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1.
Diego F. Hernández-Ramírez Elizabeth Olivares-Martínez Carlos A. Núñez-Álvarez Eneas A. Chavelas Enrique García-Hernández Gregoria Gómez-Hernández Luis Llorente Antonio R. Cabral 《Biochemical and biophysical research communications》2014
Several studies have shown that conformational changes of β2-glycoprotein I (β2GPI) when bound to negatively charged components expose cryptic epitopes and subsequent binding of anti-β2GPI from patients with antiphospholipid syndrome (APS). However, the role of the carbohydrate chains of β2GPI in this anti-β2GPI reactivity is poorly understood. We therefore studied the reactivity and inhibition of anti-β2GPI antibodies from APS patients with native, partially glycosylated β2GPI (pdβ2GPI; without sialic acid) and completely deglycosylated β2GPI (cdβ2GPI). To determine the potential biologic importance of these glycoforms and their interaction with anti-β2GPI in vitro, stimulation assays were performed with the U937 cell line. Circular dichroism (CD) and fluorescence analysis of the three β2GPI forms were also studied. We found an increased reactivity of anti-β2GPI against pdβ2GPI and cdβ2GPI compared to native β2GPI. Both deglycosylated β2GPI isoforms showed higher inhibition of the anti-β2GPI reactivity than the native protein in soluble-phase. Likewise, the antibody/β2GPI/glycoform complexes increased the synthesis of IL-6, IFNγ and TNFα and the expression of HLA-DR, CD14 and CD11c in U937 cells. CD and fluorescence studies of the glycoforms yielded considerable changes in the fluorescence signals. Our work suggests that the partial or complete removal of the carbohydrate chains uncover cryptic epitopes present in β2GPI. The differentiation and increased synthesis of pro-inflammatory cytokines by U937 cells in vitro may have pathogenetic implications. 相似文献
2.
Roberto Dominici Letizia Polito Emanuela Oldoni Giovanna Bugari Alessandro Montanelli 《Biomarkers》2018,23(6):603-608
Background: Several studies performed in the last years on the brain, showed that beta2-microglobulin (β2m) and MHC can act independently of their canonical immune function to regulate normal brain development, synaptic plasticity and behaviour. Increased systemic levels of soluble β2m have been implicated in cognitive impairments like that associated with chronic haemodialysis, or aortic valve replacement. Increased soluble β2m has also been detected in the cerebral spinal fluid (CSF) of patients with HIV-associated dementia and Alzheimer’s disease (AD).Objective: To compare plasma β2m levels in healthy subjects and subjects with dementia or cognitive impairment.Methods: We measured the concentration of β2m in a cohort of 245 individuals and compared sex matched, cognitive healthy individuals.Results: We found higher levels of β2m in AD patients compared to non-AD MCI and healthy controls (2063?ng/mL ±852 versus 1613?±?503 and 1832?±?382?ng/mL, p0.001 and <0.033, respectively), while there was no difference between mild cognitive impairment (MCI) and healthy controls (p?>?0.05).Conclusions: Our data confirm that β2m could play a role in AD. However, a replication study in an independent cohort would be necessary to confirm our preliminary results. 相似文献
3.
Migration of peritoneal exudate cells (PEC), which were prepared from mice immunized against mouse adenovirus (M-Ad), was inhibited upon exposure to the antigenic extract of M-Ad-infected cells. This inhibition was shown to be blocked when infected cells or their extracts were pretreated with antiserum against M-Ad-induced cell surface(s) antigen(s) or with antisera against alloantigens of infected cells. Immune spleen cell-mediated cytolysis of M-Ad-infected cells was also blocked in the presence of anti-S, anti-alloantigen or anti-β2m serum. Immunofluorescent antibody staining of S antigen(s) was blocked when infected cells were pretreated with anti-alloantigen or anti-β2m serum, whereas it was not blocked when they were pretreated with anti-mouse immunoglobulin or anti-Thy-1.2 serum. Conversely, immunofluoresent antibody staining of alloantigens was blocked when infected cells were pretreated with anti-S serum. These findings indicate that S and alloantigens are associated with each other or at least located very close to each other. 相似文献
4.
《Journal of Proteomics》2010,73(1):123-133
β2-glycoprotein I (β2GPI) is a five-domain protein associated with the antiphospholipid syndrome (APS), however, its normal biological function is yet to be defined. β2GPI is N-glycosylated at several asparagine residues and the glycan moiety conjugated to residue 143 has been proposed to interact with the Gly40–Arg43 motif of β2GPI. The Gly40–Arg43 motif has also been proposed to serve as the epitope for the anti-β2GPI autoantibody associated with APS. We hypothesized that the structure or composition of the glycan at Asn-143 might be associated with the APS symptom by shielding or exposing the Gly40–Arg43 motif towards the anti-β2GPI autoantibody. To test this hypothesis we used mass spectrometry (MS) for comparative glycopeptide profiling of human β2GPI obtained from blood serum from four healthy test subjects and six APS patients. It revealed significant differences in the extent of sialylation and branching of glycans at Asn-143. Biantennary glycans were more abundant than triantennary glycans at Asn-143 in both healthy subjects and patients. In APS patient samples we observed a decrease in sialylated triantennary glycans and an increase in sialylated biantennary glycan structures, as compared to controls. These data indicate that some APS patients have β2GPI molecules with a reduced number of negatively charged sialic acid units in the glycan structure at Asn-143. This alteration of the electrostatic properties of the glycan moiety may attenuate the intramolecular interactions with the positively charged Gly40–Arg43 motif of β2GPI and, in turn, leads to conformational instability and exposure of the disease-related linear epitope Gly40–Arg43 to the circulating autoantibody. Thus, our study suggests a link between site-specific glycan profiles of β2GPI and the pathology of antiphospholipid syndrome. 相似文献
5.
Yeboah-Manu D Röltgen K Opare W Asan-Ampah K Quenin-Fosu K Asante-Poku A Ampadu E Fyfe J Koram K Ahorlu C Pluschke G 《PLoS neglected tropical diseases》2012,6(1):e1460
Background
Previous analyses of sera from a limited number of Ghanaian Buruli ulcer (BU) patients, their household contacts, individuals living in BU non-endemic regions as well as European controls have indicated that antibody responses to the M. ulcerans 18 kDa small heat shock protein (shsp) reflect exposure to this pathogen. Here, we have investigated to what extent inhabitants of regions in Ghana regarded as non-endemic for BU develop anti-18 kDa shsp antibody titers.Methodology/Principal Findings
For this purpose we determined anti-18 kDa shsp IgG titers in sera collected from healthy inhabitants of the BU endemic Densu River Valley and the Volta Region, which was so far regarded as BU non-endemic. Significantly more sera from the Densu River Valley contained anti-18 kDa shsp IgG (32% versus 12%, respectively). However, some sera from the Volta Region also showed high titers. When interviewing these sero-responders, it was revealed that the person with the highest titer had a chronic wound, which was clinically diagnosed and laboratory reconfirmed as active BU. After identification of this BU index case, further BU cases were clinically diagnosed by the Volta Region local health authorities and laboratory reconfirmed. Interestingly, there was neither a difference in sero-prevalence nor in IS2404 PCR positivity of environmental samples between BU endemic and non-endemic communities located in the Densu River Valley.Conclusions
These data indicate that the intensity of exposure to M. ulcerans in endemic and non-endemic communities along the Densu River is comparable and that currently unknown host and/or pathogen factors may determine how frequently exposure is leading to clinical disease. While even high serum titers of anti-18 kDa shsp IgG do not indicate active disease, sero-epidemiological studies can be used to identify new BU endemic areas. 相似文献6.
Mohammed Akaaboune Martine Verdire-Sahuqu Sylvie Lachkar Barry W. Festoff Daniel Hantaï 《Journal of cellular physiology》1995,165(3):503-511
The balance of serine proteases and inhibitors in nerve and muscle is altered during programmed- and injury-induced remodeling. A serpin, α1-antichymotrypsin (α1-ACT), and Kunitz-inhibitor containing forms of the β-amyloid precursor protein (βAPP) may be important components of this balance. In the present study, we analyzed their expression in primary cultures of human myogenic (satellite) cells that mimic myogenic differentiation using Western blotting and immunocytochemistry. In vitro results were compared to in vivo results from normal adult human skeletal muscle biopsies. Using an anti-α1-ACT polyclonal antibody, we detected a 62 kDa immunoreactive band both in cultured human myogenic cells (mononucleated myoblasts as well as multi-nucleated myotubes) and in extracts of human muscle biopsies. With a polyclonal anti-βAPP antibody we found two bands (105 and 120 kDa) in myoblasts and myotubes in culture. However, the same antibody recognized only a single band at 92 kDa in biopsies. By immunocytochemistry, both α1-ACT and βAPP were indistinctly present on localized to the surface of myoblasts in culture. In contrast, these inhibitors were dense on myotube surfaces, where they often formed distinct aggregates and frequently co-localized. In permeabilized muscle cells, α1-ACT and βAPP appeared to be localized to the perikarya of both myoblasts and myotubes. Confirming previous results, both α1-ACT and βAPP were present at the neuromuscular junction in human muscle sections. These developmental changes found during in vitro myogenesis for α1-ACT and βAPP, both serine protease inhibitors, reinforce the hypothesis that regulation of the serine proteases and serine protease inhibitors plays an important role in neuromuscular differentiation. © 1995 Wiley-Liss Inc. 相似文献
7.
《MABS-AUSTIN》2013,5(1):246-261
Thermostabilized G protein-coupled receptors used as antigens for in vivo immunization have resulted in the generation of functional agonistic anti-β1-adrenergic (β1AR) receptor monoclonal antibodies (mAbs). The focus of this study was to examine the pharmacology of these antibodies to evaluate their mechanistic activity at β1AR. Immunization with the β1AR stabilized receptor yielded five stable hybridoma clones, four of which expressed functional IgG, as determined in cell-based assays used to evaluate cAMP stimulation. The antibodies bind diverse epitopes associated with low nanomolar agonist activity at β1AR, and they appeared to show some degree of biased signaling as they were inactive in an assay measuring signaling through β-arrestin. In vitro characterization also verified different antibody-receptor interactions reflecting the different epitopes on the extracellular surface of β1AR to which the mAbs bind. The anti-β1AR mAbs only demonstrated agonist activity when in dimeric antibody format, but not as the monomeric Fab format, suggesting that agonist activation may be mediated through promoting receptor dimerization. Finally, we have also shown that at least one of these antibodies exhibits in vivo functional activity at a therapeutically-relevant dose producing an increase in heart rate consistent with β1AR agonism. 相似文献
8.
We have evaluated optimal conditions for coupling monoclonal antibody to small unilamellar lipisomes. Coupling of an IgG2a monoclonal anti-β2-microglobulin antibody, which reacts with human cells, was examined in detail. Liposomes were composed of dipalmitoyl lecithin and cholesterol, and variable quantities of phosphatidylethanolamine substituted with the heterobifunctional cross-linking reagent N-hydroxysuccinimidyl 3-(2-pyridyldithio) propionate (SPDP). They were reacted with antibody derivatized with the same reagent at a 5- to 20-fold molar excess, and activated by mild reduction. This degree of SPDP modification had no effect on the capacity of the antibody to bind to its target antigen. More than 40% of antibody could be reproducibly bound to liposomes, resulting in the coupling of from 1 to 10 antibody molecules per liposome (mean diameter.580 Å). The coupling reaction did not lead to loss of carboxyfluorescein encapsulated within liposomes. At least 80% of liposomes carried nondenatured antibody, as confirmed by precipitation of liposomes and encapsulated carboxyfluorescein by Staphylococcus aureus, strain Cowan I. The liposome-coupled antibody retained its immunological specificity: only cells expressing human β2-microglobulin bound liposomes in vitro, and the binding was inhibited by the free antibody in solution. Results with antibodies of different antigenic specificity confirm that the technique can be generally applied. 相似文献
9.
B-ETA-Endorphin immunoreactivity in rat and human blood: radioimmunoassay, comparative levels and physiological alterations. 总被引:4,自引:0,他引:4
Antiserum against human β-Endorphin (βhEP) has been obtained from rabbit. The antiserum, diluted bound I125 βh-EP, demonstrating an effective range from 10pM to 10nM. The sensitivity of the assay is 2–3 fmoles. This antibody exhibits 10–15% cross-reactivity with human β-Lipotropin (βh-LPH). β-EP-like immunoreactivity in rat blood has been detected in unextracted samples when compared to blood from hypophysectomized rats. The whole assay and calibration curves are carried out in plasma from hypophysectomized animals. β-EP-like immunoreactivity can be detected in normal rat plasma (75 ± 15 fmole/ml), and exhibits substantial increases with adrenalectomy (287 ± 32 fmoles/ml). In contrast, samples from five healthy normal human males gave values near the limits of detection of the assay (12 fmoles ± 3.9 per ml of plasma). Such values may be due to cross-reactivity of the antiserum with βh-LPH or other circulating hormones. In contrast, patients with elevated ACTH production and normal pregnant humans exhibit significantly elevated levels of β-EP immunoreactivity in plasma. 相似文献
10.
Dorthe B. Corlin Christina K. Johnsen Niels H.H. Heegaard 《Biochemical and biophysical research communications》2009,381(2):187-251
β2-microglobulin (β2m) deposits as amyloid in dialysis-related amyloidosis (DRA), predominantly in joints. The molecular mechanisms underlying the amyloidogenicity of β2m are still largely unknown. In vitro, acidic conditions, pH < 4.5, induce amyloid fibrillation of native β2m within several days. Here, we show that amyloid fibrils are generated in less than an hour when a cleavage variant of β2m—found in the circulation of many dialysis patients—is exposed to pH levels (pH 6.6) occurring in joints during inflammation. Aggregation and fibrillation, including seeding effects with intact, native β2m were studied by Thioflavin T fluorescence spectroscopy, turbidimetry, capillary electrophoresis, and electron microscopy. We conclude that a biologically relevant variant of β2m is amyloidogenic at slightly acidic pH. Also, only a very small amount of preformed fibrils of this variant is required to induce fibrillation of native β2m. This may explain the apparent lack of detectable amounts of the variant β2m in extracts of amyloid from DRA patients. 相似文献
11.
《Endocrine practice》2015,21(3):258-263
ObjectiveVitamin D deficiency is reportedly linked to a variety of autoimmune diseases. However, the relationship between thyroid autoimmunity in Graves disease (GD) and vitamin D deficiency is unclear. The goal of this study was to determine whether increased thyroid hormone autoantibody titer is associated with vitamin D deficiency in GD patients.MethodsA total of 70 patients with GD and 70 matched control subjects were recruited to our study. The levels of 25-hydroxyvitamin D (25[OH]D), calcium, parathyroid hormone (PTH), free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), thyrotropin-receptor antibody (TRAb), thyroid-peroxidase antibody (TPOAb), and thyroglobulin antibody (TGAb) in serum collected from these patients and controls were examined.ResultsThe level of 25(OH)D in serum from TRAb-positive GD patients was significantly lower than that in serum of healthy controls or TRAb-negative patients. However, compared with control subjects, the level of PTH in serum was increased in TRAb-positive GD patients. The rate of vitamin D deficiency (defined as serum 25[OH]D < 50 nmol/L) in TRAb-positive GD patients was significantly higher than in healthy controls or TRAb-negative GD patients. The level of 25(OH)D in serum was inversely correlated with TRAb titer in serum of TRAb-positive GD patients. However, our results did not show a correlation between 25(OH)D level and the levels of TPOAb, TGAb, FT3, FT4, or TSH.ConclusionLow vitamin D status is associated with increased TRAb titer in GD, suggesting a possible link between vitamin D status and increased thyroid autoim-munity in GD patients. (Endocr Pract. 2015;21:258-263) 相似文献
12.
Experimental and bioinformatic approach to identifying antigenic epitopes in human α- and β-enolases
Jadwiga Pietkiewicz Regina Danielewicz Iwona S. Bednarz-Misa Ireneusz Ceremuga Jerzy Wiśniewski Magdalena Mierzchala-Pasierb Agnieszka Bronowicka-Szydełko Edmund Ziomek Andrzej Gamian 《Biochemistry and Biophysics Reports》2018
Human α- and β-enolases are highly homologous enzymes, difficult to differentiate immunologically. In this work, we describe production, purification and properties of anti-α- and anti-β-enolase polyclonal antibodies. To raise antibodies, rabbits were injected with enolase isoenzymes that were purified from human kidney (α-enolase) and skeletal muscle (β-enolase). Selective anti-α- and anti-β-enolase antibodies were obtained by affinity chromatography on either α- or β-enolase-Sepharose columns. On Western blots, antibodies directed against human β-enolase, did not react with human α-isoenzyme, but recognized pig and rat β-enolase. To determine what makes these antibodies selective bioinformatic tools were used to predict conformational epitopes for both enolase isoenzymes. Three predicted epitopes were mapped to the same regions in both α- and β-enolase. Peptides corresponding to predicted epitopes were synthesized and tested against purified antibodies. One of the pin-attached peptides representing α-enolase epitope (the C-terminal portion of the epitope 3 - S262PDDPSRYISPDQ273) reacted with anti-α-enolase, while the other also derived from the α-enolase sequence (epitope 2 - N193VIKEKYGKDATN205) was recognized by anti-β-enolase antibodies. Interestingly, neither anti-α- nor anti-β-antibody reacted with a peptide corresponding to the epitope 2 in β-enolase (G194VIKAKYGKDATN206). Further analysis showed that substitution of E197 with A in α-enolase epitope 2 peptide lead to 70% loss of immunological activity, while replacement of A198 with E in peptide representing β-enolase epitope 2, caused 67% increase in immunological activity. Our results suggest that E197 is essential for preserving immunologically active conformation in epitope 2 peptidic homolog, while it is not crucial for this epitope's antigenic activity in native β-enolase. 相似文献
13.
Kazuo Fukuda Kazuhiro Matsuda Sachie Matsuda Sayaka Kado Hyuma Masu Hirofumi Dohi Yoshihiro Nishida 《Bioorganic & medicinal chemistry》2018,26(4):824-832
Mycoplasma pneumoniae expresses β-glycolipids (β-GGLs) in cytoplasmic membranes, which possess a unique β(1?→?6)-linked disaccharide epitope, which has high potential in biochemical and medicinal applications. In the present study, a series of β-GGLs homologues with different acyl chains (C12, C14, C16, and C18) were prepared from a common precursor. An ELISA assay using an anti-(β-GGLs) monoclonal antibody indicated that the synthetic homologues with long acyl chains had greater diagnostic potential in the order C18?>?C16?>?C14?>?C12. Toward a simultaneous detection of natural glycolipids by mass spectrometry (MS), a deuterium-labeled C16 homologue (β-GGL-C16-d3) was prepared and applied as an internal standard for a high-resolution electrospray ionization MS (ESI-MS) analysis. The ESI-MS analysis was used to identify and quantify acyl homologues (C16/C16, C16/C18, and C18/C18) of β-GGL-C16 in cultured M. pneumoniae. A β-GGLs homologue with a 1,2-diacetyl group (C2) was also prepared as a “water soluble” glycolipid homologue and characterized by 1H NMR spectroscopy. We envisage that each of these chemosynthetic homologues will provide promising approaches to solve medical and biological problems associated with mycoplasma infectious diseases (MIDs). 相似文献
14.
《Cell communication & adhesion》2013,20(4):327-336
Murine ESb and MDAY-D2 lymphoma cells are highly metastatic, in particular to the liver, and are highly invasive in hepatocyte cultures. This may involve adhesion to hepatocyte surface-associated fibronectin (Kemperman et al., 1994, Cell Adh. and Communic. 2:45). Both ESb and MDAY-D2 cells express the fibronectin receptor α4β1, and MDAY-D2 cells in addition also α5β1. Yet, adhesion of ESb cells to fibronectin was low, and MDAY-D2 cells did not adhere at all, but adhesion of both cells was stimulated by phorbol myristate acetate (PMA) and Mn2+. In ESb cells, this adhesion was mediated by α4β1. In MDAY-D2 cells, however, only α5β1was involved, despite β4β1levels similar to ESb cells. The α4β1integrin was functional since it mediated adhesion of MDAY-D2 cells to VCAM-1. An α5β1-negative variant of MDAY-D2 adhered to fibronectin and this was mediated by α5β1. These results indicate that α4β1function in these cells is suppressed in the presence of α5β1. Adhesion of ESb cells to hepatocytes was inhibited by anti-α4antibody, but only by 30%, and fibronectin adhesion was found to have no role in the interaction of MDAY-D2 cells with hepatocytes. This suggests that α4β1and α5β1function is not activated during this interaction.The 9EG7 antibody against mouse β1integrin was described to inhibit β1integrins (Lenter et al., 1993, Proc. Natl. Acad. Sci. USA, 90, 9051). In contrast, we observed that β1stimulated Printegrin function: Adhesion of ESb and MDAY-D2 cells not only to fibronectin, but also to laminin was induced or enhanced. 相似文献
15.
Marilisa Villano Annalisa Borghini Mirko Manetti Erica Gabbrielli Antonella Rossi Piersante Sestini Anna Franca Milia Francesca Nacci Serena Guiducci Marco Matucci-Cerinic Lidia Ibba-Manneschi Elisabetta Weber 《Arthritis research & therapy》2013,15(4):R90
Introduction
Systemic sclerosis (SSc) is a connective tissue disorder characterized by endothelial cell injury, autoimmunity and fibrosis. The following three fibrillin-1 alterations have been reported in SSc. (1) Fibrillin-1 microfibrils are disorganized in SSc dermis. (2) Fibrillin-1 microfibrils produced by SSc fibroblasts are unstable. (3) Mutations in the FBN1 gene and anti-fibrillin-1 autoantibodies have been reported in SSc. Fibrillin-1 microfibrils, which are abundantly produced by blood and lymphatic microvascular endothelial cells (B-MVECs and Ly-MVECs, respectively), sequester in the extracellular matrix the latent form of the potent profibrotic cytokine transforming growth factor β (TGF-β). In the present study, we evaluated the effects of SSc sera on the deposition of fibrillin-1 and microfibril-associated glycoprotein 1 (MAGP-1) and the expression of focal adhesion molecules by dermal B-MVECs and Ly-MVECs.Methods
Dermal B-MVECs and Ly-MVECs were challenged with sera from SSc patients who were treatment-naïve or under cyclophosphamide (CYC) treatment and with sera from healthy controls. Fibrillin-1/MAGP-1 synthesis and deposition and the expression of αvβ3 integrin/phosphorylated focal adhesion kinase and vinculin/actin were evaluated by immunofluorescence and quantified by morphometric analysis.Results
Fibrillin-1 and MAGP-1 colocalized in all experimental conditions, forming a honeycomb pattern in B-MVECs and a dense mesh of short segments in Ly-MVECs. In B-MVECs, fibrillin-1/MAGP-1 production and αvβ3 integrin expression significantly decreased upon challenge with sera from naïve SSc patients compared with healthy controls. Upon challenge of B-MVECs with sera from CYC-treated SSc patients, fibrillin-1/MAGP-1 and αvβ3 integrin levels were comparable to those of cells treated with healthy sera. Ly-MVECs challenged with SSc sera did not differ from those treated with healthy control sera in the expression of any of the molecules assayed.Conclusions
Because of the critical role of fibrillin-1 in sequestering the latent form of TGF-β in the extracellular matrix, its decreased deposition by B-MVECs challenged with SSc sera might contribute to dermal fibrosis. In SSc, CYC treatment might limit fibrosis through the maintenance of physiologic fibrillin-1 synthesis and deposition by B-MVECs. 相似文献16.
Chee-Seng Hee Monika Beerbaum Bernhard Loll Martin Ballaschk Peter Schmieder Barbara Uchanska-Ziegler Andreas Ziegler 《Immunogenetics》2013,65(3):157-172
In major histocompatibility complex (MHC) class I molecules, monomorphic β2-microglobulin (β2m) is non-covalently bound to a heavy chain (HC) exhibiting a variable degree of polymorphism. β2M can stabilize a wide variety of complexes ranging from classical peptide binding to nonclassical lipid presenting MHC class I molecules as well as to MHC class I-like molecules that do not bind small ligands. Here we aim to assess the dynamics of individual regions in free as well as complexed β2m and to understand the evolution of the interfaces between β2m and different HC. Using human β2m and the HLA–B*27:09 complex as a model system, a comparison of free and HC-bound β2m by nuclear magnetic resonance spectroscopy was initially carried out. Although some regions retain their flexibility also after complex formation, these studies reveal that most parts of β2m gain rigidity upon binding to the HC. Sequence analyses demonstrate that some of the residues exhibiting flexibility participate in evolutionarily conserved β2m–HC contacts which are detectable in diverse vertebrate species or characterize a particular group of MHC class I complexes such as peptide- or lipid-binding molecules. Therefore, the spectroscopic experiments and the interface analyses demonstrate that β2m fulfills its role of interacting with diverse MHC class I HC as well as effector cell receptors not only by engaging in conserved intermolecular contacts but also by falling back upon key interface residues that exhibit a high degree of flexibility. 相似文献
17.
Du Y Yan L Du H Wang L Ding F Quan L Cheng X Song K Liu H 《Journal of cellular biochemistry》2012,113(10):3218-3228
Autoantibodies against the second extracellular loop of β1‐adrenergic receptor (β1‐AA) not only contribute to increased susceptibility to heart failure, but also play a causative role in myocardial remodeling through their catecholamine‐like effects via binding with the β1‐adrenergic receptor. The current study was designed to determine whether β1‐AA isolated from the sera of heart failure patients could cause TNF‐α secretion from the murine macrophage‐like cell line RAW264.7. Blood samples were collected from 40 patients who had suffered heart failure, as well as from 40 healthy subjects. The titer of β1‐AA and the level of TNF‐α were detected using ELISA. The effect of β1‐AA on murine macrophage‐like cell line RAW264.7 proliferation was detected by CCK‐8 kits and CFSE assay. Western blot assay was used to analyze the expression of phospho‐VASP. β1‐AA appeared more frequently in patients with heart failure than in healthy subjects. The β1‐AA isolated from heart failure patients promoted an increase of TNF‐α levels, which could be completely blocked by the selective β1‐adrenergic receptor antagonist metoprolol and the second extracellular loop of β1‐adrenergic receptor (β1‐AR‐ECII), but only partially inhibited by PKA inhibitor H89. Furthermore, the β1‐AA could enhance the proliferation of RAW264.7 cells in vitro. Meanwhile, the expression of phospho‐VASP was markedly increased in the presence of β1‐AA. These results demonstrate for the first time that the β1‐AA isolated from heart failure patients could bind with β1‐AR on the surface of RAW264.7 cells, causing the release of TNF‐α largely in a PKA‐dependent fashion. J. Cell. Biochem. 113: 3218–3228, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
18.
《Bioorganic & medicinal chemistry》2020,28(20):115700
The aggregation of β-amyloid peptides is associated to neurodegeneration in Alzheimer’s disease (AD) patients. Consequently, the inhibition of both oligomerization and fibrillation of β-amyloid peptides is considered a plausible therapeutic approach for AD. Herein, the synthesis of new naphthalene derivatives and their evaluation as anti-β-amyloidogenic agents are presented. Molecular dynamic simulations predicted the formation of thermodynamically stable complexes between the compounds, the Aβ1-42 peptide and fibrils. In human microglia cells, these compounds inhibited the aggregation of Aβ1-42 peptide. The lead compound 8 showed a high affinity to amyloid plaques in mice brain ex vivo assays and an adequate log Poct/PBS value. Compound 8 also improved the cognitive function and decreased hippocampal β-amyloid burden in the brain of 3xTg-AD female mice. Altogether, our results suggest that 8 could be a novel therapeutic agent for AD. 相似文献
19.
《Journal of biotechnology》1986,4(6):355-368
The adsorption characteristics of monoclonal anti-(β-galactosidase) immobilised to a number of commercially available pre-activated matrices have been investigated in a series of small scale experiments. Binding characteristics were determined by batch isotherm techniques and estimates were obtained of the rate constants governing adsorption to the immobilised antibodies. The capacity of the different matrices for binding antibody and the specific activity of immunosorbents were measured.There was little effect of support matrix on the dissociation constant, Kd, for the interaction between β-galactosidase and immobilised anti-(β-galactosidase). However, the maximum amounts of antibody that could be immobilised, rates of adsorption and desorption of the enzyme to the immobilised antibody and the specific activity of immunosorbents were affected by the choice of support matrix. The importance of the relative sizes of the antigen and immobilised antibody and the influence of the nature of the support matrix on the properties of the resulting immunosorbent when used in large scale applications are discussed. 相似文献
20.
Ofer Merimsky Ehud Baharav Yehuda Shoenfeld Samario Chaitchik Rosa Tsigelman Dina Cohen-Aloro Pnina Fishman 《Cancer immunology, immunotherapy : CII》1996,42(5):297-302
Anti-tyrosinase antibodies were measured by enzyme-linked immunosorbent assay in sera of patients with malignant melanoma
with either metastatic disease or no evidence of disease, in patients with melanoma and associated hypopigmentation (MAH),
in patients with vitiligo and in healthy volunteers. The mean relative absorbance (A
rel) was calculated by dividing the absorbance of each sample by the mean value for the control group. Using this method, the
A
rel of the control group was 1.000(SE 0.083). A
rel of patients with metastatic disease (1.516; SE 0.225) was significantly higher (P = 0.03) than the value for the controls, but insignificantly higher than that for patients with no evidence of disease (1.216;
SE 0.148). Patients with no evidence of disease, in whom the primary lesion originated in the lower limb, had a significantly
higher (P = 0.01) A
rel than the healthy volunteers. Patients with metastatic disease showed higher A
rel if their primary lesions were confined to the area of the head and neck or to the lower limb. Patients with vitiligo had
higher A
rel values for their anti-tyrosinase antibody than any of the other groups. However, those with melanoma and MAH (vitiligo-like)
had the same A
rel of anti-tyrosinase antibodies as the controls or the patients with metastatic melanoma. This observation reflected the possible
absorption of anti-tyrosinase antibodies to melanoma antigens, and pointed to the participation of anti-tyrosinase antibodies
in the destruction of normal melanocytes in patients with melanoma, as part of the immune reaction towards this disease.
Received: 4 January 1996 / Accepted: 11 April 1996 相似文献