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1.
Hepatol Commun ; 7(6)2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37255349

RESUMO

BACKGROUND: Short-term perioperative administration of probiotics was shown to alleviate postoperative complications and promote liver recovery among patients undergoing resection for liver malignancy. The mechanisms by which probiotic bacteria effectively influence the gut microbiome composition during the perioperative time are controversial. Here, we aim to elucidate the short-term direct biological effect of probiotic microbiota-derived vesicles on host liver cells during the perioperative period. METHODS: Probiotic-derived vesicles (pbMVs) were administered postoperatively. pbMVs were isolated and characterized from probiotics, mainly from the bacteria genus Lactobacillus, Bifidobacterium, and Lactococcus. Mice underwent bile duct ligation, sham laparotomy (SHAM), or 70% partial hepatectomy (70%PH). pbMVs were tracked in vivo, and intrahepatic cellular and molecular aspects were analyzed by flow cytometry and qRT-PCR techniques. Liver sinusoidal endothelial cells (LSECs) analysis for Vascular Cell Adhesion Molecule-1(VCAM-1) expression following pbMV stimulation of cultured liver non-parenchymal cells which had been activated by LPS. RESULTS: The administered pbMV rapidly translocated to the liver after surgery. pbMV administrations following surgeries enhanced neutrophil clearance; there was a dramatic decline in the liver neutrophil-to-lymphocyte ratio Ly6G+/CD3+ and an increase in IL6 levels. pbMVs reduced intrahepatic VCAM1 and ICAM2 expression compared with control following SHAM and decrease in IL10 levels following 70%PH. The administration of pbMV improved liver regeneration 72 hours following surgical liver resection with a significant decrease in IL17 expression. pbMVs modulated VCAM-1 on liver sinusoidal endothelial cells in liver cell culture. CONCLUSIONS: Our study findings provide mechanistic insights into the liver-gut axis following surgery and illustrate how probiotic vesicles can reduce adhesion molecule expression and affect immune cell invasion and liver immunity, resulting in improved liver recovery following hepatic surgery.


Assuntos
Vesículas Extracelulares , Microbiota , Animais , Camundongos , Células Endoteliais , Molécula 1 de Adesão de Célula Vascular/metabolismo , Fígado/metabolismo
2.
3.
J Autoimmun ; 124: 102713, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34390919

RESUMO

Despite the existence of potent anti-inflammatory biological drugs e.g., anti-TNF and anti IL-6 receptor antibodies, for treating chronic inflammatory and autoimmune diseases, these are costly and not specific. Cheaper oral available drugs remain an unmet need. Expression of the acute phase protein Serum Amyloid A (SAA) is dependent on release of pro-inflammatory cytokines IL-1, IL-6 and TNF-α during inflammation. Conversely, SAA induces pro-inflammatory cytokine secretion, including Th17, leading to a pathogenic vicious cycle and chronic inflammation. 5- MER peptide (5-MP) MTADV (methionine-threonine-alanine-aspartic acid-valine), also called Amilo-5MER, was originally derived from a sequence of a pro-inflammatory CD44 variant isolated from synovial fluid of a Rheumatoid Arthritis (RA) patient. This human peptide displays an efficient anti-inflammatory effects to ameliorate pathology and clinical symptoms in mouse models of RA, Inflammatory Bowel Disease (IBD) and Multiple Sclerosis (MS). Bioinformatics and qRT-PCR revealed that 5-MP, administrated to encephalomyelytic mice, up-regulates genes contributing to chronic inflammation resistance. Mass spectrometry of proteins that were pulled down from an RA synovial cell extract with biotinylated 5-MP, showed that it binds SAA. 5-MP disrupted SAA assembly, which is correlated with its pro-inflammatory activity. The peptide MTADV (but not scrambled TMVAD) significantly inhibited the release of pro-inflammatory cytokines IL-6 and IL-1ß from SAA-activated human fibroblasts, THP-1 monocytes and peripheral blood mononuclear cells. 5-MP suppresses the pro-inflammatory IL-6 release from SAA-activated cells, but not from non-activated cells. 5-MP could not display therapeutic activity in rats, which are SAA deficient, but does inhibit inflammations in animal models of IBD and MS, both are SAA-dependent, as shown by others in SAA knockout mice. In conclusion, 5-MP suppresses chronic inflammation in animal models of RA, IBD and MS, which are SAA-dependent, but not in animal models, which are SAA-independent.


Assuntos
Artrite Reumatoide/imunologia , Receptores de Hialuronatos/genética , Inflamação/imunologia , Doenças Inflamatórias Intestinais/imunologia , Esclerose Múltipla/imunologia , Peptídeos/genética , Proteína Amiloide A Sérica/imunologia , Animais , Anti-Inflamatórios/uso terapêutico , Autoimunidade , Células Cultivadas , Biologia Computacional , Citocinas/metabolismo , Modelos Animais de Doenças , Humanos , Mediadores da Inflamação/metabolismo , Camundongos , Camundongos Knockout , Peptídeos/uso terapêutico , Proteína Amiloide A Sérica/genética
4.
Front Oncol ; 10: 328, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32232006

RESUMO

Solid pseudopapillary neoplasm (SPN) of pancreas is a rare pancreatic neoplasm with a low metastatic potential. Up to 10% of patients with localized disease at presentation will develop systemic metastases, usually in the peritoneum or the liver. Due to the rarity of SPNs and the overall excellent prognosis, reliable prognostic factors to predict malignant biological behavior remain undetermined. Therefore, we aimed to define clinical, histological, and microRNA patterns that are associated with metastatic disease. We conducted a retrospective single center study on all patients operated for SPN of pancreas between 1995 and 2018. Clinical and pathological data were collected, and expression patterns of 2,578 human microRNAs were analyzed using microRNA array (Affimetrix 4.1) in normal pancreases (NPs), localized tumors (LTs), and metastatic tumors (MTs). The diagnosis of SPN was confirmed in 35 patients who included 28 females and 3 males, with a mean age of 33.8 ± 13.9 years. The only clinical factor associated with metastases was tumor size (mean tumor size 5.20 ± 3.78 in LT vs. 8.13± 1.03 in MT, p < 0.012). Microscopic features of malignancy were not associated with metastases, nor were immunohistochemical stains, including the proliferative index KI67. Higher expressions of miR-184, miR-10a, and miR-887, and lower expressions of miR-375, miR-217, and miR-200c were observed in metastatic tissues on microarray, and validated by real-time polymerase chain reaction. Hierarchal clustering demonstrated that the microRNA expression pattern of MTs was significantly different from that of LTs. The only clinical factor associated with metastases of SPN of pancreas was tumor size. Histological features and immunohistological staining were not predictive of metastases. A panel of six microRNAs was differentially expressed in MTs, and these findings could potentially be used to predict tumor behavior. Validation of these results is needed in larger series.

5.
Front Immunol ; 8: 615, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28611775

RESUMO

Myeloid differentiation factor 88 (MyD88) recruits signaling proteins to the intracellular domain of receptors belonging to the toll-like/interleukin-1 (IL-1) receptor superfamily. Mice lacking MyD88 are highly susceptible to infectious diseases, but tend to resist experimentally induced autoimmune diseases such as experimental autoimmune encephalomyelitis (EAE) and manifest diminished allograft rejection. We reasoned that inhibition of MyD88 should influence the cytokine profile of responding T cells by blocking costimulatory molecule expression by antigen-presenting cells (APCs) and by inhibiting T-cell responses to IL-18. We now report that inhibition of MyD88 in human APCs led to decreased IFNγ and IL-17 production and a shift to IL-4 production by responding T cells in a mixed lymphocyte reaction. Direct inhibition of Myd88 in mouse and human T cells also reduced their production of IFNγ in response to IL-12/IL-18 stimulation. Finally, systemic MyD88 antagonism significantly reduced the clinical manifestations of EAE in mice. Thus, MyD88 appears to be a key factor in determining T cell phenotype and represents a potential target for therapeutic intervention.

6.
Acta Crystallogr E Crystallogr Commun ; 72(Pt 7): 884-7, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27555923

RESUMO

The title compound, [Cs(CH3COO)(C28H16O8)(C2H5OH)]·C2H5OH, is the product of the complexation between one vasarene analogue [1], bis ninhydrin naphthalene-1,3-diol and CsF, where the F(-) ion has reacted with residual acetic acid (AcOH), to form a [1]·CsOAc complex. The inter-molecular inter-actions with the multiple oxygen-containing functional groups of the ligand, as well as O-H⋯O hydrogen bonds involving the ethanol solvent mol-ecules, stabilize the complex, forming a chain along [100]. Additional parallel-displaced π-π stacking, with an inter-planar distance of 3.669 (1) Å, connect several unit cells in a three-dimensional supra-molecular structure, though, the larger size of AcO(-) (1.60 Å) compared to F(-) (1.33 Å) prevents the tight packing that was once achieved with other vasarene complexes of CsF.

7.
Acta Crystallogr E Crystallogr Commun ; 72(Pt 3): 399-402, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-27006816

RESUMO

The reaction between bis-ninhydrin resorcinol and benzyl-tri-methyl-ammonium fluoride in ethanol has produced the title compound, 2C10H16N(+)·2C24H13O8 (-)·1.5H2O, which contains a unique centrosymmetric supra-molecular dimeric entity, where two deprotonated ligands are held together via two strong and short [O⋯O = 2.4395 (13) Å] [O-H-O](-) bonds of the type negative charge-assisted hydrogen bonds (-CAHB). The central aromatic rings of the ligands create parallel-displaced π-π stacking at an inter-planar distance of 3.381 (1) Å, which helps stabilize the dimer. In the crystal, two symmetry-related solvent water mol-ecules with a site occupancy of 0.75 are attached to the carbonyl groups of the dimer by weaker O-H⋯O hydrogen bonds, forming chains along [101].

8.
Chirality ; 27(12): 919-28, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26425788

RESUMO

The heteromerous bistricyclic aromatic ene (BAE) 2,2'-dimethyl-10-(9H-xanthylidene)-9(10H)-anthrone (DMXA) was synthesized by a condensation of 10,10-dichloro-2-methylxanthene with 2-methylanthrone. X-ray crystallography of (E)-DMXA and xanthylidene-anthrone (XA) indicated that the molecules adopt anti-folded conformations with folding dihedral angles of 44°/44° and 39°/41°, respectively. The crystal structure of anti-folded (E)-DMXA does not indicate any xanthenylium-anthracenolate push-pull effect. E,Z-diastereomerization of DMXA was studied by (1) H-NMR coalescence-temperature measurements at different magnetic field strengths and by kinetic equilibration experiments. Free energy of activation for this process was 81.5 (±1.3) kJ/mol. B3LYP/6-311+G(d,p) calculations showed that anti-folded conformers of XA, (E)-DMXA, bianthrone (AA), and dixanthylene (XX) were global minima. The twisted conformers of XA, AA, and XX were local minima (ΔG298 = 16, 18, and 24 kJ/mol) with a substantial dipolar xanthenylium-anthracenolate dipolar contribution for XA. Chirality 27:919-928, 2015. © 2015 Wiley Periodicals, Inc.

9.
Inorg Chem ; 54(16): 8058-65, 2015 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-26241061

RESUMO

Potassium (K6[Ge6(µ-OO)6(µ-O)6(OH)6]·14H2O, 1), cesium ammonium (Cs4.2(NH4)1.8[Ge6(µ-OO)6(µ-O)6(OH)6]·8H2O, 2), and potassium ammonium (K2.4(NH4)3.6[Ge6(µ-OO)6(µ-O)6(OH)6]·6H2O, 3) peroxogermanates were isolated from 3% hydrogen peroxide aqueous solutions of the corresponding hydroxogermanates and characterized by single crystal and powder X-ray diffraction studies and by Raman spectroscopy and thermal analysis. The crystal structure of all three compounds consists of cations of potassium and/or ammonium and cesium, water molecules, and centrosymmetric hexanuclear peroxogermanate anion [Ge6(µ-OO)6(µ-O)6(OH)6](6-) with six µ-oxo- and six µ-peroxo groups. Peroxogermanates demonstrate relatively high thermal stability: the peroxide remains in the structure even after water release after heating to 100-120 °C. DFT calculations of the peroxogermanate [Ge6(µ-OO)6(µ-O)6(OH)6](6-) anion confirm its higher thermodynamic stability compared to the hydroperoxo- and oxogermanate analogues.

10.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 5): o506, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24860323

RESUMO

The title compound, C24H14O9·2CH3OH, displays a chair-shaped form. The two di-hydro-indenone ring systems are located above and below the central fused-ring system, the dihedral angles between the mean planes of di-hydro-indenone ring systems and the mean plane of central fused-ring system are 67.91 (5) and 73.52 (4)°, respectively. In the crystal, extensive O-H⋯O hydrogen bonds, weak C-H⋯O hydrogen bonds and C-H⋯π inter-actions link the mol-ecules into a three-dimensional supra-molecular architecture.

11.
Blood ; 122(15): 2609-17, 2013 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-23980064

RESUMO

Kindlin-3 is an integrin-binding focal adhesion adaptor absent in patients with leukocyte and platelet adhesion deficiency syndrome and is critical for firm integrin-dependent leukocyte adhesion. The role of this adaptor in leukocyte diapedesis has never been investigated. In the present study, the functions of Kindlin-3 in this process were investigated in effector T lymphocytes trafficking to various lymphoid and nonlymphoid tissues. In vitro, Kindlin-3-deficient T cells displayed severely impaired lymphocyte function antigen-1-dependent lymphocyte adhesion but partially conserved very late antigen-4 adhesiveness. In vivo, the number of adoptively transferred Kindlin-3-deficient T effectors was dramatically elevated in the circulating pool compared with normal effectors, and the Kindlin-3 mutant effectors failed to enter inflamed skin lesions. The frequency of Kindlin-3-deficient T effectors arrested on vessel walls within inflamed skin-draining lymph nodes was also reduced. Strikingly, however, Kindlin-3-deficient effector T cells accumulated inside these vessels at significantly higher numbers than their wild-type lymphocyte counterparts and successfully extravasated into inflamed lymph nodes. Nevertheless, on entering these organs, the interstitial motility of these lymphocytes was impaired. This is the first in vivo demonstration that Kindlin-3-stabilized integrin adhesions, although essential for lymphocyte arrest on blood vessels and interstitial motility, are not obligatory for leukocyte diapedesis.


Assuntos
Proteínas do Citoesqueleto/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Migração Transendotelial e Transepitelial/imunologia , Vasculite/imunologia , Transferência Adotiva , Animais , Adesão Celular/imunologia , Movimento Celular/imunologia , Proteínas do Citoesqueleto/deficiência , Dermatite/imunologia , Dermatite/patologia , Humanos , Integrina alfa4beta1/imunologia , Linfadenite/imunologia , Linfadenite/patologia , Antígeno-1 Associado à Função Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Vasculite/patologia
12.
Biomaterials ; 33(2): 614-23, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22014947

RESUMO

An effective intracellular protein delivery system was developed based on linear poly(amidoamine)s (PAAs) that form self-assembled cationic nanocomplexes with oppositely charged proteins. Two differently functionalized PAAs were synthesized by Michael-type polyaddition of 4-amino-1-butanol (ABOL) to cystamine bisacrylamide (CBA) and to bisacryloylpiperazine (BAP), yielding p(CBA-ABOL) and p(BAP-ABOL), respectively. These water-soluble PAAs efficiently condense human serum albumin (HSA) by self-assembly into stable nanoscaled and positively-charged complexes. The disulfide-containing p(CBA-ABOL)/HSA nanocomplexes exhibited high mucoadhesive properties and, while stable under neutral (extracellular) conditions, rapidly destabilized in a reductive (intracellular) environment due to the cleavage of the repetitive disulfide linkages in the CBA units of the polymer. Human-derived intestinal Caco-2/TC7 cells and HT29-MTX mucus secreting cells were exposed to these PAAs/HSA nanoparticles and the extent of their uptake and the localization within endosomal compartments were examined. The higher uptake of p(CBA-ABOL)/HSA than that of p(BAP-ABOL)/HSA suggests that the mucoadhesive properties of the p(CBA-ABOL) are beneficial to the uptake process. The transported HSA was located within early endosomes, lysosomes and the cytosol. The enhanced uptake of the p(CBA-ABOL)/HSA nanoparticles, observed in the presence of Cyclosporin A, a non-specific Multi Drug Resistance (MDR) blocker, indicates the possible efflux of these nanoparticles through MDR transporters. The results show that bioreducible PAAs have excellent properties for intracellular protein delivery, and should be applicative in oral protein delivery.


Assuntos
Proteínas de Transporte/metabolismo , Sistemas de Liberação de Medicamentos , Intestinos/citologia , Poliaminas/metabolismo , Proteínas/metabolismo , Células CACO-2 , Endossomos/metabolismo , Citometria de Fluxo , Células HT29 , Humanos , Nanopartículas/química , Transporte Proteico , Albumina Sérica/metabolismo
13.
Am J Respir Cell Mol Biol ; 46(3): 313-22, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21997486

RESUMO

Death-associated protein kinase (DAPk) is a tumor suppressor thought to inhibit cancer by promoting apoptosis and autophagy. Because cancer progression is linked to inflammation, we investigated the in vivo functions of DAPk in lung responses to various acute and chronic inflammatory stimuli. Lungs of DAPk knockout (KO) mice secreted higher concentrations of IL-6 and keratinocyte chemoattractant (or chemokine [C-X-C motif] ligand 1) in response to transient intranasal administrations of the Toll-like receptor-4 (TLR4) agonist LPS. In addition, DAPk-null macrophages and neutrophils were hyperresponsive to ex vivo stimulation with LPS. DAPk-null neutrophils were also hyperresponsive to activation via Fc receptor and Toll-like receptor-3, indicating that the suppressive functions of this kinase are not restricted to TLR4 pathways. Even after the reconstitution of DAPk-null lungs with DAPk-expressing leukocytes by transplanting wild-type (WT) bone marrow into lethally irradiated DAPk KO mice, the chimeric mice remained hypersensitive to both acute and chronic LPS challenges, as well as to tobacco smoke exposure. DAPk-null lungs reconstituted with WT leukocytes exhibited elevated neutrophil content and augmented cytokine secretion in the bronchoalveolar space, as well as enhanced epithelial cell injury in response to both acute and chronic inflammatory conditions. These results suggest that DAPk attenuates a variety of inflammatory responses, both in lung leukocytes and in lung epithelial cells. The DAPk-mediated suppression of lung inflammation and airway injury may contribute to the tumor-suppressor functions of this kinase in epithelial carcinogenesis.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Pulmão/enzimologia , Pneumonia/prevenção & controle , Animais , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genética , Transplante de Medula Óssea , Proteínas Quinases Dependentes de Cálcio-Calmodulina/deficiência , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Quimiocina CXCL1/metabolismo , Proteínas Quinases Associadas com Morte Celular , Modelos Animais de Doenças , Células Epiteliais/enzimologia , Células Epiteliais/imunologia , Mediadores da Inflamação/metabolismo , Interleucina-6/metabolismo , Lipopolissacarídeos , Pulmão/imunologia , Macrófagos/enzimologia , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Knockout , Neutrófilos/enzimologia , Neutrófilos/imunologia , Pneumonia/induzido quimicamente , Pneumonia/enzimologia , Pneumonia/imunologia , Receptores Fc/metabolismo , Fatores de Tempo , Poluição por Fumaça de Tabaco , Receptor 3 Toll-Like/metabolismo , Receptor 4 Toll-Like/imunologia , Quimeras de Transplante
14.
Nat Immunol ; 13(1): 67-76, 2011 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-22138716

RESUMO

Chemokines presented by the endothelium are critical for integrin-dependent adhesion and transendothelial migration of naive and memory lymphocytes. Here we found that effector lymphocytes of the type 1 helper T cell (T(H)1 cell) and type 1 cytotoxic T cell (T(C)1 cell) subtypes expressed adhesive integrins that bypassed chemokine signals and established firm arrests on variably inflamed endothelial barriers. Nevertheless, the transendothelial migration of these lymphocytes strictly depended on signals from guanine nucleotide-binding proteins of the G(i) type and was promoted by multiple endothelium-derived inflammatory chemokines, even without outer endothelial surface exposure. Instead, transendothelial migration-promoting endothelial chemokines were stored in vesicles docked on actin fibers beneath the plasma membranes and were locally released within tight lymphocyte-endothelial synapses. Thus, effector T lymphocytes can cross inflamed barriers through contact-guided consumption of intraendothelial chemokines without surface-deposited chemokines or extraendothelial chemokine gradients.


Assuntos
Quimiocinas/metabolismo , Células Endoteliais/metabolismo , Linfócitos/imunologia , Migração Transendotelial e Transepitelial/imunologia , Vesículas Transportadoras/metabolismo , Animais , Membrana Celular/metabolismo , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Humanos , Receptores de Hialuronatos/metabolismo , Integrinas/metabolismo , Linfócitos/metabolismo , Linfócitos/ultraestrutura , Camundongos , Receptores CCR2/metabolismo , Transdução de Sinais , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/ultraestrutura , Fator de Necrose Tumoral alfa/farmacologia , Vasculite/imunologia , Vasculite/metabolismo
15.
J Mol Biol ; 413(4): 804-14, 2011 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-21959261

RESUMO

During sporulation, Bacillus thuringiensis subsp. israelensis produces a mosquito larvicidal protein complex containing several crystalline and cytolytic (Cyt) toxins. Here, the activated monomeric form of Cyt1Aa, the most toxic Cyt family member, was isolated and crystallized, and its structure was determined for the first time at 2.2 Å resolution. Cyt1Aa adopts a typical cytolysin fold containing a ß-sheet held by two surrounding α-helical layers. The absence of a ß-strand (between residues V26 and I37) in the dimeric structure of Cyt2Aa led us to deduce that this is the only essential segment for dimer formation and that activation of the toxin occurs by proteolytic processing of its N-terminus. Based on the Cyt1Aa structure, we suggest that the toxicity of Cyt1Aa and other nonrelated proteins, all sharing a cytolysin fold, is correlated with their ability to undergo conformational changes that are necessary prior to their membrane insertion and perforation. This fold allows the α-helical layers to swing away, exposing the ß-sheet to insert into the membrane. The identification of a putative lipid binding pocket between the ß-sheet and the helical layer of Cyt1Aa supports this mechanism. Sequence-based structural analysis of Cyt1Aa revealed that the lack of activity of Cyt1Ca may be related to the latter's inability to undergo this conformational change due to its lack of flexibility. The pattern of the hemolytic activity of Cyt1Aa presented here (resembling that of pore-forming agents), while differing from that imposed by ionic and nonionic detergents, further supports the pore-forming model by which conformational changes occur prior to membrane insertion and perforation.


Assuntos
Bacillus thuringiensis/patogenicidade , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Endotoxinas/química , Endotoxinas/metabolismo , Proteínas Hemolisinas/química , Proteínas Hemolisinas/metabolismo , Sequência de Aminoácidos , Toxinas de Bacillus thuringiensis , Membrana Celular/fisiologia , Cristalografia por Raios X , Eritrócitos/efeitos dos fármacos , Hemólise , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Dobramento de Proteína , Multimerização Proteica , Alinhamento de Sequência
17.
Electrophoresis ; 31(23-24): 3921-7, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21077217

RESUMO

A new family of copper ligand-exchange selectors, L- or D-ß-amino alcohols, is employed for the chiral separation of D,L-dansyl-amino acids, unmodified amino acid racemates, phenylalanine and tryptophan, and ß-blocker L,D-propranolol by SDS-micellar electrokinetic chromatography and by electrophoretic chromatography in a low molecular weight organogel (LMOG)-filled capillary. The LMOG comprised a self-assembled fibrillar gel of trans-(1S,2S)-1,2-bis-(dodecylamido) cyclohexane in methanol. The di-L-valinol-copper complex exhibited the best performance on LMOG-CE compared with all other ß-amino alcohol-copper selectors. The dependence of chiral resolution on the pH*, the ratio between the copper and the L-valinol ligand and the concentration of added selector complex in the run buffer were investigated revealing a marked difference between the activity of the copper-valinol and the previously studied copper-valine selector. The optimal separation conditions were achieved using a 2:1 valinol/copper ratio, in accordance with the 2:1 structure of the complex, which was proven by single crystal and powder X-ray diffractions and by elemental analysis. Unlike the copper-valine selectors that could be used only under acidic conditions (pH* 3.5), the copper-valinol selectors could be used under near-neutral conditions and even at pH* 9.1. A comparison between SDS-micellar electrokinetic chromatography and LMOG-CE under otherwise identical conditions revealed a significant superior separation on the LMOG-filled capillaries.


Assuntos
Álcoois/química , Aminoácidos/química , Cicloexanos/química , Compostos de Dansil/química , Eletroforese Capilar/métodos , Cobre/química , Eletro-Osmose , Concentração de Íons de Hidrogênio , Peso Molecular , Reprodutibilidade dos Testes , Estereoisomerismo
18.
PLoS Pathog ; 6(9): e1001085, 2010 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-20824090

RESUMO

Viruses have evolved several strategies to modify cellular processes and evade the immune response in order to successfully infect, replicate, and persist in the host. By utilizing in-silico testing of a transmembrane sequence library derived from virus protein sequences, we have pin-pointed a nine amino-acid motif shared by a group of different viruses; this motif resembles the transmembrane domain of the alpha-subunit of the T-cell receptor (TCRalpha). The most striking similarity was found within the immunodeficiency virus (SIV and HIV) glycoprotein 41 TMD (gp41 TMD). Previous studies have shown that stable interactions between TCRalpha and CD3 are localized to this nine amino acid motif within TCRalpha, and a peptide derived from it (TCRalpha TMD, GLRILLLKV) interfered and intervened in the TCR function when added exogenously. We now report that the gp41 TMD peptide co-localizes with CD3 within the TCR complex and inhibits T cell proliferation in vitro. However, the inhibitory mechanism of gp41 TMD differs from that of the TCRalpha TMD and also from the other two known immunosuppressive regions within gp41.


Assuntos
Proteína gp41 do Envelope de HIV/metabolismo , Infecções por HIV/metabolismo , HIV-1/patogenicidade , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/citologia , Linfócitos T/metabolismo , Animais , Complexo CD3/metabolismo , Biologia Computacional , Transferência de Energia , Proteína gp41 do Envelope de HIV/genética , HIV-1/imunologia , Humanos , Ionomicina/farmacologia , Ionóforos/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/metabolismo , Estrutura Terciária de Proteína , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T/imunologia
19.
Chemistry ; 16(19): 5568-71, 2010 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-20397163
20.
J Immunol ; 184(1): 212-21, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19949074

RESUMO

MyD88 is an adaptor molecule that functions in the innate signaling induced by proinflammatory adjuvants that interact with TLRs. Mice lacking MyD88, for example, resist active experimental autoimmune encephalomyelitis (EAE) induced by immunization with an encephalitogenic myelin oligodendrocyte glycoprotein (MOG) peptide in CFA. We reasoned that MyD88(-/-) mice, nevertheless, should be susceptible to EAE mediated by adoptive transfer of activated encephalitogenic T cell lines, which do not require adjuvant signaling for their effector functions. We now report, however, that mice lacking MyD88 also resist adoptive EAE mediated by an anti-MOG T cell line that is strongly encephalitogenic in wild-type (WT) mice. The transferred anti-MOG T cells proliferated, secreted INF-gamma, and migrated to the CNS in the MyD88(-/-) mice, as they did in WT mice, but inflammatory infiltrates did not progress and clinical EAE did not develop. The resistance of the MyD88(-/-) mice to adoptive EAE mediated by the otherwise encephalitogenic T cells was found to result from the secretion of IL-10 by recipient T cells of two different specificities: those specific for MOG and those responding to the T cell clone itself-both anticlonotypic and antiergotypic T regulators were detected. IL-10-producing anti-MOG T cells isolated from immunized MyD88(-/-) mice suppressed the induction of active EAE in WT recipients. Moreover, the absence of IL-10 production in MyD88/IL-10 double-knockout mice rendered the mice susceptible to adoptive transfer of EAE. Thus, MyD88 signaling appears to be a key factor in determining the cytokine phenotype of T cells involved in autoimmune inflammation and regulation.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , Interleucina-10/imunologia , Fator 88 de Diferenciação Mieloide/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T/imunologia , Transferência Adotiva , Animais , Autoimunidade/imunologia , Citocinas/imunologia , Citocinas/metabolismo , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/patologia , Citometria de Fluxo , Imuno-Histoquímica , Interleucina-10/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas da Mielina , Glicoproteína Associada a Mielina/imunologia , Glicoproteína Mielina-Oligodendrócito , Fator 88 de Diferenciação Mieloide/deficiência , Fator 88 de Diferenciação Mieloide/genética , Fenótipo , Subpopulações de Linfócitos T/metabolismo , Linfócitos T/metabolismo
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