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Kd Protein (kd + protein)
Selected AbstractsMethylene as a possible universal footprinting reagent that will include hydrophobic surface areas: Overview and feasibility: Properties of diazirine as a precursorPROTEIN SCIENCE, Issue 12 2000Frederic M. Richards Abstract Methylene is one of, if not the, most reactive organic chemical known. It has a very low specificity, which makes it essentially useless for synthesis, but suggests a possible role in protein footprinting with special importance in labeling solvent accessible nonpolar areas, identifying ligand binding sites, and outlining interaction areas on protomers that form homo or hetero oligomers in cellular assemblies. The singlet species is easily and conveniently formed by photolysis of diazirine. The reactions of interest are insertion into C-H bonds and addition to multiple bonds, both forming strong covalent bonds and stable compounds. Reaction with proteins and peptides is reported even in aqueous solutions where the vast majority of the reagent is used up in forming methanol. Species containing up to 5 to 10 extra : CH2 groups are easily detected by electrospray mass spectroscopy. In a mixture of a 14 Kd protein and a noninteracting 1.7 Kd peptide, the distribution of mass peaks in the electrospray spectra was close to that expected from random modification of the estimated solvent accessible area for the two molecules. For analysis at the single residue level, quantitation at labeling levels of one 13CH2 group per 10 to 20 kDa of protein appears to be possible with isotope ratio mass spectroscopy. In the absence of reactive solvents, photolysis of diazirine produces oily polymeric species that contain one or two nitrogen atoms, but not more, and are water soluble. [source] Inhibition of immunosuppressive effects of melanoma-inhibiting activity (MIA) by antisense techniquesINTERNATIONAL JOURNAL OF CANCER, Issue 1 2005Piotr Jachimczak Abstract Melanoma inhibitory activity (MIA) is an 11 kD protein secreted by malignant melanomas. Recent studies revealed an interaction of MIA with epitopes of extracellular matrix proteins including fibronectin. Structural homology of MIA with the binding sites of ,4,1 integrin results in complex interactions of MIA with molecules binding to ,4,1 integrin. As cells of the immune system express ,4,1 integrins (VLA-4), we investigated whether MIA may modulate the function of human leukocytes. Here we describe the effects of MIA on the activation of human PBMCs and auto-/allogeneic lymphokine-activated killer cell (LAK) cytotoxicity in human MIA-negative glioma cell lines and MIA-positive melanoma cell lines in vitro. MIA inhibits PHA- or IL-2-induced human PBMC proliferation in a dose-dependent manner up to 63% (3H-Tdr incorporation) and 59% (cell count), respectively, when added to the cell culture prior to mitogen stimulation. In addition, both autologous (GL and HW) and allogeneic (HTZ-17, HTZ-243 and HTZ-374) antitumor LAK cytotoxicity was reduced by the addition of exogenous rhMIA (500 ng/ml, f.c.). Consequently, endogenous inhibition of MIA expression in human melanoma cells by MIA-specific phosphorothioate antisense oligonucleotides enhanced the autologous LAK-cell activity to the same level as observed in MIA-negative human HMB melanoma cells expressing an MIA-antisense construct. Our results indicate that MIA may contribute to immunosuppression frequently seen in malignant melanomas by inhibiting cellular antitumor immune reactions. Antagonization of MIA activity using antisense techniques may represent a novel therapeutic strategy for treatment of malignant melanomas. [source] Increased expression of interleukin-7 in labial salivary glands of patients with primary Sjögren's syndrome correlates with increased inflammationARTHRITIS & RHEUMATISM, Issue 4 2010A. Bikker Objective To study the expression levels and immunostimulatory capacities of interleukin-7 (IL-7) in primary Sjögren's syndrome. Methods Labial salivary gland (LSG) IL-7 expression was determined by immunohistochemistry, using a quantitative scoring system, in 30 patients with sicca syndrome: 15 patients with primary Sjögren's syndrome (SS) and 15 patients with non-SS sicca syndrome. The correlation of IL-7 expression in LSGs with parameters of local and peripheral disease was studied, and serum and salivary IL-7 levels were determined. Additionally, the effects of IL-7 on cytokine production by peripheral blood mononuclear cells (PBMCs) from patients with primary SS were determined in vitro by Luminex multicytokine assay and compared with the effects in control subjects. Results The expression of IL-7 in LSGs was higher in patients with primary SS compared with that in patients with non-SS sicca syndrome. IL-7 was observed primarily in the vicinity of lymphocytic infiltrates. Salivary IL-7 levels in patients with primary SS were higher than those in control subjects. In all 30 patients with sicca syndrome, IL-7 expression in LSGs correlated with parameters of both local and peripheral disease. Furthermore, IL-7 stimulated T cell,attracting and T cell,differentiating cytokines (monokine induced by interferon-, [IFN,], IFN,-inducible 10-kd protein, IL-12, and IL-15), as well as Th1 (IFN,), Th2 (IL-4), Th17 (IL-17A), proinflammatory (tumor necrosis factor , and IL-1,), and regulatory (IL-10 and IL-13) cytokine production by PBMCs. All of these cytokines were previously shown to be associated with primary SS. The IL-7,induced increase in IL-10 production in patients with primary SS was reduced compared with that in control subjects. Conclusion The correlation between LSG IL-7 expression and (local) disease parameters in primary SS as well as the IL-7,mediated induction of inflammatory cytokines indicate that IL-7 might contribute to the immunopathology of primary SS. [source] Interleukin-6 and type I interferon,regulated genes and chemokines mark disease activity in dermatomyositisARTHRITIS & RHEUMATISM, Issue 11 2009Hatice Bilgic Objective Up-regulation of whole blood type I interferon (IFN),driven transcripts and chemokines has been described in a number of autoimmune diseases. An IFN gene expression "signature" is a candidate biomarker in patients with dermatomyositis (DM). This study was performed to evaluate the capacity of IFN-dependent peripheral blood gene and chemokine signatures and levels of proinflammatory cytokines to serve as biomarkers for disease activity in adult and juvenile DM. Methods Peripheral blood samples and clinical data were obtained from 56 patients with adult or juvenile DM. The type I IFN gene signature in the whole blood of patients with DM was defined by determining the expression levels of 3 IFN-regulated genes (IFIT1, G1P2, and IRF7) using quantitative real-time reverse transcription,polymerase chain reaction. Multiplexed immunoassays were used to quantify the serum levels of 4 type I IFN,regulated chemokines (IFN-inducible T cell , chemoattractant, IFN,-inducible 10-kd protein, monocyte chemotactic protein 1 [MCP-1], and MCP-2) and the serum levels of other proinflammatory cytokines, including interleukin-6 (IL-6). Results DM disease activity correlated significantly with the type I IFN gene signature (r = 0.41, P = 0.007) and with the type I IFN chemokine signature (r = 0.61, P < 0.0001). Furthermore, the serum levels of IL-6 were significantly correlated with disease activity (r = 0.45, P = 0.001). In addition, correlations between the serum levels of IL-6 and both the type I IFN gene signature (r = 0.47, P < 0.01) and the type I IFN chemokine signature (r = 0.71, P < 0.0001) were detected in patients with DM. Conclusion These results suggest that serum IL-6 production and the type I IFN gene signature are candidate biomarkers for disease activity in adult and juvenile DM. Coregulation of the expression of IFN-driven chemokines and IL-6 suggests a novel pathogenic linkage in DM. [source] Interferon-regulated chemokines as biomarkers of systemic lupus erythematosus disease activity: A validation studyARTHRITIS & RHEUMATISM, Issue 10 2009Jason W. Bauer Objective Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by unpredictable flares of disease activity and irreversible damage to multiple organ systems. An earlier study showed that SLE patients carrying an interferon (IFN) gene expression signature in blood have elevated serum levels of IFN-regulated chemokines. These chemokines were associated with more-severe and active disease and showed promise as SLE disease activity biomarkers. This study was designed to validate IFN-regulated chemokines as biomarkers of SLE disease activity in 267 SLE patients followed up longitudinally. Methods To validate the potential utility of serum chemokine levels as biomarkers of disease activity, we measured serum levels of CXCL10 (IFN,-inducible 10-kd protein), CCL2 (monocyte chemotactic protein 1), and CCL19 (macrophage inflammatory protein 3,) in an independent cohort of 267 SLE patients followed up longitudinally over 1 year (1,166 total clinic visits). Results Serum chemokine levels correlated with lupus activity at the current visit (P = 2 × 10,10), rising at the time of SLE flare (P = 2 × 10,3) and decreasing as disease remitted (P = 1 × 10,3); they also performed better than the currently available laboratory tests. Chemokine levels measured at a single baseline visit in patients with a Systemic Lupus Erythematosus Disease Activity Index of ,4 were predictive of lupus flare over the ensuing year (P = 1 × 10,4). Conclusion Monitoring serum chemokine levels in SLE may improve the assessment of current disease activity, the prediction of future disease flares, and the overall clinical decision-making. [source] Activation of the interferon-, signaling pathway in systemic lupus erythematosus peripheral blood mononuclear cellsARTHRITIS & RHEUMATISM, Issue 5 2009Thomas Karonitsch Objective To investigate interferon-, (IFN,) signaling in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE) by analyzing IFN, receptor (IFN,R) expression, STAT-1 expression and phosphorylation, and the regulation of IFN,-inducible genes. Methods Fluorocytometry was used to investigate expression of STAT-1, pSTAT-1, CD95, HLA,DR, class I major histocompatibility complex (MHC), IFN,-inducible 10-kd protein (IP-10), monokine induced by IFN, (Mig), and IFN,R in PBMCs from SLE patients and healthy individuals. STAT-1 phosphorylation was determined by fluorocytometry and Western blotting after stimulation with IFN, or IFN,. Quantitative polymerase chain reaction was used to assess messenger RNA (mRNA) expression of the IFN,-inducible genes IP-10 and Mig shortly after preparation or after stimulation with IFN, in monocytes. Results STAT-1 expression was increased in PBMCs from SLE patients and correlated significantly with disease activity and with the IFN-inducible expression of CD95 and HLA,DR. STAT-1 expression also showed a trend toward association with class I MHC expression. In addition, the expression of other IFN,-inducible genes, such as IP-10 or Mig, was increased in SLE monocytes. While STAT-1 phosphorylation in SLE PBMCs and PBMCs from healthy individuals was similar after IFN, stimulation, incubation with IFN, induced STAT-1 phosphorylation only in SLE lymphocytes. Moreover, SLE monocytes showed a considerably higher increase in pSTAT-1 expression upon IFN, stimulation than monocytes from healthy individuals. Increased responsiveness of SLE monocytes to IFN, was also confirmed on the mRNA level, where expression of the IFN-inducible, STAT-1,dependent genes IP-10 and Mig was more efficiently increased in SLE cells. However, IFN,R was similarly expressed on SLE lymphocytes and monocytes and those from healthy individuals. Conclusion In addition to supporting the role of IFNs in SLE immunopathogenesis in general, the findings of the present study support a role of IFN, in this disease. [source] | ||||||||||