Q54 and 1706), which are unrelated to known lactococcal phages, may belong to new emerging groups. The multiplex PCR method currently used for the rapid identification of phages from the three main lactococcal groups (936, c2, and P335) was improved and tested against the other groups, none of which gave a PCR product, confirming the specificity of this detection tool. However, this method does not detect all members of the highly diverse P335 group. The lactococcal phages characterized here were deposited in the Félix d'Hérelle Reference Center for Bacterial Viruses and represent a highly diverse viral community from the dairy environment. 相似文献
95.
Cholesterol-induced apoptotic macrophages elicit an inflammatory response in phagocytes, which is partially attenuated by the Mer receptor 总被引:1,自引:0,他引:1
Li Y Gerbod-Giannone MC Seitz H Cui D Thorp E Tall AR Matsushima GK Tabas I 《The Journal of biological chemistry》2006,281(10):6707-6717
Macrophage apoptosis and the ability of phagocytes to clear these apoptotic cells are important processes in advanced atherosclerosis. Phagocytic clearance not only disposes of dead cells but usually elicits an anti-inflammatory response. To study this process in a model of advanced lesional macrophage death, macrophages rendered apoptotic by free cholesterol loading (FC-AMs) were incubated briefly with fresh macrophages ("phagocytes"). FC-AMs were promptly ingested by the phagocytes, which was dependent upon actin polymerization and the phagocyte Mer receptor. Surprisingly, this brief exposure to FC-AMs triggered a modest proinflammatory response in the phagocytes: tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1beta were induced, whereas the levels of transforming growth factor-beta and IL-10 were not increased. This response required cell contact between the FC-AMs and phagocytes but not FC-AM ingestion. TNF-alpha and IL-1beta induction required one or more proteins on the FC-AM surface and was dependent on signaling through extracellular signal-regulated kinase-1/2 mitogen-activated protein kinase and nuclear factor-kappaB in the phagocytes. TNF-alpha production was markedly greater when Mer-defective phagocytes were used, indicating that Mer attenuated the inflammatory response. Interestingly, a more typical anti-inflammatory response was elicited when phagocytes were exposed to macrophages rendered apoptotic by oxidized low density lipoprotein or UV radiation. Thus, the proinflammatory milieu of advanced atherosclerotic lesions may be promoted, or at least not dampened, by contact between FC-induced apoptotic macrophages and neighboring phagocytes prior to apoptotic cell ingestion. 相似文献
96.
The main chemical and physical features of the Acacia senegal exudate gum and its molecular fractions isolated by chromatographies were determined using a wide variety of methods. Three main molecular fractions were isolated after hydrophobic interaction chromatography (HIC) and biochemical analyses confirmed the presence of an arabinogalactan-peptide (FI), an arabinogalactan-protein (FII), and a glycoprotein (FIII) fraction as described commonly in the literature. Further purification of FIII using size exclusion chromatography revealed three distinct populations. A wide molecular weight distribution within each population with the presence of at least two distinct molecular species per population was identified by high performance size exclusion chromatography coupled to on line multi-angle laser light scattering (HPSEC-MALLS). In addition, both sugars content (neutral and uronic acids) and UV profiles revealed that FIII was composed of a continuum of molecular species differing both by their protein-to-sugar ratio and molecular weight. FI and FII had average molecular weight M(w) of 2.86 x 10(5) and 1.86 x 10(6) g.mol(-1), respectively, and a low polydispersity index (M(w)()/M(n) approximately 1.3). The three populations identified in FIII after HIC separation had M(w) of 2.67 x 10(6), 7.76 x 10(5), and 2.95 x 10(5) g.mol(-1) and very low polydispersity indexes (1.13, 1.04, and 1.01). Estimation of the polypeptide backbone length in the three fractions gave 43, 2253, and 4443 amino acid residues, respectively, hydroxyproline (Hyp) and serine being the most prominent residues within FI and FII, Hyp and Asx (asparagine + aspartic acid) within FIII. Secondary structure prediction from circular dichroism data resulted in polyproline II, beta-sheet, and random coil structures for FII and FIII, whereas no secondary structure was identified in FI. The existence of exposed tryptophanyl residues to the solvent was noticed by fluorescence in FII and FIII, tryptophan residues being absent from FI. In addition, 8-5' non cyclic diferulic acid was identified to be covalently linked to carbohydrate moieties of FII. Infrared spectroscopy identified the different vibrations of saccharidic and peptidic bonds with absorbance amplitudes in agreement with sugar and protein elementary analyses. Titration measurements in order to evaluate the number of charges on total Acacia gum and its molecular fractions revealed that 100% of charges came from polysaccharidic moieties (i.e., glucuronic acids) in FI. Charges coming from polysaccharidic moieties were of 91.3% and 37.9% for FII and FIII, respectively, the remaining 8.7% and 62.1% charges in FII and FIII molecular fractions coming from the polypeptidic backbone. 相似文献
97.
A new member of the PBAN family in Spodoptera littoralis: molecular cloning and immunovisualisation in scotophase hemolymph 总被引:2,自引:0,他引:2
Iglesias F Marco P François MC Camps F Fabriàs G Jacquin-Joly E 《Insect biochemistry and molecular biology》2002,32(8):901-908
In this article, we report evidence suggesting that the immunoreactive factor previously detected in Spodoptera littoralis scotophase hemolymph is PBAN, which supports a humoral route of the hormone to the pheromone gland. Western blot after native-PAGE of prepurified scotophase hemolymph extracts yielded an immunoreactive band with the same mobility as S. littoralis Br-SOG factor and the expected mobility for a noctuid PBAN. This band was not detected in photophase hemolymph extract. The identity of S. littoralis Br-SOG factor as PBAN was obtained from cDNA cloning using RT-PCR strategy. This allowed us to deduce the amino acid sequence of Spl-PBAN, which is highly homologous to other known PBANs. Moreover, we found that the PBAN encoding cDNA also encoded four other putative amidated peptides (Spl-DH homologue, Spl-alpha-NP, Spl-beta-NP and Spl-gamma-NP) that are identical or highly conserved among noctuids, and two non amidated peptides of unknown function. This cDNA organization is common to all known cDNAs encoding PBANs, leading to the release of different peptides after putative enzymatic cleavage of the preprohormone. 相似文献
98.
Henriette L. Pedersen Jonatan U. Fangel Barry McCleary Christian Ruzanski Maja G. Rydahl Marie-Christine Ralet Vladimir Farkas Laura von Schantz Susan E. Marcus Mathias C. F. Andersen Rob Field Mats Ohlin J. Paul Knox Mads H. Clausen William G. T. Willats 《The Journal of biological chemistry》2012,287(47):39429-39438
Microarrays are powerful tools for high throughput analysis, and hundreds or thousands of molecular interactions can be assessed simultaneously using very small amounts of analytes. Nucleotide microarrays are well established in plant research, but carbohydrate microarrays are much less established, and one reason for this is a lack of suitable glycans with which to populate arrays. Polysaccharide microarrays are relatively easy to produce because of the ease of immobilizing large polymers noncovalently onto a variety of microarray surfaces, but they lack analytical resolution because polysaccharides often contain multiple distinct carbohydrate substructures. Microarrays of defined oligosaccharides potentially overcome this problem but are harder to produce because oligosaccharides usually require coupling prior to immobilization. We have assembled a library of well characterized plant oligosaccharides produced either by partial hydrolysis from polysaccharides or by de novo chemical synthesis. Once coupled to protein, these neoglycoconjugates are versatile reagents that can be printed as microarrays onto a variety of slide types and membranes. We show that these microarrays are suitable for the high throughput characterization of the recognition capabilities of monoclonal antibodies, carbohydrate-binding modules, and other oligosaccharide-binding proteins of biological significance and also that they have potential for the characterization of carbohydrate-active enzymes. 相似文献
99.
Dsamou M Palicki O Septier C Chabanet C Lucchi G Ducoroy P Chagnon MC Morzel M 《Chemical senses》2012,37(1):87-95
The interindividual variation in the sensitivity to bitterness is attributed in part to genetic polymorphism at the taste receptor level, but other factors, such as saliva composition, might be involved. In order to investigate this, 2 groups of subjects (hyposensitive, hypersensitive) were selected from 29 healthy male volunteers based on their detection thresholds for caffeine, and their salivary proteome composition was compared. Abundance of 26 of the 255 spots detected on saliva electrophoretic patterns was significantly different between hypo- and hypersensitive subjects. Saliva of hypersensitive subjects contained higher levels of amylase fragments, immunoglobulins, and serum albumin and/or serum albumin fragments. It also contained lower levels of cystatin SN, an inhibitor of protease. The results suggest that proteolysis occurring within the oral cavity is an important perireceptor factor associated to the sensitivity to the bitter taste of caffeine. 相似文献