90 research outputs found
cDNA Cloning of Biologically Active Chicken Interleukin-18
By searching a chicken EST database, we identified a cDNA clone that appeared to contain the entire open
reading frame (ORF) of chicken interleukin-18 (ChIL-18). The encoded protein consists of 198 amino acids
and exhibits approximately 30% sequence identity to IL-18 of humans and various others mammals. Sequence
comparisons reveals a putative caspase-1 cleavage site at aspartic acid 29 of the primary translation product,
indicating that mature ChIL-18 might consist of 169 amino acids. Bacterially expressed ChIL-18 in which the
N-terminal 29 amino acids of the putative precursor molecule were replaced by a histidine tag induced the
synthesis of interferon-γ (IFN-γ) in cultured primary chicken spleen cells, indicating that the recombinant
protein is biologically active
Cell-specific synaptic plasticity induced by network oscillations
Gamma rhythms are known to contribute to the process of memory encoding.
However, little is known about the underlying mechanisms at the molecular,
cellular and network levels. Using local field potential recording in awake
behaving mice and concomitant field potential and whole-cell recordings in
slice preparations we found that gamma rhythms lead to activity-dependent
modification of hippocampal networks, including alterations in sharp wave-
ripple complexes. Network plasticity, expressed as long-lasting increases in
sharp wave-associated synaptic currents, exhibits enhanced excitatory synaptic
strength in pyramidal cells that is induced postsynaptically and depends on
metabotropic glutamate receptor-5 activation. In sharp contrast, alteration of
inhibitory synaptic strength is independent of postsynaptic activation and
less pronounced. Further, we found a cell type-specific, directionally biased
synaptic plasticity of two major types of GABAergic cells, parvalbumin- and
cholecystokinin-expressing interneurons. Thus, we propose that gamma frequency
oscillations represent a network state that introduces long-lasting synaptic
plasticity in a cell-specific manner
Side-by-side analysis of five clinically tested anti-EpCAM monoclonal antibodies
Background: Epithelial cell adhesion molecule (EpCAM) is frequently and highly expressed on human carcinomas. The emerging role of EpCAM as a signalling receptor and activator of the wnt pathway, and its expression on tumor-initiating cells, further add to its attractiveness as target for immunotherapy of cancer. Thus far, five conventional monoclonal IgG antibodies have been tested in cancer patients. These are murine IgG2a edrecolomab and its murine/human chimeric IgG1 antibody version, and humanized, human-engineered and fully human IgG1 antibodies 3622W94, ING-1, and adecatumumab (MT201), respectively. Here we compared all anti-EpCAM antibodies in an attempt to explain differences in clinical activity and safety. Methods: We recombinantly produced all antibodies but murine edrecolomab and investigated them for binding affinity, EpCAM epitope recognition, ADCC and CDC, and inhibition of breast cancer cell proliferation. Results: ING-1 and 3622W94 bound to EpCAM with much higher affinity than adecatumumab and edrecolomab. Edrecolomab, ING-1, and 3622W94 all recognized epitopes in the exon 2-encoded N-terminal domain of EpCAM, while adecatumumab recognized a more membrane proximal epitope encoded by exon 5. All antibodies induced lysis of EpCAM-expressing cancer cell lines by both ADCC and CDC with potencies that correlated with their binding affinities. The chimeric version of edrecolomab with a human Fc gamma 1 domain was much more potent in ADCC than the murine IgG2a version. Only adecatumumab showed a significant inhibition of MCF-7 breast cancer cell proliferation in the absence of complement and immune cells. Conclusion: A moderate binding affinity and recognition of a distinct domain of EpCAM may best explain why adecatumumab showed a larger therapeutic window in cancer patients than the two high-affinity IgG1 antibodies ING-1 and 3622W94, both of which caused acute pancreatitis
A Thiophene-Based Anchoring Ligand and Its Heteroleptic Ru(II)-Complex for Efficient Thin-Film Dye-Sensitized Solar Cells
A novel heteroleptic Ru-II complex (BTC-2) employing 5,5'-(2,2'-bipyridine-4,4'-diyl)-bis(thiophene-2-carboxylic acid) (BTC) as the anchoring group and 4,4'-dinonyl-2,2'-bipiridyl and two thiocyanates as ligands is prepared. The photovoltaic performance and device stability achieved with this sensitizer are compared to those of the Z-907 dye, which lacks the thiophene moieties. For thin mesoporous TiO2 films, the devices with BTC-2 achieve higher power conversion efficiencies than those of Z-907 but with a double-layer thicker film the device performance is similar. Using a volatile electrolyte and a double layer 7 + 5 mu m mesoporous TiO2 film, BTC-2 achieves a solar-to-electricity conversion efficiency of 9.1% under standard global AM 1.5 sunlight. Using this sensitizer in combination with a low volatile electrolyte, a photovoltaic efficiency of 8.3% is obtained under standard global AM 1.5 sunlight. These devices show excellent stability when subjected to light soaking at 60 degrees C for 1000 h. Electrochemical impedance spectroscopy and transient photovoltage decay measurements are performed to help understand the changes in the photovoltaic parameters during the aging process. In solid state dye-sensitized solar cells (DSSCs) using an organic hole-transporting material (spiro-MeOTAD, 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene), the BTC-2 sensitizer exhibits an overall power conversion efficiency of 3.6% under AM 1.5 solar (100 mW cm(-2)) irradiation
Читательская культура в современном обществе
Additional file 4. Available patient numbers (N) for analysis of distribution profiles of CD8+ and CD4+ T cells and subsets in Fig. 4
The secretion inhibitor Exo2 perturbs trafficking of Shiga toxin between endosomes and the trans-Golgi network
The small-molecule inhibitor Exo2 {4-hydroxy-3-methoxy-(5,6,7,8-tetrahydrol[1]benzothieno[2,3-d]pyrimidin-4-yl)hydraz-one benzaldehyde} has been reported to disrupt the Golgi apparatus completely and to stimulate Golgi–ER (endoplasmic reticulum) fusion in mammalian cells, akin to the well-characterized fungal toxin BFA (brefeldin A). It has also been reported that Exo2 does not affect the integrity of the TGN (trans-Golgi network), or the direct retrograde trafficking of the glycolipid-binding cholera toxin from the TGN to the ER lumen. We have examined the effects of BFA and Exo2, and found that both compounds are indistinguishable in their inhibition of anterograde transport and that both reagents significantly disrupt the morphology of the TGN in HeLa and in BS-C-1 cells. However, Exo2, unlike BFA, does not induce tubulation and merging of the TGN and endosomal compartments. Furthermore, and in contrast with its effects on cholera toxin, Exo2 significantly perturbs the delivery of Shiga toxin to the ER. Together, these results suggest that the likely target(s) of Exo2 operate at the level of the TGN, the Golgi and a subset of early endosomes, and thus Exo2 provides a more selective tool than BFA for examining membrane trafficking in mammalian cells
Highly Efficient Elimination of Colorectal Tumor-Initiating Cells by an EpCAM/CD3-Bispecific Antibody Engaging Human T Cells
With their resistance to genotoxic and anti-proliferative drugs and potential to grow tumors and metastases from very few cells, cancer stem or tumor-initiating cells (TICs) are a severe limitation for the treatment of cancer by conventional therapies. Here, we explored whether human T cells that are redirected via an EpCAM/CD3-bispecific antibody called MT110 can lyse colorectal TICs and prevent tumor growth from TICs. MT110 recognizes EpCAM, a cell adhesion molecule expressed on TICs from diverse human carcinoma, which was recently shown to promote tumor growth through engagement of elements of the wnt pathway. MT110 was highly potent in mediating complete redirected lysis of KRAS-, PI3 kinase- and BRAF-mutated colorectal TICs, as demonstrated in a soft agar assay. In immunodeficient mice, MT110 prevented growth of tumors from a 5,000-fold excess of a minimally tumorigenic TIC dose. T cells engaged by MT110 may provide a potent therapeutic means to eradicate TICs and bulk tumor cells derived thereof
Геофизические закономерности локализации месторождений углеводородов Баренцево-Карского региона
Background: Rising serum levels of prostate-specific antigen (PSA) after radical prostatectomy are indicative of recurrent prostate cancer. This double-blind, placebo-controlled phase II study evaluated the anti-tumour activity of the anti-epithelial cell adhesion molecule (EpCAM) antibody adecatumumab in delaying biochemical disease progression. Patients and Methods: Prostate cancer patients with increasing serum PSA levels following radical prostatectomy were randomized to low- (2 mg/kg) or high-dose adecatumumab (6 mg/kg) or placebo. The primary efficacy endpoint was the mean change from baseline in total serum PSA at week 24. Secondary endpoints included PSA response rate, prolongation of serum PSA doubling time and time to biochemical disease progression. Results: The primary and secondary endpoints of the study were not met in the predefined analyses. In a retrospective analysis of patients with baseline PSA <= 1 ng/ml and a high EpCAM expression, both the mean increase in PSA from baseline to week 24 and the PSA doubling time at week 15 were significantly improved in the high-dose adecatumumab group compared with the placebo group. Most frequent treatment-related clinical adverse events were gastrointestinal (diarrhoea and nausea) or general events (chills), showing a dose dependency but no grade 3/4 intensity in any patient. Conclusion: In men with rising PSA levels after radical prostatectomy and no evidence of clinical relapse, adecatumumab delayed disease progression in a subgroup of patients with baseline PSA levels <= 1 ng/ml and high EpCAM-expressing tumours. Copyright (C) 2010 S. Karger AG, Base
The astrocyte-produced growth factor HB-EGF limits autoimmune CNS pathology
Central nervous system (CNS)-resident cells such as microglia, oligodendrocytes and astrocytes are gaining increasing attention in respect to their contribution to CNS pathologies including multiple sclerosis (MS). Several studies have demonstrated the involvement of pro-inflammatory glial subsets in the pathogenesis and propagation of inflammatory events in MS and its animal models. However, it has only recently become clear that the underlying heterogeneity of astrocytes and microglia can not only drive inflammation, but also lead to its resolution through direct and indirect mechanisms. Failure of these tissue-protective mechanisms may potentiate disease and increase the risk of conversion to progressive stages of MS, for which currently available therapies are limited. Using proteomic analyses of cerebrospinal fluid specimens from patients with MS in combination with experimental studies, we here identify Heparin-binding EGF-like growth factor (HB-EGF) as a central mediator of tissue-protective and anti-inflammatory effects important for the recovery from acute inflammatory lesions in CNS autoimmunity. Hypoxic conditions drive the rapid upregulation of HB-EGF by astrocytes during early CNS inflammation, while pro-inflammatory conditions suppress trophic HB-EGF signaling through epigenetic modifications. Finally, we demonstrate both anti-inflammatory and tissue-protective effects of HB-EGF in a broad variety of cell types in vitro and use intranasal administration of HB-EGF in acute and post-acute stages of autoimmune neuroinflammation to attenuate disease in a preclinical mouse model of MS. Altogether, we identify astrocyte-derived HB-EGF and its epigenetic regulation as a modulator of autoimmune CNS inflammation and potential therapeutic target in MS. Linnerbauer and colleagues find that HB-EGF produced by reactive astrocytes is protective during autoimmune neuroinflammation, but epigenetically suppressed during late stages
Systemic Inhibition of NF-κB Activation Protects from Silicosis
Background: Silicosis is a complex lung disease for which no successful treatment is available and therefore lung transplantation is a potential alternative. Tumor necrosis factor alpha (TNFα) plays a central role in the pathogenesis of silicosis. TNFα signaling is mediated by the transcription factor, Nuclear Factor (NF)-κB, which regulates genes controlling several physiological processes including the innate immune responses, cell death, and inflammation. Therefore, inhibition of NF-κB activation represents a potential therapeutic strategy for silicosis. Methods/Findings: In the present work we evaluated the lung transplant database (May 1986-July 2007) at the University of Pittsburgh to study the efficacy of lung transplantation in patients with silicosis (n = 11). We contrasted the overall survival and rate of graft rejection in these patients to that of patients with idiopathic pulmonary fibrosis (IPF, n = 79) that was selected as a control group because survival benefit of lung transplantation has been identified for these patients. At the time of lung transplantation, we found the lungs of silica-exposed subjects to contain multiple foci of inflammatory cells and silicotic nodules with proximal TNFα expressing macrophage and NF-κB activation in epithelial cells. Patients with silicosis had poor survival (median survival 2.4 yr; confidence interval (CI): 0.16-7.88 yr) compared to IPF patients (5.3 yr; CI: 2.8-15 yr; p = 0.07), and experienced early rejection of their lung grafts (0.9 yr; CI: 0.22-0.9 yr) following lung transplantation (2.4 yr; CI:1.5-3.6 yr; p<0.05). Using a mouse experimental model in which the endotracheal instillation of silica reproduces the silica-induced lung injury observed in humans we found that systemic inhibition of NF-κB activation with a pharmacologic inhibitor (BAY 11-7085) of IκBα phosphorylation decreased silica-induced inflammation and collagen deposition. In contrast, transgenic mice expressing a dominant negative IκBα mutant protein under the control of epithelial cell specific promoters demonstrate enhanced apoptosis and collagen deposition in their lungs in response to silica. Conclusions: Although limited by its size, our data support that patients with silicosis appear to have poor outcome following lung transplantation. Experimental data indicate that while the systemic inhibition of NF-κB protects from silica-induced lung injury, epithelial cell specific NF-κB inhibition appears to aggravate the outcome of experimental silicosis. © 2009 Di Giuseppe et al
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