Antibody-Induced Internalization of the Human Respiratory Syncytial Virus Fusion Protein.

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Leemans, A; De Schryver, M; Van der Gucht, W; Heykers, A; Pintelon, I; Hotard, A L; Moore, M L; Melero, J A; McLellan, J S; Graham, B S; Broadbent, L; Power, U F; Caljon, G; Cos, P; Maes, L; Delputte, P

2017-07-15

Respiratory syncytial virus (RSV) infections remain a major cause of respiratory disease and hospitalizations among infants. Infection recurs frequently and establishes a weak and short-lived immunity. To date, RSV immunoprophylaxis and vaccine research is mainly focused on the RSV fusion (F) protein, but a vaccine remains elusive. The RSV F protein is a highly conserved surface glycoprotein and is the main target of neutralizing antibodies induced by natural infection. Here, we analyzed an internalization process of antigen-antibody complexes after binding of RSV-specific antibodies to RSV antigens expressed on the surface of infected cells. The RSV F protein and attachment (G) protein were found to be internalized in both infected and transfected cells after the addition of either RSV-specific polyclonal antibodies (PAbs) or RSV glycoprotein-specific monoclonal antibodies (MAbs), as determined by indirect immunofluorescence staining and flow-cytometric analysis. Internalization experiments with different cell lines, well-differentiated primary bronchial epithelial cells (WD-PBECs), and RSV isolates suggest that antibody internalization can be considered a general feature of RSV. More specifically for RSV F, the mechanism of internalization was shown to be clathrin dependent. All RSV F-targeted MAbs tested, regardless of their epitopes, induced internalization of RSV F. No differences could be observed between the different MAbs, indicating that RSV F internalization was epitope independent. Since this process can be either antiviral, by affecting virus assembly and production, or beneficial for the virus, by limiting the efficacy of antibodies and effector mechanism, further research is required to determine the extent to which this occurs in vivo and how this might impact RSV replication. IMPORTANCE Current research into the development of new immunoprophylaxis and vaccines is mainly focused on the RSV F protein since, among others, RSV F-specific antibodies are

Preparation of GST Fusion Proteins.

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Einarson, Margret B; Pugacheva, Elena N; Orlinick, Jason R

2007-04-01

INTRODUCTIONThis protocol describes the preparation of glutathione-S-transferase (GST) fusion proteins, which have had a wide range of applications since their introduction as tools for synthesis of recombinant proteins in bacteria. GST was originally selected as a fusion moiety because of several desirable properties. First and foremost, when expressed in bacteria alone, or as a fusion, GST is not sequestered in inclusion bodies (in contrast to previous fusion protein systems). Second, GST can be affinity-purified without denaturation because it binds to immobilized glutathione, which provides the basis for simple purification. Consequently, GST fusion proteins are routinely used for antibody generation and purification, protein-protein interaction studies, and biochemical analysis.

Fc-fusion Proteins in Therapy: An Updated View.

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Jafari, Reza; Zolbanin, Naime M; Rafatpanah, Houshang; Majidi, Jafar; Kazemi, Tohid

2017-01-01

Fc-fusion proteins are composed of Fc region of IgG antibody (Hinge-CH2-CH3) and a desired linked protein. Fc region of Fc-fusion proteins can bind to neonatal Fc receptor (FcRn) thereby rescuing it from degradation. The first therapeutic Fc-fusion protein was introduced for the treatment of AIDS. The molecular designing is the first stage in production of Fc-fusion proteins. The amino acid residues in the Fc region and linked protein are very important in the bioactivity and affinity of the fusion proteins. Although, therapeutic monoclonal antibodies are the top selling biologics but the application of therapeutic Fc-fusion proteins in clinic is in progress and among these medications Etanercept is the most effective in therapy. At present, eleven Fc-fusion proteins have been approved by FDA. There are novel Fc-fusion proteins which are in pre-clinical and clinical development. In this article, we review the molecular and biological characteristics of Fc-fusion proteins and then further discuss the features of novel therapeutic Fc-fusion proteins. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Expression of GDNF and GFR alpha 1 in mouse taste bud cells.

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Takeda, Masako; Suzuki, Yuko; Obara, Nobuko; Uchida, Nobuhiko; Kawakoshi, Kentaro

2004-11-01

GDNF (glial cell line-derived neurotrophic factor) affects the survival and maintenance of central and peripheral neurons. Using an immunocytochemical method, we examined whether the taste bud cells in the circumvallate papillae of normal mice expressed GDNF and its GFR alpha 1 receptor. Using double immunostaining for either of them and NCAM, PGP 9.5, or alpha-gustducin, we additionally sought to determine what type of taste bud cells expressed GDNF or GFR alpha 1, because NCAM is reported to be expressed in type-III cells, PGP 9.5, in type-III and some type-II cells, and alpha-gustducin, in some type-II cells. Normal taste bud cells expressed both GDNF and GFR alpha 1. The percentage of GDNF-immunoreactive cells among all taste bud cells was 31.63%, and that of GFR alpha 1-immunoreactive cells, 83.21%. Confocal laser scanning microscopic observations after double immunostaining showed that almost none of the GDNF-immunoreactive cells in the taste buds were reactive with anti-NCAM or anti-PGP 9.5 antibody, but could be stained with anti-alpha-gustducin antibody. On the other hand, almost all anti-PGP 9.5- or anti-alpha-gustducin-immunoreactive cells were positive for GFR alpha 1. Thus, GDNF-immunoreactive cells did not include type-III cells, but type-II cells, which are alpha-gustducin-immunoreactive; on the other hand, GFR alpha 1-immunoreactive cells included type-II and -III cells, and perhaps type-I cells. We conclude that GDNF in the type-II cells may exert trophic actions on type-I, -II, and -III taste bud cells by binding to their GFR alpha 1 receptors.

Identification of Protein-Protein Interactions with Glutathione-S-Transferase (GST) Fusion Proteins.

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Einarson, Margret B; Pugacheva, Elena N; Orlinick, Jason R

2007-08-01

INTRODUCTIONGlutathione-S-transferase (GST) fusion proteins have had a wide range of applications since their introduction as tools for synthesis of recombinant proteins in bacteria. GST was originally selected as a fusion moiety because of several desirable properties. First and foremost, when expressed in bacteria alone, or as a fusion, GST is not sequestered in inclusion bodies (in contrast to previous fusion protein systems). Second, GST can be affinity-purified without denaturation because it binds to immobilized glutathione, which provides the basis for simple purification. Consequently, GST fusion proteins are routinely used for antibody generation and purification, protein-protein interaction studies, and biochemical analysis. This article describes the use of GST fusion proteins as probes for the identification of protein-protein interactions.

New sensitive and specific assay for human immunodeficiency virus antibodies using labeled recombinant fusion protein and time-resolved fluoroimmunoassay.

OpenAIRE

Siitari, H; Turunen, P; Schrimsher, J; Nunn, M

1990-01-01

A new, rapid method for the detection of human immunodeficiency virus type 1 (HIV-1) antibody by time-resolved fluoroimmunoassay (TR-FIA) was developed. In this assay format, microtitration strips were coated with a recombinant fusion protein, and the same protein was labeled with europium and added into the wells simultaneously with the test specimens. The recombinant fusion protein contained the HIV-1 p24 gag protein sequence that carried an insertion, near the carboxyl terminus, of a 23-am...

The GDNF System Is Altered in Diverticular Disease – Implications for Pathogenesis

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Böttner, Martina; Barrenschee, Martina; Hellwig, Ines; Harde, Jonas; Egberts, Jan-Hendrik; Becker, Thomas; Zorenkov, Dimitri; Schäfer, Karl-Herbert; Wedel, Thilo

2013-01-01

Background & Aims Absence of glial cell line-derived neurotrophic factor (GDNF) leads to intestinal aganglionosis. We recently demonstrated that patients with diverticular disease (DD) exhibit hypoganglionosis suggesting neurotrophic factor deprivation. Thus, we screened mRNA expression pattern of the GDNF system in DD and examined the effects of GDNF on cultured enteric neurons. Methods Colonic specimens obtained from patients with DD (n = 21) and controls (n = 20) were assessed for mRNA expression levels of the GDNF system (GDNF, GDNF receptors GFRα1 and RET). To identify the tissue source of GDNF and its receptors, laser-microdissected (LMD) samples of human myenteric ganglia and intestinal muscle layers were analyzed separately by qPCR. Furthermore, the effects of GDNF treatment on cultured enteric neurons (receptor expression, neuronal differentiation and plasticity) were monitored. Results mRNA expression of GDNF and its receptors was significantly down-regulated in the muscularis propria of patients with DD. LMD samples revealed high expression of GDNF in circular and longitudinal muscle layers, whereas GDNF receptors were also expressed in myenteric ganglia. GDNF treatment of cultured enteric neurons increased mRNA expression of its receptors and promoted neuronal differentiation and plasticity revealed by synaptophysin mRNA and protein expression. Conclusions Our results suggest that the GDNF system is compromised in DD. In vitro studies demonstrate that GDNF enhances expression of its receptors and promotes enteric neuronal differentiation and plasticity. Since patients with DD exhibit hypoganglionosis, we propose that the observed enteric neuronal loss in DD may be due to lacking neurotrophic support mediated by the GDNF system. PMID:23805210

Induction of human immunodeficiency virus neutralizing antibodies using fusion complexes.

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Zipeto, Donato; Matucci, Andrea; Ripamonti, Chiara; Scarlatti, Gabriella; Rossolillo, Paola; Turci, Marco; Sartoris, Silvia; Tridente, Giuseppe; Bertazzoni, Umberto

2006-05-01

Human immunodeficiency virus-1 (HIV-1) infects cells by membrane fusion that is mediated by the envelope proteins gp120/gp41 and the cellular receptors CD4 and CCR5. During this process, some conserved viral epitopes are temporarily exposed and may induce a neutralizing antibody response when fixed in the fusogenic conformation. These transient structures are conserved and may be effective antigens for use in an anti-HIV-1 vaccine. In this study we tested different conditions of preparation of fusion complexes inducing neutralizing antibodies against both R5 and X4 tropic HIV-1 strains. Cell lines expressing HIV-1 gp120/gp41 and CD4-CCR5 were prepared and conditions for producing fusion complexes were tested. Complexes produced at different temperature and fixative combinations were used to immunize mice. Results indicated that (a) fusion complexes prepared at either 21 degrees C, 30 degrees C or 37 degrees C were immunogenic and induced neutralizing antibodies against both R5 and X4 HIV-1 heterologous isolates; (b) after extensive purification of antibodies there was no cytotoxic effect; (c) complexes prepared at 37 degrees C were more immunogenic and induced higher titers of neutralizing antibodies than complexes prepared at either 21 degrees C or 30 degrees C; (d) the fixative used did not affect the titer of neutralizing antibodies except for glutaraldehyde which was ineffective; (e) the neutralizing activity was retained after CD4-CCR5 antibody removal. The production of higher titers of neutralizing antibody with fusion complexes prepared at 37 degrees C, as compared to lower temperatures, may be related to the induction of antibodies against many different conformation intermediates that subsequently act synergistically at different steps in the fusion process.

Comparative immunoblot analysis with 10 different, partially overlapping recombinant fusion proteins derived from 5 different cytomegalovirus proteins

NARCIS (Netherlands)

van Zanten, J.; LAZZAROTTO, T; CAMPISI, B; VORNHAGEN, R; JAHN, G; LANDINI, MP; The, T. Hauw

Ten fusion proteins derived from five various CMV encoded proteins were used for the detection of specific antibody response by immunoblot technique in sera from renal transplant recipients. The fusion proteins were derived from the following CMV specific proteins: the assembly protein ppUL80a with

Modular protein switches derived from antibody mimetic proteins.

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Nicholes, N; Date, A; Beaujean, P; Hauk, P; Kanwar, M; Ostermeier, M

2016-02-01

Protein switches have potential applications as biosensors and selective protein therapeutics. Protein switches built by fusion of proteins with the prerequisite input and output functions are currently developed using an ad hoc process. A modular switch platform in which existing switches could be readily adapted to respond to any ligand would be advantageous. We investigated the feasibility of a modular protein switch platform based on fusions of the enzyme TEM-1 β-lactamase (BLA) with two different antibody mimetic proteins: designed ankyrin repeat proteins (DARPins) and monobodies. We created libraries of random insertions of the gene encoding BLA into genes encoding a DARPin or a monobody designed to bind maltose-binding protein (MBP). From these libraries, we used a genetic selection system for β-lactamase activity to identify genes that conferred MBP-dependent ampicillin resistance to Escherichia coli. Some of these selected genes encoded switch proteins whose enzymatic activity increased up to 14-fold in the presence of MBP. We next introduced mutations into the antibody mimetic domain of these switches that were known to cause binding to different ligands. To different degrees, introduction of the mutations resulted in switches with the desired specificity, illustrating the potential modularity of these platforms. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Evaluation of the Potency, Neutralizing Antibody Response, and Stability of a Recombinant Fusion Protein Vaccine for Streptococcus pyogenes.

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Burlet, E; HogenEsch, H; Dunham, A; Morefield, G

2017-05-01

Streptococcus pyogenes or group A streptococcus (GAS) is a Gram-positive bacterium that can cause a wide range of diseases, including pharyngitis, impetigo, scarlet fever, necrotizing fasciitis, rheumatic fever, and streptococcal toxic shock syndrome. Despite the increasing burden on global health caused by GAS, there is currently no licensed vaccine available. In this study, we evaluated immunogenicity, induction of neutralizing antibodies, and stability of a new recombinant fusion protein vaccine that targets infections from GAS. The recombinant fusion protein (SpeAB) combines inactive mutant forms of streptococcal pyrogenic exotoxin A (SpeA) and streptococcal pyrogenic exotoxin B (SpeB). The SpeAB vaccine evaluated in this study was adsorbed to an aluminum adjuvant and demonstrated robust immunogenicity, eliciting production of specific neutralizing antibodies against SpeA and SpeB, two major virulence factors of S. pyogenes. Stability studies suggest that the vaccine will retain immunogenicity for at least 2 years when stored at refrigerated temperatures. This novel vaccine shows great potential to provide protection against GAS infections and to reduce the burden of GAS disease globally.

Pre-α-pro-GDNF and Pre-β-pro-GDNF Isoforms Are Neuroprotective in the 6-hydroxydopamine Rat Model of Parkinson's Disease

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Anna-Maija Penttinen

2018-06-01

Full Text Available Glial cell line-derived neurotrophic factor (GDNF is one of the most studied neurotrophic factors. GDNF has two splice isoforms, full-length pre-α-pro-GDNF (α-GDNF and pre-β-pro-GDNF (β-GDNF, which has a 26 amino acid deletion in the pro-region. Thus far, studies have focused solely on the α-GDNF isoform, and nothing is known about the in vivo effects of the shorter β-GDNF variant. Here we compare for the first time the effects of overexpressed α-GDNF and β-GDNF in non-lesioned rat striatum and the partial 6-hydroxydopamine lesion model of Parkinson's disease. GDNF isoforms were overexpressed with their native pre-pro-sequences in the striatum using an adeno-associated virus (AAV vector, and the effects on motor performance and dopaminergic phenotype of the nigrostriatal pathway were assessed. In the non-lesioned striatum, both isoforms increased the density of dopamine transporter-positive fibers at 3 weeks after viral vector delivery. Although both isoforms increased the activity of the animals in cylinder assay, only α-GDNF enhanced the use of contralateral paw. Four weeks later, the striatal tyrosine hydroxylase (TH-immunoreactivity was decreased in both α-GDNF and β-GDNF treated animals. In the neuroprotection assay, both GDNF splice isoforms increased the number of TH-immunoreactive cells in the substantia nigra but did not promote behavioral recovery based on amphetamine-induced rotation or cylinder assays. Thus, the shorter GDNF isoform, β-GDNF, and the full-length α-isoform have comparable neuroprotective efficacy on dopamine neurons of the nigrostriatal circuitry.

Conjugation of biotin-coated luminescent quantum dots with single domain antibody-rhizavidin fusions

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Jinny L. Liu

2016-06-01

Full Text Available Straightforward and effective methods are required for the bioconjugation of proteins to surfaces and particles. Previously we demonstrated that the fusion of a single domain antibody with the biotin binding molecule rhizavidin provided a facile method to coat biotin-modified surfaces with a highly active and oriented antibody. Here, we constructed similar single domain antibody—rhizavidin fusions as well as unfused rhizavidin with a His-tag. The unfused rhizavidin produced efficiently and its utility for assay development was demonstrated in surface plasmon resonance experiments. The single domain antibody-rhizavidin fusions were utilized to coat quantum dots that had been prepared with surface biotins. Preparation of antibody coated quantum dots by this means was found to be both easy and effective. The prepared single domain antibody-quantum dot reagent was characterized by surface plasmon resonance and applied to toxin detection in a fluoroimmunoassay sensing format.

TRANSGENIC GDNF POSITIVELY INFLUENCES PROLIFERATION, DIFFERENTIATION, MATURATION AND SURVIVAL OF MOTOR NEURONS PRODUCED FROM MOUSE EMBRYONIC STEM CELLS.

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Daniel Édgar Cortés

2016-09-01

Full Text Available Embryonic stem cells (ESC are pluripotent and thus can differentiate into every cell type present in the body. Directed differentiation into motor neurons has been described for pluripotent cells. Although neurotrophic factors promote neuronal survival, their role in neuronal commitment is elusive. Here, we developed double-transgenic lines of mouse ESC that constitutively produce Glial cell-derived neurotrophic factor (GDNF and also contain a GFP reporter, driven by HB9, which is expressed only by postmitotic motor neurons. After lentiviral transduction, ESC lines integrated and expressed the human GDNF gene without altering pluripotency markers before differentiation. Further, GDNF-ESC showed significantly higher spontaneous release of this neurotrophin to the medium, when compared to controls. To study motor neuron induction, control and GDNF cell lines were grown as embryoid bodies and stimulated with retinoic acid and Sonic Hedgehog. In GDNF-overexpressing cells, a significant increase of proliferative Olig2+ precursors, which are specified as spinal motor neurons, was found. Accordingly, GDNF increases the yield of cells with the pan motor neuronal markers HB9, monitored by GFP expression, and Isl1. At terminal differentiation, almost all differentiated neurons express phenotypic markers of motor neurons in GDNF cultures, with lower proportions in control cells. To test if the effects of GDNF were present at early differentiation stages, exogenous recombinant human GDNF was added to control ESC, also resulting in enhanced motor neuron differentiation. This effect was abolished by the co-addition of neutralizing anti-GDNF antibodies, strongly suggesting that differentiating ESC are responsive to GDNF. Using the HB9::GFP reporter, motor neurons were selected for electrophysiological recordings. Motor neurons differentiated from GDNF-ESC, compared to control motor neurons, showed greater electrophysiological maturation, characterized by

The binding affinity of a soluble TCR-Fc fusion protein is significantly improved by crosslinkage with an anti-C{beta} antibody

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Ozawa, Tatsuhiko; Horii, Masae; Kobayashi, Eiji [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan); Jin, Aishun [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan); Department of Immunology, College of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin 150081 (China); Kishi, Hiroyuki, E-mail: immkishi@med.u-toyama.ac.jp [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan); Muraguchi, Atsushi [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan)

2012-06-01

Highlights: Black-Right-Pointing-Pointer A novel soluble TCR composed of TCR V and C regions with Ig Fc region is generated. Black-Right-Pointing-Pointer TCR-Fc protein immobilized by an anti-C{beta} antibody bound to a p/MHC tetramer. Black-Right-Pointing-Pointer Binding affinity of TCR-Fc was markedly increased by binding with anti-C{beta} antibody. -- Abstract: The identification and cloning of tumor antigen-specific T cell receptors (TCRs) and the production of the soluble form of the TCR (sTCR) contributed to the development of diagnostic and therapeutic tools for cancer. Recently, several groups have reported the development of technologies for the production of sTCRs. The native sTCR has a very low binding affinity for the antigenic peptide/MHC (p/MHC) complex. In this study, we established a technology to produce high affinity, functional sTCRs. We generated a novel sTCR-Fc fusion protein composed of the TCR V and C regions of the TCR linked to the immunoglobulin (Ig) Fc region. A Western blot analysis revealed that the molecular weight of the fusion protein was approximately 60 kDa under reducing conditions and approximately 100-200 kDa under non-reducing conditions. ELISAs using various antibodies showed that the structure of each domain of the TCR-Fc protein was intact. The TCR-Fc protein immobilized by an anti-C{beta} antibody effectively bound to a p/MHC tetramer. An SPR analysis showed that the TCR-Fc protein had a low binding affinity (KD; 1.1 Multiplication-Sign 10{sup -5} M) to the p/MHC monomer. Interestingly, when the TCR-Fc protein was pre-incubated with an anti-C{beta} antibody, its binding affinity for p/MHC increased by 5-fold (2.2 Multiplication-Sign 10{sup -6} M). We demonstrated a novel method for constructing a functional soluble TCR using the Ig Fc region and showed that the binding affinity of the functional sTCR-Fc was markedly increased by an anti-C{beta} antibody, which is probably due to the stabilization of the V

The Fusion Loops of the Initial Prefusion Conformation of Herpes Simplex Virus 1 Fusion Protein Point Toward the Membrane

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Juan Fontana

2017-08-01

Full Text Available All enveloped viruses, including herpesviruses, must fuse their envelope with the host membrane to deliver their genomes into target cells, making this essential step subject to interference by antibodies and drugs. Viral fusion is mediated by a viral surface protein that transits from an initial prefusion conformation to a final postfusion conformation. Strikingly, the prefusion conformation of the herpesvirus fusion protein, gB, is poorly understood. Herpes simplex virus (HSV, a model system for herpesviruses, causes diseases ranging from mild skin lesions to serious encephalitis and neonatal infections. Using cryo-electron tomography and subtomogram averaging, we have characterized the structure of the prefusion conformation and fusion intermediates of HSV-1 gB. To this end, we have set up a system that generates microvesicles displaying full-length gB on their envelope. We confirmed proper folding of gB by nondenaturing electrophoresis-Western blotting with a panel of monoclonal antibodies (MAbs covering all gB domains. To elucidate the arrangement of gB domains, we labeled them by using (i mutagenesis to insert fluorescent proteins at specific positions, (ii coexpression of gB with Fabs for a neutralizing MAb with known binding sites, and (iii incubation of gB with an antibody directed against the fusion loops. Our results show that gB starts in a compact prefusion conformation with the fusion loops pointing toward the viral membrane and suggest, for the first time, a model for gB’s conformational rearrangements during fusion. These experiments further illustrate how neutralizing antibodies can interfere with the essential gB structural transitions that mediate viral entry and therefore infectivity.

[Construction and prokaryotic expression of recombinant gene EGFRvIII HBcAg and immunogenicity analysis of the fusion protein].

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Duan, Xiao-yi; Wang, Jian-sheng; Guo, You-min; Han, Jun-li; Wang, Quan-ying; Yang, Guang-xiao

2007-01-01

To construct recombinant prokaryotic expression plasmid pET28a(+)/c-PEP-3-c and evaluate the immunogenicity of the fusion protein. cDNA fragment encoding PEP-3 was obtained from pGEM-T Easy/PEP-3 and inserted into recombinant plasmid pGEMEX/HBcAg. Then it was subcloned in prokaryotic expression vector and transformed into E.coli BL21(DE3). The fusion protein was expressed by inducing IPTG and purified by Ni(2+)-NTA affinity chromatography. BALB/c mice were immunized with fusion protein and the antibody titre was determined by indirect ELISA. The recombinant gene was confirmed to be correct by restriction enzyme digestion and DNA sequencing. After prokaryotic expression, fusion protein existed in sediment and accounted for 56% of all bacterial lysate. The purified product accounted for 92% of all protein and its concentration was 8 g/L. The antibody titre in blood serum reached 1:16 000 after the fourth immunization and reached 1:2.56x10(5) after the sixth immunization. The titre of anti-PEP-3 antibody reached 1:1.28x10(5) and the titre of anti-HBcAg antibody was less than 1:4x10(3). Fusion gene PEP-3-HBcAg is highly expressed in E.coli BL21. The expressed fusion protein can induce neutralizing antibody with high titer and specificity, which lays a foundation for the study of genetically engineering vaccine for malignant tumors with the high expression of EGFRvIII.

Zebrafish GDNF and its co-receptor GFRα1 activate the human RET receptor and promote the survival of dopaminergic neurons in vitro.

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Tuulia Saarenpää

Full Text Available Glial cell line-derived neurotrophic factor (GDNF is a ligand that activates, through co-receptor GDNF family receptor alpha-1 (GFRα1 and receptor tyrosine kinase "RET", several signaling pathways crucial in the development and sustainment of multiple neuronal populations. We decided to study whether non-mammalian orthologs of these three proteins have conserved their function: can they activate the human counterparts? Using the baculovirus expression system, we expressed and purified Danio rerio RET, and its binding partners GFRα1 and GDNF, and Drosophila melanogaster RET and two isoforms of co-receptor GDNF receptor-like. Our results report high-level insect cell expression of post-translationally modified and dimerized zebrafish RET and its binding partners. We also found that zebrafish GFRα1 and GDNF are comparably active as mammalian cell-produced ones. We also report the first measurements of the affinity of the complex to RET in solution: at least for zebrafish, the Kd for GFRα1-GDNF binding RET is 5.9 μM. Surprisingly, we also found that zebrafish GDNF as well as zebrafish GFRα1 robustly activated human RET signaling and promoted the survival of cultured mouse dopaminergic neurons with comparable efficiency to mammalian GDNF, unlike E. coli-produced human proteins. These results contradict previous studies suggesting that mammalian GFRα1 and GDNF cannot bind and activate non-mammalian RET and vice versa.

The niche-derived glial cell line-derived neurotrophic factor (GDNF induces migration of mouse spermatogonial stem/progenitor cells.

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Lisa Dovere

Full Text Available In mammals, the biological activity of the stem/progenitor compartment sustains production of mature gametes through spermatogenesis. Spermatogonial stem cells and their progeny belong to the class of undifferentiated spermatogonia, a germ cell population found on the basal membrane of the seminiferous tubules. A large body of evidence has demonstrated that glial cell line-derived neurotrophic factor (GDNF, a Sertoli-derived factor, is essential for in vivo and in vitro stem cell self-renewal. However, the mechanisms underlying this activity are not completely understood. In this study, we show that GDNF induces dose-dependent directional migration of freshly selected undifferentiated spermatogonia, as well as germline stem cells in culture, using a Boyden chamber assay. GDNF-induced migration is dependent on the expression of the GDNF co-receptor GFRA1, as shown by migration assays performed on parental and GFRA1-transduced GC-1 spermatogonial cell lines. We found that the actin regulatory protein vasodilator-stimulated phosphoprotein (VASP is specifically expressed in undifferentiated spermatogonia. VASP belongs to the ENA/VASP family of proteins implicated in actin-dependent processes, such as fibroblast migration, axon guidance, and cell adhesion. In intact seminiferous tubules and germline stem cell cultures, GDNF treatment up-regulates VASP in a dose-dependent fashion. These data identify a novel role for the niche-derived factor GDNF, and they suggest that GDNF may impinge on the stem/progenitor compartment, affecting the actin cytoskeleton and cell migration.

Enhanced neutralization potency of botulinum neurotoxin antibodies using a red blood cell-targeting fusion protein.

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Sharad P Adekar

2011-03-01

Full Text Available Botulinum neurotoxin (BoNT potently inhibits cholinergic signaling at the neuromuscular junction. The ideal countermeasures for BoNT exposure are monoclonal antibodies or BoNT antisera, which form BoNT-containing immune complexes that are rapidly cleared from the general circulation. Clearance of opsonized toxins may involve complement receptor-mediated immunoadherence to red blood cells (RBC in primates or to platelets in rodents. Methods of enhancing immunoadherence of BoNT-specific antibodies may increase their potency in vivo. We designed a novel fusion protein (FP to link biotinylated molecules to glycophorin A (GPA on the RBC surface. The FP consists of an scFv specific for murine GPA fused to streptavidin. FP:mAb:BoNT complexes bound specifically to the RBC surface in vitro. In a mouse model of BoNT neutralization, the FP increased the potency of single and double antibody combinations in BoNT neutralization. A combination of two antibodies with the FP gave complete neutralization of 5,000 LD50 BoNT in mice. Neutralization in vivo was dependent on biotinylation of both antibodies and correlated with a reduction of plasma BoNT levels. In a post-exposure model of intoxication, FP:mAb complexes gave complete protection from a lethal BoNT/A1 dose when administered within 2 hours of toxin exposure. In a pre-exposure prophylaxis model, mice were fully protected for 72 hours following administration of the FP:mAb complex. These results demonstrate that RBC-targeted immunoadherence through the FP is a potent enhancer of BoNT neutralization by antibodies in vivo.

Overexpression of GDNF in the uninjured DRG exerts analgesic effects on neuropathic pain following segmental spinal nerve ligation in mice.

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Takasu, Kumiko; Sakai, Atsushi; Hanawa, Hideki; Shimada, Takashi; Suzuki, Hidenori

2011-11-01

Glial cell line-derived neurotrophic factor (GDNF), a survival-promoting factor for a subset of nociceptive small-diameter neurons, has been shown to exert analgesic effects on neuropathic pain. However, its detailed mechanisms of action are still unknown. In the present study, we investigated the site-specific analgesic effects of GDNF in the neuropathic pain state using lentiviral vector-mediated GDNF overexpression in mice with left fifth lumbar (L5) spinal nerve ligation (SNL) as a neuropathic pain model. A lentiviral vector expressing both GDNF and enhanced green fluorescent protein (EGFP) was constructed and injected into the left dorsal spinal cord, uninjured fourth lumbar (L4) dorsal root ganglion (DRG), injured L5 DRG, or plantar skin of mice. In SNL mice, injection of the GDNF-EGFP-expressing lentivirus into the dorsal spinal cord or uninjured L4 DRG partially but significantly reduced the mechanical allodynia in association with an increase in GDNF protein expression in each virus injection site, whereas injection into the injured L5 DRG or plantar skin had no effects. These results suggest that GDNF exerts its analgesic effects in the neuropathic pain state by acting on the central terminals of uninjured DRG neurons and/or on the spinal cells targeted by the uninjured DRG neurons. This article shows that GDNF exerts its analgesic effects on neuropathic pain by acting on the central terminals of uninjured DRG neurons and/or on the spinal cells targeted by these neurons. Therefore, research focusing on these GDNF-dependent neurons in the uninjured DRG would provide a new strategy for treating neuropathic pain. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

IB4(+) nociceptors mediate persistent muscle pain induced by GDNF.

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Alvarez, Pedro; Chen, Xiaojie; Bogen, Oliver; Green, Paul G; Levine, Jon D

2012-11-01

Skeletal muscle is a well-known source of glial cell line-derived neurotrophic factor (GDNF), which can produce mechanical hyperalgesia. Since some neuromuscular diseases are associated with both increased release of GDNF and intense muscle pain, we explored the role of GDNF as an endogenous mediator in muscle pain. Intramuscularly injected GDNF induced a dose-dependent (0.1-10 ng/20 μl) persistent (up to 3 wk) mechanical hyperalgesia in the rat. Once hyperalgesia subsided, injection of prostaglandin E(2) at the site induced a prolonged mechanical hyperalgesia (>72 h) compared with naïve rats (vibration increased muscle GDNF levels at 24 h, a time point where rats also exhibited marked muscle hyperalgesia. Intrathecal antisense oligodeoxynucleotides to mRNA encoding GFRα1, the canonical binding receptor for GDNF, reversibly inhibited eccentric exercise- and mechanical vibration-induced muscle hyperalgesia. Finally, electrophysiological recordings from nociceptors innervating the gastrocnemius muscle in anesthetized rats, revealed significant increase in response to sustained mechanical stimulation after local GDNF injection. In conclusion, these data indicate that GDNF plays a role as an endogenous mediator in acute and induction of chronic muscle pain, an effect likely to be produced by GDNF action at GFRα1 receptors located in IB4(+) nociceptors.

Therapeutic Fc-fusion proteins and peptides as successful alternatives to antibodies.

Science.gov (United States)

Beck, Alain; Reichert, Janice M

2011-01-01

Therapeutic antibodies have captured substantial attention due to the relatively high rate at which these products reach marketing approval, and the subsequent commercial success they frequently achieve. In the 2000s, a total of 20 antibodies (18 full-length IgG and 2 Fab) were approved by the Food and Drug Administration (FDA) or European Medicines Agency (EMA). In the 2010s to date, an additional 3 antibodies (denosumab, belimumab, ipilimumab) have been approved and one antibody-drug conjugate (brentuximab vedotin) is undergoing regulatory review and may be approved in the US by August 30, 2011. However, a less heralded group of antibody-based therapeutics comprising proteins or peptides fused with an Fc is following the success of classical antibodies.

Antibodies to a recombinant glutamate-rich Plasmodium falciparum protein

DEFF Research Database (Denmark)

Hogh, B; Petersen, E; Dziegiel, Morten Hanefeld

1992-01-01

A Plasmodium falciparum antigen gene coding for a 220-kD glutamate-rich protein (GLURP) has been cloned, and the 783 C-terminal amino acids of this protein (GLURP489-1271) have been expressed as a beta-galactosidase fusion protein in Escherichia coli. The encoded 783 amino acid residues contain two...... areas of repeated amino acid sequences. Antibodies against recombinant GLURP489-1271, as well as against a synthetic peptide corresponding to GLURP899-916, and against a synthetic peptide representing the major glutamate rich repeat sequence from the P. falciparum ring erythrocyte surface antigen (Pf155...... between the anti-GLURP489-1271 and anti-(EENV)6 antibody responses. The data provide indirect evidence for a protective role of antibodies reacting with recombinant GLURP489-1271 as well as with the synthetic peptide (EENV)6 from the Pf155/RESA....

Fusion Peptide Improves Stability and Bioactivity of Single Chain Antibody against Rabies Virus.

Science.gov (United States)

Xi, Hualong; Zhang, Kaixin; Yin, Yanchun; Gu, Tiejun; Sun, Qing; Shi, Linqing; Zhang, Renxia; Jiang, Chunlai; Kong, Wei; Wu, Yongge

2017-04-28

The combination of rabies immunoglobulin (RIG) with a vaccine is currently effective against rabies infections, but improvements are needed. Genetic engineering antibody technology is an attractive approach for developing novel antibodies to replace RIG. In our previous study, a single-chain variable fragment, scFv57R, against rabies virus glycoprotein was constructed. However, its inherent weak stability and short half-life compared with the parent RIG may limit its diagnostic and therapeutic application. Therefore, an acidic tail of synuclein (ATS) derived from the C-terminal acidic tail of human alpha-synuclein protein was fused to the C-terminus of scFv57R in order to help it resist adverse stress and improve the stability and halflife. The tail showed no apparent effect on the preparation procedure and affinity of the protein, nor did it change the neutralizing potency in vitro. In the ELISA test of molecular stability, the ATS fusion form of the protein, scFv57R-ATS, showed an increase in thermal stability and longer half-life in serum than scFv57R. The protection against fatal rabies virus challenge improved after fusing the tail to the scFv, which may be attributed to the improved stability. Thus, the ATS fusion approach presented here is easily implemented and can be used as a new strategy to improve the stability and half-life of engineered antibody proteins for practical applications.

The dengue virus type 2 envelope protein fusion peptide is essential for membrane fusion

International Nuclear Information System (INIS)

Huang, Claire Y.-H.; Butrapet, Siritorn; Moss, Kelly J.; Childers, Thomas; Erb, Steven M.; Calvert, Amanda E.; Silengo, Shawn J.; Kinney, Richard M.; Blair, Carol D.; Roehrig, John T.

2010-01-01

The flaviviral envelope (E) protein directs virus-mediated membrane fusion. To investigate membrane fusion as a requirement for virus growth, we introduced 27 unique mutations into the fusion peptide of an infectious cDNA clone of dengue 2 virus and recovered seven stable mutant viruses. The fusion efficiency of the mutants was impaired, demonstrating for the first time the requirement for specific FP AAs in optimal fusion. Mutant viruses exhibited different growth kinetics and/or genetic stabilities in different cell types and adult mosquitoes. Virus particles could be recovered following RNA transfection of cells with four lethal mutants; however, recovered viruses could not re-infect cells. These viruses could enter cells, but internalized virus appeared to be retained in endosomal compartments of infected cells, thus suggesting a fusion blockade. Mutations of the FP also resulted in reduced virus reactivity with flavivirus group-reactive antibodies, confirming earlier reports using virus-like particles.

Fluorescent IgG fusion proteins made in E. coli

Science.gov (United States)

Luria, Yael; Raichlin, Dina; Benhar, Itai

2012-01-01

Antibodies are among the most powerful tools in biological and biomedical research and are presently the fastest growing category of new bio-pharmaceutics. The most common format of antibody applied for therapeutic, diagnostic and analytical purposes is the IgG format. For medical applications, recombinant IgGs are made in cultured mammalian cells in a process that is too expensive to be considered for producing antibodies for diagnostic and analytical purposes. Therefore, for such purposes, mouse monoclonal antibodies or polyclonal sera from immunized animals are used. While looking for an easier and more rapid way to prepare full-length IgGs for therapeutic purposes, we recently developed and reported an expression and purification protocol for full-length IgGs, and IgG-based fusion proteins in E. coli, called “Inclonals.” By applying the Inclonals technology, we could generate full-length IgGs that are genetically fused to toxins. The aim of the study described herein was to evaluate the possibility of applying the “Inclonals” technology for preparing IgG-fluorophore fusion proteins. We found that IgG fused to the green fluorescent proteins enhanced GFP (EGFP) while maintaining functionality in binding, lost most of its fluorescence during the refolding process. In contrast, we found that green fluorescent Superfolder GFP (SFGFP)-fused IgG and red fluorescent mCherry-fused IgG were functional in antigen binding and maintained fluorescence intensity. In addition, we found that we can link several SFGFPs in tandem to each IgG, with fluorescence intensity increasing accordingly. Fluorescent IgGs made in E. coli may become attractive alternatives to monoclonal or polyclonal fluorescent antibodies derived from animals. PMID:22531449

Inhibition of EBV-mediated membrane fusion by anti-gHgL antibodies

Energy Technology Data Exchange (ETDEWEB)

Sathiyamoorthy, Karthik; Jiang, Jiansen; Möhl, Britta S.; Chen, Jia; Zhou, Z. Hong; Longnecker, Richard; Jardetzky, Theodore S. (UCLA); (Stanford-MED); (NWU)

2017-09-22

Herpesvirus entry into cells requires the coordinated action of multiple virus envelope glycoproteins, including gH, gL, and gB. For EBV, the gp42 protein assembles into complexes with gHgL heterodimers and binds HLA class II to activate gB-mediated membrane fusion with B cells. EBV tropism is dictated by gp42 levels in the virion, as it inhibits entry into epithelial cells while promoting entry into B cells. The gHgL and gB proteins are targets of neutralizing antibodies and potential candidates for subunit vaccine development, but our understanding of their neutralizing epitopes and the mechanisms of inhibition remain relatively unexplored. Here we studied the structures and mechanisms of two anti-gHgL antibodies, CL40 and CL59, that block membrane fusion with both B cells and epithelial cells. We determined the structures of the CL40 and CL59 complexes with gHgL using X-ray crystallography and EM to identify their epitope locations. CL59 binds to the C-terminal domain IV of gH, while CL40 binds to a site occupied by the gp42 receptor binding domain. CL40 binding to gHgL/gp42 complexes is not blocked by gp42 and does not interfere with gp42 binding to HLA class II, indicating that its ability to block membrane fusion with B cells represents a defect in gB activation. These data indicate that anti-gHgL neutralizing antibodies can block gHgL-mediated activation of gB through different surface epitopes and mechanisms.

Escape from neutralization by the respiratory syncytial virus-specific neutralizing monoclonal antibody palivizumab is driven by changes in on-rate of binding to the fusion protein

International Nuclear Information System (INIS)

Bates, John T.; Keefer, Christopher J.; Slaughter, James C.; Kulp, Daniel W.; Schief, William R.; Crowe, James E.

2014-01-01

The role of binding kinetics in determining neutralizing potency for antiviral antibodies is poorly understood. While it is believed that increased steady-state affinity correlates positively with increased virus-neutralizing activity, the relationship between association or dissociation rate and neutralization potency is unclear. We investigated the effect of naturally-occurring antibody resistance mutations in the RSV F protein on the kinetics of binding to palivizumab. Escape from palivizumab-mediated neutralization of RSV occurred with reduced association rate (K on ) for binding to RSV F protein, while alteration of dissociation rate (K off ) did not significantly affect neutralizing activity. Interestingly, linkage of reduced K on with reduced potency mirrored the effect of increased K on found in a high-affinity enhanced potency palivizumab variant (motavizumab). These data suggest that association rate is the dominant factor driving neutralization potency for antibodies to RSV F protein antigenic site A and determines the potency of antibody somatic variants or efficiency of escape of viral glycoprotein variants. - Highlights: • The relationship of affinity to neutralization for virus antibodies is uncertain. • Palivizumab binds to RSV escape mutant fusion proteins, but with reduced affinity. • Association rate (K on ) correlated well with the potency of neutralization

Escape from neutralization by the respiratory syncytial virus-specific neutralizing monoclonal antibody palivizumab is driven by changes in on-rate of binding to the fusion protein

Energy Technology Data Exchange (ETDEWEB)

Bates, John T. [The Vanderbilt Vaccine Center, Departments of Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); Keefer, Christopher J. [The Vanderbilt Vaccine Center, Departments of Pediatrics, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); Slaughter, James C. [The Vanderbilt Vaccine Center, Departments of Biostatistics and Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); Kulp, Daniel W. [IAVI Neutralizing Antibody Center and Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA (United States); Schief, William R. [IAVI Neutralizing Antibody Center and Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA (United States); Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA (United States); Crowe, James E., E-mail: james.crowe@vanderbilt.edu [The Vanderbilt Vaccine Center, Departments of Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); The Vanderbilt Vaccine Center, Departments of Pediatrics, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States)

2014-04-15

The role of binding kinetics in determining neutralizing potency for antiviral antibodies is poorly understood. While it is believed that increased steady-state affinity correlates positively with increased virus-neutralizing activity, the relationship between association or dissociation rate and neutralization potency is unclear. We investigated the effect of naturally-occurring antibody resistance mutations in the RSV F protein on the kinetics of binding to palivizumab. Escape from palivizumab-mediated neutralization of RSV occurred with reduced association rate (K{sub on}) for binding to RSV F protein, while alteration of dissociation rate (K{sub off}) did not significantly affect neutralizing activity. Interestingly, linkage of reduced K{sub on} with reduced potency mirrored the effect of increased K{sub on} found in a high-affinity enhanced potency palivizumab variant (motavizumab). These data suggest that association rate is the dominant factor driving neutralization potency for antibodies to RSV F protein antigenic site A and determines the potency of antibody somatic variants or efficiency of escape of viral glycoprotein variants. - Highlights: • The relationship of affinity to neutralization for virus antibodies is uncertain. • Palivizumab binds to RSV escape mutant fusion proteins, but with reduced affinity. • Association rate (K{sub on}) correlated well with the potency of neutralization.

Impaired Latent Inhibition in GDNF-Deficient Mice Exposed to Chronic Stress

Directory of Open Access Journals (Sweden)

Mona Buhusi

2017-10-01

Full Text Available Increased reactivity to stress is maladaptive and linked to abnormal behaviors and psychopathology. Chronic unpredictable stress (CUS alters catecholaminergic neurotransmission and remodels neuronal circuits involved in learning, attention and decision making. Glial-derived neurotrophic factor (GDNF is essential for the physiology and survival of dopaminergic neurons in substantia nigra and of noradrenergic neurons in the locus coeruleus. Up-regulation of GDNF expression during stress is linked to resilience; on the other hand, the inability to up-regulate GDNF in response to stress, as a result of either genetic or epigenetic modifications, induces behavioral alterations. For example, GDNF-deficient mice exposed to chronic stress exhibit alterations of executive function, such as increased temporal discounting. Here we investigated the effects of CUS on latent inhibition (LI, a measure of selective attention and learning, in GDNF-heterozygous (HET mice and their wild-type (WT littermate controls. No differences in LI were found between GDNF HET and WT mice under baseline experimental conditions. However, following CUS, GDNF-deficient mice failed to express LI. Moreover, stressed GDNF-HET mice, but not their WT controls, showed decreased neuronal activation (number of c-Fos positive neurons in the nucleus accumbens shell and increased activation in the nucleus accumbens core, both key regions in the expression of LI. Our results add LI to the list of behaviors affected by chronic stress and support a role for GDNF deficits in stress-induced pathological behaviors relevant to schizophrenia and other psychiatric disorders.

“Inclonals”: IgGs and IgG-enzyme fusion proteins produced in an E. coli expression-refolding system

OpenAIRE

Hakim, Rahely; Benhar, Itai

2009-01-01

Full-length antibodies and antibodies that ferry a cargo to target cells are desired biopharmaceuticals. We describe the production of full-length IgGs and IgG-toxin fusion proteins in E. coli. In the presented examples of anti CD30 and anti EGF-receptor antibodies, the antibody heavy and light chains or toxin fusions thereof were expressed in separate bacterial cultures, where they accumulated as insoluble inclusion bodies. Following refolding and purification, high yields (up to 50 mg/L of ...

The biodistribution and pretargeting radioimmunoimaging of the fusion protein of anti-CEA single-chain antibody and core-streptavidin in human rectocolonic tumor bearing nude mice

International Nuclear Information System (INIS)

Yang Weidong; Li Biao; Zhu Chengmo; Jiang Xufeng; Feng Guowei; Wu Xiangpu

2002-01-01

Objective: To investigate the biodistribution and two-step pretargeting radioimmunoimaging of the fusion protein of anti-carcinoembryonic antigen (CEA) single-chain antibody (ScFv) and core-streptavidin in human rectocolonic tumor bearing nude mice. Methods: Before the injection of 153 Sm-biotin, the fusion protein of ScFv-core-streptavidin was pretargeted for 24 h (200 μg every nude mouse), 24 h later 153 Sm-biotin was injected. The uptake of radioactivity in tumor and normal tissues in 20 nude mice was measured at 1, 4, 8 and 24 h and the other 3 nude mice was scanned at 8 and 24 h after peritoneal injection of 153 Sm-biotin. Results: The tumor to blood ratio (tumor/blood) reached 0.49 , 1.21, 1.56 and 3.09 at 1, 4, 8 and 24 h respectively. Radioactivity concentration peaked at 8 h in tumor site and demonstrated a 'hot' area, with significant decreasing its background at 24 h. Conclusion: The fusion protein can elevate the tumor/blood ratio, shorten pretargeting and imaging process and also improve image quality

Combining glial cell line-derived neurotrophic factor gene delivery (AdGDNF) with L-arginine decreases contusion size but not behavioral deficits after traumatic brain injury.

Science.gov (United States)

Degeorge, M L; Marlowe, D; Werner, E; Soderstrom, K E; Stock, M; Mueller, A; Bohn, M C; Kozlowski, D A

2011-07-27

Our laboratory has previously demonstrated that viral administration of glial cell line-derived neurotrophic factor (AdGDNF), one week prior to a controlled cortical impact (CCI) over the forelimb sensorimotor cortex of the rat (FL-SMC) is neuroprotective, but does not significantly enhance recovery of sensorimotor function. One possible explanation for this discrepancy is that although protected, neurons may not have been functional due to enduring metabolic deficiencies. Additionally, metabolic events following TBI may interfere with expression of therapeutic proteins administered to the injured brain via gene therapy. The current study focused on enhancing the metabolic function of the brain by increasing cerebral blood flow (CBF) with l-arginine in conjunction with administration of AdGDNF immediately following CCI. An adenoviral vector harboring human GDNF was injected unilaterally into FL-SMC of the rat immediately following a unilateral CCI over the FL-SMC. Within 30min of the CCI and AdGDNF injections, some animals were injected with l-arginine (i.v.). Tests of forelimb function and asymmetry were administered for 4weeks post-injury. Animals were sacrificed and contusion size and GDNF protein expression measured. This study demonstrated that rats treated with AdGDNF and l-arginine post-CCI had a significantly smaller contusion than injured rats who did not receive any treatment, or injured rats treated with either AdGDNF or l-arginine alone. Nevertheless, no amelioration of behavioral deficits was seen. These findings suggest that AdGDNF alone following a CCI was not therapeutic and although combining it with l-arginine decreased contusion size, it did not enhance behavioral recovery. Copyright © 2011 Elsevier B.V. All rights reserved.

Lipopolysaccharide inhibits the self-renewal of spermatogonial stem cells in vitro via downregulation of GDNF expression in Sertoli cells.

Science.gov (United States)

Zhang, Xiaoli; Shi, Kun; Li, Yi; Zhang, Haiyu; Hao, Jing

2014-06-01

Lipopolysaccharide (LPS) can reduce sperm count and sperm quality. The molecular mechanisms underlying this process are not fully understood. In this report, we investigated the effects of LPS-treated Sertoli cells on self-renewal and differentiation of spermatogoinial stem cells (SSCs). Sertoli cell cultures were established and incubated with LPS (10μg/ml) for 1, 2 or 3 days, respectively. The culture media were collected and used as conditioned media (CM) to culture SSCs. The expression of glial cell-derived neurotrophic factor (GDNF), stem cell factor (SCF) and bone morphogenetic protein 4 (BMP4) in Sertoli cells treated with LPS was analyzed by RT-PCR and Western blotting. The results showed that the expression of SSC differentiation markers, c-kit and Sohlh2, was increased, while the expression of SSC self-renewal markers, plzf, oct4, and PCNA, was repressed when cultured in CM from LPS-treated Sertoli cells. GDNF levels in Sertoli cells and CM reduced dramatically after LPS treatments, while SCF and BMP4 levels did not show any significant changes. Moreover, correlated with the GDNF levels in CM, GDNF target genes, Bcl6b and Etv5, were reduced markedly in SSCs. Our results suggest that LPS inhibits the expression of GDNF in Sertoli cells, and might prevent the SSC self-renewal via down-regulation of GDNF target genes. Copyright © 2014 Elsevier Inc. All rights reserved.

Addressing the Immunogenicity of the Cargo and of the Targeting Antibodies with a Focus on Deimmunized Bacterial Toxins and on Antibody-Targeted Human Effector Proteins

Science.gov (United States)

Grinberg, Yehudit; Benhar, Itai

2017-01-01

Third-generation immunotoxins are composed of a human, or humanized, targeting moiety, usually a monoclonal antibody or an antibody fragment, and a non-human effector molecule. Due to the non-human origin of the cytotoxic domain, these molecules stimulate potent anti-drug immune responses, which limit treatment options. Efforts are made to deimmunize such immunotoxins or to combine treatment with immunosuppression. An alternative approach is using the so-called “human cytotoxic fusion proteins”, in which antibodies are used to target human effector proteins. Here, we present three relevant approaches for reducing the immunogenicity of antibody-targeted protein therapeutics: (1) reducing the immunogenicity of the bacterial toxin, (2) fusing human cytokines to antibodies to generate immunocytokines and (3) addressing the immunogenicity of the targeting antibodies. PMID:28574434

Integrin αvβ1 Modulation Affects Subtype B Avian Metapneumovirus Fusion Protein-mediated Cell-Cell Fusion and Virus Infection.

Science.gov (United States)

Yun, Bing-Ling; Guan, Xiao-Lu; Liu, Yong-Zhen; Zhang, Yao; Wang, Yong-Qiang; Qi, Xiao-Le; Cui, Hong-Yu; Liu, Chang-Jun; Zhang, Yan-Ping; Gao, Hong-Lei; Gao, Li; Li, Kai; Gao, Yu-Long; Wang, Xiao-Mei

2016-07-08

Avian metapneumovirus (aMPV) fusion (F) protein mediates virus-cell membrane fusion to initiate viral infection, which requires F protein binding to its receptor(s) on the host cell surface. However, the receptor(s) for aMPV F protein is still not identified. All known subtype B aMPV (aMPV/B) F proteins contain a conserved Arg-Asp-Asp (RDD) motif, suggesting that the aMPV/B F protein may mediate membrane fusion via the binding of RDD to integrin. When blocked with integrin-specific peptides, aMPV/B F protein fusogenicity and viral replication were significantly reduced. Specifically we identified integrin αv and/or β1-mediated F protein fusogenicity and viral replication using antibody blocking, small interfering RNAs (siRNAs) knockdown, and overexpression. Additionally, overexpression of integrin αv and β1 in aMPV/B non-permissive cells conferred aMPV/B F protein binding and aMPV/B infection. When RDD was altered to RAE (Arg-Ala-Glu), aMPV/B F protein binding and fusogenic activity were profoundly impaired. These results suggest that integrin αvβ1 is a functional receptor for aMPV/B F protein-mediated membrane fusion and virus infection, which will provide new insights on the fusogenic mechanism and pathogenesis of aMPV. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Integrin αvβ1 Modulation Affects Subtype B Avian Metapneumovirus Fusion Protein-mediated Cell-Cell Fusion and Virus Infection*

Science.gov (United States)

Yun, Bing-Ling; Guan, Xiao-Lu; Liu, Yong-Zhen; Zhang, Yao; Wang, Yong-Qiang; Qi, Xiao-Le; Cui, Hong-Yu; Liu, Chang-Jun; Zhang, Yan-Ping; Gao, Hong-Lei; Gao, Li; Li, Kai; Gao, Yu-Long; Wang, Xiao-Mei

2016-01-01

Avian metapneumovirus (aMPV) fusion (F) protein mediates virus-cell membrane fusion to initiate viral infection, which requires F protein binding to its receptor(s) on the host cell surface. However, the receptor(s) for aMPV F protein is still not identified. All known subtype B aMPV (aMPV/B) F proteins contain a conserved Arg-Asp-Asp (RDD) motif, suggesting that the aMPV/B F protein may mediate membrane fusion via the binding of RDD to integrin. When blocked with integrin-specific peptides, aMPV/B F protein fusogenicity and viral replication were significantly reduced. Specifically we identified integrin αv and/or β1-mediated F protein fusogenicity and viral replication using antibody blocking, small interfering RNAs (siRNAs) knockdown, and overexpression. Additionally, overexpression of integrin αv and β1 in aMPV/B non-permissive cells conferred aMPV/B F protein binding and aMPV/B infection. When RDD was altered to RAE (Arg-Ala-Glu), aMPV/B F protein binding and fusogenic activity were profoundly impaired. These results suggest that integrin αvβ1 is a functional receptor for aMPV/B F protein-mediated membrane fusion and virus infection, which will provide new insights on the fusogenic mechanism and pathogenesis of aMPV. PMID:27226547

Cloning, Expression and Purification of the Recombinant HIV-1 Tat-Nef Fusion Protein in Prokaryotic Expression System

Directory of Open Access Journals (Sweden)

Somayeh Kadkhodayan

2016-07-01

Full Text Available Abstract Background: Nef is one of the HIV-1 critical proteins, because it is essential for viral replication and AIDS disease progression and induction of immune response against it can partially inhibit viral infection. Moreover, a domain of the HIV-1 Trans-Activator of Transcription (Tat, 48-60 aa could act as a cell penetrating peptide (CPP. In current study, cloning and expression of Tat-Nef fusion protein was performed in E. coli for the first time. The protein expression was confirmed by western blot analysis and was purified using reverse staining method. Materials and Methods: In this experimental study, primarily, cloning of Tat-Nef fusion gene was done in pGEX6p2 expression vector. Then, the expression of Tat-Nef recombinat protein in E.coli BL21 (DE3 strain was performed by using IPTG inducer. The protein expression was confirmed by SDS-PAGE and western blotting using anti-Nef monoclonal antibody. Then, the recombinant fusion protein was purified from gel using reverse staining method. Results: The results of PCR analysis and enzyme digestion showed a clear band of ~ 726 bp in agarose gel indicating the correct Tat-Nef fusion cloning in pGEX6p2 prokaryotic expression vector. In addition, a 54 kDa band of Tat-Nef on SDS-PAGE revealed Tat-Nef protein expression that western blot analysis using anti-Nef monoclonal antibody confirmed it. Conclusion: The purified Tat-Nef recombinant fusion protein will be used as an antigen for protein vaccine design against HIV infection.

Insight into the potential for DNA idiotypic fusion vaccines designed for patients by analysing xenogeneic anti-idiotypic antibody responses

Science.gov (United States)

Forconi, Francesco; King, Catherine A; Sahota, Surinder S; Kennaway, Christopher K; Russell, Nigel H; Stevenson, Freda K

2002-01-01

DNA vaccines induce immune responses against encoded proteins, and have clear potential for cancer vaccines. For B-cell tumours, idiotypic (Id) immunoglobulin encoded by the variable region genes provides a target antigen. When assembled as single chain Fv (scFv), and fused to an immunoenhancing sequence from tetanus toxin (TT), DNA fusion vaccines induce anti-Id antibodies. In lymphoma models, these antibodies have a critical role in mediating protection. For application to patients with lymphoma, two questions arise: first, whether pre-existing antibody against TT affects induction of anti-scFv antibodies; second, whether individual human scFv fusion sequences are able to fold consistently to generate antibodies able to recognize private conformational Id determinants expressed by tumour cells. Using xenogeneic vaccination with scFv sequences from four patients, we have shown that pre-existing anti-TT immunity slows, but does not prevent, anti-Id antibody responses. To determine folding, we have monitored the ability of nine DNAscFv–FrC patients' vaccines to induce xenogeneic anti-Id antibodies. Antibodies were induced in all cases, and were strikingly specific for each patient's immunoglobulin with little cross-reactivity between patients, even when similar VH or VL genes were involved. Blocking experiments with human serum confirmed reactivity against private determinants in 26–97% of total antibody. Both immunoglobulin G1 (IgG1) and IgG2a subclasses were present at 1·3 : 1–15 : 1 consistent with a T helper 2-dominated response. Xenogeneic vaccination provides a simple route for testing individual patients' DNAscFv–FrC fusion vaccines, and offers a strategy for production of anti-Id antibodies. The findings underpin the approach of DNA idiotypic fusion vaccination for patients with B-cell tumours. PMID:12225361

Somatotropinomas, but not nonfunctioning pituitary adenomas, maintain a functional apoptotic RET/Pit1/ARF/p53 pathway that is blocked by excess GDNF.

Science.gov (United States)

Diaz-Rodriguez, Esther; Garcia-Rendueles, Angela R; Ibáñez-Costa, Alejandro; Gutierrez-Pascual, Ester; Garcia-Lavandeira, Montserrat; Leal, Alfonso; Japon, Miguel A; Soto, Alfonso; Venegas, Eva; Tinahones, Francisco J; Garcia-Arnes, Juan A; Benito, Pedro; Angeles Galvez, Maria; Jimenez-Reina, Luis; Bernabeu, Ignacio; Dieguez, Carlos; Luque, Raul M; Castaño, Justo P; Alvarez, Clara V

2014-11-01

Acromegaly is caused by somatotroph cell adenomas (somatotropinomas [ACROs]), which secrete GH. Human and rodent somatotroph cells express the RET receptor. In rodents, when normal somatotrophs are deprived of the RET ligand, GDNF (Glial Cell Derived Neurotrophic Factor), RET is processed intracellularly to induce overexpression of Pit1 [Transcription factor (gene : POUF1) essential for transcription of Pituitary hormones GH, PRL and TSHb], which in turn leads to p19Arf/p53-dependent apoptosis. Our purpose was to ascertain whether human ACROs maintain the RET/Pit1/p14ARF/p53/apoptosis pathway, relative to nonfunctioning pituitary adenomas (NFPAs). Apoptosis in the absence and presence of GDNF was studied in primary cultures of 8 ACROs and 3 NFPAs. Parallel protein extracts were analyzed for expression of RET, Pit1, p19Arf, p53, and phospho-Akt. When GDNF deprived, ACRO cells, but not NFPAs, presented marked level of apoptosis that was prevented in the presence of GDNF. Apoptosis was accompanied by RET processing, Pit1 accumulation, and p14ARF and p53 induction. GDNF prevented all these effects via activation of phospho-AKT. Overexpression of human Pit1 (hPit1) directly induced p19Arf/p53 and apoptosis in a pituitary cell line. Using in silico studies, 2 CCAAT/enhancer binding protein alpha (cEBPα) consensus-binding sites were found to be 100% conserved in mouse, rat, and hPit1 promoters. Deletion of 1 cEBPα site prevented the RET-induced increase in hPit1 promoter expression. TaqMan qRT-PCR (real time RT-PCR) for RET, Pit1, Arf, TP53, GDNF, steroidogenic factor 1, and GH was performed in RNA from whole ACRO and NFPA tumors. ACRO but not NFPA adenomas express RET and Pit1. GDNF expression in the tumors was positively correlated with RET and negatively correlated with p53. In conclusion, ACROs maintain an active RET/Pit1/p14Arf/p53/apoptosis pathway that is inhibited by GDNF. Disruption of GDNF's survival function might constitute a new therapeutic route in

Overproduction, purification and characterization of human interferon alpha2a-human serum albumin fusion protein produced in methilotropic yeast Pichia pastoris

Science.gov (United States)

Ningrum, R. A.; Santoso, A.; Herawati, N.

2017-05-01

Human interferon alpha2a (hIFNα2a) is a therapeutic protein that used in cancer and hepatitis B/C therapy. The main problem of using hIFNα-2a is its short elimination half life due to its low molecular weight. Development of higher molecular weight protein by albumin fusion technology is a rational strategy to solve the problem. In our previous research we constructed an open reading frame (ORF) encoding hIFNα2a-human serum albumin (HSA) fusion protein that expressed in Pichia pastoris (P. pastoris) protease deficient strain SMD1168. This research was performed to overproduce, purify and characterize the fusion protein. To overproduce the protein, cultivation was performed in buffered complex medium containing glyserol (BMGY) for 24 h and protein overproduction was applied in buffered complex medium containing methanol (BMMY) for 48 hours at 30°C. The fusion protein was purified by blue sepharose affinity chromatography. Molecular weight characterization by SDS PAGE corresponds with its theoretical size, 85 kDa. Western blot analysis demonstrated that the fusion protein was recognized by anti hIFNα2 and anti HSA monoclonal antibody as well. Amino acid sequence of the fusion protein was determined by LC MS/MS2 mass spectrometry with trypsin as proteolitic enzyme. There were three fragments that identified as hIFNα2a and seven fragments that identified as HSA. Total identified amino acids were 150 residues with 20% coverage from total residues. To conclude, hIFNα2a-HSA fusion protein was overproduced, purified and characterized. Characterization based on molecular weight, antibody recognition and amino acid sequence confirmed that the fusion protein has correct identity as theoretically thought.

Overproduction, purification and characterization of human interferon alpha2a-human serum albumin fusion protein produced in methilotropic yeast Pichia pastoris

International Nuclear Information System (INIS)

Ningrum, R A; Santoso, A; Herawati, N

2017-01-01

Human interferon alpha2a (hIFNα2a) is a therapeutic protein that used in cancer and hepatitis B/C therapy. The main problem of using hIFNα-2a is its short elimination half life due to its low molecular weight. Development of higher molecular weight protein by albumin fusion technology is a rational strategy to solve the problem. In our previous research we constructed an open reading frame (ORF) encoding hIFNα2a-human serum albumin (HSA) fusion protein that expressed in Pichia pastoris (P. pastoris) protease deficient strain SMD1168. This research was performed to overproduce, purify and characterize the fusion protein. To overproduce the protein, cultivation was performed in buffered complex medium containing glyserol (BMGY) for 24 h and protein overproduction was applied in buffered complex medium containing methanol (BMMY) for 48 hours at 30°C. The fusion protein was purified by blue sepharose affinity chromatography. Molecular weight characterization by SDS PAGE corresponds with its theoretical size, 85 kDa. Western blot analysis demonstrated that the fusion protein was recognized by anti hIFNα2 and anti HSA monoclonal antibody as well. Amino acid sequence of the fusion protein was determined by LC MS/MS2 mass spectrometry with trypsin as proteolitic enzyme. There were three fragments that identified as hIFNα2a and seven fragments that identified as HSA. Total identified amino acids were 150 residues with 20% coverage from total residues. To conclude, hIFNα2a-HSA fusion protein was overproduced, purified and characterized. Characterization based on molecular weight, antibody recognition and amino acid sequence confirmed that the fusion protein has correct identity as theoretically thought. (paper)

Radiolabelling of glycosylated MFE-23::CPG2 fusion protein (MFECP1) with 99mTc for quantitation of tumour antibody-enzyme localisation in antibody-directed enzyme pro-drug therapy (ADEPT).

Science.gov (United States)

Francis, R J; Mather, S J; Chester, K; Sharma, S K; Bhatia, J; Pedley, R B; Waibel, R; Green, A J; Begent, R H J

2004-08-01

MFECP1 is a glycosylated recombinant fusion protein composed of MFE-23, a high-affinity anti-carcinoembryonic antigen (CEA) single chain Fv (scFv), fused to the enzyme carboxypeptidase G2 (CPG2), and has been constructed for use in antibody-directed enzyme pro-drug therapy (ADEPT). Radiolabelling of glycosylated MFECP1 with technetium-99m was developed for the purpose of determining tumour localisation of MFECP1 in a phase I ADEPT clinical study. The method used was 99mTc-carbonyl [99mTc(H2O)3(CO)3]+ (abbreviated to TcCO) mediated labelling of 99mTc to the hexahistidine (His) tag of MFECP1. MFECP1 fusion protein was labelled with TcCO under a variety of conditions, and this was shown to be a relatively simple and robust method. Tissue biodistribution was assessed in a CEA-expressing LS174T (human colon carcinoma) nude mouse xenograft model. Tissues were taken at 1, 4 and 6 h for assessment of distribution of radioactivity and for measurement of CPG2 enzyme levels. The amount of radioactivity retained by the tumour proved to be an accurate estimation of actual measured enzyme activity, indicating that this radiolabelling method does not appear to damage the antibody-antigen binding or the enzyme activity of MFECP1. However, correlation between CPG2 enzyme activity and measured radioactivity in liver, spleen and kidney was poor, indicating retention of radioactivity in non-tumour sites but loss of enzyme activity. The high retention of technetium radioisotope in normal tissues may limit the clinical applicability of this radiolabelling method for MFECP1; however, these results suggest that this technique does have applicability for measuring the biodistribution of His-tagged recombinant proteins.

Radiolabelling of glycosylated MFE-23::CPG2 fusion protein (MFECP1) with 99mTc for quantitation of tumour antibody-enzyme localisation in antibody-directed enzyme pro-drug therapy (ADEPT)

International Nuclear Information System (INIS)

Francis, R.J.; Chester, K.; Sharma, S.K.; Bhatia, J.; Pedley, R.B.; Green, A.J.; Begent, R.H.J.; Mather, S.J.; Waibel, R.

2004-01-01

MFECP1 is a glycosylated recombinant fusion protein composed of MFE-23, a high-affinity anti-carcinoembryonic antigen (CEA) single chain Fv (scFv), fused to the enzyme carboxypeptidase G2 (CPG2), and has been constructed for use in antibody-directed enzyme pro-drug therapy (ADEPT). Radiolabelling of glycosylated MFECP1 with technetium-99m was developed for the purpose of determining tumour localisation of MFECP1 in a phase I ADEPT clinical study. The method used was 99m Tc-carbonyl [ 99m Tc(H 2 O) 3 (CO) 3 ] + (abbreviated to TcCO) mediated labelling of 99m Tc to the hexahistidine (His) tag of MFECP1. MFECP1 fusion protein was labelled with TcCO under a variety of conditions, and this was shown to be a relatively simple and robust method. Tissue biodistribution was assessed in a CEA-expressing LS174T (human colon carcinoma) nude mouse xenograft model. Tissues were taken at 1, 4 and 6 h for assessment of distribution of radioactivity and for measurement of CPG2 enzyme levels. The amount of radioactivity retained by the tumour proved to be an accurate estimation of actual measured enzyme activity, indicating that this radiolabelling method does not appear to damage the antibody-antigen binding or the enzyme activity of MFECP1. However, correlation between CPG2 enzyme activity and measured radioactivity in liver, spleen and kidney was poor, indicating retention of radioactivity in non-tumour sites but loss of enzyme activity. The high retention of technetium radioisotope in normal tissues may limit the clinical applicability of this radiolabelling method for MFECP1; however, these results suggest that this technique does have applicability for measuring the biodistribution of His-tagged recombinant proteins. (orig.)

Expression and Purification of Neurotrophin-Elastin-Like Peptide Fusion Proteins for Neural Regeneration.

Science.gov (United States)

Johnson, Tamina; Koria, Piyush

2016-04-01

Neural injuries such as spinal cord injuries, traumatic brain injuries, or nerve transection injuries pose a major health problem. Neurotrophins such as nerve growth factor (NGF) or brain-derived neurotrophic factor (BDNF) have been shown to improve the outcome of neural injuries in several pre-clinical models, but their use in clinics is limited by the lack of a robust delivery system that enhances their bioavailability and half-life. We describe two fusion proteins comprising NGF or BDNF fused with elastin-like peptides (ELPs). The aim of this study was to investigate the biological activity of neurotrophin-ELP (N-ELP) fusion proteins via in vitro culture models. NGF and BDNF were cloned in front of an elastin-like polypeptide sequence V40C2. These proteins were expressed in bacteria as inclusion bodies. These fusion proteins underwent solubilization via 8 M urea and purification via inverse transition cycling (ITC). We measured the particle size and the effect of temperature on precipitated particles using dynamic light scattering (DLS). We used western blot analysis to confirm the specificity of NGF-ELP to tropomyosin receptor kinase A (TrkA) antibody and to confirm the specificity of BDNF-ELP to TrkB antibody. PC12 cells were used to perform a neurite outgrowth assay to determine the biological activity of NGF-ELP. Bioactivity of BDNF-ELP was ascertained via transfecting human epithelial kidney (HEK 293-T) cells to express the TrkB receptor. The proteins were successfully purified to high homogeneity by exploiting the phase transition property of ELPs and urea, which solubilize inclusion bodies. Using PC12 neurite outgrowth assay, we further demonstrated that the biological activity of NGF was retained in the fusion. Similarly, BDNF-ELP phosphorylated the TrkB receptor, suggesting the biological activity of BDNF was also retained in the fusion. We further show that owing to the phase transition property of ELPs in the fusion, these proteins self-assembled into

BMP6 down-regulates GDNF expression through SMAD1/5 and ERK1/2 signaling pathways in human granulosa-lutein cells.

Science.gov (United States)

Zhang, Xin-Yue; Chang, Hsun-Ming; Taylor, Elizabeth L; Leung, Peter C K; Liu, Rui-Zhi

2018-05-09

Bone morphogenetic protein 6 (BMP6) is a critical regulator of follicular development that is expressed in mammalian oocytes and granulosa cells. Glial cell line-derived neurotrophic factor (GDNF) is an intraovarian neurotrophic factor that plays an essential role in regulating mammalian oocyte maturation. The aim of this study was to investigate the effect of BMP6 on the regulation of GDNF expression and the potential underlying mechanisms. We used an established immortalized human granulosa cell line (SVOG cells) and primary human granulosa-lutein cells as in vitro cell models. Our results showed that BMP6 significantly down-regulated the expression of GDNF in both SVOG and primary human granulosa-lutein cells. Using dual inhibition approaches (kinase receptor inhibitor and small interfering RNA knockdown), our results showed that both ALK2 and ALK3 are involved in BMP6-induced down-regulation of GDNF. In addition, BMP6 induced the phosphorylation of SMAD1/5/8 and ERK1/2 but not AKT or p38. Among three downstream mediators, both SMAD1 and SMAD5 are involved in BMP6-induced down-regulation of GDNF. Moreover, concomitant knockdown of endogenous SMAD4 and inhibition of ERK1/2 activity completely reversed BMP6-induced down-regulation of GDNF, indicating that both SMAD and ERK1/2 signaling pathways are required for the regulatory effect of BMP6 on GDNF expression. Our findings suggest an additional role for an intrafollicular growth factor in regulating follicular function through their paracrine interactions in human granulosa cells.

Universal antibodies against the highly conserved influenza fusion peptide cross-neutralize several subtypes of influenza A virus

Energy Technology Data Exchange (ETDEWEB)

Hashem, Anwar M. [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Department of Microbiology, Faculty of Medicine, King Abdulaziz University, Jeddah (Saudi Arabia); Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON (Canada); Van Domselaar, Gary [National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB (Canada); Li, Changgui; Wang, Junzhi [National Institute for the Control of Pharmaceutical and Biological Products, Beijing (China); She, Yi-Min; Cyr, Terry D. [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Sui, Jianhua [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States); He, Runtao [National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB (Canada); Marasco, Wayne A. [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States); Li, Xuguang, E-mail: Sean.Li@hc-sc.gc.ca [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON (Canada)

2010-12-10

Research highlights: {yields} The fusion peptide is the only universally conserved epitope in all influenza viral hemagglutinins. {yields} Anti-fusion peptide antibodies are universal antibodies that cross-react with all influenza HA subtypes. {yields} The universal antibodies cross-neutralize different influenza A subtypes. {yields} The universal antibodies inhibit the fusion process between the viruses and the target cells. -- Abstract: The fusion peptide of influenza viral hemagglutinin plays a critical role in virus entry by facilitating membrane fusion between the virus and target cells. As the fusion peptide is the only universally conserved epitope in all influenza A and B viruses, it could be an attractive target for vaccine-induced immune responses. We previously reported that antibodies targeting the first 14 amino acids of the N-terminus of the fusion peptide could bind to virtually all influenza virus strains and quantify hemagglutinins in vaccines produced in embryonated eggs. Here we demonstrate that these universal antibodies bind to the viral hemagglutinins in native conformation presented in infected mammalian cell cultures and neutralize multiple subtypes of virus by inhibiting the pH-dependant fusion of viral and cellular membranes. These results suggest that this unique, highly-conserved linear sequence in viral hemagglutinin is exposed sufficiently to be attacked by the antibodies during the course of infection and merits further investigation because of potential importance in the protection against diverse strains of influenza viruses.

Universal antibodies against the highly conserved influenza fusion peptide cross-neutralize several subtypes of influenza A virus

International Nuclear Information System (INIS)

Hashem, Anwar M.; Van Domselaar, Gary; Li, Changgui; Wang, Junzhi; She, Yi-Min; Cyr, Terry D.; Sui, Jianhua; He, Runtao; Marasco, Wayne A.; Li, Xuguang

2010-01-01

Research highlights: → The fusion peptide is the only universally conserved epitope in all influenza viral hemagglutinins. → Anti-fusion peptide antibodies are universal antibodies that cross-react with all influenza HA subtypes. → The universal antibodies cross-neutralize different influenza A subtypes. → The universal antibodies inhibit the fusion process between the viruses and the target cells. -- Abstract: The fusion peptide of influenza viral hemagglutinin plays a critical role in virus entry by facilitating membrane fusion between the virus and target cells. As the fusion peptide is the only universally conserved epitope in all influenza A and B viruses, it could be an attractive target for vaccine-induced immune responses. We previously reported that antibodies targeting the first 14 amino acids of the N-terminus of the fusion peptide could bind to virtually all influenza virus strains and quantify hemagglutinins in vaccines produced in embryonated eggs. Here we demonstrate that these universal antibodies bind to the viral hemagglutinins in native conformation presented in infected mammalian cell cultures and neutralize multiple subtypes of virus by inhibiting the pH-dependant fusion of viral and cellular membranes. These results suggest that this unique, highly-conserved linear sequence in viral hemagglutinin is exposed sufficiently to be attacked by the antibodies during the course of infection and merits further investigation because of potential importance in the protection against diverse strains of influenza viruses.

Immunological characteristics of outer membrane protein omp31 of goat Brucella and its monoclonal antibody.

Science.gov (United States)

Zheng, W Y; Wang, Y; Zhang, Z C; Yan, F

2015-10-05

We examined the immunological characteristics of outer membrane protein omp31 of goat Brucella and its monoclonal antibody. Genomic DNA from the M5 strain of goat Brucella was amplified by polymerase chain reaction and cloned into the prokaryotic expression vector pGEX-4T-1. The expression and immunological characteristics of the fusion protein GST-omp31 were subjected to preliminary western blot detection with goat Brucella rabbit immune serum. The Brucella immunized BALB/c mouse serum was detected using purified protein. The high-potency mouse splenocytes and myeloma Sp2/0 cells were fused. Positive clones were screened by enzyme-linked immunosorbent assay to establish a hybridoma cell line. Mice were inoculated intraperitoneally with hybridoma cells to prepare ascites. The mAb was purified using the n-caprylic acid-ammonium sulfate method. The characteristics of mAb were examined using western blotting and enzyme-linked immunosorbent assay. A 680-base pair band was observed after polymerase chain reaction. Enzyme digestion identification and sequencing showed that the pGEX-4T-1-omp31 prokaryotic expression vector was successfully established; a target band of approximately 57 kDa with an apparent molecular weight consistent with the size of the target fusion protein. At 25°C, the expression of soluble expression increased significantly; the fusion protein GST-omp31 was detected by western blotting. Anti-omp31 protein mAb was obtained from 2 strains of Brucella. The antibody showed strong specificity and sensitivity and did not cross-react with Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Mycobacterium tuberculosis, or Bacillus pyocyaneus. The pGEX-4T-1-omp31 prokaryotic expression vector was successfully established and showed good immunogenicity. The antibody also showed strong specificity and good sensitivity.

[Prokaryotic expression of Nanog gene and preparation of anti-Nanog antibody].

Science.gov (United States)

Li, Jun; Wang, Xiao-min; Dou, Zhong-ying; Li, Yong

2012-07-01

To express Nanog fusion protein in Escherichia coli ( E.coli), and to prepare rabbit anti-mouse polyclonal antibodies to the Nanog fusion protein. Mouse Nanog gene was amplified from the pNA992 recombinant plasmid and inserted into pET-32a vector to construct a recombinant expression vector pET-32a-Nanog. The recombinant vector was transfected into E.coli BL21 and induced by IPTG to express in them. The acquired Nanog fusion protein was purified with HisTrap affinity column and injected as an antigen into rabbits for preparing polyclonal antibodies. At last, the titer and specificity of the polyclonal antibodies were analyzed with indirect ELISA, Western blotting and immunocytochemical staining, respectively. The recombinant expression vector pET-32a-Nanog was successfully prepared, transfected and induced to obtain the high expression of the Nanog fusion protein in a form of inclusion bodies in E.coli. After purification, its purity was up to 97%. The titer of anti-Nanog antibodies was 1:32 000 in the immunized rabbit serum, and exhibited a high specificity to Nanog protein. The rabbit anti-mouse polyclonal antibodies have been prepared successfully with a high titer and specificity to the Nanog fusion protein.

Systemic injection of AAV9-GDNF provides modest functional improvements in the SOD1G93A ALS rat but has adverse side effects.

Science.gov (United States)

Thomsen, G M; Alkaslasi, M; Vit, J-P; Lawless, G; Godoy, M; Gowing, G; Shelest, O; Svendsen, C N

2017-04-01

Injecting proteins into the central nervous system that stimulate neuronal growth can lead to beneficial effects in animal models of disease. In particular, glial cell line-derived neurotrophic factor (GDNF) has shown promise in animal and cell models of Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis (ALS). Here, systemic AAV9-GDNF was delivered via tail vein injections to young rats to determine whether this could be a safe and functional strategy to treat the SOD1 G93A rat model of ALS and, therefore, translated to a therapy for ALS patients. We found that GDNF administration in this manner resulted in modest functional improvement, whereby grip strength was maintained for longer and the onset of forelimb paralysis was delayed compared to non-treated rats. This did not, however, translate into an extension in survival. In addition, ALS rats receiving GDNF exhibited slower weight gain, reduced activity levels and decreased working memory. Collectively, these results confirm that caution should be applied when applying growth factors such as GDNF systemically to multiple tissues.

Cyclical and patch-like GDNF distribution along the basal surface of Sertoli cells in mouse and hamster testes.

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Takeshi Sato

Full Text Available BACKGROUND AND AIMS: In mammalian spermatogenesis, glial cell line-derived neurotrophic factor (GDNF is one of the major Sertoli cell-derived factors which regulates the maintenance of undifferentiated spermatogonia including spermatogonial stem cells (SSCs through GDNF family receptor α1 (GFRα1. It remains unclear as to when, where and how GDNF molecules are produced and exposed to the GFRα1-positive spermatogonia in vivo. METHODOLOGY AND PRINCIPAL FINDINGS: Here we show the cyclical and patch-like distribution of immunoreactive GDNF-positive signals and their close co-localization with a subpopulation of GFRα1-positive spermatogonia along the basal surface of Sertoli cells in mice and hamsters. Anti-GDNF section immunostaining revealed that GDNF-positive signals are mainly cytoplasmic and observed specifically in the Sertoli cells in a species-specific as well as a seminiferous cycle- and spermatogenic activity-dependent manner. In contrast to the ubiquitous GDNF signals in mouse testes, high levels of its signals were cyclically observed in hamster testes prior to spermiation. Whole-mount anti-GDNF staining of the seminiferous tubules successfully visualized the cyclical and patch-like extracellular distribution of GDNF-positive granular deposits along the basal surface of Sertoli cells in both species. Double-staining of GDNF and GFRα1 demonstrated the close co-localization of GDNF deposits and a subpopulation of GFRα1-positive spermatogonia. In both species, GFRα1-positive cells showed a slender bipolar shape as well as a tendency for increased cell numbers in the GDNF-enriched area, as compared with those in the GDNF-low/negative area of the seminiferous tubules. CONCLUSION/SIGNIFICANCE: Our data provide direct evidence of regionally defined patch-like GDNF-positive signal site in which GFRα1-positive spermatogonia possibly interact with GDNF in the basal compartment of the seminiferous tubules.

Role of glial cell line-derived neurotrophic factor (GDNF)-neural cell adhesion molecule (NCAM) interactions in induction of neurite outgrowth and identification of a binding site for NCAM in the heel region of GDNF

DEFF Research Database (Denmark)

Nielsen, Janne; Gotfryd, Kamil; Li, Shizhong

2009-01-01

NCAM-induced neurite outgrowth by being independent of NCAM polysialylation. Additionally, we investigated the structural basis for GDNF-NCAM interactions and find that NCAM Ig3 is necessary for GDNF binding. Furthermore, we identify within the heel region of GDNF a binding site for NCAM...

GDNF facilitates differentiation of the adult dentate gyrus-derived neural precursor cells into astrocytes via STAT3

International Nuclear Information System (INIS)

Boku, Shuken; Nakagawa, Shin; Takamura, Naoki; Kato, Akiko; Takebayashi, Minoru; Hisaoka-Nakashima, Kazue; Omiya, Yuki; Inoue, Takeshi; Kusumi, Ichiro

2013-01-01

Highlights: •GDNF has no effect on ADP proliferation and apoptosis. •GDNF increases ADP differentiation into astrocyte. •A specific inhibitor of STAT3 decreases the astrogliogenic effect of GDNF. •STAT3 knockdown by lentiviral shRNA vector also decreases the astrogliogenic effect of GDNF. •GDNF increases the phosphorylation of STAT3. -- Abstract: While the pro-neurogenic actions of antidepressants in the adult hippocampal dentate gyrus (DG) are thought to be one of the mechanisms through which antidepressants exert their therapeutic actions, antidepressants do not increase proliferation of neural precursor cells derived from the adult DG. Because previous studies showed that antidepressants increase the expression and secretion of glial cell line-derived neurotrophic factor (GDNF) in C6 glioma cells derived from rat astrocytes and GDNF increases neurogenesis in adult DG in vivo, we investigated the effects of GDNF on the proliferation, differentiation and apoptosis of cultured neural precursor cells derived from the adult DG. Data showed that GDNF facilitated the differentiation of neural precursor cells into astrocytes but had no effect on their proliferation or apoptosis. Moreover, GDNF increased the phosphorylation of STAT3, and both a specific inhibitor of STAT3 and lentiviral shRNA for STAT3 decreased their differentiation into astrocytes. Taken together, our findings suggest that GDNF facilitates astrogliogenesis from neural precursor cells in adult DG through activating STAT3 and that this action might indirectly affect neurogenesis

GDNF facilitates differentiation of the adult dentate gyrus-derived neural precursor cells into astrocytes via STAT3

Energy Technology Data Exchange (ETDEWEB)

Boku, Shuken, E-mail: shuboku@med.hokudai.ac.jp [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Nakagawa, Shin [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Takamura, Naoki [Pharmaceutical Laboratories, Dainippon Sumitomo Pharma Co. Ltd., Osaka (Japan); Kato, Akiko [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Takebayashi, Minoru [Department of Psychiatry, National Hospital Organization Kure Medical Center, Kure (Japan); Hisaoka-Nakashima, Kazue [Department of Pharmacology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima (Japan); Omiya, Yuki; Inoue, Takeshi; Kusumi, Ichiro [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan)

2013-05-17

Highlights: •GDNF has no effect on ADP proliferation and apoptosis. •GDNF increases ADP differentiation into astrocyte. •A specific inhibitor of STAT3 decreases the astrogliogenic effect of GDNF. •STAT3 knockdown by lentiviral shRNA vector also decreases the astrogliogenic effect of GDNF. •GDNF increases the phosphorylation of STAT3. -- Abstract: While the pro-neurogenic actions of antidepressants in the adult hippocampal dentate gyrus (DG) are thought to be one of the mechanisms through which antidepressants exert their therapeutic actions, antidepressants do not increase proliferation of neural precursor cells derived from the adult DG. Because previous studies showed that antidepressants increase the expression and secretion of glial cell line-derived neurotrophic factor (GDNF) in C6 glioma cells derived from rat astrocytes and GDNF increases neurogenesis in adult DG in vivo, we investigated the effects of GDNF on the proliferation, differentiation and apoptosis of cultured neural precursor cells derived from the adult DG. Data showed that GDNF facilitated the differentiation of neural precursor cells into astrocytes but had no effect on their proliferation or apoptosis. Moreover, GDNF increased the phosphorylation of STAT3, and both a specific inhibitor of STAT3 and lentiviral shRNA for STAT3 decreased their differentiation into astrocytes. Taken together, our findings suggest that GDNF facilitates astrogliogenesis from neural precursor cells in adult DG through activating STAT3 and that this action might indirectly affect neurogenesis.

Exo-endo cellulase fusion protein

Science.gov (United States)

Bower, Benjamin S [Palo Alto, CA; Larenas, Edmund A [Palo Alto, CA; Mitchinson, Colin [Palo Alto, CA

2012-01-17

The present invention relates to a heterologous exo-endo cellulase fusion construct, which encodes a fusion protein having cellulolytic activity comprising a catalytic domain derived from a fungal exo-cellobiohydrolase and a catalytic domain derived from an endoglucanase. The invention also relates to vectors and fungal host cells comprising the heterologous exo-endo cellulase fusion construct as well as methods for producing a cellulase fusion protein and enzymatic cellulase compositions.

Role of protein disulfide isomerase and other thiol-reactive proteins in HIV-1 envelope protein-mediated fusion

International Nuclear Information System (INIS)

Ou Wu; Silver, Jonathan

2006-01-01

Cell-surface protein disulfide isomerase (PDI) has been proposed to promote disulfide bond rearrangements in HIV-1 envelope protein (Env) that accompany Env-mediated fusion. We evaluated the role of PDI in ways that have not been previously tested by downregulating PDI with siRNA and by overexpressing wild-type or variant forms of PDI in transiently and stably transfected cells. These manipulations, as well as treatment with anti-PDI antibodies, had only small effects on infection or cell fusion mediated by NL4-3 or AD8 strains of HIV-1. However, the cell-surface thiol-reactive reagent 5, 5'-dithiobis(2-nitrobenzoic acid) (DTNB) had a much stronger inhibitory effect in our system, suggesting that cell-surface thiol-containing molecules other than PDI, acting alone or in concert, have a greater effect than PDI on HIV-1 Env-mediated fusion. We evaluated one such candidate, thioredoxin, a PDI family member reported to reduce a labile disulfide bond in CD4. We found that the ability of thioredoxin to reduce the disulfide bond in CD4 is enhanced in the presence of HIV-1 Env gp120 and that thioredoxin also reduces disulfide bonds in gp120 directly in the absence of CD4. We discuss the implications of these observations for identification of molecules involved in disulfide rearrangements in Env during fusion

Applications of recombinant antibodies in plant pathology.

Science.gov (United States)

Ziegler, Angelika; Torrance, Lesley

2002-09-01

Summary Advances in molecular biology have made it possible to produce antibody fragments comprising the binding domains of antibody molecules in diverse heterologous systems, such as Escherichia coli, insect cells, or plants. Antibody fragments specific for a wide range of antigens, including plant pathogens, have been obtained by cloning V-genes from lymphoid tissue, or by selection from large naive phage display libraries, thus avoiding the need for immunization. The antibody fragments have been expressed as fusion proteins to create different functional molecules, and fully recombinant assays have been devised to detect plant viruses. The defined binding properties and unlimited cheap supply of antibody fusion proteins make them useful components of standardized immunoassays. The expression of antibody fragments in plants was shown to confer resistance to several plant pathogens. However, the antibodies usually only slowed the progress of infection and durable 'plantibody' resistance has yet to be demonstrated. In future, it is anticipated that antibody fragments from large libraries will be essential tools in high-throughput approaches to post-genomics research, such as the assignment of gene function, characterization of spatio-temporal patterns of protein expression, and elucidation of protein-protein interactions.

Addressing the Immunogenicity of the Cargo and of the Targeting Antibodies with a Focus on Deimmunized Bacterial Toxins and on Antibody-Targeted Human Effector Proteins

OpenAIRE

Grinberg, Yehudit; Benhar, Itai

2017-01-01

Third-generation immunotoxins are composed of a human, or humanized, targeting moiety, usually a monoclonal antibody or an antibody fragment, and a non-human effector molecule. Due to the non-human origin of the cytotoxic domain, these molecules stimulate potent anti-drug immune responses, which limit treatment options. Efforts are made to deimmunize such immunotoxins or to combine treatment with immunosuppression. An alternative approach is using the so-called ?human cytotoxic fusion protein...

Analysis of antigenic cross-reactivity between subgroup C avian pneumovirus and human metapneumovirus by using recombinant fusion proteins.

Science.gov (United States)

Luo, L; Sabara, M I; Li, Y

2009-10-01

Avian pneumovirus subgroup C (APV/C) has recently been reported to be more closely related to human metapneumovirus (hMPV) as determined by sequence analysis. To examine the antigenic relationship between APV/C and hMPV, the APV/C fusion (F) gene was cloned and expressed as an uncleaved glycoprotein in a baculovirus system. The reactivity of the APV/C F protein with antibodies against APV subgroups A, B, C, and hMPV was examined by Western blot analysis. The results showed that the expressed APV/C F protein was not only recognized by APV/C-specific antibodies but also by antibodies raised against hMPV. Previously expressed recombinant hMPV F protein also reacted with APV/C-specific antibodies, suggesting that there was significant antigenic cross-reactivity and a potential evolutionary relationship between hMPV and APV/C. Interestingly, the recombinant F proteins from APV/C and hMPV were not recognized by polyclonal antibodies specific to APV subgroups A and B.

GDNF and neublastin protect against NMDA-induced excitotoxicity in hippocampal slice cultures

DEFF Research Database (Denmark)

Bonde, C; Kristensen, B W; Blaabjerg, M

2000-01-01

-producing HiB5 cells, were added to slice cultures I h before exposure to 10 microM NMDA for 48h. Neuronal cell death was monitored, before and during the NMDA exposure, by densitometric measurements of propidium iodide (PI) uptake and loss of Nissl staining. Both the addition of rhGDNF and NBN......The potential neuroprotective effects of glial cell line-derived neurotrophic factor (GDNF) and neublastin (NBN) against NMDA-induced excitotoxicity were examined in hippocampal brain slice cultures. Recombinant human GDNF (25-100 ng/ ml) or NBN, in medium conditioned by growth of transfected, NBN...

GDNF-transduced Schwann cell grafts enhance regeneration of erectile nerves.

Science.gov (United States)

May, Florian; Matiasek, Kaspar; Vroemen, Maurice; Caspers, Christiane; Mrva, Thomas; Arndt, Christian; Schlenker, Boris; Gais, Peter; Brill, Thomas; Buchner, Alexander; Blesch, Armin; Hartung, Rudolf; Stief, Christian; Gansbacher, Bernd; Weidner, Norbert

2008-11-01

Schwann cell-seeded guidance tubes have been shown to promote cavernous nerve regeneration, and the local delivery of neurotrophic factors may additionally enhance nerve regenerative capacity. The present study evaluates whether the transplantation of GDNF-overexpressing Schwann cells may enhance regeneration of bilaterally transected erectile nerves in rats. Silicon tubes seeded with either GDNF-overexpressing or GFP-expressing Schwann cells were implanted into the gaps between transected cavernous nerve endings. Six (10 study nerves) or 12 wk (20 study nerves) postoperatively, erectile function was evaluated by relaparotomy, electrical nerve stimulation, and intracavernous pressure recording, followed by ultrastructural evaluation of reconstructed nerves employing bright-field and electron microscopy. Additional animals were either sham-operated (positive control; 20 study nerves) or received bilateral nerve transection without nerve reconstruction (negative control; 20 study nerves). The combination of GDNF delivery and Schwann cell application promoted an intact erectile response in 90% (9 of 10) of grafted nerves after 6 wk and in 95% (19 of 20) after 12 wk, versus 50% (5 of 10) and 80% (16 of 20) of GFP-expressing Schwann cell grafts (p=0.02). The functional recovery was paralleled by enhanced axonal regeneration in GDNF-overexpressing Schwann cell grafts, as indicated by larger cross-sectional areas and a significantly higher percentage of neural tissue compared with GFP-transduced controls. These findings demonstrate that the time required to elicit functional recovery of erectile nerves can be reduced by local delivery of GDNF. In terms of clinical application, this enhanced nerve repair might be critical for timely reinnervation of the corpus cavernosum as a prerequisite for functional recovery in men.

SorLA controls neurotrophic activity by sorting of GDNF and its receptors GFRα1 and RET

DEFF Research Database (Denmark)

Glerup, Simon; Lume, Maria; Olsen, Ditte

2013-01-01

is targeted to lysosomes and degraded while GFRα1 recycles, creating an efficient GDNF clearance pathway. The SorLA/GFRα1 complex further targets RET for endocytosis but not for degradation, affecting GDNF-induced neurotrophic activities. SorLA-deficient mice display elevated GDNF levels, altered dopaminergic...

Fluorescent S-layer fusion proteins

International Nuclear Information System (INIS)

Kainz, B.

2010-01-01

This work describes the construction and characterisation of fluorescent S-layer fusion proteins used as building blocks for the fabrication of nanostructured monomolecular biocoatings on silica particles with defined fluorescence properties. The S-layer protein SgsE of Geobacillus stearothermophilus NRS 2004/3a was fused with the pH-dependant cyan, green and yellow variant of the green fluorescent protein (GFP) and the red fluorescent protein mRFP1. These fluorescent S-layer fusion proteins, acting as scaffold and optical sensing element simultaneously, were able to reassemble in solution and on silica particles forming 2D nanostructures with p2 lattice symmetry (a=11 ±0.5 nm, b=14 ±0.4 nm, g=80 ±1 o ). The pH-dependant fluorescence behaviour was studied with fluorimetry, confocal microscopy and flow cytometry. These fluorescent S-layer fusion proteins can be used as pH-sensor. 50% of the fluorescence intensity decreases at their calculated pKa values (pH6 - pH5). The fluorescence intensity of the GFP variants vanished completely between pH4 and pH3 whereas the chromophore of the red protein mRFP1 was only slightly affected in acidic conditions. At the isoelectric point of the S-layer coated silica particles (pH4.6 ±0.2) an increase in particle aggregation was detected by flow cytometry. The cyan and yellow fluorescent proteins were chosen to create a bi-fluorescent S-layer tandem fusion protein with the possibility for resonance energy transfer (FRET). A transfer efficiency of 20% and a molecular distance between the donor (ECFP) and acceptor (YFP) chromophores of around 6.2 nm could be shown. This bi-fluorescent ECFP-SgsE-YFP tandem fusion protein was able to reassemble on solid surfaces. The remarkable combination of fluorescence and self-assembly and the design of bi-functional S-layer tandem fusion protein matrices makes them to a promising tool in nanobiotechnology. (author) [de

GDNF/GFRα1 Complex Abrogates Self-Renewing Activity of Cortical Neural Precursors Inducing Their Differentiation

Directory of Open Access Journals (Sweden)

Antonela Bonafina

2018-03-01

Full Text Available Summary: The balance between factors leading to proliferation and differentiation of cortical neural precursors (CNPs determines the correct cortical development. In this work, we show that GDNF and its receptor GFRα1 are expressed in the neocortex during the period of cortical neurogenesis. We show that the GDNF/GFRα1 complex inhibits the self-renewal capacity of mouse CNP cells induced by fibroblast growth factor 2 (FGF2, promoting neuronal differentiation. While GDNF leads to decreased proliferation of cultured cortical precursor cells, ablation of GFRα1 in glutamatergic cortical precursors enhances its proliferation. We show that GDNF treatment of CNPs promoted morphological differentiation even in the presence of the self-renewal-promoting factor, FGF2. Analysis of GFRα1-deficient mice shows an increase in the number of cycling cells during cortical development and a reduction in dendrite development of cortical GFRα1-expressing neurons. Together, these results indicate that GDNF/GFRα1 signaling plays an essential role in regulating the proliferative condition and the differentiation of cortical progenitors. : In this article, Ledda and colleagues show that GDNF acting through its receptor GFRα1 plays a critical role in the maturation of cortical progenitors by counteracting FGF2 self-renewal activity on neural stem cells and promoting neuronal differentiation. Keywords: GDNF, GFRα1, cortical precursors, proliferation, postmitotic neurons, neuronal differentiation

Receptor-binding domain of SARS-CoV spike protein induces highly potent neutralizing antibodies: implication for developing subunit vaccine

International Nuclear Information System (INIS)

He Yuxian; Zhou Yusen; Liu Shuwen; Kou Zhihua; Li Wenhui; Farzan, Michael; Jiang Shibo

2004-01-01

The spike (S) protein of severe acute respiratory syndrome (SARS) coronavirus (CoV), a type I transmembrane envelope glycoprotein, consists of S1 and S2 domains responsible for virus binding and fusion, respectively. The S1 contains a receptor-binding domain (RBD) that can specifically bind to angiotensin-converting enzyme 2 (ACE2), the receptor on target cells. Here we show that a recombinant fusion protein (designated RBD-Fc) containing 193-amino acid RBD (residues 318-510) and a human IgG1 Fc fragment can induce highly potent antibody responses in the immunized rabbits. The antibodies recognized RBD on S1 domain and completely inhibited SARS-CoV infection at a serum dilution of 1:10,240. Rabbit antisera effectively blocked binding of S1, which contains RBD, to ACE2. This suggests that RBD can induce highly potent neutralizing antibody responses and has potential to be developed as an effective and safe subunit vaccine for prevention of SARS

DNA vaccines expressing soluble CD4-envelope proteins fused to C3d elicit cross-reactive neutralizing antibodies to HIV-1

International Nuclear Information System (INIS)

Bower, Joseph F.; Green, Thomas D.; Ross, Ted M.

2004-01-01

DNA vaccines expressing the envelope (Env) of the human immunodeficiency virus type 1 (HIV-1) have been relatively ineffective at generating high-titer, long-lasting, neutralizing antibodies in a variety of animal models. In this study, DNA vaccines were constructed to express a fusion protein of the soluble human CD4 (sCD4) and the gp120 subunit of the HIV-1 envelope. To enhance the immunogenicity of the expressed fusion protein, three copies of the murine C3d (mC3d 3 ) were added to the carboxyl terminus of the complex. Monoclonal antibodies that recognize CD4-induced epitopes on gp120 efficiently bound to sCD4-gp120 or sCD4-gp120-mC3d 3 . In addition, both sCD4-gp120 and sCD4-gp120-mC3d 3 bound to cells expressing appropriate coreceptors in the absence of cell surface hCD4. Mice (BALB/c) vaccinated with DNA vaccines expressing either gp120-mC3d 3 or sCD4-gp120-mC3d 3 elicited antibodies that neutralized homologous virus infection. However, the use of sCD4-gp120-mC3d 3 -DNA elicited the highest titers of neutralizing antibodies that persisted after depletion of anti-hCD4 antibodies. Interestingly, only mice vaccinated with DNA expressing sCD4-gp120-mC3d 3 had antibodies that elicited cross-protective neutralizing antibodies. The fusion of sCD4 to the HIV-1 envelope exposes neutralizing epitopes that elicit broad protective immunity when the fusion complex is coupled with the molecular adjuvant, C3d

Antigenic Fingerprinting following Primary RSV Infection in Young Children Identifies Novel Antigenic Sites and Reveals Unlinked Evolution of Human Antibody Repertoires to Fusion and Attachment Glycoproteins.

Directory of Open Access Journals (Sweden)

Sandra Fuentes

2016-04-01

Full Text Available Respiratory Syncytial Virus (RSV is the major cause of pneumonia among infants. Here we elucidated the antibody repertoire following primary RSV infection and traced its evolution through adolescence and adulthood. Whole genome-fragment phage display libraries (GFPDL expressing linear and conformational epitopes in the RSV fusion protein (F and attachment protein (G were used for unbiased epitope profiling of infant sera prior to and following RSV infection. F-GFPDL analyses demonstrated modest changes in the anti-F epitope repertoires post-RSV infection, while G-GFPDL analyses revealed 100-fold increase in number of bound phages. The G-reactive epitopes spanned the N- and C-terminus of the G ectodomain, along with increased reactivity to the central conserved domain (CCD. Panels of F and G antigenic sites were synthesized to evaluate sera from young children (<2 yr, adolescents (14-18 yr and adults (30-45 yr in SPR real-time kinetics assays. A steady increase in RSV-F epitope repertoires from young children to adults was observed using peptides and F proteins. Importantly, several novel epitopes were identified in pre-fusion F and an immunodominant epitope in the F-p27. In all age groups, antibody binding to pre-fusion F was 2-3 folds higher than to post-fusion form. For RSV-G, antibody responses were high following early RSV infection in children, but declined significantly in adults, using either G proteins or peptides. This study identified unlinked evolution of anti-F and anti G responses and supportive evidence for immune pressure driven evolution of RSV-G. These findings could help development of effective countermeasures including vaccines.

A synthetic peptide derived from the animo acid sequence of canine parvovirus structural proteins which defines a B cell epitope and elicits antiviral antibody in BALB c mice.

NARCIS (Netherlands)

G.F. Rimmelzwaan (Guus); J. Carlson; F.G.C.M. Uytdehaag (Fons); A.D.M.E. Osterhaus (Albert)

1990-01-01

textabstractSynthetic peptides, recombinant fusion proteins and mouse monoclonal antibodies were used to delineate a B cell epitope of the VP'2 structural protein of canine parvovirus (CPV). Although this epitope is not preferentially recognized in the normal antibody response to CPV, virus-specific

Fcγ1 fragment of IgG1 as a powerful affinity tag in recombinant Fc-fusion proteins: immunological, biochemical and therapeutic properties.

Science.gov (United States)

Soleimanpour, Saman; Hassannia, Tahereh; Motiee, Mahdieh; Amini, Abbas Ali; Rezaee, S A R

2017-05-01

Affinity tags are vital tools for the production of high-throughput recombinant proteins. Several affinity tags, such as the hexahistidine tag, maltose-binding protein, streptavidin-binding peptide tag, calmodulin-binding peptide, c-Myc tag, glutathione S-transferase and FLAG tag, have been introduced for recombinant protein production. The fragment crystallizable (Fc) domain of the IgG1 antibody is one of the useful affinity tags that can facilitate detection, purification and localization of proteins and can improve the immunogenicity, modulatory effects, physicochemical and pharmaceutical properties of proteins. Fcγ recombinant forms a group of recombinant proteins called Fc-fusion proteins (FFPs). FFPs are widely used in drug discovery, drug delivery, vaccine design and experimental research on receptor-ligand interactions. These fusion proteins have become successful alternatives to monoclonal antibodies for drug developments. In this review, the physicochemical, biochemical, immunological, pharmaceutical and therapeutic properties of recombinant FFPs were discussed as a new generation of bioengineering strategies.

Protection by GDNF and other trophic factors against the dopamine-depleting effects of neurotoxic doses of methamphetamine.

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Cass, Wayne A; Peters, Laura E; Harned, Michael E; Seroogy, Kim B

2006-08-01

Repeated methamphetamine (METH) administration to animals can result in long-lasting decreases in striatal dopamine (DA) content. It has previously been shown that glial cell line-derived neurotrophic factor (GDNF) can reduce the DA-depleting effects of neurotoxic doses of METH. However, there are several other trophic factors that are protective against dopaminergic toxins. Thus, the present experiments further investigated the protective effect of GDNF as well as the protective effects of several other trophic factors. Male Fischer-344 rats were given an intracerebral injection of trophic factor (2-10 microg) 1 day before METH (5 mg/kg, s.c., 4 injections at 2-h intervals). Seven days later DA levels in the striatum were measured using high-performance liquid chromatography (HPLC). Initial experiments indicated that only intrastriatal GDNF, and not intranigral GDNF, was protective. Thereafter, all other trophic factors were administered into the striatum. Members of the GDNF family (GDNF, neurturin, and artemin) all provided significant protection against the DA-depleting effects of METH, with GDNF providing the greatest protection. Brain-derived neurotrophic factor, neurotrophin-3, acidic fibroblast growth factor, basic fibroblast growth factor, ciliary neurotrophic factor, transforming growth factor-alpha (TGF-alpha), heregulin beta1 (HRG-beta1), and amphiregulin (AR) provided no significant protection at the doses examined. These results suggest that the GDNF family of trophic factors can provide significant protection against the DA-depleting effects of neurotoxic doses of METH.

[Preparation and characterization of mouse polyclonal antibody against conserved region of human FOXO3].

Science.gov (United States)

Li, Lei; Lyu, Dan

2017-06-01

Objective To purify the recombinant protein specific to conserved region of forkhead box O3 (FOXO3) and prepare mouse anti-human FOXO3 polyclonal antibody. Methods The DNA fragment (aa290-472) encoding conserved domain of FOXO3 was amplified by PCR, and subsequently cloned into pET28a vector. Following transformation into E.coli BL21, the soluble fusion protein His-FOXO3 was induced by IPTG and purified by Ni-NTA affinity chromatography. The purified protein was used to immunize BALB/c mice to generate polyclonal antibody. The characteristics of the polyclonal antibody were assessed by ELISA, Western blotting and immunoprecipitation assays. Results We successfully prepared the expression vector pET28a-FOXO3 (aa290-472) and expressed the purified fusion protein in a soluble form. By immunizing mice with the fusion protein, we obtained anti-human FOXO3 polyclonal antibody. ELISA and Western blotting showed that the mouse antibody could recognize specifically the endogenous FOXO3 protein. Conclusion The polyclonal antibody against conserved domain of FOXO3 can identify the endogenous FOXO3 protein. It can be used to analyze the endogenous FOXO3 expression level.

Immunoglobulin M and G antibody responses to Plasmodium falciparum glutamate-rich protein

DEFF Research Database (Denmark)

Dziegiel, Morten Hanefeld; Rowe, P; Bennett, S

1993-01-01

were measured with a recombinant fusion protein consisting of the carboxy-terminal 783 amino acids of the GLURP. Samples for the study were obtained during a longitudinal malaria morbidity survey performed in The Gambia; cross-sectional surveys were performed at the beginning of the transmission season......The aims of the present study were to describe the age-related immunoglobulin M (IgM) and IgG response to part of a 220-kDa glutamate-rich protein (GLURP) from Plasmodium falciparum and to determine possible correlations of possession of these antibodies with malaria morbidity. IgM and IgG levels...

Heterologous production of peptides in plants: fusion proteins and beyond.

Science.gov (United States)

Viana, Juliane Flávia Cançado; Dias, Simoni Campos; Franco, Octávio Luiz; Lacorte, Cristiano

2013-11-01

Recombinant DNA technology has allowed the ectopic production of proteins and peptides of different organisms leading to biopharmaceutical production in large cultures of bacterial, yeasts and mammalian cells. Otherwise, the expression of recombinant proteins and peptides in plants is an attractive alternative presenting several advantages over the commonly used expression systems including reduced production costs, easy scale-up and reduced risks of pathogen contamination. Different types of proteins and peptides have been expressed in plants, including antibodies, antigens, and proteins and peptides of medical, veterinary and industrial applications. However, apart from providing a proof of concept, the use of plants as platforms for heterologous protein and peptide production still depends on key steps towards optimization including the enhancement of expression levels, manipulation of post-transcriptional modifications and improvements in purification methods. In this review, strategies to increase heterologous protein and peptide stability and accumulation are discussed, focusing on the expression of peptides through the use of gene fusions.

Introduction to current and future protein therapeutics: a protein engineering perspective.

Science.gov (United States)

Carter, Paul J

2011-05-15

Protein therapeutics and its enabling sister discipline, protein engineering, have emerged since the early 1980s. The first protein therapeutics were recombinant versions of natural proteins. Proteins purposefully modified to increase their clinical potential soon followed with enhancements derived from protein or glycoengineering, Fc fusion or conjugation to polyethylene glycol. Antibody-based drugs subsequently arose as the largest and fastest growing class of protein therapeutics. The rationale for developing better protein therapeutics with enhanced efficacy, greater safety, reduced immunogenicity or improved delivery comes from the convergence of clinical, scientific, technological and commercial drivers that have identified unmet needs and provided strategies to address them. Future protein drugs seem likely to be more extensively engineered to improve their performance, e.g., antibodies and Fc fusion proteins with enhanced effector functions or extended half-life. Two old concepts for improving antibodies, namely antibody-drug conjugates and bispecific antibodies, have advanced to the cusp of clinical success. As for newer protein therapeutic platform technologies, several engineered protein scaffolds are in early clinical development and offer differences and some potential advantages over antibodies. Copyright © 2011 Elsevier Inc. All rights reserved.

Cell-to-Cell Measles Virus Spread between Human Neurons Is Dependent on Hemagglutinin and Hyperfusogenic Fusion Protein.

Science.gov (United States)

Sato, Yuma; Watanabe, Shumpei; Fukuda, Yoshinari; Hashiguchi, Takao; Yanagi, Yusuke; Ohno, Shinji

2018-03-15

Measles virus (MV) usually causes acute infection but in rare cases persists in the brain, resulting in subacute sclerosing panencephalitis (SSPE). Since human neurons, an important target affected in the disease, do not express the known MV receptors (signaling lymphocyte activation molecule [SLAM] and nectin 4), how MV infects neurons and spreads between them is unknown. Recent studies have shown that many virus strains isolated from SSPE patients possess substitutions in the extracellular domain of the fusion (F) protein which confer enhanced fusion activity. Hyperfusogenic viruses with such mutations, unlike the wild-type MV, can induce cell-cell fusion even in SLAM- and nectin 4-negative cells and spread efficiently in human primary neurons and the brains of animal models. We show here that a hyperfusogenic mutant MV, IC323-F(T461I)-EGFP (IC323 with a fusion-enhancing T461I substitution in the F protein and expressing enhanced green fluorescent protein), but not the wild-type MV, spreads in differentiated NT2 cells, a widely used human neuron model. Confocal time-lapse imaging revealed the cell-to-cell spread of IC323-F(T461I)-EGFP between NT2 neurons without syncytium formation. The production of virus particles was strongly suppressed in NT2 neurons, also supporting cell-to-cell viral transmission. The spread of IC323-F(T461I)-EGFP was inhibited by a fusion inhibitor peptide as well as by some but not all of the anti-hemagglutinin antibodies which neutralize SLAM- or nectin-4-dependent MV infection, suggesting the presence of a distinct neuronal receptor. Our results indicate that MV spreads in a cell-to-cell manner between human neurons without causing syncytium formation and that the spread is dependent on the hyperfusogenic F protein, the hemagglutinin, and the putative neuronal receptor for MV. IMPORTANCE Measles virus (MV), in rare cases, persists in the human central nervous system (CNS) and causes subacute sclerosing panencephalitis (SSPE) several

Monoclonal antibodies against a synthetic peptide from human immunodeficiency virus type 1 Nef protein

DEFF Research Database (Denmark)

Steinaa, L; Wulff, A M; Saermark, T

1994-01-01

Monoclonal antibodies against a synthetic peptide (aa 138-152) from HIV-1 Nef protein were produced and characterized. Three hybridoma lines producing monoclonal antibodies (MAbs) against the synthetic peptide were generated by fusion between P3-X63 Ag8.653 myeloma cells and BALB/c splenocytes from...... mice immunized with the synthetic peptide coupled to keyhole limpet hemocyanin (KLH). The hybridomas were screened and selected by ELISA with the peptide coupled to bovine serum albumin (BSA) immobilized to the polystyrene surface and specificity for the peptide was confirmed by competitive ELISA...... with the peptide free in solution. The reactions of the MAbs with a 5-aa motif (WCYKL) included in the sequence were examined with synthetic peptides and two of the MAbs reacted with the motif. The recognitions of recombinant full-length Nef protein were also tested. One MAb reacted with the protein in both ELISA...

Expression and Activation of Horseradish Peroxidase-Protein A/G Fusion Protein in Silkworm Larvae for Diagnostic Purposes.

Science.gov (United States)

Xxxx, Patmawati; Minamihata, Kosuke; Tatsuke, Tsuneyuki; Lee, Jae Man; Kusakabe, Takahiro; Kamiya, Noriho

2018-06-01

Recombinant protein production can create artificial proteins with desired functions by introducing genetic modifications to the target proteins. Horseradish peroxidase (HRP) has been used extensively as a reporter enzyme in biotechnological applications; however, recombinant production of HRP has not been very successful, hampering the utilization of HRP with genetic modifications. A fusion protein comprising an antibody binding protein and HRP will be an ideal bio-probe for high-quality HRP-based diagnostic systems. A HRP-protein A/G fusion protein (HRP-pAG) is designed and its production in silkworm (Bombyx mori) is evaluated for the first time. HRP-pAG is expressed in a soluble apo form, and is activated successfully by incubating with hemin. The activated HRP-pAG is used directly for ELISA experiments and retains its activity over 20 days at 4 °C. Moreover, HRP-pAG is modified with biotin by the microbial transglutaminase (MTG) reaction. The biotinylated HRP-pAG is conjugated with streptavidin to form a HRP-pAG multimer and the multimeric HRP-pAG produced higher signals in the ELISA system than monomeric HRP-pAG. The successful production of recombinant HRP in silkworm will contribute to creating novel HRP-based bioconjugates as well as further functionalization of HRP by applying enzymatic post-translational modifications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Expression of human mag-1 gene in E. coli and preparation of its antibody

International Nuclear Information System (INIS)

Lin Huiyun; Xu Yuanji; Wang Yan; Chen Huihua; Du Zhiyan; Tan Xiaogang; Lu Yinglin

2006-01-01

Objective: To further investigate the new metastasis associated gene, mag-1 expressed in E. coli and its anti-body was prepared in rabbit. Methods: mag-1 was amplified by PCR from pcDNA3-mag-1 and directly cloned into pET-28a vector. The fusion protein was expressed in BL21 and identified by Western blot using anti-His monoclonal antibody. Rabbit was immunized with partially purified fusion protein subcutaneously. Results: Sequence analysis revealed identity of the sequence obtained to the previous report. The recombinant His-mag-1 could be expressed in E. coli as a fusion protein of 18 x 10 3 . The recombinant protein was mostly expressed in the inclusion bodies on the induction by 0.1 mmol/L IPTG at 37 degree C for 6 hours. Western blot analysis showed that the recombinant protein could be recognized by His monoclonal anti-body. The titer of polyclonal antibody against mag-1 was 1:160000. Conclusion: The mag-1 gene is expressed in E. coli highly and its antibody is prepared successfully. (authors)

Rho GTPase activity modulates paramyxovirus fusion protein-mediated cell-cell fusion

International Nuclear Information System (INIS)

Schowalter, Rachel M.; Wurth, Mark A.; Aguilar, Hector C.; Lee, Benhur; Moncman, Carole L.; McCann, Richard O.; Dutch, Rebecca Ellis

2006-01-01

The paramyxovirus fusion protein (F) promotes fusion of the viral envelope with the plasma membrane of target cells as well as cell-cell fusion. The plasma membrane is closely associated with the actin cytoskeleton, but the role of actin dynamics in paramyxovirus F-mediated membrane fusion is unclear. We examined cell-cell fusion promoted by two different paramyxovirus F proteins in three cell types in the presence of constitutively active Rho family GTPases, major cellular coordinators of actin dynamics. Reporter gene and syncytia assays demonstrated that expression of either Rac1 V12 or Cdc42 V12 could increase cell-cell fusion promoted by the Hendra or SV5 glycoproteins, though the effect was dependent on the cell type expressing the viral glycoproteins. In contrast, RhoA L63 decreased cell-cell fusion promoted by Hendra glycoproteins but had little affect on SV5 F-mediated fusion. Also, data suggested that GTPase activation in the viral glycoprotein-containing cell was primarily responsible for changes in fusion. Additionally, we found that activated Cdc42 promoted nuclear rearrangement in syncytia

Vaccine-induced anti-HA2 antibodies promote virus fusion and enhance influenza virus respiratory disease.

Science.gov (United States)

Khurana, Surender; Loving, Crystal L; Manischewitz, Jody; King, Lisa R; Gauger, Phillip C; Henningson, Jamie; Vincent, Amy L; Golding, Hana

2013-08-28

Vaccine-induced disease enhancement has been described in connection with several viral vaccines in animal models and in humans. We investigated a swine model to evaluate mismatched influenza vaccine-associated enhanced respiratory disease (VAERD) after pH1N1 infection. Vaccinating pigs with whole inactivated H1N2 (human-like) virus vaccine (WIV-H1N2) resulted in enhanced pneumonia and disease after pH1N1 infection. WIV-H1N2 immune sera contained high titers of cross-reactive anti-pH1N1 hemagglutinin (HA) antibodies that bound exclusively to the HA2 domain but not to the HA1 globular head. No hemagglutination inhibition titers against pH1N1 (challenge virus) were measured. Epitope mapping using phage display library identified the immunodominant epitope recognized by WIV-H1N2 immune sera as amino acids 32 to 77 of pH1N1-HA2 domain, close to the fusion peptide. These cross-reactive anti-HA2 antibodies enhanced pH1N1 infection of Madin-Darby canine kidney cells by promoting virus membrane fusion activity. The enhanced fusion activity correlated with lung pathology in pigs. This study suggests a role for fusion-enhancing anti-HA2 antibodies in VAERD, in the absence of receptor-blocking virus-neutralizing antibodies. These findings should be considered during the evaluation of universal influenza vaccines designed to elicit HA2 stem-targeting antibodies.

Levels of antibody to conserved parts of Plasmodium falciparum merozoite surface protein 1 in Ghanaian children are not associated with protection from clinical malaria

DEFF Research Database (Denmark)

Dodoo, D; Theander, T G; Kurtzhals, J A

1999-01-01

malaria season in April and after the season in November. Using enzyme-linked immunosorbent assay, we measured antibody responses to recombinant gluthathione S-transferase-PfMSP119 fusion proteins corresponding to the Wellcome and MAD20 allelic variants in these samples. Prevalence of antibodies......The 19-kDa conserved C-terminal part of the Plasmodium falciparum merozoite surface protein 1 (PfMSP119) is a malaria vaccine candidate antigen, and human antibody responses to PfMSP119 have been associated with protection against clinical malaria. In this longitudinal study carried out in an area...

Monoclonal Antibody and Fusion Protein Biosimilars Across Therapeutic Areas: A Systematic Review of Published Evidence.

Science.gov (United States)

Jacobs, Ira; Petersel, Danielle; Shane, Lesley G; Ng, Chee-Keng; Kirchhoff, Carol; Finch, Gregory; Lula, Sadiq

2016-12-01

Despite regulatory efforts to formalize guidance policies on biosimilars, there remains a need to educate healthcare stakeholders on the acknowledged definition of biosimilarity and the data that underpin it. The objectives of the study were to systematically collate published data for monoclonal antibodies and fusion protein biosimilars indicated for cancer, chronic inflammatory diseases, and other indications, and to explore differences in the type and weight (quantity and quality) of available evidence. MEDLINE, Embase, and ISI Web of Science were searched to September 2015. Conference proceedings (n = 17) were searched 2012 to July 2015. Included studies were categorized by originator, study type, and indication. To assess data strength and validity, risk of bias assessments were undertaken. Across therapeutic areas, 43 named (marketed or proposed) biosimilars were identified for adalimumab, abciximab, bevacizumab, etanercept, infliximab, omalizumab, ranibizumab, rituximab, and trastuzumab originators. Infliximab CT-P13, SB2, and etanercept SB4 biosimilars have the greatest amount of published evidence of similarity with their originators, based on results of clinical studies involving larger numbers of patients or healthy subjects (N = 1405, 743, and 734, respectively). Published data were also retrieved for marketed intended copies of etanercept and rituximab. This unbiased synthesis of the literature exposed significant differences in the extent of published evidence between molecules at preclinical, clinical, and post-marketing stages of development, providing clinicians and payers with a consolidated view of the available data and remaining gaps.

Paramyxovirus F1 protein has two fusion peptides: implications for the mechanism of membrane fusion.

Science.gov (United States)

Peisajovich, S G; Samuel, O; Shai, Y

2000-03-10

Viral fusion proteins contain a highly hydrophobic segment, named the fusion peptide, which is thought to be responsible for the merging of the cellular and viral membranes. Paramyxoviruses are believed to contain a single fusion peptide at the N terminus of the F1 protein. However, here we identified an additional internal segment in the Sendai virus F1 protein (amino acids 214-226) highly homologous to the fusion peptides of HIV-1 and RSV. A synthetic peptide, which includes this region, was found to induce membrane fusion of large unilamellar vesicles, at concentrations where the known N-terminal fusion peptide is not effective. A scrambled peptide as well as several peptides from other regions of the F1 protein, which strongly bind to membranes, are not fusogenic. The functional and structural characterization of this active segment suggest that the F1 protein has an additional internal fusion peptide that could participate in the actual fusion event. The presence of homologous regions in other members of the same family suggests that the concerted action of two fusion peptides, one N-terminal and the other internal, is a general feature of paramyxoviruses. Copyright 2000 Academic Press.

Expression of the Acyl-Coenzyme A: Cholesterol Acyltransferase GFP Fusion Protein in Sf21 Insect Cells

Science.gov (United States)

Mahtani, H. K.; Richmond, R. C.; Chang, T. Y.; Chang, C. C. Y.; Rose, M. Franklin (Technical Monitor)

2001-01-01

The enzyme acyl-coenzyme A:cholesterol acyltransferase (ACAT) is an important contributor to the pathological expression of plaque leading to artherosclerosis n a major health problem. Adequate knowledge of the structure of this protein will enable pharmaceutical companies to design drugs specific to the enzyme. ACAT is a membrane protein located in the endoplasmic reticulum.t The protein has never been purified to homogeneity.T.Y. Chang's laboratory at Dartmouth College provided a 4-kb cDNA clone (K1) coding for a structural gene of the protein. We have modified the gene sequence and inserted the cDNA into the BioGreen His Baculovirus transfer vector. This was successfully expressed in Sf2l insect cells as a GFP-labeled ACAT protein. The advantage to this ACAT-GFP fusion protein (abbreviated GCAT) is that one can easily monitor its expression as a function of GFP excitation at 395 nm and emission at 509 nm. Moreover, the fusion protein GCAT can be detected on Western blots with the use of commercially available GFP antibodies. Antibodies against ACAT are not readily available. The presence of the 6xHis tag in the transfer vector facilitates purification of the recombinant protein since 6xHis fusion proteins bind with high affinity to Ni-NTA agarose. Obtaining highly pure protein in large quantities is essential for subsequent crystallization. The purified GCAT fusion protein can readily be cleaved into distinct GFP and ACAT proteins in the presence of thrombin. Thrombin digests the 6xHis tag linking the two protein sequences. Preliminary experiments have indicated that both GCAT and ACAT are expressed as functional proteins. The ultimate aim is to obtain large quantities of the ACAT protein in pure and functional form appropriate for protein crystal growth. Determining protein structure is the key to the design and development of effective drugs. X-ray analysis requires large homogeneous crystals that are difficult to obtain in the gravity environment of earth

Nucleolin modulates the subcellular localization of GDNF-inducible zinc finger protein 1 and its roles in transcription and cell proliferation

International Nuclear Information System (INIS)

Dambara, Atsushi; Morinaga, Takatoshi; Fukuda, Naoyuki; Yamakawa, Yoshinori; Kato, Takuya; Enomoto, Atsushi; Asai, Naoya; Murakumo, Yoshiki; Matsuo, Seiichi; Takahashi, Masahide

2007-01-01

GZF1 is a zinc finger protein induced by glial cell-line-derived neurotrophic factor (GDNF). It is a sequence-specific transcriptional repressor with a BTB/POZ (Broad complex, Tramtrack, Bric a brac/Poxvirus and zinc finger) domain and ten zinc finger motifs. In the present study, we used immunoprecipitation and mass spectrometry to identify nucleolin as a GZF1-binding protein. Deletion analysis revealed that zinc finger motifs 1-4 of GZF1 mediate its association with nucleolin. When zinc fingers 1-4 were deleted from GZF1 or nucleolin expression was knocked down by short interference RNA (siRNA), nuclear localization of GZF1 was impaired. These results suggest that nucleolin is involved in the proper subcellular distribution of GZF1. In addition, overexpression of nucleolin moderately inhibited the transcriptional repressive activity of GZF1 whereas knockdown of nucleolin expression by siRNA enhanced its activity. Thus, the repressive activity of GZF1 is modulated by the level at which nucleolin is expressed. Finally, we found that knockdown of GZF1 and nucleolin expression markedly impaired cell proliferation. These findings suggest that the physiological functions of GZF1 may be regulated by the protein's association with nucleolin

High production of llama variable heavy-chain antibody fragment (VHH) fused to various reader proteins by Aspergillus oryzae.

Science.gov (United States)

Hisada, Hiromoto; Tsutsumi, Hiroko; Ishida, Hiroki; Hata, Yoji

2013-01-01

Llama variable heavy-chain antibody fragment (VHH) fused to four different reader proteins was produced and secreted in culture medium by Aspergillus oryzae. These fusion proteins consisted of N-terminal reader proteins, VHH, and a C-terminal his-tag sequence which facilitated purification using one-step his-tag affinity chromatography. SDS-PAGE analysis of the deglycosylated purified fusion proteins confirmed that the molecular weight of each corresponded to the expected sum of VHH and the respective reader proteins. The apparent high molecular weight reader protein glucoamylase (GlaB) was found to be suitable for efficient VHH production. The GlaB-VHH-His protein bound its antigen, human chorionic gonadotropin, and was detectable by a new ELISA-based method using a coupled assay with glucoamylase, glucose oxidase, peroxidase, maltose, and 3,3',5,5'-tetramethylbenzidine as substrates. Addition of potassium phosphate to the culture medium induced secretion of 0.61 mg GlaB-VHH-His protein/ml culture medium in 5 days.

Mitochondrial Fusion Proteins and Human Diseases

Directory of Open Access Journals (Sweden)

Michela Ranieri

2013-01-01

Full Text Available Mitochondria are highly dynamic, complex organelles that continuously alter their shape, ranging between two opposite processes, fission and fusion, in response to several stimuli and the metabolic demands of the cell. Alterations in mitochondrial dynamics due to mutations in proteins involved in the fusion-fission machinery represent an important pathogenic mechanism of human diseases. The most relevant proteins involved in the mitochondrial fusion process are three GTPase dynamin-like proteins: mitofusin 1 (MFN1 and 2 (MFN2, located in the outer mitochondrial membrane, and optic atrophy protein 1 (OPA1, in the inner membrane. An expanding number of degenerative disorders are associated with mutations in the genes encoding MFN2 and OPA1, including Charcot-Marie-Tooth disease type 2A and autosomal dominant optic atrophy. While these disorders can still be considered rare, defective mitochondrial dynamics seem to play a significant role in the molecular and cellular pathogenesis of more common neurodegenerative diseases, for example, Alzheimer’s and Parkinson’s diseases. This review provides an overview of the basic molecular mechanisms involved in mitochondrial fusion and focuses on the alteration in mitochondrial DNA amount resulting from impairment of mitochondrial dynamics. We also review the literature describing the main disorders associated with the disruption of mitochondrial fusion.

Treatment with glial derived neurotropic factor (GDNF attenuates oxidative damages of spinal

Directory of Open Access Journals (Sweden)

Tao Li

2016-05-01

Full Text Available Spinal cord injury (SCI is a serious and debilitating issue being suffered by wide population worldwide. Extensive treatment approaches have been tested and being verified for their efficacy. Owing to the nature of central nervous system (CNS, the resident stem cells would be triggered in response to any sort of trauma with nerve factors as their communication signals. Apart from physical injuries, damages due to oxidative stress also need to be addressed while CNS repair mechanism takes place. This study looks at the potential of glial derived nerve factor (GDNF in addressing the SCI in regard to oxidative damages. A total of 60 Wistar rats were clustered into five groups and GDNF at various concentrations was tested in each group. Assessments in terms of oxidative stress parameters were noted and analyzed accordingly. It was noted that GDNF had reduced oxidative damages and increased the levels of anti-oxidants in dose-dependent manner (p < 0.05. Though treatment with 10 mg/mL and 20 mg/mL showed significant changes as compared to control group, these treatment modalities remained insignificant among each other. In conclusion, we demonstrated that GDNF exerted a neuro-protective effect on CNS by inducing anti-oxidants and reducing the levels of oxidative stress in SCI induced rat models.

Crosstalk between VEGF-A/VEGFR2 and GDNF/RET signaling pathways

International Nuclear Information System (INIS)

Tufro, Alda; Teichman, Jason; Banu, Nazifa; Villegas, Guillermo

2007-01-01

Vascular endothelial growth factor (VEGF-A) plays multiple roles in kidney development: stimulates cell proliferation, survival, tubulogenesis, and branching morphogenesis. However, the mechanism that mediates VEGF-A induced ureteric bud branching is unclear. Glial-derived neurotrophic factor (GDNF) signaling through tyrosine kinase c-RET is the major regulator of ureteric bud branching. Here we examined whether VEGF-A regulates RET signaling. We determined that ureteric bud-derived cells express the main VEGF-A signaling receptor, VEGFR2 and RET, by RT-PCR, immunoblotting, and immunocytochemistry. We show that the VEGF-A isoform VEGF 165 induces RET-tyr 1062 phosphorylation in addition to VEGFR2 autophosphorylation, that VEGF 165 and GDNF have additive effects on RET-tyr 1062 phosphorylation, and that VEGFR2 and RET co-immunoprecipitate. Functionally, VEGF 165 induces ureteric bud cell proliferation and branching morphogenesis. Similarly, in embryonic kidney explants VEGF 165 induces RET-tyr 1062 phosphorylation and upregulates GDNF. These findings provide evidence for a novel cooperative interaction between VEGFR2 and RET that mediates VEGF-A functions in ureteric bud cells

MEMBRANE-FUSION OF SEMLIKI FOREST VIRUS INVOLVES HOMOTRIMERS OF THE FUSION PROTEIN

NARCIS (Netherlands)

WAHLBERG, JM; WILSCHUT, J; GAROFF, H

1992-01-01

Infection of cells with enveloped viruses is accomplished through membrane fusion. The binding and fusion Processes are mediated by the spike proteins in the envelope of the virus particle and usually involve a series of conformational changes in these proteins. We have studied the low-pH-mediated

In vivo dynamics of GFRα1-positive spermatogonia stimulated by GDNF signals using a bead transplantation assay

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Uchida, Aya; Kishi, Kasane; Aiyama, Yoshimi; Miura, Kento [Department of Veterinary Anatomy, The University of Tokyo, Yayoi, Tokyo, 113-8657 (Japan); Takase, Hinako M.; Suzuki, Hitomi; Kanai-Azuma, Masami [Department of Experimental Animal Model for Human Disease, Tokyo Medical and Dental University, Tokyo, 113-8510 (Japan); Iwamori, Tokuko [Center of Biomedical Research, Kyusyu University, Fukuoka, 812-8582 (Japan); Kurohmaru, Masamichi; Tsunekawa, Naoki [Department of Veterinary Anatomy, The University of Tokyo, Yayoi, Tokyo, 113-8657 (Japan); Kanai, Yoshiakira, E-mail: aykanai@mail.ecc.u-tokyo.ac.jp [Department of Veterinary Anatomy, The University of Tokyo, Yayoi, Tokyo, 113-8657 (Japan)

2016-08-05

In mouse testes, spermatogonial stem cells (SSCs), a subpopulation of GFRα1 (GDNF family receptor-α1)-positive spermatogonia, are widely distributed along the convoluted seminiferous tubules. The proliferation and differentiation of the SSCs are regulated in part by local expression of GDNF (glial cell-derived neurotorphic factor), one of major niche factors for SSCs. However, the in vivo dynamics of the GDNF-stimulated GFRα1-positive spermatogonia remains unclear. Here, we developed a simple method for transplanting DiI-labeled and GDNF-soaked beads into the mouse testicular interstitium. By using this method, we examined the dynamics of GFRα1-positive spermatogonia in the tubular walls close to the transplanted GDNF-soaked beads. The bead-derived GDNF signals were able to induce the stratified aggregate formation of GFRα1-positive undifferentiated spermatogonia by day 3 post-transplantation. Each aggregate consisted of tightly compacted A{sub single} and marginal A{sub paired}–A{sub aligned} GFRα1-positive spermatogonia and was surrounded by A{sub aligned} GFRα1-negative spermatogonia at more advanced stages. These data not only provide in vivo evidence for the inductive roles of GDNF in forming a rapid aggregation of GFRα1-positive spermatogonia but also indicate the usefulness of this in vivo assay system of various growth factors for the stem/progenitor spermatogonia in mammalian spermatogenesis. - Highlights: • A novel bead transplantation assay was developed to examine the in vivo effects of growth factors on spermatogonia. • A rapid aggregation of GFRα1-positive spermatogonia was induced by the transplanted GDNF-soaked beads. • Tightly-compacted A{sub single} and marginal A{sub paired}–A{sub aligned} spermatogonia were formed in each GFRα1-positive aggregate.

Mode of action of LciA, the lactococcin A immunity protein

NARCIS (Netherlands)

Venema, K.; Haverkort, R.E.; Abee, T.; Haandrikman, A.J.; Leenhouts, K.J.; Leij, L. de; Venema, G.; Kok, J.

Monoclonal antibodies were raised against a fusion between the Escherichia coli maltose-binding protein and LciA, the immunity protein that protects Lactococcus lactis against the effects of the bacteriocin lactococcin A. One of the antibodies directed against the LciA moiety of the fusion protein

Tissue-specific and pathogen-inducible expression of a fusion protein containing a Fusarium-specific antibody and a fungal chitinase protects wheat against Fusarium pathogens and mycotoxins.

Science.gov (United States)

Cheng, Wei; Li, He-Ping; Zhang, Jing-Bo; Du, Hong-Jie; Wei, Qi-Yong; Huang, Tao; Yang, Peng; Kong, Xian-Wei; Liao, Yu-Cai

2015-06-01

Fusarium head blight (FHB) in wheat and other small grain cereals is a globally devastating disease caused by toxigenic Fusarium pathogens. Controlling FHB is a challenge because germplasm that is naturally resistant against these pathogens is inadequate. Current control measures rely on fungicides. Here, an antibody fusion comprised of the Fusarium spp.-specific recombinant antibody gene CWP2 derived from chicken, and the endochitinase gene Ech42 from the biocontrol fungus Trichoderma atroviride was introduced into the elite wheat cultivar Zhengmai9023 by particle bombardment. Expression of this fusion gene was regulated by the lemma/palea-specific promoter Lem2 derived from barley; its expression was confirmed as lemma/palea-specific in transgenic wheat. Single-floret inoculation of independent transgenic wheat lines of the T3 to T6 generations revealed significant resistance (type II) to fungal spreading, and natural infection assays in the field showed significant resistance (type I) to initial infection. Gas chromatography-mass spectrometry analysis revealed marked reduction of mycotoxins in the grains of the transgenic wheat lines. Progenies of crosses between the transgenic lines and the FHB-susceptible cultivar Huamai13 also showed significantly enhanced FHB resistance. Quantitative real-time PCR analysis revealed that the tissue-specific expression of the antibody fusion was induced by salicylic acid drenching and induced to a greater extent by F. graminearum infection. Histochemical analysis showed substantial restriction of mycelial growth in the lemma tissues of the transgenic plants. Thus, the combined tissue-specific and pathogen-inducible expression of this Fusarium-specific antibody fusion can effectively protect wheat against Fusarium pathogens and reduce mycotoxin content in grain. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Recombinant fusion protein of albumin-retinol binding protein inactivates stellate cells

International Nuclear Information System (INIS)

Choi, Soyoung; Park, Sangeun; Kim, Suhyun; Lim, Chaeseung; Kim, Jungho; Cha, Dae Ryong; Oh, Junseo

2012-01-01

Highlights: ► We designed novel recombinant albumin-RBP fusion proteins. ► Expression of fusion proteins inactivates pancreatic stellate cells (PSCs). ► Fusion proteins are successfully internalized into and inactivate PSCs. ► RBP moiety mediates cell specific uptake of fusion protein. -- Abstract: Quiescent pancreatic- (PSCs) and hepatic- (HSCs) stellate cells store vitamin A (retinol) in lipid droplets via retinol binding protein (RBP) receptor and, when activated by profibrogenic stimuli, they transform into myofibroblast-like cells which play a key role in the fibrogenesis. Despite extensive investigations, there is, however, currently no appropriate therapy available for tissue fibrosis. We previously showed that the expression of albumin, composed of three homologous domains (I–III), inhibits stellate cell activation, which requires its high-affinity fatty acid-binding sites asymmetrically distributed in domain I and III. To attain stellate cell-specific uptake, albumin (domain I/III) was coupled to RBP; RBP-albumin domain III (R-III) and albumin domain I -RBP-albumin III (I-R-III). To assess the biological activity of fusion proteins, cultured PSCs were used. Like wild type albumin, expression of R-III or I-R-III in PSCs after passage 2 (activated PSCs) induced phenotypic reversal from activated to fat-storing cells. On the other hand, R-III and I-R-III, but not albumin, secreted from transfected 293 cells were successfully internalized into and inactivated PSCs. FPLC-purified R-III was found to be internalized into PSCs via caveolae-mediated endocytosis, and its efficient cellular uptake was also observed in HSCs and podocytes among several cell lines tested. Moreover, tissue distribution of intravenously injected R-III was closely similar to that of RBP. Therefore, our data suggest that albumin-RBP fusion protein comprises of stellate cell inactivation-inducing moiety and targeting moiety, which may lead to the development of effective anti

The glial cell line-derived neurotrophic factor (GDNF) does not acutely change acetylcholine release in developing and adult neuromuscular junction.

Science.gov (United States)

Garcia, Neus; Santafé, Manel M; Tomàs, Marta; Lanuza, Maria A; Besalduch, Nuria; Priego, Merche; Tomàs, Josep

2010-08-16

We use immunocytochemistry to show that the trophic molecule glial cell line-derived neurotrophic factor (GDNF) and its receptor GDNF family receptor alpha-1 (GFRalpha-1) are present in both neonatal (P6) and adult (P45) rodent neuromuscular junctions (NMJ) colocalized with several synaptic markers. However, incubation with exogenous GDNF (10-200ng/ml, 1-3h), does not affect spontaneous ACh release. Moreover, GDNF does not change the size of the evoked ACh release from the weak and the strong axonal inputs on dually innervated postnatal endplates nor in the most developed singly-innervated synapses at P6 and P45. Our findings indicate that GDNF (unlike neurotrophins) does not acutely modulate transmitter release during the developmental process of synapse elimination nor as the NMJ matures. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Construction of bifunctional molecules specific to antigen and antibody’s Fc-fragment by fusion of scFv-antibodies with staphylococcal protein A

Directory of Open Access Journals (Sweden)

Kolibo D. V.

2009-06-01

Full Text Available Aim. To develop approach for detection of scFv and their complexes with antigens. Methods. The fusion proteins, which include sequences of scFv and staphylococcal protein A, were constructed and the obtained bifunctional molecules were immunochemically analysed. Results. It was shown, that scFv fused with protein A and their complexes with antigens are effectively recognized by labelled immunoglobulins with unrestricted antigenic specificity. Conclusions. The fusion of scFv with protein A fragment is a perspective approach to increase the efficiency of application in ELISA. The obtained scFv, fused with protein A, could be used for development of test-systems for the detection of diphtheria toxin.

Exercise enhanced functional recovery and expression of GDNF after photochemically induced cerebral infarction in the rat.

Science.gov (United States)

Ohwatashi, Akihiko; Ikeda, Satoshi; Harada, Katsuhiro; Kamikawa, Yurie; Yoshida, Akira

2013-01-01

Exercise has been considered to affect the functional recovery from central nervous damage. Neurotrophic factors have various effects on brain damage. However, the effects of exercise for expression of GDNF on functional recovery with brain damage are not well known. We investigated the difference in functional recovery between non-exercise and beam-walking exercise groups, and the expression of GDNF in both groups after photochemical infarction. Adult male Wistar rats (N = 64) were used. Animals were divided into two groups: non-exercise (N = 35), and beam-walking exercise (N = 29). All rats underwent surgical photochemical infarction. The rats of the beam-walking group were trained every day to walk on a narrow beam after a one-day recovery period and those of the non-exercise group were left to follow a natural course. Animals were evaluated for hind limb function every day using a beam-walking task with an elevated narrow beam. The number of GDNF-like immunoreactive cells in the temporal cortex surrounding the lesion was counted 1, 3, 5, and 7 days after the infarction. Functional recovery of the beam-walking exercise group was significantly earlier than that of the non-exercise group. At 3 days after infarction, the number of GDNF-positive cells in the temporal cortex surrounding the infarction was significantly increased in the beam-walking exercise group compared with that in the non-exercise group. In the exercise group, motor function was remarkably recovered with the increased expression of GDNF-like immunoreactive cells. Our results suggested that a rehabilitative approach increased the expression of GDNF and facilitated functional recovery from cerebral infarction.

Localization of a Region in the Fusion Protein of Avian Metapneumovirus That Modulates Cell-Cell Fusion

Science.gov (United States)

Wei, Yongwei; Feng, Kurtis; Yao, Xiangjie; Cai, Hui; Li, Junan; Mirza, Anne M.; Iorio, Ronald M.

2012-01-01

The genus Metapneumovirus within the subfamily Pneumovirinae of the family Paramyxoviridae includes two members, human metapneumovirus (hMPV) and avian metapneumovirus (aMPV), causing respiratory tract infections in humans and birds, respectively. Paramyxoviruses enter host cells by fusing the viral envelope with a host cell membrane. Membrane fusion of hMPV appears to be unique, in that fusion of some hMPV strains requires low pH. Here, we show that the fusion (F) proteins of aMPV promote fusion in the absence of the attachment protein and low pH is not required. Furthermore, there are notable differences in cell-cell fusion among aMPV subtypes. Trypsin was required for cell-cell fusion induced by subtype B but not subtypes A and C. The F protein of aMPV subtype A was highly fusogenic, whereas those from subtypes B and C were not. By construction and evaluation of chimeric F proteins composed of domains from the F proteins of subtypes A and B, we localized a region composed of amino acid residues 170 to 338 in the F protein that is responsible for the hyperfusogenic phenotype of the F from subtype A. Further mutagenesis analysis revealed that residues R295, G297, and K323 in this region collectively contributed to the hyperfusogenicity. Taken together, we have identified a region in the aMPV F protein that modulates the extent of membrane fusion. A model for fusion consistent with these data is presented. PMID:22915815

Localization of a region in the fusion protein of avian metapneumovirus that modulates cell-cell fusion.

Science.gov (United States)

Wei, Yongwei; Feng, Kurtis; Yao, Xiangjie; Cai, Hui; Li, Junan; Mirza, Anne M; Iorio, Ronald M; Li, Jianrong

2012-11-01

The genus Metapneumovirus within the subfamily Pneumovirinae of the family Paramyxoviridae includes two members, human metapneumovirus (hMPV) and avian metapneumovirus (aMPV), causing respiratory tract infections in humans and birds, respectively. Paramyxoviruses enter host cells by fusing the viral envelope with a host cell membrane. Membrane fusion of hMPV appears to be unique, in that fusion of some hMPV strains requires low pH. Here, we show that the fusion (F) proteins of aMPV promote fusion in the absence of the attachment protein and low pH is not required. Furthermore, there are notable differences in cell-cell fusion among aMPV subtypes. Trypsin was required for cell-cell fusion induced by subtype B but not subtypes A and C. The F protein of aMPV subtype A was highly fusogenic, whereas those from subtypes B and C were not. By construction and evaluation of chimeric F proteins composed of domains from the F proteins of subtypes A and B, we localized a region composed of amino acid residues 170 to 338 in the F protein that is responsible for the hyperfusogenic phenotype of the F from subtype A. Further mutagenesis analysis revealed that residues R295, G297, and K323 in this region collectively contributed to the hyperfusogenicity. Taken together, we have identified a region in the aMPV F protein that modulates the extent of membrane fusion. A model for fusion consistent with these data is presented.

Structural characterization of Mumps virus fusion protein core

International Nuclear Information System (INIS)

Liu Yueyong; Xu Yanhui; Lou Zhiyong; Zhu Jieqing; Hu Xuebo; Gao, George F.; Qiu Bingsheng; Rao Zihe; Tien, Po

2006-01-01

The fusion proteins of enveloped viruses mediating the fusion between the viral and cellular membranes comprise two discontinuous heptad repeat (HR) domains located at the ectodomain of the enveloped glycoproteins. The crystal structure of the fusion protein core of Mumps virus (MuV) was determined at 2.2 A resolution. The complex is a six-helix bundle in which three HR1 peptides form a central highly hydrophobic coiled-coil and three HR2 peptides pack against the hydrophobic grooves on the surface of central coiled-coil in an oblique antiparallel manner. Fusion core of MuV, like those of simian virus 5 and human respiratory syncytium virus, forms typical 3-4-4-4-3 spacing. The similar charecterization in HR1 regions, as well as the existence of O-X-O motif in extended regions of HR2 helix, suggests a basic rule for the formation of the fusion core of viral fusion proteins

Effects of combined BDNF and GDNF treatment on cultured dopaminergic midbrain neurons

DEFF Research Database (Denmark)

Sautter, J; Meyer, Morten; Spenger, C

1998-01-01

Neural transplantation is an experimental therapy for Parkinson's disease. Pretreatment of fetal donor tissue with neurotrophic factors may improve survival of grafted dopaminergic neurons. Free-floating roller tube cultures of fetal rat ventral mesencephalon were treated with brain-derived neuro......Neural transplantation is an experimental therapy for Parkinson's disease. Pretreatment of fetal donor tissue with neurotrophic factors may improve survival of grafted dopaminergic neurons. Free-floating roller tube cultures of fetal rat ventral mesencephalon were treated with brain......-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), or a combination of both. Dopamine content of the culture medium, the number of tyrosine hydroxylase-immunoreactive neurons, and culture volumes were moderately increased in the BDNF- and GDNF-treated cultures but significantly...... increased by 6.8-, 3.2- and 2.4-fold, respectively after treatment with the combination of both factors. We conclude that pretreatment of dopaminergic tissue in culture with a combination of BDNF and GDNF may be an effective means to improve the quality of tissue prior to grafting....

Characterization of dendritic morphology and neurotransmitter phenotype of thoracic descending propriospinal neurons after complete spinal cord transection and GDNF treatment

Science.gov (United States)

Deng, Lingxiao; Ruan, Yiwen; Chen, Chen; Frye, Christian Corbin; Xiong, Wenhui; Jin, Xiaoming; Jones, Kathryn; Sengelaub, Dale; Xu, Xiao-Ming

2016-01-01

After spinal cord injury (SCI), poor regeneration of damaged axons of the central nervous system (CNS) causes limited functional recovery. This limited spontaneous functional recovery has been attributed, to a large extent, to the plasticity of propriospinal neurons, especially the descending propriospinal neurons (dPSNs). Compared with the supraspinal counterparts, dPSNs have displayed significantly greater regenerative capacity, which can be further enhanced by glial cell line-derived neurotrophic factor (GDNF). In the present study, we applied a G-mutated rabies virus (G-Rabies) co-expressing green fluorescence protein (GFP) to reveal Golgi-like dendritic morphology of dPSNs. We also investigated the neurotransmitters expressed by dPSNs after labeling with a retrograde tracer Fluoro-Gold (FG). dPSNs were examined in animals with sham injuries or complete spinal transections with or without GDNF treatment. Bilateral injections of G-Rabies and FG were made into the 2nd lumbar (L2) spinal cord at 3 days prior to a spinal cord transection performed at the 11th thoracic level (T11). The lesion gap was filled with Gelfoam containing either saline or GDNF in the injury groups. Four days post-injury, the rats were sacrificed for analysis. For those animals receiving G-rabies injection, the GFP signal in the T7–9 spinal cord was visualized via 2-photon microscopy. Dendritic morphology from stack images was traced and analyzed using a Neurolucida software. We found that dPSNs in sham injured animals had a predominantly dorsal-ventral distribution of dendrites. Transection injury resulted in alterations in the dendritic distribution with dorsal-ventral retraction and lateral-medial extension. Treatment with GDNF significantly increased the terminal dendritic length of dPSNs. The density of spine-like structures was increased after injury, and treatment with GDNF enhanced this effect. For the group receiving FG injections, immunohistochemistry for glutamate, choline

Antibody mimetics: promising complementary agents to animal-sourced antibodies.

Science.gov (United States)

Baloch, Abdul Rasheed; Baloch, Abdul Wahid; Sutton, Brian J; Zhang, Xiaoying

2016-01-01

Despite their wide use as therapeutic, diagnostic and detection agents, the limitations of polyclonal and monoclonal antibodies have inspired scientists to design the next generation biomedical agents, so-called antibody mimetics that offer many advantages over conventional antibodies. Antibody mimetics can be constructed by protein-directed evolution or fusion of complementarity-determining regions through intervening framework regions. Substantial progress in exploiting human, butterfly (Pieris brassicae) and bacterial systems to design and select mimetics using display technologies has been made in the past 10 years, and one of these mimetics [Kalbitor® (Dyax)] has made its way to market. Many challenges lie ahead to develop mimetics for various biomedical applications, especially those for which conventional antibodies are ineffective, and this review describes the current characteristics, construction and applications of antibody mimetics compared to animal-sourced antibodies. The possible limitations of mimetics and future perspectives are also discussed.

Baculovirus display of functional antibody Fab fragments.

Science.gov (United States)

Takada, Shinya; Ogawa, Takafumi; Matsui, Kazusa; Suzuki, Tasuku; Katsuda, Tomohisa; Yamaji, Hideki

2015-08-01

The generation of a recombinant baculovirus that displays antibody Fab fragments on the surface was investigated. A recombinant baculovirus was engineered so that the heavy chain (Hc; Fd fragment) of a mouse Fab fragment was expressed as a fusion to the N-terminus of baculovirus gp64, while the light chain of the Fab fragment was simultaneously expressed as a secretory protein. Following infection of Sf9 insect cells with the recombinant baculovirus, the culture supernatant was analyzed by enzyme-linked immunosorbent assay using antigen-coated microplates and either an anti-mouse IgG or an anti-gp64 antibody. A relatively strong signal was obtained in each case, showing antigen-binding activity in the culture supernatant. In western blot analysis of the culture supernatant using the anti-gp64 antibody, specific protein bands were detected at an electrophoretic mobility that coincided with the molecular weight of the Hc-gp64 fusion protein as well as that of gp64. Flow cytometry using a fluorescein isothiocyanate-conjugated antibody specific to mouse IgG successfully detected the Fab fragments on the surface of the Sf9 cells. These results suggest that immunologically functional antibody Fab fragments can be displayed on the surface of baculovirus particles, and that a fluorescence-activated cell sorter with a fluorescence-labeled antigen can isolate baculoviruses displaying specific Fab fragments. This successful baculovirus display of antibody Fab fragments may offer a novel approach for the efficient selection of specific antibodies.

Cellulose binding domain fusion proteins

Science.gov (United States)

Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc A.; Doi, Roy H.

1998-01-01

A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

F-18 Labeled Diabody-Luciferase Fusion Proteins for Optical-ImmunoPET

Energy Technology Data Exchange (ETDEWEB)

Wu, Anna M. [Univ. of California, Los Angeles, CA (United States)

2013-01-18

The goal of the proposed work is to develop novel dual-labeled molecular imaging probes for multimodality imaging. Based on small, engineered antibodies called diabodies, these probes will be radioactively tagged with Fluorine-18 for PET imaging, and fused to luciferases for optical (bioluminescence) detection. Performance will be evaluated and validated using a prototype integrated optical-PET imaging system, OPET. Multimodality probes for optical-PET imaging will be based on diabodies that are dually labeled with 18F for PET detection and fused to luciferases for optical imaging. 1) Two sets of fusion proteins will be built, targeting the cell surface markers CEA or HER2. Coelenterazine-based luciferases and variant forms will be evaluated in combination with native substrate and analogs, in order to obtain two distinct probes recognizing different targets with different spectral signatures. 2) Diabody-luciferase fusion proteins will be labeled with 18F using amine reactive [18F]-SFB produced using a novel microwave-assisted, one-pot method. 3) Sitespecific, chemoselective radiolabeling methods will be devised, to reduce the chance that radiolabeling will inactivate either the target-binding properties or the bioluminescence properties of the diabody-luciferase fusion proteins. 4) Combined optical and PET imaging of these dual modality probes will be evaluated and validated in vitro and in vivo using a prototype integrated optical-PET imaging system, OPET. Each imaging modality has its strengths and weaknesses. Development and use of dual modality probes allows optical imaging to benefit from the localization and quantitation offered by the PET mode, and enhances the PET imaging by enabling simultaneous detection of more than one probe.

Optimal doses of EGF and GDNF act as biological response modifiers to improve porcine oocyte maturation and quality

DEFF Research Database (Denmark)

Valleh, Mehdi Vafaye; Zandi, Nahid Karimi; Rasmussen, Mikkel Aabech

2017-01-01

It is well documented that both epidermal growth factor (EGF) and glial cell line-derived neurotrophic factor (GDNF) are critical for porcine oocyte maturation, however, little information is known about their mechanism of action in vitro. To gain insight into the mechanisms of action of the opti......It is well documented that both epidermal growth factor (EGF) and glial cell line-derived neurotrophic factor (GDNF) are critical for porcine oocyte maturation, however, little information is known about their mechanism of action in vitro. To gain insight into the mechanisms of action...... of the optimum doses of EGF and GDNF on porcine oocyte maturation, porcine cumulus-oocyte complexes (COCs) were matured in defined porcine oocyte medium supplemented with EGF, GDNF or a combination of both at varying concentrations (0-100 ng/ml) for 44 h. Nuclear and cytoplasmic maturation were determined...

Fluorescent sensors based on bacterial fusion proteins

International Nuclear Information System (INIS)

Mateu, Batirtze Prats; Pum, Dietmar; Sleytr, Uwe B; Toca-Herrera, José L; Kainz, Birgit

2014-01-01

Fluorescence proteins are widely used as markers for biomedical and technological purposes. Therefore, the aim of this project was to create a fluorescent sensor, based in the green and cyan fluorescent protein, using bacterial S-layers proteins as scaffold for the fluorescent tag. We report the cloning, expression and purification of three S-layer fluorescent proteins: SgsE-EGFP, SgsE-ECFP and SgsE-13aa-ECFP, this last containing a 13-amino acid rigid linker. The pH dependence of the fluorescence intensity of the S-layer fusion proteins, monitored by fluorescence spectroscopy, showed that the ECFP tag was more stable than EGFP. Furthermore, the fluorescent fusion proteins were reassembled on silica particles modified with cationic and anionic polyelectrolytes. Zeta potential measurements confirmed the particle coatings and indicated their colloidal stability. Flow cytometry and fluorescence microscopy showed that the fluorescence of the fusion proteins was pH dependent and sensitive to the underlying polyelectrolyte coating. This might suggest that the fluorescent tag is not completely exposed to the bulk media as an independent moiety. Finally, it was found out that viscosity enhanced the fluorescence intensity of the three fluorescent S-layer proteins. (paper)

Recombinant fusion protein of albumin-retinol binding protein inactivates stellate cells

Energy Technology Data Exchange (ETDEWEB)

Choi, Soyoung; Park, Sangeun; Kim, Suhyun [Laboratory of Cellular Oncology, Korea University Graduate School of Medicine, Ansan, Gyeonggi do 425-707 (Korea, Republic of); Lim, Chaeseung [Department of Laboratory Medicine, Korea University Guro Hospital, Seoul 152-703 (Korea, Republic of); Kim, Jungho [Department of Life Science, Sogang University, Seoul 121-742 (Korea, Republic of); Cha, Dae Ryong [Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Gyeonggi do 425-020 (Korea, Republic of); Oh, Junseo, E-mail: ohjs@korea.ac.kr [Laboratory of Cellular Oncology, Korea University Graduate School of Medicine, Ansan, Gyeonggi do 425-707 (Korea, Republic of)

2012-02-03

Highlights: Black-Right-Pointing-Pointer We designed novel recombinant albumin-RBP fusion proteins. Black-Right-Pointing-Pointer Expression of fusion proteins inactivates pancreatic stellate cells (PSCs). Black-Right-Pointing-Pointer Fusion proteins are successfully internalized into and inactivate PSCs. Black-Right-Pointing-Pointer RBP moiety mediates cell specific uptake of fusion protein. -- Abstract: Quiescent pancreatic- (PSCs) and hepatic- (HSCs) stellate cells store vitamin A (retinol) in lipid droplets via retinol binding protein (RBP) receptor and, when activated by profibrogenic stimuli, they transform into myofibroblast-like cells which play a key role in the fibrogenesis. Despite extensive investigations, there is, however, currently no appropriate therapy available for tissue fibrosis. We previously showed that the expression of albumin, composed of three homologous domains (I-III), inhibits stellate cell activation, which requires its high-affinity fatty acid-binding sites asymmetrically distributed in domain I and III. To attain stellate cell-specific uptake, albumin (domain I/III) was coupled to RBP; RBP-albumin{sup domain} {sup III} (R-III) and albumin{sup domain} {sup I}-RBP-albumin{sup III} (I-R-III). To assess the biological activity of fusion proteins, cultured PSCs were used. Like wild type albumin, expression of R-III or I-R-III in PSCs after passage 2 (activated PSCs) induced phenotypic reversal from activated to fat-storing cells. On the other hand, R-III and I-R-III, but not albumin, secreted from transfected 293 cells were successfully internalized into and inactivated PSCs. FPLC-purified R-III was found to be internalized into PSCs via caveolae-mediated endocytosis, and its efficient cellular uptake was also observed in HSCs and podocytes among several cell lines tested. Moreover, tissue distribution of intravenously injected R-III was closely similar to that of RBP. Therefore, our data suggest that albumin-RBP fusion protein comprises

Incidence of Lettuce mosaic virus in lettuce and its detection by polyclonal antibodies produced against recombinant coat protein expressed in Escherichia coli.

Science.gov (United States)

Sharma, Prachi; Sharma, Susheel; Singh, Jasvir; Saha, Swati; Baranwal, V K

2016-04-01

Lettuce mosaic virus (LMV), a member of the genus Potyvirus of family Potyviridae, causes mosaic disease in lettuce has recently been identified in India. The virus is seed borne and secondary infection occurs through aphids. To ensure virus freedom in seeds it is important to develop diagnostic tools, for serological methods the production of polyclonal antibodies is a prerequisite. The coat protein (CP) gene of LMV was amplified, cloned and expressed using pET-28a vector in Escherichia coli BL21DE3 competent cells. The LMV CP was expressed as a fusion protein containing a fragment of the E. coli His tag. The LMV CP/His protein reacted positively with a commercial antiserum against LMV in an immunoblot assay. Polyclonal antibodies purified from serum of rabbits immunized with the fusion protein gave positive results when LMV infected lettuce (Lactuca sativa) was tested at 1:1000 dilution in PTA-ELISA. These were used for specific detection of LMV in screening lettuce accessions. The efficacy of the raised polyclonal antiserum was high and it can be utilized in quarantine and clean seed production. Copyright © 2016 Elsevier B.V. All rights reserved.

Viral membrane fusion: is glycoprotein G of rhabdoviruses a representative of a new class of viral fusion proteins?

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A.T. Da Poian

2005-06-01

Full Text Available Enveloped viruses always gain entry into the cytoplasm by fusion of their lipid envelope with a cell membrane. Some enveloped viruses fuse directly with the host cell plasma membrane after virus binding to the cell receptor. Other enveloped viruses enter the cells by the endocytic pathway, and fusion depends on the acidification of the endosomal compartment. In both cases, virus-induced membrane fusion is triggered by conformational changes in viral envelope glycoproteins. Two different classes of viral fusion proteins have been described on the basis of their molecular architecture. Several structural data permitted the elucidation of the mechanisms of membrane fusion mediated by class I and class II fusion proteins. In this article, we review a number of results obtained by our laboratory and by others that suggest that the mechanisms involved in rhabdovirus fusion are different from those used by the two well-studied classes of viral glycoproteins. We focus our discussion on the electrostatic nature of virus binding and interaction with membranes, especially through phosphatidylserine, and on the reversibility of the conformational changes of the rhabdovirus glycoprotein involved in fusion. Taken together, these data suggest the existence of a third class of fusion proteins and support the idea that new insights should emerge from studies of membrane fusion mediated by the G protein of rhabdoviruses. In particular, the elucidation of the three-dimensional structure of the G protein or even of the fusion peptide at different pH's might provide valuable information for understanding the fusion mechanism of this new class of fusion proteins.

Specificity of anti-phospholipid antibodies in infectious mononucleosis: a role for anti-cofactor protein antibodies

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Sorice, M; Pittoni, V; Griggi, T; Losardo, A; Leri, O; Magno, M S; Misasi, R; Valesini, G

2000-01-01

The antigen specificity of anti-phospholipid antibodies in infectious mononucleosis (IM) was studied using ELISA for the detection of anti-β2-glycoprotein I (β2-GPI), anti-annexin V, anti-protein S and anti-prothrombin antibodies and TLC immunostaining for the detection of anti-phospholipid antibodies. This technique enabled us to look at antibodies reacting to ‘pure’ phospholipid antigens in the absence of protein contamination. Sera from 46 patients with IM, 18 with systemic lupus erythematosus (SLE), 21 with primary anti-phospholipid antibody syndrome (PAPS), 50 with Helicobacter pylori infection and 30 healthy blood donors were tested. This study highlights anti-phospholipid antibodies in patients with IM as specific ‘pure’ anti-cardiolipin antibodies, while in PAPS and SLE patients anti-phosphatidylserine and anti-phosphatidylethanolamine antibodies were also found. This investigation also shows that the anti-cardiolipin antibodies found in IM can be present with anti-cofactor protein antibodies. The higher prevalence of anti-cofactor antibodies found in IM sera than in Helicobacter pylori sera may be due to the immunostimulatory effect and/or the polyclonal activation often observed in course of Epstein–Barr virus infection. However, anti-β2-GPI and, to a lesser extent, anti-prothrombin antibodies occur with a significantly lower prevalence in IM than in PAPS patients. This finding suggests that these antibodies should be regarded as the expression of the broad autoimmune syndrome involving the phospholipid-binding plasma proteins. PMID:10792380

Silk-Silk Interactions between Silkworm Fibroin and Recombinant Spider Silk Fusion Proteins Enable the Construction of Bioactive Materials.

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Nilebäck, Linnea; Chouhan, Dimple; Jansson, Ronnie; Widhe, Mona; Mandal, Biman B; Hedhammar, My

2017-09-20

Natural silk is easily accessible from silkworms and can be processed into different formats suitable as biomaterials and cell culture matrixes. Recombinant DNA technology enables chemical-free functionalization of partial silk proteins through fusion with peptide motifs and protein domains, but this constitutes a less cost-effective production process. Herein, we show that natural silk fibroin (SF) can be used as a bulk material that can be top-coated with a thin layer of the recombinant spider silk protein 4RepCT in fusion with various bioactive motifs and domains. The coating process is based on a silk assembly to achieve stable interactions between the silk types under mild buffer conditions. The assembly process was studied in real time by quartz crystal microbalance with dissipation. Coatings, electrospun mats, and microporous scaffolds were constructed from Antheraea assama and Bombyx mori SFs. The morphology of the fibroin materials before and after coating with recombinant silk proteins was analyzed by scanning electron microscopy and atomic force microscopy. SF materials coated with various bioactive 4RepCT fusion proteins resulted in directed antibody capture, enzymatic activity, and improved cell attachment and spreading, respectively, compared to pristine SF materials. The herein-described procedure allows a fast and easy route for the construction of bioactive materials.

Computational and biological characterization of fusion proteins of two insecticidal proteins for control of insect pests.

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Javaid, Shaista; Naz, Sehrish; Amin, Imran; Jander, Georg; Ul-Haq, Zaheer; Mansoor, Shahid

2018-03-19

Sucking pests pose a serious agricultural challenge, as available transgenic technologies such as Bacillus thuringiensis crystal toxins (Bt) are not effective against them. One approach is to produce fusion protein toxins for the control of these pests. Two protein toxins, Hvt (ω-atracotoxin from Hadronyche versuta) and onion leaf lectin, were translationally fused to evaluate the negative effects of fusion proteins on Phenacoccus solenopsis (mealybug), a phloem-feeding insect pest. Hvt was cloned both N-terminally (HL) and then C-terminally (LH) in the fusion protein constructs, which were expressed transiently in Nicotiana tabacum using a Potato Virus X (PVX) vector. The HL fusion protein was found to be more effective against P. solenopsis, with an 83% mortality rate, as compared to the LH protein, which caused 65% mortality. Hvt and lectin alone caused 42% and 45%, respectively, under the same conditions. Computational studies of both fusion proteins showed that the HL protein is more stable than the LH protein. Together, these results demonstrate that translational fusion of two insecticidal proteins improved the insecticidal activity relative to each protein individually and could be expressed in transgenic plants for effective control of sucking pests.

GABARAPL1 antibodies: target one protein, get one free!

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Le Grand, Jaclyn Nicole; Chakrama, Fatima Zahra; Seguin-Py, Stéphanie; Fraichard, Annick; Delage-Mourroux, Régis; Jouvenot, Michèle; Risold, Pierre-Yves; Boyer-Guittaut, Michaël

2011-11-01

Atg8 is a yeast protein involved in the autophagic process and in particular in the elongation of autophagosomes. In mammals, several orthologs have been identified and are classed into two subfamilies: the LC3 subfamily and the GABARAP subfamily, referred to simply as the LC3 or GABARAP families. GABARAPL1 (GABARAP-like protein 1), one of the proteins belonging to the GABARAP (GABA(A) receptor-associated protein) family, is highly expressed in the central nervous system and implicated in processes such as receptor and vesicle transport as well as autophagy. The proteins that make up the GABARAP family demonstrate conservation of their amino acid sequences and protein structures. In humans, GABARAPL1 shares 86% identity with GABARAP and 61% with GABARAPL2 (GATE-16). The identification of the individual proteins is thus very limited when working in vivo due to a lack of unique peptide sequences from which specific antibodies can be developed. Actually, and to our knowledge, there are no available antibodies on the market that are entirely specific to GABARAPL1 and the same may be true of the anti-GABARAP antibodies. In this study, we sought to examine the specificity of three antibodies targeted against different peptide sequences within GABARAPL1: CHEM-CENT (an antibody raised against a short peptide sequence within the center of the protein), PTG-NTER (an antibody raised against the N-terminus of the protein) and PTG-FL (an antibody raised against the full-length protein). The results described in this article demonstrate the importance of testing antibody specificity under the conditions for which it will be used experimentally, a caution that should be taken when studying the expression of the GABARAP family proteins.

Alterations in BDNF (brain derived neurotrophic factor) and GDNF (glial cell line-derived neurotrophic factor) serum levels in bipolar disorder: The role of lithium.

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Tunca, Zeliha; Ozerdem, Aysegul; Ceylan, Deniz; Yalçın, Yaprak; Can, Güneş; Resmi, Halil; Akan, Pınar; Ergör, Gül; Aydemir, Omer; Cengisiz, Cengiz; Kerim, Doyuran

2014-09-01

Brain-derived neurotrophic factor (BDNF) has been consistently reported to be decreased in mania or depression in bipolar disorders. Evidence suggests that Glial cell line-derived neurotrophic factor (GDNF) has a role in the pathogenesis of mood disorders. Whether GDNF and BDNF act in the same way across different episodes in bipolar disorders is unclear. BDNF and GDNF serum levels were measured simultaneously by enzyme-linked immunosorbent assay (ELISA) method in 96 patients diagnosed with bipolar disorder according to DSM-IV (37 euthymic, 33 manic, 26 depressed) in comparison to 61 healthy volunteers. SCID- I and SCID-non patient version were used for clinical evaluation of the patients and healthy volunteers respectively. Correlations between the two trophic factor levels, and medication dose, duration and serum levels of lithium or valproate were studied across different episodes of illness. Patients had significantly lower BDNF levels during mania and depression compared to euthymic patients and healthy controls. GDNF levels were not distinctive. However GDNF/BDNF ratio was higher in manic state compared to euthymia and healthy controls. Significant negative correlation was observed between BDNF and GDNF levels in euthymic patients. While BDNF levels correlated positively, GDNF levels correlated negatively with lithium levels. Regression analysis confirmed that lithium levels predicted only GDNF levels positively in mania, and negatively in euthymia. Small sample size in different episodes and drug-free patients was the limitation of thestudy. Current data suggests that lithium exerts its therapeutic action by an inverse effect on BDNF and GDNF levels, possibly by up-regulating BDNF and down-regulating GDNF to achieve euthymia. Copyright © 2014 Elsevier B.V. All rights reserved.

Protein functional links in Trypanosoma brucei, identified by gene fusion analysis

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Trimpalis Philip

2011-07-01

Full Text Available Abstract Background Domain or gene fusion analysis is a bioinformatics method for detecting gene fusions in one organism by comparing its genome to that of other organisms. The occurrence of gene fusions suggests that the two original genes that participated in the fusion are functionally linked, i.e. their gene products interact either as part of a multi-subunit protein complex, or in a metabolic pathway. Gene fusion analysis has been used to identify protein functional links in prokaryotes as well as in eukaryotic model organisms, such as yeast and Drosophila. Results In this study we have extended this approach to include a number of recently sequenced protists, four of which are pathogenic, to identify fusion linked proteins in Trypanosoma brucei, the causative agent of African sleeping sickness. We have also examined the evolution of the gene fusion events identified, to determine whether they can be attributed to fusion or fission, by looking at the conservation of the fused genes and of the individual component genes across the major eukaryotic and prokaryotic lineages. We find relatively limited occurrence of gene fusions/fissions within the protist lineages examined. Our results point to two trypanosome-specific gene fissions, which have recently been experimentally confirmed, one fusion involving proteins involved in the same metabolic pathway, as well as two novel putative functional links between fusion-linked protein pairs. Conclusions This is the first study of protein functional links in T. brucei identified by gene fusion analysis. We have used strict thresholds and only discuss results which are highly likely to be genuine and which either have already been or can be experimentally verified. We discuss the possible impact of the identification of these novel putative protein-protein interactions, to the development of new trypanosome therapeutic drugs.

Expression of the A56 and K2 proteins is sufficient to inhibit vaccinia virus entry and cell fusion.

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Wagenaar, Timothy R; Moss, Bernard

2009-02-01

Many animal viruses induce cells to fuse and form syncytia. For vaccinia virus, this phenomenon is associated with mutations affecting the A56 and K2 proteins, which form a multimer (A56/K2) on the surface of infected cells. Recent evidence that A56/K2 interacts with the entry/fusion complex (EFC) and that the EFC is necessary for syncytium formation furnishes a strong connection between virus entry and cell fusion. Among the important remaining questions are whether A56/K2 can prevent virus entry as well as cell-cell fusion and whether these two viral proteins are sufficient as well as necessary for this. To answer these questions, we transiently and stably expressed A56 and K2 in uninfected cells. Uninfected cells expressing A56 and K2 exhibited resistance to fusing with A56 mutant virus-infected cells, whereas expression of A56 or K2 alone induced little or no resistance, which fits with the need for both proteins to bind the EFC. Furthermore, transient or stable expression of A56/K2 interfered with virus entry and replication as determined by inhibition of early expression of a luciferase reporter gene, virus production, and plaque formation. The specificity of this effect was demonstrated by restoring entry after enzymatically removing a chimeric glycophosphatidylinositol-anchored A56/K2 or by binding a monoclonal antibody to A56. Importantly, the antibody disrupted the interaction between A56/K2 and the EFC without disrupting the A56-K2 interaction itself. Thus, we have shown that A56/K2 is sufficient to prevent virus entry and fusion as well as formation of syncytia through interaction with the EFC.

Cell-penetrating anti-GFAP VHH and corresponding fluorescent fusion protein VHH-GFP spontaneously cross the blood-brain barrier and specifically recognize astrocytes: application to brain imaging.

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Li, Tengfei; Bourgeois, Jean-Pierre; Celli, Susanna; Glacial, Fabienne; Le Sourd, Anne-Marie; Mecheri, Salah; Weksler, Babette; Romero, Ignacio; Couraud, Pierre-Olivier; Rougeon, François; Lafaye, Pierre

2012-10-01

Antibodies normally do not cross the blood-brain barrier (BBB) and cannot bind an intracellular cerebral antigen. We demonstrate here for the first time that a new class of antibodies can cross the BBB without treatment. Camelids produce native homodimeric heavy-chain antibodies, the paratope being composed of a single-variable domain called VHH. Here, we used recombinant VHH directed against human glial fibrillary acidic protein (GFAP), a specific marker of astrocytes. Only basic VHHs (e.g., pI=9.4) were able to cross the BBB in vitro (7.8 vs. 0% for VHH with pI=7.7). By intracarotid and intravenous injections into live mice, we showed that these basic VHHs are able to cross the BBB in vivo, diffuse into the brain tissue, penetrate into astrocytes, and specifically label GFAP. To analyze their ability to be used as a specific transporter, we then expressed a recombinant fusion protein VHH-green fluorescent protein (GFP). These "fluobodies" specifically labeled GFAP on murine brain sections, and a basic variant (pI=9.3) of the fusion protein VHH-GFP was able to cross the BBB and to label astrocytes in vivo. The potential of VHHs as diagnostic or therapeutic agents in the central nervous system now deserves attention.

Generation of neutralising antibodies against porcine endogenous retroviruses (PERVs)

International Nuclear Information System (INIS)

Kaulitz, Danny; Fiebig, Uwe; Eschricht, Magdalena; Wurzbacher, Christian; Kurth, Reinhard; Denner, Joachim

2011-01-01

Antibodies neutralising porcine endogenous retroviruses (PERVs) were induced in different animal species by immunisation with the transmembrane envelope protein p15E. These antibodies recognised epitopes, designated E1, in the fusion peptide proximal region (FPPR) of p15E, and E2 in the membrane proximal external region (MPER). E2 is localised in a position similar to that of an epitope in the transmembrane envelope protein gp41 of the human immunodeficiency virus-1 (HIV-1), recognised by the monoclonal antibody 4E10 that is broadly neutralising. To detect neutralising antibodies specific for PERV, a novel assay was developed, which is based on quantification of provirus integration by real-time PCR. In addition, for the first time, highly effective neutralising antibodies were obtained by immunisation with the surface envelope protein of PERV. These data indicate that neutralising antibodies can be induced by immunisation with both envelope proteins.

[Preparation and preliminary application of rabbit anti-human PON2 antibodies(paraoxonase-2)].

Science.gov (United States)

Chen, Miao; Yang, Jin-Ju; Li, Shu-Zhen; Liu, Xiao-Lan; Liu, Ying; Zhang, Lin-Jie; Gao, Jian-En; Sun, Qi-Hong

2008-07-01

To preparation and characterize the rabbit polyclonal antibodies against human PON2 (paraoxonase-2). A fragment of human PON2 gene which was of low homology with rabbits but of higher hydrophilicity and immunogenicity was selected for recombinant expression in prokaryotic expression system. The rabbits were immunized with the purified GST fusion protein 3 times. The specificity and sensitivity of the anti-human PON2 polyclonal antibodies were detected by Western blot and indirect immunofluorescence. The GST-PON2 fusion protein was highly expressed in Ecoli with a molecular weight of 46 kDa. Western blot analysis proved the rabbit polyclonal antibodies could specifically recognize 39 kDa native PON2 protein expressed in several cells and tissues, such as HeLa cells, U937 cells, and human liver tissue. Indirect immunofluorescence analysis confirmed that PON2 protein was located in the cytoplasm of SY5Y cells. The rabbit polyclonal antibodies against human PON2 can specifically recognize natural protein expressed in human cells and tissues, Which can be used for further study and clinical detection of human PON2.

Rapid screening of monoclonal antibodies: new 'microstick' radioimmunoassay

International Nuclear Information System (INIS)

Scheinberg, D.A.; Strand, M.; Wilsnack, R.

1983-01-01

A new system for assaying monoclonal antibodies consisting of an 8 x 12 array of sticks which fits into a 96-well microtiter plate is described. Tests using virus specific monoclonal antibodies and virus proteins demonstrated sensitivity equivalent to the conventional microtiter plate assay. Antibody production, antigen specific antibody, and immunoglobulin isotypes could be measured under sterile conditions directly in the original fusion mixture wells and much greater rapidity than with the microtiter plate assay. (Auth.)

Impact of fluorescent protein fusions on the bacterial flagellar motor.

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Heo, M; Nord, A L; Chamousset, D; van Rijn, E; Beaumont, H J E; Pedaci, F

2017-10-03

Fluorescent fusion proteins open a direct and unique window onto protein function. However, they also introduce the risk of perturbation of the function of the native protein. Successful applications of fluorescent fusions therefore rely on a careful assessment and minimization of the side effects, but such insight is still lacking for many applications. This is particularly relevant in the study of the internal dynamics of motor proteins, where both the chemical and mechanical reaction coordinates can be affected. Fluorescent proteins fused to the stator of the Bacterial Flagellar Motor (BFM) have previously been used to unveil the motor subunit dynamics. Here we report the effects on single motors of three fluorescent proteins fused to the stators, all of which altered BFM behavior. The torque generated by individual stators was reduced while their stoichiometry remained unaffected. MotB fusions decreased the switching frequency and induced a novel bias-dependent asymmetry in the speed in the two directions. These effects could be mitigated by inserting a linker at the fusion point. These findings provide a quantitative account of the effects of fluorescent fusions to the stator on BFM dynamics and their alleviation- new insights that advance the use of fluorescent fusions to probe the dynamics of protein complexes.

Species-Specific Monoclonal Antibodies to Escherichia coli-Expressed p36 Cytosolic Protein of Mycoplasma hyopneumoniae

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Caron, J.; Sawyer, N.; Moumen, B. Ben Abdel; Bouh, K. Cheikh Saad; Dea, S.

2000-01-01

The p36 protein of Mycoplasma hyopneumoniae is a cytosolic protein carrying species-specific antigenic determinants. Based on the genomic sequence of the reference strain ATCC 25934, primers were designed for PCR amplification of the p36-encoding gene (948 bp). These primers were shown to be specific to M. hyopneumoniae since no DNA amplicons could be obtained with other mycoplasma species and pathogenic bacteria that commonly colonize the porcine respiratory tract. The amplified p36 gene was subcloned into the pGEX-4T-1 vector to be expressed in Escherichia coli as a fusion protein with glutathione S-transferase (GST). The GST-p36 recombinant fusion protein was purified by affinity chromatography and cut by thrombin, and the enriched p36 protein was used to immunize female BALB/c mice for the production of anti-p36 monoclonal antibodies (MAbs). The polypeptide specificity of the nine MAbs obtained was confirmed by Western immunoblotting with cell lysates prepared from the homologous strain. Cross-reactivity studies of the anti-p36 MAbs towards two other M. hyopneumoniae reference strains (ATCC 25095 and J strains) and Quebec field strains that had been isolated in culture suggested that these anti-p36 MAbs were directed against a highly conserved epitope, or closely located epitopes, of the p36 protein. No reactivity was demonstrated against other mycoplasma species tested. Clinical signs and lesions suggestive of enzootic pneumonia were reproduced in specific-pathogen-free pigs infected experimentally with a virulent Quebec field strain (IAF-DM9827) of M. hyopneumoniae. The bacteria could be recovered from lung homogenates of pigs that were killed after the 3-week observation period by both PCR and cultivation procedures. Furthermore, the anti-p36 MAbs permitted effective detection by indirect immunofluorescence of M. hyopneumoniae in frozen lung sections from experimentally infected pigs. However, attempts to use the recombinant p36 protein as an antigen in an

A mutation in the envelope protein fusion loop attenuates mouse neuroinvasiveness of the NY99 strain of West Nile virus

International Nuclear Information System (INIS)

Zhang Shuliu; Li Li; Woodson, Sara E.; Huang, Claire Y.-H.; Kinney, Richard M.; Barrett, Alan D.T.; Beasley, David W.C.

2006-01-01

Substitutions were engineered individually and in combinations at the fusion loop, receptor-binding domain and a stem-helix structure of the envelope protein of a West Nile virus strain, NY99, and their effects on mouse virulence and presentation of epitopes recognized by monoclonal antibodies (MAbs) were assessed. A single substitution within the fusion loop (L107F) attenuated mouse neuroinvasiveness of NY99. No substitutions attenuated NY99 neurovirulence. The L107F mutation also abolished binding of a non-neutralizing MAb, 3D9, whose epitope had not been previously identified. MAb 3D9 was subsequently shown to be broadly cross-reactive with other flaviviruses, consistent with binding near the highly conserved fusion loop

GDNF family ligands display distinct action profiles on cultured GABAergic and serotonergic neurons of rat ventral mesencephalon

DEFF Research Database (Denmark)

Ducray, Angélique; Krebs, Sandra H:; Schaller, Benoft

2006-01-01

Glial-cell-line-derived neurotrophic factor (GDNF), neurturin (NRTN), artemin (ARTN) and persephin (PSPN), known as the GDNF family ligands (GFLs), influence the development, survival and differentiation of cultured dopaminergic neurons from ventral mesencephalon (VM). Detailed knowledge about...... factors for VM GABAergic and serotonergic neurons, demonstrating characteristic individual action profiles emphasizing their important and distinct roles during brain development....

Human cytomegaloviruses expressing yellow fluorescent fusion proteins--characterization and use in antiviral screening.

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Sarah Straschewski

Full Text Available Recombinant viruses labelled with fluorescent proteins are useful tools in molecular virology with multiple applications (e.g., studies on intracellular trafficking, protein localization, or gene activity. We generated by homologous recombination three recombinant cytomegaloviruses carrying the enhanced yellow fluorescent protein (EYFP fused with the viral proteins IE-2, ppUL32 (pp150, and ppUL83 (pp65. In growth kinetics, the three viruses behaved all like wild type, even at low multiplicity of infection (MOI. The expression of all three fusion proteins was detected, and their respective localizations were the same as for the unmodified proteins in wild-type virus-infected cells. We established the in vivo measurement of fluorescence intensity and used the recombinant viruses to measure inhibition of viral replication by neutralizing antibodies or antiviral substances. The use of these viruses in a pilot screen based on fluorescence intensity and high-content analysis identified cellular kinase inhibitors that block viral replication. In summary, these viruses with individually EYFP-tagged proteins will be useful to study antiviral substances and the dynamics of viral infection in cell culture.

Preparation of monoclonal antibodies against radiation-induced protein

International Nuclear Information System (INIS)

Nozawa, R.; Tanaka, A.; Watanabe, H.; Kitayama, S.

1992-01-01

We obtained the 6 monoclonal antibodies against gamma-induced proteins of Deinococcus radiodurans, and these antibodies were designated as Mab-3F, 4B, 4D, 4F, 4G and 12G. Using these antibodies, we investigated the relations between gamma-induced proteins and other stress protein in strain R1, and the induction of proteins were compared among strain R1, resistant mutant (rec1) and radiosensitive mutant (rec30). We found new 6 proteins recognized by these monoclonal antibodies which were induced after gamma-irradiation especially in strain R1 and rec 1, but not induced in strain rec30. We suppose that these proteins participate in repair of DNA damages including double strand breaks caused by gamma-irradiation. One of them was around 46kDa protein band recognized by Mab-12G, and this protein was so induced in a large quantity after irradiation that the protein could detect by gold staining. In addition to this observation, we found some proteins which were induced in R1 and rec 1 by gamma-irradiation and other stress, but not in strain rec30, such as 31kDa protein band recognized by Mab-3F, 4B and 4G, and other 11 proteins which were especially induced in irradiated strain R1. The latter proteins might be reinforcement factor to radioresistance such as GroE and DnaK, or participant in repair of damage by gamma-irradiation in strain R1. (author)

Expression and purification of chimeric peptide comprising EGFR B-cell epitope and measles virus fusion protein T-cell epitope in Escherichia coli.

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Wu, Meizhi; Zhao, Lin; Zhu, Lei; Chen, Zhange; Li, Huangjin

2013-03-01

Chimeric peptide MVF-EGFR(237-267), comprising a B-cell epitope from the dimerization interface of human epidermal growth factor receptor (EGFR) and a promiscuous T-cell epitope from measles virus fusion protein (MVF), is a promising candidate antigen peptide for therapeutic vaccine. To establish a high-efficiency preparation process of this small peptide, the coding sequence was cloned into pET-21b and pET-32a respectively, to be expressed alone or in the form of fusion protein with thioredoxin (Trx) and His(6)-tag in Escherichia coli BL21 (DE3). The chimeric peptide failed to be expressed alone, but over-expressed in the fusion form, which presented as soluble protein and took up more than 30% of total proteins of host cells. The fusion protein was seriously degraded during the cell disruption, in which endogenous metalloproteinase played a key role. Degradation of target peptide was inhibited by combined application of EDTA in the cell disruption buffer and a step of Source 30Q anion exchange chromatography (AEC) before metal-chelating chromatography (MCAC) for purifying His(6)-tagged fusion protein. The chimeric peptide was recovered from the purified fusion protein by enterokinase digestion at a yield of 3.0 mg/L bacteria culture with a purity of more than 95%. Immunogenicity analysis showed that the recombinant chimeric peptide was able to arouse more than 1×10(4) titers of specific antibody in BALB/c mice. Present work laid a solid foundation for the development of therapeutic peptide vaccine targeting EGFR dimerization and provided a convenient and low-cost preparation method for small peptides. Copyright © 2012 Elsevier Inc. All rights reserved.

Clinical Applications of Phage-Derived sFvs and sFv Fusion Proteins

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K. A. Chester

2000-01-01

Full Text Available Single chain Fv antibodies (sFvs have been produced from filamentous bacteriophage libraries obtained from immunised mice. MFE-23, the most characterised of these sFvs, is reactive with carcinoembryonic antigen (CEA, a glycoprotein that is highly expressed in colorectal adenocarcinomas. MFE-23 has been expressed in bacteria and purified in our laboratory for two clinical trials; a gamma camera imaging trial using 123I-MFE-23 and a radioimmunoguided surgery trial using 125I-MFE-23, where tumour deposits are detected by a hand-held probe during surgery. Both these trials show MFE-23 is safe and effective in localising tumour deposits in patients with cancer. We are now developing fusion proteins which use MFE-23 to deliver a therapeutic moiety; MFE-23::CPG2 targets the enzyme carboxypeptidase G2 (CPG2 for use in the ADEPT (antibody directed enzyme prodrug therapy system and MFE::TNFα aims to reduce sequestration and increase tumor concentrations of systemically administered TNFα.

Targeted in vivo inhibition of specific protein-protein interactions using recombinant antibodies.

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Matej Zábrady

Full Text Available With the growing availability of genomic sequence information, there is an increasing need for gene function analysis. Antibody-mediated "silencing" represents an intriguing alternative for the precise inhibition of a particular function of biomolecules. Here, we describe a method for selecting recombinant antibodies with a specific purpose in mind, which is to inhibit intrinsic protein-protein interactions in the cytosol of plant cells. Experimental procedures were designed for conveniently evaluating desired properties of recombinant antibodies in consecutive steps. Our selection method was successfully used to develop a recombinant antibody inhibiting the interaction of ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 3 with such of its upstream interaction partners as the receiver domain of CYTOKININ INDEPENDENT HISTIDINE KINASE 1. The specific down-regulation of the cytokinin signaling pathway in vivo demonstrates the validity of our approach. This selection method can serve as a prototype for developing unique recombinant antibodies able to interfere with virtually any biomolecule in the living cell.

Identification of a human protein-derived HIV-1 fusion inhibitor targeting the gp41 fusion core structure.

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Lijun Chao

Full Text Available The HIV-1 envelope glycoprotein (Env gp41 plays a crucial role in the viral fusion process. The peptides derived from the C-terminal heptad repeat (CHR of gp41 are potent HIV fusion inhibitors. However, the activity of these anti-HIV-1 peptides in vivo may be attenuated by their induction of anti-gp41 antibodies. Thus, it is essential to identify antiviral peptides or proteins with low, or no, immunogenicity to humans. Here, we found that the C-terminal fragment (aa 462-521 of the human POB1 (the partner of RalBP1, designated C60, is an HIV-1 fusion inhibitor. It bound to N36, the peptide derived from the N-terminal heptad repeat (NHR of gp41, and to the six-helix bundle (6-HB formed by N36 and C34, a CHR-peptide, but it did not bind to C34. Unlike the CHR-peptides, C60 did not block gp41 6-HB formation. Rather, results suggest that C60 inhibits HIV-1 fusion by binding to the 6-HB, in particular, the residues in the gp41 NHR domain that are exposed on the surface of 6-HB. Since 6-HB plays a crucial role in the late stage of fusion between the viral envelope and endosomal membrane during the endocytic process of HIV-1, C60 may serve as a host restriction factor to suppress HIV-1 entry into CD4+ T lymphocytes. Taken together, it can be concluded from these results that C60 can be used as a lead for the development of anti-HIV-1 therapeutics or microbicides for the treatment and prevention of HIV-1 infection, as well as a molecular probe to study the fusogenic mechanism of HIV-1.

Assessment of a recombinant F1-V fusion protein vaccine intended to protect Canada lynx (Lynx canadensis) from plague

Science.gov (United States)

Wolfe, Lisa L.; Shenk, Tanya M.; Powell, Bradford; Rocke, Tonie E.

2011-01-01

As part of an ongoing restoration program in Colorado, USA, we evaluated adverse reactions and seroconversion in captive Canada lynx (Lynx canadensis) after vaccination with a recombinant F1-V fusion protein vaccine against Yersinia pestis, the bacterium that causes plague. Ten adult female lynx received the F1-V vaccine; 10 source- and age-matched lynx remained unvaccinated as controls. All of the vaccinated and control lynx remained apparently healthy throughout the confinement period. We observed no evidence of injection site or systemic reactions to the F1-V vaccine. Among vaccinated lynx, differences in log10 reciprocal antibody titers measured in sera collected before and after vaccination (two doses) ranged from 1.2 to 5.2 for anti-F1 antibodies and from 0.6 to 5.2 for anti-V antibodies; titers in unvaccinated lynx did not change appreciably over the course of confinement prior to release, and thus differences in anti-F1 (P=0.003) and anti-V (P=0.0005) titers were greater among vaccinated lynx than among controls. Although our findings suggest that the F1-V fusion protein vaccine evaluated here is likely to stimulate antibody responses that may help protect Canada lynx from plague, we observed no apparent differences in survival between vaccinated and unvaccinated subject animals. Retrospectively, 22 of 50 (44%; 95% confidence interval 29–59%) unvaccinated lynx captured or recaptured in Colorado during 2000–08 had passive hemagglutination antibody titers >1:16, consistent with exposure to Y. pestis; paired pre- and postrelease titers available for eight of these animals showed titer increases similar in magnitude to those seen in response to vaccination, suggesting at least some lynx may naturally acquire immunity to plague in Colorado habitats.

Impact of fluorescent protein fusions on the bacterial flagellar motor

NARCIS (Netherlands)

Heo, M.; Nord, A. L.; Chamousset, D.; van Rijn, E.; Beaumont, H.J.E.; Pedaci, F.

2017-01-01

Fluorescent fusion proteins open a direct and unique window onto protein function. However, they also introduce the risk of perturbation of the function of the native protein. Successful applications of fluorescent fusions therefore rely on a careful assessment and minimization of the side

Reduction in Brain Heparan Sulfate with Systemic Administration of an IgG Trojan Horse-Sulfamidase Fusion Protein in the Mucopolysaccharidosis Type IIIA Mouse.

Science.gov (United States)

Boado, Ruben J; Lu, Jeff Zhiqiang; Hui, Eric Ka-Wai; Pardridge, William M

2018-02-05

Mucopolysaccharidosis Type IIIA (MPSIIIA), also known as Sanfilippo A syndrome, is an inherited neurodegenerative disease caused by mutations in the lysosomal enzyme, N-sulfoglucosamine sulfohydrolase (SGSH), also known as sulfamidase. Mutations in the SGSH enzyme, the only mammalian heparan N-sulfatase, cause accumulation of lysosomal inclusion bodies in brain cells comprising heparan sulfate (HS) glycosaminoglycans (GAGs). Treatment of MPSIIIA with intravenous recombinant SGSH is not possible because this large molecule does not cross the blood-brain barrier (BBB). BBB penetration by SGSH was enabled in the present study by re-engineering this enzyme as an IgG-SGSH fusion protein, where the IgG domain is a chimeric monoclonal antibody (mAb) against the mouse transferrin receptor (TfR), designated the cTfRMAb. The IgG domain of the fusion protein acts as a molecular Trojan horse to deliver the enzyme into brain via transport on the endogenous BBB TfR. The cTfRMAb-SGSH fusion protein bound to the mouse TfR with high affinity, ED 50 = 0.74 ± 0.07 nM, and retained high SGSH enzyme activity, 10 043 ± 1003 units/mg protein, which is comparable to recombinant human SGSH. Male and female MPSIIIA mice, null for the SGSH enzyme, were treated for 6 weeks with thrice-weekly intraperitoneal injections of vehicle, 5 mg/kg of the cTfRMAb alone, or 5 mg/kg of the cTfRMAb-SGSH fusion protein, starting at the age of 2 weeks, and were euthanized 1 week after the last injection. Brain and liver HS, as determined by liquid chromatography-mass spectrometry, were elevated 30-fold and 36-fold, respectively, in the MPSIIIA mouse. Treatment of the mice with the cTfRMAb-SGSH fusion protein caused a 70% and 85% reduction in brain and liver HS, respectively. The reduction in brain HS was associated with a 28% increase in latency on the rotarod test of motor activity in male mice. The mice exhibited no injection related reactions, and only a low titer end of study antidrug antibody

A Plasmodium falciparum 48/45 single epitope R0.6C subunit protein elicits high levels of transmission blocking antibodies

DEFF Research Database (Denmark)

Singh, Susheel K; Roeffen, Will; Andersen, Gorm

2015-01-01

as a chimera with the N-terminal region of GLURP (R0). The resulting fusion protein elicited high titer TB antibodies in rodents. To increase the relatively low yield of correctly folded Pfs48/45 we have generated a series of novel chimera truncating the 10C-fragments to 6 cysteine residues containing sub...

Development of radioactivity labelling method of new antibody by using the antibody engineering

International Nuclear Information System (INIS)

Yamazaki, Takeshi; Nakajima, Osamu; Saito, Yoshiro; Hachisuka, Akiko; Tanaka, Toichi; Sawada, Junichi

1999-01-01

With an aim to develop a method to produce labelled antibodies with low immunogenicity, two recombinant fusion proteins; scFv-His and scFv-MTβ were produced using gene engineering techniques. The former was constructed with scFv-antibody and histidine hexamer, a metal-chelated protein (or peptide). The latter was done with scFv-antibody and β-domain of metallothionein. Then, antigen-binding activity and metal-binding activity of these fusion proteins were determined using gel-filtration chromatography and ELISA. The main antigen-binding activity of scFv-His preparation was detected in a domain of about 25-30 kDa, which agreed with the peak of 29 kDa corresponding to the presumed molecular weight for the protein. Whereas the antigen-binding activity of scFv-MTβ was found in a domain of 30-35 kDa, which agreed with 32 kDa, the presumed molecular weight of scFv-MTβ. Gel-filtration chromatography of scFv-His preparation after the addition of Cu 2+ ion revealed an optical absorption at 280 nm and a Cu-peak near at 14 kDa. These results suggested that the metal affinity of the histidine-hexamer was too weak to chelate Cu 2+ in a solution. The chromatography of scFv-MTβ preparation added with Cd 2+ showed a peak of Cd appeared around a position of about 20 kDa but the peak was not coincident with that of the antigen-binding activity (ca. 30 kDa), suggesting that the present preparation of scFv-MTβ had no Cd-binding activity due to metal-exchange reaction. Based on these results, problems on the production of recombinant scFv-antibody fused with metal-binding domain of cystein-binding type or histidine-binding one were discussed. (M.N.)

Herpesvirus glycoproteins undergo multiple antigenic changes before membrane fusion.

Directory of Open Access Journals (Sweden)

Daniel L Glauser

Full Text Available Herpesvirus entry is a complicated process involving multiple virion glycoproteins and culminating in membrane fusion. Glycoprotein conformation changes are likely to play key roles. Studies of recombinant glycoproteins have revealed some structural features of the virion fusion machinery. However, how the virion glycoproteins change during infection remains unclear. Here using conformation-specific monoclonal antibodies we show in situ that each component of the Murid Herpesvirus-4 (MuHV-4 entry machinery--gB, gH/gL and gp150--changes in antigenicity before tegument protein release begins. Further changes then occurred upon actual membrane fusion. Thus virions revealed their final fusogenic form only in late endosomes. The substantial antigenic differences between this form and that of extracellular virions suggested that antibodies have only a limited opportunity to block virion membrane fusion.

Structural characterization of respiratory syncytial virus fusion inhibitor escape mutants: homology model of the F protein and a syncytium formation assay

International Nuclear Information System (INIS)

Morton, Craig J.; Cameron, Rachel; Lawrence, Lynne J.; Lin Bo; Lowe, Melinda; Luttick, Angela; Mason, Anthony; McKimm-Breschkin, Jenny; Parker, Michael W.; Ryan, Jane; Smout, Michael; Sullivan, Jayne; Tucker, Simon P.; Young, Paul R.

2003-01-01

Respiratory syncytial virus (RSV) is a ubiquitous human pathogen and the leading cause of lower respiratory tract infections in infants. Infection of cells and subsequent formation of syncytia occur through membrane fusion mediated by the RSV fusion protein (RSV-F). A novel in vitro assay of recombinant RSV-F function has been devised and used to characterize a number of escape mutants for three known inhibitors of RSV-F that have been isolated. Homology modeling of the RSV-F structure has been carried out on the basis of a chimera derived from the crystal structures of the RSV-F core and a fragment from the orthologous fusion protein from Newcastle disease virus (NDV). The structure correlates well with the appearance of RSV-F in electron micrographs, and the residues identified as contributing to specific binding sites for several monoclonal antibodies are arranged in appropriate solvent-accessible clusters. The positions of the characterized resistance mutants in the model structure identify two promising regions for the design of fusion inhibitors

Stressed and depressed? Check your GDNF for epigenetic repression.

Science.gov (United States)

Miller, Courtney A

2011-01-27

Some adults fail to adapt to chronic stress, developing symptoms of depression and anxiety. In this issue of Neuron, Uchida and colleagues link maladaptive stress responses to GDNF through a comprehensive investigation of the neurotrophic factor's regulation. Further, this study is an excellent example for investigators interested in neuroepigenetics research. © 2011 Elsevier Inc. All rights reserved.

The Multifaceted Role of SNARE Proteins in Membrane Fusion.

Science.gov (United States)

Han, Jing; Pluhackova, Kristyna; Böckmann, Rainer A

2017-01-01

Membrane fusion is a key process in all living organisms that contributes to a variety of biological processes including viral infection, cell fertilization, as well as intracellular transport, and neurotransmitter release. In particular, the various membrane-enclosed compartments in eukaryotic cells need to exchange their contents and communicate across membranes. Efficient and controllable fusion of biological membranes is known to be driven by cooperative action of SNARE proteins, which constitute the central components of the eukaryotic fusion machinery responsible for fusion of synaptic vesicles with the plasma membrane. During exocytosis, vesicle-associated v-SNARE (synaptobrevin) and target cell-associated t-SNAREs (syntaxin and SNAP-25) assemble into a core trans-SNARE complex. This complex plays a versatile role at various stages of exocytosis ranging from the priming to fusion pore formation and expansion, finally resulting in the release or exchange of the vesicle content. This review summarizes current knowledge on the intricate molecular mechanisms underlying exocytosis triggered and catalyzed by SNARE proteins. Particular attention is given to the function of the peptidic SNARE membrane anchors and the role of SNARE-lipid interactions in fusion. Moreover, the regulatory mechanisms by synaptic auxiliary proteins in SNARE-driven membrane fusion are briefly outlined.

Novel Antibody-Based Proteins for Cancer Immunotherapy

Energy Technology Data Exchange (ETDEWEB)

Fuenmayor, Jaheli; Montaño, Ramon F., E-mail: jfuenmay@ivic.gob.ve [Laboratorio de Patología Celular y Molecular, Centro de Medicina Experimental, Instituto Venezolano de Investigaciones Científicas. Caracas, 1020-A (Venezuela, Bolivarian Republic of)

2011-08-19

The relative success of monoclonal antibodies in cancer immunotherapy and the vast manipulation potential of recombinant antibody technology have encouraged the development of novel antibody-based antitumor proteins. Many insightful reagents have been produced, mainly guided by studies on the mechanisms of action associated with complete and durable remissions, results from experimental animal models, and our current knowledge of the human immune system. Strikingly, only a small percent of these new reagents has demonstrated clinical value. Tumor burden, immune evasion, physiological resemblance, and cell plasticity are among the challenges that cancer therapy faces, and a number of antibody-based proteins are already available to deal with many of them. Some of these novel reagents have been shown to specifically increase apoptosis/cell death of tumor cells, recruit and activate immune effectors, and reveal synergistic effects not previously envisioned. In this review, we look into different approaches that have been followed during the past few years to produce these biologics and analyze their relative success, mainly in terms of their clinical performance. The use of antibody-based antitumor proteins, in combination with standard or novel therapies, is showing significant improvements in objective responses, suggesting that these reagents will become important components of the antineoplastic protocols of the future.

Antigenic specificity of serum antibodies in mice fed soy protein

DEFF Research Database (Denmark)

Christensen, Hanne Risager; Bruun, S.W.; Frøkiær, Hanne

2003-01-01

Background: Soybean protein is used in a number of food products but unfortunately is also a common cause of food allergy. Upon ingestion of soy protein, healthy mice like other animals and humans generate a soy-specific antibody response in the absence of signs of illness. Not much is known about...... the relationship between the immunogenic proteins involved in this nondeleterious antibody response and the pathological response associated with food allergy. The objective of the present study was to characterize the antigenic specificity of the soy protein-specific antibody response generated in healthy mice...... ingesting soy protein. Methods: Blood from mice fed a soy-containing diet was analyzed using ELISA and immunoblot for antibody reactivity towards various soy protein fractions and pure soy proteins/subunits. Mice bred on a soy-free diet were used as controls. Results: The detectable antigenic specificity...

ACCUMULATION OF RECOMBINANT FUSION PROTEIN – SECRETORY ANALOG OF Ag85B AND ESAT6 MYCOBACTERIUM TUBERCULOSIS PROTEINS – IN TRANSGENIC Lemna minor L. PLANTS

Directory of Open Access Journals (Sweden)

A.A.Peterson

2015-10-01

Full Text Available Determination of the presence of the recombinant fusion protein (ESAT6-Ag85B(ΔTMD-6His and its accumulation level in duckweed plants (Lemna minor L. was the aim of the research. ESAT6 and Ag85B are secretory proteins of Mycobacterium tuberculosis and are considered as potential candidates for development of new vaccine against tuberculosis (TB. Transgenic duckweed plants were obtained previously by Agrobacterium rhizogenes-mediated transformation and possessed fusion gene sequence esxA-fbpBΔTMD. Specific polyclonal antibodies were produced in immunized mice to identify levels of accumulation of TB antigens in plants. Recombinant antigen used for mice immunization was obtained in our laboratory by expression in E. coli. Western blot analysis revealed the recombinant tuberculosis antigen ESAT6-Ag85B(ΔTMD-6His in extracts from transgenic L. minor plants. The level of accumulation of the protein corresponds to 0.4-0.5 µg protein per 1 g of fresh weight of plant. Additionally, the accumulation of recombinant protein was investigated in lyophilized transgenic plants after 1.5 year storage. Duckweed plants accumulating a recombinant analogue of M. tuberculosis secretory proteins can be used for development of plant-based edible vaccines.

Antibody-Based Detection of ERG Rearrangement-Positive Prostate Cancer

Directory of Open Access Journals (Sweden)

Kyung Park

2010-07-01

Full Text Available TMPRSS2-ERG gene fusions occur in 50% of prostate cancers and result in the overexpression of a chimeric fusion transcript that encodes a truncated ERG product. Previous attempts to detect truncated ERG products have been hindered by a lack of specific antibodies. Here, we characterize a rabbit anti-ERG monoclonal antibody (clone EPR 3864; Epitomics, Burlingame, CA using immunoblot analysis on prostate cancer cell lines, synthetic TMPRSS2-ERG constructs, chromatin immunoprecipitation, and immunofluorescence. We correlated ERG protein expression with the presence of ERG gene rearrangements in prostate cancertissues using a combined immunohistochemistry(IHC and fluorescence in situ hybridization (FISH analysis. We independently evaluated two patient cohorts and observed ERG expression confined to prostate cancer cells and high-grade prostatic intraepithelial reoplasia associated with ERG-positive cancer, as well as vessels and lymphocytes (where ERG has a known biologic role. Image analysis of 131 cases demonstrated nearly 100% sensitivity for detecting ERG rearrangement prostate cancer, with only 2 (1.5% of 131 cases demonstrating strong ERG protein expression without any known ERG gene fusion. The combired pathology evaluation of 207 patient tumors for ERG protein expression had 95.7% sensitivity and 96.5% specificity for determining ERG rearrangement prostate cancer. Ir conclusion, this study qualifies a specific anti-ERG antibody and demonstrates exquisite association between ERG gene rearrangement and truncated ERG protein product expression. Giver the ease of performing IHC versus FISH, ERG protein expression may be useful for molecularly subtypirg prostate cancer based or ERG rearrangement status and suggests clinical utility it prostate needle biopsy evaluation.

Designing proteins for therapeutic applications.

Science.gov (United States)

Lazar, Greg A; Marshall, Shannon A; Plecs, Joseph J; Mayo, Stephen L; Desjarlais, John R

2003-08-01

Protein design is becoming an increasingly useful tool for optimizing protein drugs and creating novel biotherapeutics. Recent progress includes the engineering of monoclonal antibodies, cytokines, enzymes and viral fusion inhibitors.

Mono-(2-ethylhexyl)-phthalate (MEHP) affects ERK-dependent GDNF signalling in mouse stem-progenitor spermatogonia

International Nuclear Information System (INIS)

Lucas, Benjamin E.G.; Fields, Christopher; Joshi, Neeraj; Hofmann, Marie-Claude

2012-01-01

Highlights: ► MEHP affects SSC proliferation in a dose- and time-dependent manner. ► MEHP does not increase apoptosis, necrosis or the production of ROS in SSCs. ► MEHP reduces the activity of the GDNF/ERK1/2/FOS signalling pathway in SSCs. ► MEHP does not affect the GDNF/SRC/MYCN signalling pathway in SSCs. -- Abstract: Many commercial and household products such as lubricants, cosmetics, plastics, and paint contain phthalates, in particular bis-(2-ethyhexyl)-phthalate (DEHP). As a consequence, phthalates have been found in a number of locations and foods (streambeds, household dust, bottled water and dairy products). Epidemiological and animal studies analysing phthalate exposure in males provide evidence of degradation in sperm quality, associated to an increase in the incidence of genital birth defects and testicular cancers. In the testis, spermatogenesis is maintained throughout life by a small number of spermatogonial stem cells (SSCs) that self-renew or differentiate to produce adequate numbers of spermatozoa. Disruption or alteration of SSC self-renewal induce decreased sperm count and sperm quality, or may potentially lead to testicular cancer. GDNF, or glial cell-line-derived neurotrophic factor, is a growth factor that is essential for the self-renewal of SSCs and continuous spermatogenesis. In the present study, the SSC-derived cell line C18-4 was used as a model for preliminary assessment of the effects of mono-(2-ethylhexyl)-phthalate (MEHP, main metabolite of DEHP) on spermatogonial stem cells. Our data demonstrate that MEHP disrupts one of the known GDNF signalling pathways in these cells. MEHP induced a decrease of C18-4 cell viability in a time- and dose-dependent manner, as well as a disruption of ERK1/2 activation but not of SRC signalling. As a result, we observed a decrease of expression of the transcription factor FOS, which is downstream of the GDNF/ERK1/2 axis in these cells. Taken together, our data suggest that MEHP exposure

Construction, expression, and function of 6B11ScFv-mIL-12, a fusion protein that attacks human ovarian carcinoma.

Science.gov (United States)

Cheng, Hongyan; Ye, Xue; Chang, Xiaohong; Ma, Ruiqiong; Cong, Xu; Niu, Yidong; Zhang, Menglei; Liu, Kai; Cui, Heng; Sang, Jianli

2015-04-01

We previously produced an anti-idiotypic monoclonal antibody, 6B11, which mimics ovarian cancer antigen CA166-9 and induces cellular and humoral immunity. Here, to enhance the immunogenicity of 6B11, we constructed the 6B11ScFv-mIL-12 fusion protein (FP), by fusing single-chain fragment of 6B11 variable region (6B11ScFv) with mouse interleukin-12 (mIL-12), which was expressed in eukaryotic 293EBNA cells transfected with pSBI vectors. A binding activity assay showed 6B11ScFv-mIL-12 to have activities of both 6B11 and mIL-12-it specifically bound both ovarian monoclonal antibody COC166-9 and rabbit anti-mouse IL-12 antibody. The immune activity assay showed 6B11ScFv-mIL-12 to promote proliferation of lymphocytes stimulated by phytohemagglutinin, increase the absolute numbers and percentages of CD3(-)/CD56(+) natural killer cells and CD3(+)/CD56(+) natural killer T cells among peripheral lymphocytes, and increase interferon-γ. The FP was specifically cytotoxic to the CA166-9(+) ovarian cancer cell lines HOC1A and SKOV3 and inhibited growth of ID8 subcutaneous tumors in C57BL/6J mice. This study provides an experimental basis for clinical use of 6B11ScFv-mIL-12 in ovarian cancer therapy. To our knowledge, this is the first report of a fusion protein from an anti-idiotypic antibody and IL-12.

Exceptionally potent anti-tumor bystander activity of an scFv : sTRAIL fusion protein with specificity for EGP2 toward target antigen-negative tumor cells

NARCIS (Netherlands)

Bremer, E; Samplonius, D; Kroesen, BJ; van Genne, L; de Leij, L; Helfrich, W

2004-01-01

Previously, we reported on the target cell-restricted fratricide apoptotic activity of scFvC54:sTRAIL, a fusion protein comprising human-soluble tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) genetically linked to the antibody fragment scFvC54 specific for the cell surface target

Age and lesion-induced increases of GDNF transgene expression in brain following intracerebral injections of DNA nanoparticles.

Science.gov (United States)

Yurek, D M; Hasselrot, U; Cass, W A; Sesenoglu-Laird, O; Padegimas, L; Cooper, M J

2015-01-22

In previous studies that used compacted DNA nanoparticles (DNP) to transfect cells in the brain, we observed higher transgene expression in the denervated striatum when compared to transgene expression in the intact striatum. We also observed that long-term transgene expression occurred in astrocytes as well as neurons. Based on these findings, we hypothesized that the higher transgene expression observed in the denervated striatum may be a function of increased gliosis. Several aging studies have also reported an increase of gliosis as a function of normal aging. In this study we used DNPs that encoded for human glial cell line-derived neurotrophic factor (hGDNF) and either a non-specific human polyubiquitin C (UbC) or an astrocyte-specific human glial fibrillary acidic protein (GFAP) promoter. The DNPs were injected intracerebrally into the denervated or intact striatum of young, middle-aged or aged rats, and glial cell line-derived neurotrophic factor (GDNF) transgene expression was subsequently quantified in brain tissue samples. The results of our studies confirmed our earlier finding that transgene expression was higher in the denervated striatum when compared to intact striatum for DNPs incorporating either promoter. In addition, we observed significantly higher transgene expression in the denervated striatum of old rats when compared to young rats following injections of both types of DNPs. Stereological analysis of GFAP+ cells in the striatum confirmed an increase of GFAP+ cells in the denervated striatum when compared to the intact striatum and also an age-related increase; importantly, increases in GFAP+ cells closely matched the increases in GDNF transgene levels. Thus neurodegeneration and aging may lay a foundation that is actually beneficial for this particular type of gene therapy while other gene therapy techniques that target neurons are actually targeting cells that are decreasing as the disease progresses. Copyright © 2014 IBRO. Published by

GDNF family ligands display distinct action profiles on cultured GABAergic and serotonergic neurons of rat ventral mesencephalon

DEFF Research Database (Denmark)

Ducray, Angélique; Krebs, Sandra H:; Schaller, Benoft

2006-01-01

the effects of GFLs on other neuronal populations in the VM is essential for their potential application as therapeutic molecules for Parkinson's disease. Hence, in a comparative study, we investigated the effects of GFLs on cell densities and morphological differentiation of gamma-aminobutyric acid......Glial-cell-line-derived neurotrophic factor (GDNF), neurturin (NRTN), artemin (ARTN) and persephin (PSPN), known as the GDNF family ligands (GFLs), influence the development, survival and differentiation of cultured dopaminergic neurons from ventral mesencephalon (VM). Detailed knowledge about......-immunoreactive (GABA-ir) and serotonin-ir (5-HT-ir) neurons in primary cultures of E14 rat VM. We observed that all GFLs [10 ng/ml] significantly increased GABA-ir cell densities (1.6-fold) as well as neurite length/neuron. However, only GDNF significantly increased the number of primary neurites/neuron, and none...

Chaperone activity of human small heat shock protein-GST fusion proteins.

Science.gov (United States)

Arbach, Hannah; Butler, Caley; McMenimen, Kathryn A

2017-07-01

Small heat shock proteins (sHsps) are a ubiquitous part of the machinery that maintains cellular protein homeostasis by acting as molecular chaperones. sHsps bind to and prevent the aggregation of partially folded substrate proteins in an ATP-independent manner. sHsps are dynamic, forming an ensemble of structures from dimers to large oligomers through concentration-dependent equilibrium dissociation. Based on structural studies and mutagenesis experiments, it is proposed that the dimer is the smallest active chaperone unit, while larger oligomers may act as storage depots for sHsps or play additional roles in chaperone function. The complexity and dynamic nature of their structural organization has made elucidation of their chaperone function challenging. HspB1 and HspB5 are two canonical human sHsps that vary in sequence and are expressed in a wide variety of tissues. In order to determine the role of the dimer in chaperone activity, glutathione-S-transferase (GST) was genetically linked as a fusion protein to the N-terminus regions of both HspB1 and HspB5 (also known as Hsp27 and αB-crystallin, respectively) proteins in order to constrain oligomer formation of HspB1 and HspB5, by using GST, since it readily forms a dimeric structure. We monitored the chaperone activity of these fusion proteins, which suggest they primarily form dimers and monomers and function as active molecular chaperones. Furthermore, the two different fusion proteins exhibit different chaperone activity for two model substrate proteins, citrate synthase (CS) and malate dehydrogenase (MDH). GST-HspB1 prevents more aggregation of MDH compared to GST-HspB5 and wild type HspB1. However, when CS is the substrate, both GST-HspB1 and GST-HspB5 are equally effective chaperones. Furthermore, wild type proteins do not display equal activity toward the substrates, suggesting that each sHsp exhibits different substrate specificity. Thus, substrate specificity, as described here for full-length GST

Oral or parenteral administration of replication-deficient adenoviruses expressing the measles virus haemagglutinin and fusion proteins: protective immune responses in rodents.

Science.gov (United States)

Fooks, A R; Jeevarajah, D; Lee, J; Warnes, A; Niewiesk, S; ter Meulen, V; Stephenson, J R; Clegg, J C

1998-05-01

The genes encoding the measles virus (MV) haemagglutinin (H) and fusion (F) proteins were placed under the control of the human cytomegalovirus immediate early promoter in a replication-deficient adenovirus vector. Immunofluorescence and radioimmune precipitation demonstrated the synthesis of each protein and biological activity was confirmed by the detection of haemadsorption and fusion activities in infected cells. Oral as well as parenteral administration of the H-expressing recombinant adenovirus elicited a significant protective response in mice challenged with MV. While the F-expressing adenovirus failed to protect mice, cotton rats immunized with either the H- or F-expressing recombinant showed reduced MV replication in the lungs. Antibodies elicited in mice following immunization with either recombinant had no in vitro neutralizing activity, suggesting a protective mechanism involving a cell-mediated immune response. This study demonstrates the feasibility of using oral administration of adenovirus recombinants to induce protective responses to heterologous proteins.

Protein-induced fusion can be modulated by target membrane lipids through a structural switch at the level of the fusion peptide

NARCIS (Netherlands)

Pecheur, EI; Martin, [No Value; Bienvenue, A; Ruysschaert, JM; Hoekstra, D

2000-01-01

Regulatory features of protein-induced membrane fusion are largely unclear, particularly at the level of the fusion peptide. Fusion peptides being part of larger protein complexes, such investigations are met with technical limitations. Here, we show that the fusion activity of influenza virus or

Production and characterization of monoclonal antibodies against cathepsin B and cathepsin B-Like proteins of Naegleria fowleri.

Science.gov (United States)

Seong, Gi-Sang; Sohn, Hae-Jin; Kang, Heekyoung; Seo, Ga-Eun; Kim, Jong-Hyun; Shin, Ho-Joon

2017-12-01

Naegleria fowleri causes fatal primary amoebic meningoencephalitis (PAM) in humans and experimental animals. In previous studies, cathepsin B (nfcpb) and cathepsin B-like (nfcpb-L) genes of N. fowleri were cloned, and it was suggested that refolding rNfCPB and rNfCPB-L proteins could play important roles in host tissue invasion, immune response evasion and nutrient uptake. In this study, we produced anti-NfCPB and anti-NfCPB-L monoclonal antibodies (McAb) using a cell fusion technique, and observed their immunological characteristics. Seven hybridoma cells secreting rNfCPB McAbs and three hybridoma cells secreting rNfCPB-L McAbs were produced. Among these, 2C9 (monoclone for rNfCPB) and 1C8 (monoclone for rNfCPB-L) McAb showed high antibody titres and were finally selected for use. As determined by western blotting, 2C9 McAb bound to N. fowleri lysates, specifically the rNfCPB protein, which had bands of 28 kDa and 38.4 kDa. 1C8 McAb reacted with N. fowleri lysates, specifically the rNfCPB-L protein, which had bands of 24 kDa and 34 kDa. 2C9 and 1C8 monoclonal antibodies did not bind to lysates of other amoebae, such as N. gruberi, Acanthamoeba castellanii and A. polyphaga in western blot analyses. Immuno-cytochemistry analysis detected NfCPB and NfCPB-L proteins in the cytoplasm of N. fowleri trophozoites, particularly in the pseudopodia and food-cup. These results suggest that monoclonal antibodies produced against rNfCPB and rNfCPB-L proteins may be useful for further immunological study of PAM. Copyright © 2017 Elsevier Inc. All rights reserved.

Foot-and-mouth disease virus-like particles produced by a SUMO fusion protein system in Escherichia coli induce potent protective immune responses in guinea pigs, swine and cattle

Science.gov (United States)

2013-01-01

Foot-and-mouth disease virus (FMDV) causes a highly contagious infection in cloven-hoofed animals. The format of FMD virus-like particles (VLP) as a non-replicating particulate vaccine candidate is a promising alternative to conventional inactivated FMDV vaccines. In this study, we explored a prokaryotic system to express and assemble the FMD VLP and validated the potential of VLP as an FMDV vaccine candidate. VLP composed entirely of FMDV (Asia1/Jiangsu/China/2005) capsid proteins (VP0, VP1 and VP3) were simultaneously produced as SUMO fusion proteins by an improved SUMO fusion protein system in E. coli. Proteolytic removal of the SUMO moiety from the fusion proteins resulted in the assembly of VLP with size and shape resembling the authentic FMDV. Immunization of guinea pigs, swine and cattle with FMD VLP by intramuscular inoculation stimulated the FMDV-specific antibody response, neutralizing antibody response, T-cell proliferation response and secretion of cytokine IFN-γ. In addition, immunization with one dose of the VLP resulted in complete protection of these animals from homologous FMDV challenge. The 50% protection dose (PD50) of FMD VLP in cattle is up to 6.34. These results suggest that FMD VLP expressed in E. coli are an effective vaccine in guinea pigs, swine and cattle and support further development of these VLP as a vaccine candidate for protection against FMDV. PMID:23826638

A phage-displayed chicken single-chain antibody fused to alkaline phosphatase detects Fusarium pathogens and their presence in cereal grains

International Nuclear Information System (INIS)

Hu, Zu-Quan; Li, He-Ping; Zhang, Jing-Bo; Huang, Tao; Liu, Jin-Long; Xue, Sheng; Wu, Ai-Bo; Liao, Yu-Cai

2013-01-01

Graphical abstract: A phage-displayed chicken scFv antibody, FvSG7, binds on the surface antigen of conidiospores and the mycelia of F. verticillioides. Its fusion with alkaline phosphatase (AP) through a 218 linker displayed a 4-fold higher affinity compared with the parent scFv antibody and efficiently detected toxigenic Fusarium pathogens in cereal grains. Highlights: ► Generation of a highly reactive scFv antibody against F. verticillioides. ► Localization of the antibody binding to the surface target of F. verticillioides. ► Expression of the antibody–alkaline phosphatase (AP) fusion linked by a 218 linker. ► The antibody–AP fusion has a higher affinity than the parental antibody. ► The antibody–AP fusion detects toxigenic Fusarium pathogens in cereal grains. -- Abstract: Fusarium and its poisonous mycotoxins are distributed worldwide and are of particular interest in agriculture and food safety. A simple analytical method to detect pathogens is essential for forecasting diseases and controlling mycotoxins. This article describes a proposed method for convenient and sensitive detection of Fusarium pathogens that uses the fusion of single-chain variable fragment (scFv) and alkaline phosphatase (AP). A highly reactive scFv antibody specific to soluble cell wall-bound proteins (SCWPs) of F. verticillioides was selected from an immunized chicken phagemid library by phage display. The antibody was verified to bind on the surface of ungerminated conidiospores and mycelia of F. verticillioides. The scFv–AP fusion was constructed, and soluble expression in bacteria was confirmed. Both the antibody properties and enzymatic activity were retained, and the antigen-binding capacity of the fusion was enhanced by the addition of a linker. Surface plasmon resonance measurements confirmed that the fusion displayed 4-fold higher affinity compared with the fusion's parental scFv antibody. Immunoblot analyses showed that the fusion had good binding capacity to

A phage-displayed chicken single-chain antibody fused to alkaline phosphatase detects Fusarium pathogens and their presence in cereal grains

Energy Technology Data Exchange (ETDEWEB)

Hu, Zu-Quan [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); Li, He-Ping [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Zhang, Jing-Bo [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Huang, Tao [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Liu, Jin-Long; Xue, Sheng [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); Wu, Ai-Bo [Institute for Agri-food Standards and Testing Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products, Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, 1000 Jinqi Road, Shanghai 201403 (China); Liao, Yu-Cai, E-mail: ycliao06@yahoo.com.cn [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); National Center of Plant Gene Research, Wuhan 430070 (China)

2013-02-18

Graphical abstract: A phage-displayed chicken scFv antibody, FvSG7, binds on the surface antigen of conidiospores and the mycelia of F. verticillioides. Its fusion with alkaline phosphatase (AP) through a 218 linker displayed a 4-fold higher affinity compared with the parent scFv antibody and efficiently detected toxigenic Fusarium pathogens in cereal grains. Highlights: ► Generation of a highly reactive scFv antibody against F. verticillioides. ► Localization of the antibody binding to the surface target of F. verticillioides. ► Expression of the antibody–alkaline phosphatase (AP) fusion linked by a 218 linker. ► The antibody–AP fusion has a higher affinity than the parental antibody. ► The antibody–AP fusion detects toxigenic Fusarium pathogens in cereal grains. -- Abstract: Fusarium and its poisonous mycotoxins are distributed worldwide and are of particular interest in agriculture and food safety. A simple analytical method to detect pathogens is essential for forecasting diseases and controlling mycotoxins. This article describes a proposed method for convenient and sensitive detection of Fusarium pathogens that uses the fusion of single-chain variable fragment (scFv) and alkaline phosphatase (AP). A highly reactive scFv antibody specific to soluble cell wall-bound proteins (SCWPs) of F. verticillioides was selected from an immunized chicken phagemid library by phage display. The antibody was verified to bind on the surface of ungerminated conidiospores and mycelia of F. verticillioides. The scFv–AP fusion was constructed, and soluble expression in bacteria was confirmed. Both the antibody properties and enzymatic activity were retained, and the antigen-binding capacity of the fusion was enhanced by the addition of a linker. Surface plasmon resonance measurements confirmed that the fusion displayed 4-fold higher affinity compared with the fusion's parental scFv antibody. Immunoblot analyses showed that the fusion had good binding

Treatment of trigeminal ganglion neurons in vitro with NGF, GDNF or BDNF: effects on neuronal survival, neurochemical properties and TRPV1-mediated neuropeptide secretion

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Patwardhan Amol M

2005-01-01

Full Text Available Abstract Background Nerve growth factor (NGF, glial cell line-derived neurotrophic factor (GDNF and brain-derived neurotrophic factor (BDNF all play important roles in the development of the peripheral sensory nervous system. Additionally, these growth factors are proposed to modulate the properties of the sensory system in the adult under pathological conditions brought about by nerve injury or inflammation. We have examined the effects of NGF, GDNF and BDNF on adult rat trigeminal ganglion (TG neurons in culture to gain a better understanding of how these growth factors alter the cytochemical and functional phenotype of these neurons, with special attention to properties associated with nociception. Results Compared with no growth factor controls, GDNF, at 1 and 100 ng/ml, significantly increased by nearly 100% the number of neurons in culture at 5 days post-plating. A significant, positive, linear trend of increasing neuron number as a function of BDNF concentration was observed, also peaking at nearly 100%. NGF treatment was without effect. Chronic treatment with NGF and GDNF significantly and concentration-dependently increased 100 nM capsaicin (CAP-evoked calcitonin gene-related peptide (CGRP release, reaching approximately 300% at the highest concentration tested (100 ng/ml. Also, NGF and GDNF each augmented anandamide (AEA- and arachidonyl-2-chloroethylamide (ACEA-evoked CGRP release, while BDNF was without effect. Utilizing immunohistochemistry to account for the proportions of TRPV1- or CGRP-positive neurons under each growth factor treatment condition and then standardizing evoked CGRP release to these proportions, we observed that NGF was much more effective in enhancing CAP- and 50 mM K+-evoked CGRP release than was GDNF. Furthermore, NGF and GDNF each altered the concentration-response function for CAP- and AEA-evoked CGRP release, increasing the Emax without altering the EC50 for either compound. Conclusions Taken together, our

Expression of POTE protein in human testis detected by novel monoclonal antibodies

International Nuclear Information System (INIS)

Ise, Tomoko; Das, Sudipto; Nagata, Satoshi; Maeda, Hiroshi; Lee, Yoomi; Onda, Masanori; Anver, Miriam R.; Bera, Tapan K.; Pastan, Ira

2008-01-01

The POTE gene family is composed of 13 highly homologous paralogs preferentially expressed in prostate, ovary, testis, and placenta. We produced 10 monoclonal antibodies (MAbs) against three representative POTE paralogs: POTE-21, POTE-2γC, and POTE-22. One reacted with all three paralogs, six MAbs reacted with POTE-2γC and POTE-22, and three MAbs were specific to POTE-21. Epitopes of all 10 MAbs were located in the cysteine-rich repeats (CRRs) motifs located at the N-terminus of each POTE paralog. Testing the reactivity of each MAb with 12 different CRRs revealed slight differences among the antigenic determinants, which accounts for differences in cross-reactivity. Using MAbs HP8 and PG5 we were able to detect a POTE-actin fusion protein in human testis by immunoprecipitation followed by Western blotting. By immunohistochemistry we demonstrated that the POTE protein is expressed in primary spermatocytes, implying a role in spermatogenesis

Production of unnaturally linked chimeric proteins using a combination of sortase-catalyzed transpeptidation and click chemistry.

Science.gov (United States)

Witte, Martin D; Theile, Christopher S; Wu, Tongfei; Guimaraes, Carla P; Blom, Annet E M; Ploegh, Hidde L

2013-09-01

Chimeric proteins, including bispecific antibodies, are biological tools with therapeutic applications. Genetic fusion and ligation methods allow the creation of N-to-C and C-to-N fused recombinant proteins, but not unnaturally linked N-to-N and C-to-C fusion proteins. This protocol describes a simple procedure for the production of such chimeric proteins, starting from correctly folded proteins and readily available peptides. By equipping the N terminus or C terminus of the proteins of interest with a set of click handles using sortase A, followed by a strain-promoted click reaction, unnatural N-to-N and C-to-C linked (hetero) fusion proteins are established. Examples of proteins that have been conjugated via this method include interleukin-2, interferon-α, ubiquitin, antibodies and several single-domain antibodies. If the peptides, sortase A and the proteins of interest are in hand, the unnaturally N-to-N and C-to-C fused proteins can be obtained in 3-4 d.

Ebolavirus Glycoprotein Fc Fusion Protein Protects Guinea Pigs against Lethal Challenge

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Konduru, Krishnamurthy; Shurtleff, Amy C.; Bradfute, Steven B.; Nakamura, Siham; Bavari, Sina; Kaplan, Gerardo

2016-01-01

Ebola virus (EBOV), a member of the Filoviridae that can cause severe hemorrhagic fever in humans and nonhuman primates, poses a significant threat to the public health. Currently, there are no licensed vaccines or therapeutics to prevent and treat EBOV infection. Several vaccines based on the EBOV glycoprotein (GP) are under development, including vectored, virus-like particles, and protein-based subunit vaccines. We previously demonstrated that a subunit vaccine containing the extracellular domain of the Ebola ebolavirus (EBOV) GP fused to the Fc fragment of human IgG1 (EBOVgp-Fc) protected mice against EBOV lethal challenge. Here, we show that the EBOVgp-Fc vaccine formulated with QS-21, alum, or polyinosinic-polycytidylic acid-poly-L-lysine carboxymethylcellulose (poly-ICLC) adjuvants induced strong humoral immune responses in guinea pigs. The vaccinated animals developed anti-GP total antibody titers of approximately 105−106 and neutralizing antibody titers of approximately 103 as assessed by a BSL-2 neutralization assay based on vesicular stomatitis virus (VSV) pseudotypes. The poly-ICLC formulated EBOVgp-Fc vaccine protected all the guinea pigs against EBOV lethal challenge performed under BSL-4 conditions whereas the same vaccine formulated with QS-21 or alum only induced partial protection. Vaccination with a mucin-deleted EBOVgp-Fc construct formulated with QS-21 adjuvant did not have a significant effect in anti-GP antibody levels and protection against EBOV lethal challenge compared to the full-length GP construct. The bulk of the humoral response induced by the EBOVgp-Fc vaccine was directed against epitopes outside the EBOV mucin region. Our findings indicate that different adjuvants can eliciting varying levels of protection against lethal EBOV challenge in guinea pigs vaccinated with EBOVgp-Fc, and suggest that levels of total anti-GP antibodies elicit by protein-based GP subunit vaccines do not correlate with protection. Our data further support

Ebolavirus Glycoprotein Fc Fusion Protein Protects Guinea Pigs against Lethal Challenge.

Science.gov (United States)

Konduru, Krishnamurthy; Shurtleff, Amy C; Bradfute, Steven B; Nakamura, Siham; Bavari, Sina; Kaplan, Gerardo

2016-01-01

Ebola virus (EBOV), a member of the Filoviridae that can cause severe hemorrhagic fever in humans and nonhuman primates, poses a significant threat to the public health. Currently, there are no licensed vaccines or therapeutics to prevent and treat EBOV infection. Several vaccines based on the EBOV glycoprotein (GP) are under development, including vectored, virus-like particles, and protein-based subunit vaccines. We previously demonstrated that a subunit vaccine containing the extracellular domain of the Ebola ebolavirus (EBOV) GP fused to the Fc fragment of human IgG1 (EBOVgp-Fc) protected mice against EBOV lethal challenge. Here, we show that the EBOVgp-Fc vaccine formulated with QS-21, alum, or polyinosinic-polycytidylic acid-poly-L-lysine carboxymethylcellulose (poly-ICLC) adjuvants induced strong humoral immune responses in guinea pigs. The vaccinated animals developed anti-GP total antibody titers of approximately 105-106 and neutralizing antibody titers of approximately 103 as assessed by a BSL-2 neutralization assay based on vesicular stomatitis virus (VSV) pseudotypes. The poly-ICLC formulated EBOVgp-Fc vaccine protected all the guinea pigs against EBOV lethal challenge performed under BSL-4 conditions whereas the same vaccine formulated with QS-21 or alum only induced partial protection. Vaccination with a mucin-deleted EBOVgp-Fc construct formulated with QS-21 adjuvant did not have a significant effect in anti-GP antibody levels and protection against EBOV lethal challenge compared to the full-length GP construct. The bulk of the humoral response induced by the EBOVgp-Fc vaccine was directed against epitopes outside the EBOV mucin region. Our findings indicate that different adjuvants can eliciting varying levels of protection against lethal EBOV challenge in guinea pigs vaccinated with EBOVgp-Fc, and suggest that levels of total anti-GP antibodies elicit by protein-based GP subunit vaccines do not correlate with protection. Our data further support

Ebolavirus Glycoprotein Fc Fusion Protein Protects Guinea Pigs against Lethal Challenge.

Directory of Open Access Journals (Sweden)

Krishnamurthy Konduru

Full Text Available Ebola virus (EBOV, a member of the Filoviridae that can cause severe hemorrhagic fever in humans and nonhuman primates, poses a significant threat to the public health. Currently, there are no licensed vaccines or therapeutics to prevent and treat EBOV infection. Several vaccines based on the EBOV glycoprotein (GP are under development, including vectored, virus-like particles, and protein-based subunit vaccines. We previously demonstrated that a subunit vaccine containing the extracellular domain of the Ebola ebolavirus (EBOV GP fused to the Fc fragment of human IgG1 (EBOVgp-Fc protected mice against EBOV lethal challenge. Here, we show that the EBOVgp-Fc vaccine formulated with QS-21, alum, or polyinosinic-polycytidylic acid-poly-L-lysine carboxymethylcellulose (poly-ICLC adjuvants induced strong humoral immune responses in guinea pigs. The vaccinated animals developed anti-GP total antibody titers of approximately 105-106 and neutralizing antibody titers of approximately 103 as assessed by a BSL-2 neutralization assay based on vesicular stomatitis virus (VSV pseudotypes. The poly-ICLC formulated EBOVgp-Fc vaccine protected all the guinea pigs against EBOV lethal challenge performed under BSL-4 conditions whereas the same vaccine formulated with QS-21 or alum only induced partial protection. Vaccination with a mucin-deleted EBOVgp-Fc construct formulated with QS-21 adjuvant did not have a significant effect in anti-GP antibody levels and protection against EBOV lethal challenge compared to the full-length GP construct. The bulk of the humoral response induced by the EBOVgp-Fc vaccine was directed against epitopes outside the EBOV mucin region. Our findings indicate that different adjuvants can eliciting varying levels of protection against lethal EBOV challenge in guinea pigs vaccinated with EBOVgp-Fc, and suggest that levels of total anti-GP antibodies elicit by protein-based GP subunit vaccines do not correlate with protection. Our data

[Production of monoclonal antibodies against a wild strain of rabies virus].

Science.gov (United States)

Akacem, O; Benmansour, A; Coulon, P; Brahimi, M; Benhassine, M

1992-01-01

Production of monoclonal antibodies against a wild strain of rabies virus. Cell fusion of SP 2/O, a murine myeloma against a wild strain of rabies virus has originated five monoclonal antibodies (M.A.) specific for virus nucleocapsid , one M.A. specific for virus glycoprotein and one M.A. specific for a viral membrane protein.

Elastin-like-polypeptide based fusion proteins for osteogenic factor delivery in bone healing.

Science.gov (United States)

McCarthy, Bryce; Yuan, Yuan; Koria, Piyush

2016-07-08

Modern treatments of bone injuries and diseases are becoming increasingly dependent on the usage of growth factors to stimulate bone growth. Bone morphogenetic protein-2 (BMP-2), a potent osteogenic inductive protein, exhibits promising results in treatment models, but recently has had its practical efficacy questioned due to the lack of local retention, ectopic bone formation, and potentially lethal inflammation. Where a new delivery technique of the BMP-2 is necessary, here we demonstrate the viability of an elastin-like peptide (ELP) fusion protein containing BMP-2 for delivery of the BMP-2. This fusion protein retains the performance characteristics of both the BMP-2 and ELP. The fusion protein was found to induce osteogenic differentiation of mesenchymal stem cells as evidenced by the production of alkaline phosphatase and extracellular calcium deposits in response to treatment by the fusion protein. Retention of the ELPs inverse phase transition property has allowed for expression of the fusion protein within a bacterial host (such as Escherichia coli) and easy and rapid purification using inverse transition cycling. The fusion protein formed self-aggregating nanoparticles at human-body temperature. The data collected suggests the viability of these fusion protein nanoparticles as a dosage-efficient and location-precise noncytotoxic delivery vehicle for BMP-2 in bone treatment. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1029-1037, 2016. © 2016 American Institute of Chemical Engineers.

Radiometric immunosorbent assay for the detection of anti-hormone-binding protein antibodies

International Nuclear Information System (INIS)

Pierce, E.A.; Dame, M.C.; DeLuca, H.F.

1986-01-01

A radiometric immunosorbent assay (RISA) for the detection of monoclonal antibodies to hormone-binding proteins has been developed. The assay involves incubating hybridoma supernatants in microtiter wells that have been coated with goat anti-mouse IgG antibodies. Any mouse IgG in the test supernatant is thus specifically retained in the wells. Radioactive ligand-binding protein complexes are then incubated in the wells. The presence of anti-binding protein antibodies in the supernatant is indicated by specific retention of radioactive ligand-binding protein complexes in the wells. Crude antigen preparations, such as tissue homogenates, can be used to detect antibodies. The assay is capable of detecting antibody at concentrations 20 ng/ml (approx. 100 pM IgG). The RISA has been used successfully to screen for monoclonal antibodies to the intracellular receptor for 1,25-dihydroxyvitamin D 3 and should be useful for the detection of antibodies to ligand-binding proteins in general

Fusion peptides from oncogenic chimeric proteins as putative specific biomarkers of cancer.

Science.gov (United States)

Conlon, Kevin P; Basrur, Venkatesha; Rolland, Delphine; Wolfe, Thomas; Nesvizhskii, Alexey I; MacCoss, Michael J; Lim, Megan S; Elenitoba-Johnson, Kojo S J

2013-10-01

Chromosomal translocations encoding chimeric fusion proteins constitute one of the most common mechanisms underlying oncogenic transformation in human cancer. Fusion peptides resulting from such oncogenic chimeric fusions, though unique to specific cancer subtypes, are unexplored as cancer biomarkers. Here we show, using an approach termed fusion peptide multiple reaction monitoring mass spectrometry, the direct identification of different cancer-specific fusion peptides arising from protein chimeras that are generated from the juxtaposition of heterologous genes fused by recurrent chromosomal translocations. Using fusion peptide multiple reaction monitoring mass spectrometry in a clinically relevant scenario, we demonstrate the specific, sensitive, and unambiguous detection of a specific diagnostic fusion peptide in clinical samples of anaplastic large cell lymphoma, but not in a diverse array of benign lymph nodes or other forms of primary malignant lymphomas and cancer-derived cell lines. Our studies highlight the utility of fusion peptides as cancer biomarkers and carry broad implications for the use of protein biomarkers in cancer detection and monitoring.

GDNF gene is associated with tourette syndrome in a family study.

Science.gov (United States)

Huertas-Fernández, Ismael; Gómez-Garre, Pilar; Madruga-Garrido, Marcos; Bernal-Bernal, Inmaculada; Bonilla-Toribio, Marta; Martín-Rodríguez, Juan Francisco; Cáceres-Redondo, María Teresa; Vargas-González, Laura; Carrillo, Fátima; Pascual, Alberto; Tischfield, Jay A; King, Robert A; Heiman, Gary A; Mir, Pablo

2015-07-01

Tourette syndrome is a disorder characterized by persistent motor and vocal tics, and frequently accompanied by the comorbidities attention deficit hyperactivity disorder and obsessive-compulsive disorder. Impaired synaptic neurotransmission has been implicated in its pathogenesis. Our aim was to investigate the association of 28 candidate genes, including genes related to synaptic neurotransmission and neurotrophic factors, with Tourette syndrome. We genotyped 506 polymorphisms in a discovery cohort from the United States composed of 112 families and 47 unrelated singletons with Tourette syndrome (201 cases and 253 controls). Genes containing significant polymorphisms were imputed to fine-map the signal(s) to potential causal variants. Allelic analyses in Tourette syndrome cases were performed to check the role in attention deficit hyperactivity disorder and obsessive-compulsive disorder comorbidities. Target polymorphisms were further studied in a replication cohort from southern Spain composed of 37 families and three unrelated singletons (44 cases and 73 controls). The polymorphism rs3096140 in glial cell line-derived neurotrophic factor gene (GDNF) was significant in the discovery cohort after correction (P = 1.5 × 10(-4) ). No linkage disequilibrium was found between rs3096140 and other functional variants in the gene. We selected rs3096140 as target polymorphism, and the association was confirmed in the replication cohort (P = 0.01). No association with any comorbidity was found. As a conclusion, a common genetic variant in GDNF is associated with Tourette syndrome. A defect in the production of GDNF could compromise the survival of parvalbumin interneurons, thus altering the excitatory/inhibitory balance in the corticostriatal circuitry. Validation of this variant in other family cohorts is necessary. © 2015 International Parkinson and Movement Disorder Society.

GDNF Gene Is Associated With Tourette Syndrome in a Family Study

Science.gov (United States)

Huertas-Fernández, Ismael; Gómez-Garre, Pilar; Madruga-Garrido, Marcos; Bernal-Bernal, Inmaculada; Bonilla-Toribio, Marta; Martín-Rodríguez, Juan Francisco; Cáceres-Redondo, María Teresa; Vargas-González, Laura; Carrillo, Fátima; Pascual, Alberto; Tischfield, Jay A.; King, Robert A.; Heiman, Gary A.; Mir, Pablo

2016-01-01

Background Tourette syndrome is a disorder characterized by persistent motor and vocal tics, and frequently accompanied by the comorbidities attention deficit hyperactivity disorder and obsessive-compulsive disorder. Impaired synaptic neurotransmission has been implicated in its pathogenesis. Our aim was to investigate the association of 28 candidate genes, including genes related to synaptic neurotransmission and neurotrophic factors, with Tourette syndrome. Methods We genotyped 506 polymorphisms in a discovery cohort from the United States composed of 112 families and 47 unrelated singletons with Tourette syndrome (201 cases and 253 controls). Genes containing significant polymorphisms were imputed to fine-map the signal(s) to potential causal variants. Allelic analyses in Tourette syndrome cases were performed to check the role in attention deficit hyperactivity disorder and obsessive-compulsive disorder comorbidities. Target polymorphisms were further studied in a replication cohort from southern Spain composed of 37 families and three unrelated singletons (44 cases and 73 controls). Results The polymorphism rs3096140 in glial cell line–derived neurotrophic factor gene (GDNF) was significant in the discovery cohort after correction (P = 1.5 × 10−4). No linkage disequilibrium was found between rs3096140 and other functional variants in the gene. We selected rs3096140 as target polymorphism, and the association was confirmed in the replication cohort (P = 0.01). No association with any comorbidity was found. Conclusions As a conclusion, a common genetic variant in GDNF is associated with Tourette syndrome. A defect in the production of GDNF could compromise the survival of parvalbumin interneurons, thus altering the excitatory/inhibitory balance in the corticostriatal circuitry. Validation of this variant in other family cohorts is necessary. PMID:26096985

Anti-carbamylated Protein Antibody Levels Correlate with Anti-Sa (Citrullinated Vimentin) Antibody Levels in Rheumatoid Arthritis.

Science.gov (United States)

Challener, Gregory J; Jones, Jonathan D; Pelzek, Adam J; Hamilton, B JoNell; Boire, Gilles; de Brum-Fernandes, Artur José; Masetto, Ariel; Carrier, Nathalie; Ménard, Henri A; Silverman, Gregg J; Rigby, William F C

2016-02-01

The presence of anticitrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA) indicates a breach in immune tolerance. Recent studies indicate that this breach extends to homocitrullination of lysines with the formation of anti-carbamylated protein (anti-CarP) antibodies. We analyzed the clinical and serologic relationships of anti-CarP in 2 RA cohorts. Circulating levels of immunoglobulin G anti-CarP antibodies were determined by ELISA in established (Dartmouth-Hitchcock Medical Center) and early (Sherbrooke University Hospital Center) cohorts and evaluated for anticyclic citrullinated peptide antibodies (anti-CCP), specific ACPA, and rheumatoid factor (RF) levels using the Student t test and correlation analysis. We identified elevated anti-CarP antibodies titers in 47.0% of seropositive patients (Dartmouth, n = 164), with relationships to anti-CCP (p < 0.0001) and IgM-RF (p = 0.001). Similarly, 38.2% of seropositive patients from the Sherbrooke cohort (n = 171) had elevated anti-CarP antibodies; titers correlated to anti-CCP (p = 0.01) but not IgM-RF (p = 0.09). A strong correlation with anti-Sa was observed: 47.9% anti-Sa+ patients were anti-CarP antibodies+ versus only 25.4% anti-Sa- in the Sherbrooke cohort (p = 0.0002), and 62.6% anti-Sa+ patients versus 26.9% anti-Sa- were anti-CarP antibodies+ in Dartmouth (p < 0.0001). We found a more variable response for reactivity to citrullinated fibrinogen or to citrullinated peptides from fibrinogen and α enolase. In 2 North American RA cohorts, we observed a high prevalence of anti-CarP antibody positivity. We also describe a surprising and unexpected association of anti-CarP with anti-Sa antibodies that could not be explained by cross-reactivity. Further, considerable heterogeneity exists between anti-CarP reactivity and other citrullinated peptide reactivity, raising the question of how the pathogenesis of antibody responses for carbamylated proteins and citrullinated proteins may be linked in vivo.

Menin-MLL inhibitors reverse oncogenic activity of MLL fusion proteins in leukemia.

Science.gov (United States)

Grembecka, Jolanta; He, Shihan; Shi, Aibin; Purohit, Trupta; Muntean, Andrew G; Sorenson, Roderick J; Showalter, Hollis D; Murai, Marcelo J; Belcher, Amalia M; Hartley, Thomas; Hess, Jay L; Cierpicki, Tomasz

2012-01-29

Translocations involving the mixed lineage leukemia (MLL) gene result in human acute leukemias with very poor prognosis. The leukemogenic activity of MLL fusion proteins is critically dependent on their direct interaction with menin, a product of the multiple endocrine neoplasia (MEN1) gene. Here we present what are to our knowledge the first small-molecule inhibitors of the menin-MLL fusion protein interaction that specifically bind menin with nanomolar affinities. These compounds effectively reverse MLL fusion protein-mediated leukemic transformation by downregulating the expression of target genes required for MLL fusion protein oncogenic activity. They also selectively block proliferation and induce both apoptosis and differentiation of leukemia cells harboring MLL translocations. Identification of these compounds provides a new tool for better understanding MLL-mediated leukemogenesis and represents a new approach for studying the role of menin as an oncogenic cofactor of MLL fusion proteins. Our findings also highlight a new therapeutic strategy for aggressive leukemias with MLL rearrangements.

Comparison of Palivizumab-Like Antibody Binding to Different Conformations of the RSV F Protein in RSV-Infected Adult Hematopoietic Cell Transplant Recipients.

Science.gov (United States)

Ye, Xunyan; Iwuchukwu, Obinna P; Avadhanula, Vasanthi; Aideyan, Letisha O; McBride, Trevor J; Ferlic-Stark, Laura L; Patel, Kirtida D; Piedra, Felipe-Andres; Shah, Dimpy P; Chemaly, Roy F; Piedra, Pedro A

2018-03-28

Most respiratory syncytial virus (RSV) vaccine candidates include fusion (F) protein in different conformations. Antigenic site II found in the different F conformations is the target of palivizumab, the only US Food and Drug Administration approved monoclonal antibody (mAb). Serum palivizumab-like antibody (PLA) is a potential serologic correlate of immunity. Our objective was to determine if different conformations of F protein in a palivizumab competitive antibody (PCA) assay affect the PLA concentrations. Four PCA assays were standardized using mAbs. Each contained prefusion, postfusion, or intermediate F forms. PLA concentrations were measured in acute and convalescent sera from 22 RSV/A and 18 RSV/B-infected adult hematopoietic cell transplant (HCT) recipients. PLA concentrations were calculated using a 4-parameter logistic regression model and analyzed for statistical significance. PCA assays revealed significantly greater PLA concentrations in convalescent sera; comparable increases in PLA concentration in RSV/A and RSV/B-infected HCT recipients; and significantly reduced PLA concentrations in HCT recipients who shed RSV ≥14 days. A significant positive correlation was observed between PCA assays and RSV neutralizing antibody titers. F protein conformation does not appear to have a measurable impact on PCA assays for measuring PLA induced by RSV/A or RSV/B infection.

Respiratory syncytial virus subunit vaccine based on a recombinant fusion protein expressed transiently in mammalian cells.

Science.gov (United States)

Nallet, Sophie; Amacker, Mario; Westerfeld, Nicole; Baldi, Lucia; König, Iwo; Hacker, David L; Zaborosch, Christiane; Zurbriggen, Rinaldo; Wurm, Florian M

2009-10-30

Although respiratory syncytial virus (RSV) causes severe lower respiratory tract infection in infants and adults at risk, no RSV vaccine is currently available. In this report, efforts toward the generation of an RSV subunit vaccine using recombinant RSV fusion protein (rRSV-F) are described. The recombinant protein was produced by transient gene expression (TGE) in suspension-adapted human embryonic kidney cells (HEK-293E) in 4 L orbitally shaken bioreactors. It was then purified and formulated in immunostimulating reconstituted influenza virosomes (IRIVs). The candidate vaccine induced anti-RSV-F neutralizing antibodies in mice, and challenge studies in cotton rats are ongoing. If successful in preclinical and clinical trials, this will be the first recombinant subunit vaccine produced by large-scale TGE in mammalian cells.

Enzyme-linked immunosorbent assays for insulin-like growth factor-I using six-histidine tag fused proteins

International Nuclear Information System (INIS)

Huang Yong; Shi Ruina; Zhong Xuefei; Wang Dan; Zhao Meiping; Li Yuanzong

2007-01-01

The fusion proteins of insulin-like growth factor-I (IGF-I) and six-histidine tag (IGF-I-6H, 6H-IGF-I-6H) were cloned, expressed, purified and renatured, with their immunoreaction properties and biological activities intact. The binding kinetics between these fusion proteins and anti-IGF-I antibody or anti-6H antibody were studied using surface plasmon resonance (SPR). Two enzyme-linked immunosorbent assay (ELISA) modes, which proved feasible in the measurement of human serum samples, were used to detect IGF-I with the help of the six-histidine tagged proteins. Furthermore, combining the production technique of the six-histidine tagged fusion protein with the competitive sandwich ELISA mode, using an enzyme labeled anti-6H antibody as a tracer, can be a universal immunochemical method to quantitate other polypeptides or proteins

S100B protein, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor in human milk.

Directory of Open Access Journals (Sweden)

Ruisong Li

Full Text Available Human milk contains a wide variety of nutrients that contribute to the fulfillment of its functions, which include the regulation of newborn development. However, few studies have investigated the concentrations of S100B protein, brain-derived neurotrophic factor (BDNF, and glial cell line-derived neurotrophic factor (GDNF in human milk. The associations of the concentrations of S100B protein, BDNF, and GDNF with maternal factors are not well explored.To investigate the concentrations of S100B protein, BDNF, and GDNF in human milk and characterize the maternal factors associated with their levels in human milk, human milk samples were collected at days 3, 10, 30, and 90 after parturition. Levels of S100B protein, BDNF, and GDNF, and their mRNAs in the samples were detected. Then, these concentrations were compared with lactation and other maternal factors. S100B protein levels in human milk samples collected at 3, 10, 30, and 90 d after parturition were 1249.79±398.10, 1345.05±539.16, 1481.83±573.30, and 1414.39±621.31 ng/L, respectively. On the other hand, the BDNF concentrations in human milk samples were 10.99±4.55, 13.01±5.88, 13.35±6.43, and 2.83±5.47 µg/L, while those of GDNF were 10.90±1.65, 11.38±1., 11.29±3.10, and 11.40±2.21 g/L for the same time periods. Maternal post-pregnancy body mass index was positively associated with S100B levels in human milk (r = 0.335, P = 0.030<0.05. In addition, there was a significant correlation between the levels of S100B protein and BDNF (z = 2.09, P = 0.037<0.05. Delivery modes were negatively associated with the concentration of GDNF in human milk.S100B protein, BDNF, and GDNF are present in all samples of human milk, and they may be responsible for the long term effects of breast feeding.

CT-SPECT fusion to correlate radiolabeled monoclonal antibody uptake with abdominal CT findings

International Nuclear Information System (INIS)

Kramer, E.L.; Noz, M.E.; Sanger, J.J.; Megibow, A.J.; Maguire, G.Q.

1989-01-01

To enhance the information provided by computed tomography (CT) and single photon emission computed tomography (SPECT) performed with radiolabeled, anti-carcinoembryonic antigen monoclonal antibody (MoAb), the authors performed fusion of these types of images from eight subjects with suspected colorectal adenocarcinoma. Section thickness and pixel size of the two studies were matched, coordinates of corresponding points from each study were identified, and CT sections were translated, rotated, and reprojected to match the corresponding SPECT scans. The CT-SPECT fusion enabled identification of anatomic sites of tumor-specific MoAb accumulation in four cases, showed non-specific MoAb accumulation in two, and helped confirm information only suggested by the two studies separately in one

Recombinant Envelope-Proteins with Mutations in the Conserved Fusion Loop Allow Specific Serological Diagnosis of Dengue-Infections.

Directory of Open Access Journals (Sweden)

Alexandra Rockstroh

2015-11-01

Full Text Available Dengue virus (DENV is a mosquito-borne flavivirus and a major international public health concern in many tropical and sub-tropical areas worldwide. DENV is divided into four major serotypes, and infection with one serotype leads to immunity against the same, but not the other serotypes. The specific diagnosis of DENV-infections via antibody-detection is problematic due to the high degree of cross-reactivity displayed by antibodies against related flaviviruses, such as West Nile virus (WNV, Yellow Fever virus (YFV or Tick-borne encephalitis virus (TBEV. Especially in areas where several flaviviruses co-circulate or in the context of vaccination e.g. against YFV or TBEV, this severely complicates diagnosis and surveillance. Most flavivirus cross-reactive antibodies are produced against the highly conserved fusion loop (FL domain in the viral envelope (E protein. We generated insect-cell derived recombinant E-proteins of the four DENV-serotypes which contain point mutations in the FL domain. By using specific mixtures of these mutant antigens, cross-reactivity against heterologous flaviviruses was strongly reduced, enabling sensitive and specific diagnosis of the DENV-infected serum samples in IgG and IgM-measurements. These results have indications for the development of serological DENV-tests with improved specificity.

Development of highly sensitive detection method for toxins and other pathogenic factors by phage-displayed monoclonal antibody using radioisotopes

International Nuclear Information System (INIS)

Izumiya, Hidemasa; Watanabe, Haruo

2000-01-01

To prepare anti-Shiga toxin (Stx) antibody, a recombinant strain of E coli that can produce the subunit B of Stx was constructed. DNA fragment coding the Stx subunit B, about 0.2 kb in length was amplified using a plasmid containing Stx gene as the template by PCR. After digesting with a restriction enzyme, the DNA fragment was inserted into pmal-c2 vector (New England Biolabs) to produce a fusion protein with maltose binding protein (MBP). E.coli K12 (DH5α) including the pmal-stx plasmid was cultured in the presence of isopropylthiogalactoside (IPTG) and thus, MBP-stx fusion protein was obtained. After purification by Millipore membrane filter, this fusion protein was used as the antigen. Then, mice BALB/c were immunized by intraperitoneal injection of the suspension of MBP-stx and adjuvant. The antibody purified from the spleen was submitted to phage display system. The phage specifically binding to the antigen was proliferated through repeated infection to E coli and the anti-Stx antibody was obtained from the culture of its colony grown on IPTG plate. Three different colonies specifically responding to the recombinant Stx antigen were obtained. In near future, labeled antibody would be produced by addition of 35 S compound in to the culture medium. (M.N.)

The coronavirus spike protein : mechanisms of membrane fusion and virion incorporation

NARCIS (Netherlands)

Bosch, B.J.

2004-01-01

The coronavirus spike protein is a membrane-anchored glycoprotein responsible for virus-cell attachment and membrane fusion, prerequisites for a successful virus infection. In this thesis, two aspects are described regarding the molecular biology of the coronavirus spike protein: its membrane fusion

Antibody response to the lipopolysaccharide and protein antigens of Salmonella typhi during typhoid infection. I. Measurement of serum antibodies by radioimmunoassay

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Tsang, R S.W.; Chau, P Y; Lam, S K [Hong Kong Univ.; La Brooy, J T; Rowley, D [Adelaide Univ. (Australia)

1981-12-01

Serum antibody responses to the lipopolysaccharide and protein antigens of S. typhi in typhoid patients were studied using a solid-phase radioimmunoassay technique with /sup 125/I labelled anti-immunoglobulin antibody. Sera from 24 adult typhoid patients and 20 non-typhoid adult controls were compared. As a group, sera from typhoid patients showed increased IgA, IgG and IgM immunoglobulin levels and gave significantly higher anti-LPS and anti-protein antibody titres in all three major immunoglobulin classes than did non-typhoid controls. Levels of antibodies against LPS or protein in sera of typhoid patients were highly variable with a skew distribution. A good correlation was found between antibody titres to the LPS antigen and those to a protein antigen. No correlation, however, was found between the anti-LPS antibody titres measured by radioimmunoassay and the anti-O antibody titres measured by the Widal agglutination test. Titration of anti-LPS or anti-protein antibodies by radioimmunoassay was found to be more sensitive and specific than Widal test for the serological diagnosis of typhoid fever. The advantages of measuring antibody response by radioimmunoassay over conventional Widal test are discussed.

Distinct roles for key karyogamy proteins during yeast nuclear fusion.

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Melloy, Patricia; Shen, Shu; White, Erin; Rose, Mark D

2009-09-01

During yeast mating, cell fusion is followed by the congression and fusion of the two nuclei. Proteins required for nuclear fusion are found at the surface (Prm3p) and within the lumen (Kar2p, Kar5p, and Kar8p) of the nuclear envelope (NE). Electron tomography (ET) of zygotes revealed that mutations in these proteins block nuclear fusion with different morphologies, suggesting that they act in different steps of fusion. Specifically, prm3 zygotes were blocked before formation of membrane bridges, whereas kar2, kar5, and kar8 zygotes frequently contained them. Membrane bridges were significantly larger and occurred more frequently in kar2 and kar8, than in kar5 mutant zygotes. The kinetics of NE fusion in prm3, kar5, and kar8 mutants, measured by live-cell fluorescence microscopy, were well correlated with the size and frequency of bridges observed by ET. However the kar2 mutant was defective for transfer of NE lumenal GFP, but not diffusion within the lumen, suggesting that transfer was blocked at the NE fusion junction. These observations suggest that Prm3p acts before initiation of outer NE fusion, Kar5p may help dilation of the initial fusion pore, and Kar2p and Kar8p act after outer NE fusion, during inner NE fusion.

Indirect enzyme-linked immunosorbent assay method based on Streptococcus agalactiae rSip-Pgk-FbsA fusion protein for detection of bovine mastitis.

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Bu, Ri-E; Wang, Jin-Liang; Wu, Jin-Hua; Xilin, Gao-Wa; Chen, Jin-Long; Wang, Hua

2017-03-01

The aim of this study was to establish a rapid and accurate method for the detection of the Streptococcus agalactiae antibody (SA-Ab) to determine the presence of the bovine mastitis (BM)-causative pathogen. The multi-subunit fusion protein rSip-Pgk-FbsA was prokaryotically expressed and purified. The triple activities of the membrane surface-associated proteins Sip, phosphoglycerate kinase (Pgk), and fibronectin (FbsA) were used as the diagnostic antigens to establish an indirect enzyme-linked immunosorbent assay (ELISA) method for the detection of SA-Ab in BM. The optimal antigen coating concentration was 2 μg/mL, the optimal serum dilution was 1:160, and the optimal dilution of the enzyme-labeled secondary antibody was 1:6000. The sensitivity, specificity, and repeatability tests showed that the method established in this study had no cross-reaction with antibodies to Streptococcus pyogenes, Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis in the sera. The results of the sensitivity test showed that a positive result could be obtained even if the serum dilution reached 1:12,800, indicating the high sensitivity and good repeatability of the method. The positive coincidence rate of this method was 98.6%, which is higher than that of previous tests established with the Sip or Pgk mono-antigen fusion protein, respectively, demonstrating the relatively higher sensitivity of this newly established method. The detection rate for 389 clinical samples was 46.53%. The indirect ELISA method established in this study could provide a more accurate and reliable serological method for the rapid detection of S. agalactiae in cases of BM.

Dengue E Protein Domain III-Based DNA Immunisation Induces Strong Antibody Responses to All Four Viral Serotypes.

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Monica Poggianella

Full Text Available Dengue virus (DENV infection is a major emerging disease widely distributed throughout the tropical and subtropical regions of the world affecting several millions of people. Despite constants efforts, no specific treatment or effective vaccine is yet available. Here we show a novel design of a DNA immunisation strategy that resulted in the induction of strong antibody responses with high neutralisation titres in mice against all four viral serotypes. The immunogenic molecule is an engineered version of the domain III (DIII of the virus E protein fused to the dimerising CH3 domain of the IgG immunoglobulin H chain. The DIII sequences were also codon-optimised for expression in mammalian cells. While DIII alone is very poorly secreted, the codon-optimised fusion protein is rightly expressed, folded and secreted at high levels, thus inducing strong antibody responses. Mice were immunised using gene-gun technology, an efficient way of intradermal delivery of the plasmid DNA, and the vaccine was able to induce neutralising titres against all serotypes. Additionally, all sera showed reactivity to a recombinant DIII version and the recombinant E protein produced and secreted from mammalian cells in a mono-biotinylated form when tested in a conformational ELISA. Sera were also highly reactive to infective viral particles in a virus-capture ELISA and specific for each serotype as revealed by the low cross-reactive and cross-neutralising activities. The serotype specific sera did not induce antibody dependent enhancement of infection (ADE in non-homologous virus serotypes. A tetravalent immunisation protocol in mice showed induction of neutralising antibodies against all four dengue serotypes as well.

Monoclonal antibodies to drosophila cytochrome P-450's

International Nuclear Information System (INIS)

Sundseth, S.S.; Kennel, S.J.; Waters, L.C.

1987-01-01

Hybridomas producing monoclonal antibodies were prepared by the fusion of SP2/0 myeloma cells and spleen cells from a female BALB/c mouse immunized by cytochrome P-450-A and P-450-B purified from Drosophila Hikone-R (BG) microsomes. P-450-A and P-450-B are electrophoretically distinct subsets of Drosophila P-450. P-450-A is ubiquitous among strains tested, while P-450-B is present in only a few strains displaying unique enzyme activities and increased insecticide resistance. The Oregon-R strain contains only cytochromes P-450-A and is susceptible to insecticides. The authors Hikone-R (BG) strain expresses both cytochromes P-450-A and P-450-B and is insecticide resistant. Antibody producing hybridomas were detected in a solid-phase radioimmunoassay (RIA) by binding to Hikone-R (BG) or Oregon-R microsomes. Four independent hybridomas were identified as producing monoclonal antibodies that recognized proteins in the P-450 complex by immunoblot experiments. Three monoclonal antibodies recognized P-450-A proteins, while one monoclonal antibody bound predominantly P-450-B. This monoclonal antibody also recognized southern armyworm (Spodoptera eridania, Cramer) microsomal proteins

Myristylation of gag-onc fusion proteins in mammalian transforming retroviruses

International Nuclear Information System (INIS)

Schultz, A.; Oroszlan, S.

1984-01-01

Four cell lines producing transforming proteins encoded by three mammalian oncogenes (fes, abl, and ras) were investigated for incorporation of [ 3 H]myristate into gag-onc fusion proteins. Using 5-min pulse-labelings, fusion proteins of Abelson murine leukemia virus, Gardner-Arnstein strain of feline sarcoma virus (FeSV), and Snyder-Theilen strain of FeSV were shown to be myristylated. In a 4-hr pulse, p29gag-ras of rat sarcoma virus (RaSV) was also shown to incorporate radiolabel. The fatty acid was recovered from this labeled protein by acid hydrolysis, and identified by reverse-phase thin-layer chromatography to be [ 3 H]myristic acid. The results indicate that substitution of viral gag sequences by cellular oncogene sequences does not abolish their ability to become post-translationally modified by this long chain fatty acid. It is assumed that in the fusion proteins the myristyl moiety is linked through an amide linkage to the amino-terminal glycine as previously found for several retroviral gag precursor polyproteins. The possible role of myristylation of transforming proteins is discussed

Myristylation of gag-onc fusion proteins in mammalian transforming retroviruses

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Schultz, A.; Oroszlan, S.

1984-03-01

Four cell lines producing transforming proteins encoded by three mammalian oncogenes (fes, abl, and ras) were investigated for incorporation of (/sup 3/H)myristate into gag-onc fusion proteins. Using 5-min pulse-labelings, fusion proteins of Abelson murine leukemia virus, Gardner-Arnstein strain of feline sarcoma virus (FeSV), and Snyder-Theilen strain of FeSV were shown to be myristylated. In a 4-hr pulse, p29gag-ras of rat sarcoma virus (RaSV) was also shown to incorporate radiolabel. The fatty acid was recovered from this labeled protein by acid hydrolysis, and identified by reverse-phase thin-layer chromatography to be (/sup 3/H)myristic acid. The results indicate that substitution of viral gag sequences by cellular oncogene sequences does not abolish their ability to become post-translationally modified by this long chain fatty acid. It is assumed that in the fusion proteins the myristyl moiety is linked through an amide linkage to the amino-terminal glycine as previously found for several retroviral gag precursor polyproteins. The possible role of myristylation of transforming proteins is discussed.

Isolation of recombinant antibodies directed against surface proteins of Clostridium difficile.

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Shirvan, Ali Nazari; Aitken, Robert

2016-01-01

Clostridium difficile has emerged as an increasingly important nosocomial pathogen and the prime causative agent of antibiotic-associated diarrhoea and pseudomembranous colitis in humans. In addition to toxins A and B, immunological studies using antisera from patients infected with C. difficile have shown that a number of other bacterial factors contribute to the pathogenesis, including surface proteins, which are responsible for adhesion, motility and other interactions with the human host. In this study, various clostridial targets, including FliC, FliD and cell wall protein 66, were expressed and purified. Phage antibody display yielded a large panel of specific recombinant antibodies, which were expressed, purified and characterised. Reactions of the recombinant antibodies with their targets were detected by enzyme-linked immunosorbent assay; and Western blotting suggested that linear rather than conformational epitopes were recognised. Binding of the recombinant antibodies to surface-layer proteins and their components showed strain specificity, with good recognition of proteins from C. difficile 630. However, no reaction was observed for strain R20291-a representative of the 027 ribotype. Binding of the recombinant antibodies to C. difficile M120 extracts indicated that a component of a surface-layer protein of this strain might possess immunoglobulin-binding activities. The recombinant antibodies against FliC and FliD proteins were able to inhibit bacterial motility. Copyright © 2016. Published by Elsevier Editora Ltda.

Effects of GDNF pretreatment on function and survival of transplanted fetal ventral mesencephalic cells in the 6-OHDA rat model of Parkinson's disease

DEFF Research Database (Denmark)

Andereggen, Lukas; Meyer, Morten; Guzman, Raphael

2009-01-01

assessed at 9 weeks posttransplantation. However, a tendency for higher TH-ir fiber outgrowth from the transplants in the GDNF pretreated groups as compared to corresponding controls was observed. Furthermore, GDNF pretreatment showed a tendency for a higher number of GIRK2 positive neurons in the grafts...

S-layer fusion protein as a tool functionalizing emulsomes and CurcuEmulsomes for antibody binding and targeting.

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Ucisik, Mehmet H; Küpcü, Seta; Breitwieser, Andreas; Gelbmann, Nicola; Schuster, Bernhard; Sleytr, Uwe B

2015-04-01

Selective targeting of tumor cells by nanoparticle-based drug delivery systems is highly desirable because it maximizes the drug concentration at the desired target while simultaneously protecting the surrounding healthy tissues. Here, we show a design for smart nanocarriers based on a biomimetic approach that utilizes the building principle of virus envelope structures. Emulsomes and CurcuEmulsomes comprising a tripalmitin solid core surrounded by phospholipid layers are modified by S-layer proteins that self-assemble into a two-dimensional array to form a surface layer. One significant advantage of this nanoformulation is that it increases the solubility of the lipophilic anti-cancer agent curcumin in the CurcuEmulsomes by a factor of 2700. In order to make the emulsomes specific for IgG, the S-layer protein is fused with two protein G domains. This S-layer fusion protein preserves its recrystallization characteristics, forming an ordered surface layer (square lattice with 13 nm unit-by-unit distance). The GG domains are presented in a predicted orientation and exhibit a selective binding affinity for IgG. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Anti-liver-kidney microsome antibody type 1 recognizes human cytochrome P450 db1.

Science.gov (United States)

Gueguen, M; Yamamoto, A M; Bernard, O; Alvarez, F

1989-03-15

Anti-liver-kidney microsome antibody type 1 (LKM1), present in the sera of a group of children with autoimmune hepatitis, was recently shown to recognize a 50 kDa protein identified as rat liver cytochromes P450 db1 and db2. High homology between these two members of the rat P450 IID subfamily and human P450 db1 suggested that anti-LKM1 antibody is directed against this human protein. To test this hypothesis, a human liver cDNA expression library in phage lambda GT-11 was screened using rat P450 db1 cDNA as a probe. Two human cDNA clones were found to be identical to human P450 db1 by restriction mapping. Immunoblot analysis using as antigen, the purified fusion protein from one of the human cDNA clones showed that only anti-LKM1 with anti-50 kDa reactivity recognized the fusion protein. This fusion protein was further used to develop an ELISA test that was shown to be specific for sera of children with this disease. These results: 1) identify the human liver antigen recognized by anti-LKM1 auto-antibodies as cytochrome P450 db1, 2) allow to speculate that mutation on the human P450 db1 gene could alter its expression in the hepatocyte and make it auto-antigenic, 3) provide a simple and specific diagnostic test for this disease.

Investigating interactions between phospholipase B-Like 2 and antibodies during Protein A chromatography.

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Tran, Benjamin; Grosskopf, Vanessa; Wang, Xiangdan; Yang, Jihong; Walker, Don; Yu, Christopher; McDonald, Paul

2016-03-18

Purification processes for therapeutic antibodies typically exploit multiple and orthogonal chromatography steps in order to remove impurities, such as host-cell proteins. While the majority of host-cell proteins are cleared through purification processes, individual host-cell proteins such as Phospholipase B-like 2 (PLBL2) are more challenging to remove and can persist into the final purification pool even after multiple chromatography steps. With packed-bed chromatography runs using host-cell protein ELISAs and mass spectrometry analysis, we demonstrated that different therapeutic antibodies interact to varying degrees with host-cell proteins in general, and PLBL2 specifically. We then used a high-throughput Protein A chromatography method to further examine the interaction between our antibodies and PLBL2. Our results showed that the co-elution of PLBL2 during Protein A chromatography is highly dependent on the individual antibody and PLBL2 concentration in the chromatographic load. Process parameters such as antibody resin load density and pre-elution wash conditions also influence the levels of PLBL2 in the Protein A eluate. Furthermore, using surface plasmon resonance, we demonstrated that there is a preference for PLBL2 to interact with IgG4 subclass antibodies compared to IgG1 antibodies. Copyright © 2016 Elsevier B.V. All rights reserved.

Escherichia coli fusion carrier proteins act as solubilizing agents for recombinant uncoupling protein 1 through interactions with GroEL

International Nuclear Information System (INIS)

Douette, Pierre; Navet, Rachel; Gerkens, Pascal; Galleni, Moreno; Levy, Daniel; Sluse, Francis E.

2005-01-01

Fusing recombinant proteins to highly soluble partners is frequently used to prevent aggregation of recombinant proteins in Escherichia coli. Moreover, co-overexpression of prokaryotic chaperones can increase the amount of properly folded recombinant proteins. To understand the solubility enhancement of fusion proteins, we designed two recombinant proteins composed of uncoupling protein 1 (UCP1), a mitochondrial membrane protein, in fusion with MBP or NusA. We were able to express soluble forms of MBP-UCP1 and NusA-UCP1 despite the high hydrophobicity of UCP1. Furthermore, the yield of soluble fusion proteins depended on co-overexpression of GroEL that catalyzes folding of polypeptides. MBP-UCP1 was expressed in the form of a non-covalent complex with GroEL. MBP-UCP1/GroEL was purified and characterized by dynamic light scattering, gel filtration, and electron microscopy. Our findings suggest that MBP and NusA act as solubilizing agents by forcing the recombinant protein to pass through the bacterial chaperone pathway in the context of fusion protein

Inhibitory effect of PTD-OD-HA fusion protein on Bcr-Abl in K562 cells

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Miao GAO

2012-10-01

Full Text Available Objective　To study the transduction dynamics, location of PTD-OD-HA fusion protein and its interaction with Bcr-Abl oncoprotein in K562 cell lines, and explore the influence of PTD-OD-HA fusion protein on oligomerization and tyrosine kinase activity of Bcr-Abl. Methods　PTD-OD-HA fusion protein was labeled with FITC and co-cultured with K562 cells. The transduction efficiency of labeled PTD-OD-HA at different doses and time intervals was observed under fluorescence microscope. The location of labeled PTD-OD-HA fusion protein in K562 cells was detected by confocal microscopy. The interaction of PTD-OD-HA fusion protein with Bcr-Abl oncoprotein was confirmed by coimmunoprecipitation. The phosphorylation of Bcr-Abl oncoprotein was detected by Western blotting. Results　PTD-OD-HA fusion protein labeled with FITC was transduced into K562 cells in a dose- and time-dependent manner. PTD-OD-HA fusion protein was located in the cytoplasm of K562 cells and was consistent with the location of Bcr-Abl oncoprotein. The interaction of PTD-OD-HA fusion protein with Bcr-Abl oncoprotein was proved in K562 cells. This interaction could interrupt the homologous oligomerization of Bcr-Abl oncoprotein and reduce the phosphorylation of Bcr-Abl oncoprotein. Conclusion　PTD-OD-HA fusion protein could be transduced into K562 cells efficiently, inhibit the oligomerization and reduce the phosphorylation of Bcr-Abl oncoprotein.

Development of a single-chain variable fragment-alkaline phosphatase fusion protein and a sensitive direct competitive chemiluminescent enzyme immunoassay for detection of ractopamine in pork

Energy Technology Data Exchange (ETDEWEB)

Dong Jiexian; Li Zhenfeng; Lei Hongtao; Sun Yuanming [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China); Ducancel, Frederic [CEA, iBiTec-S, Service de Pharmacologie et d' Immnoanalyse (SPI), CEA Saclay, F-91191 Gif sur Yvette (France); Xu Zhenlin [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China); Boulain, Jean-Claude [CEA, iBiTec-S, Service de Pharmacologie et d' Immnoanalyse (SPI), CEA Saclay, F-91191 Gif sur Yvette (France); Yang Jinyi; Shen Yudong [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China); Wang Hong, E-mail: gzwhongd@63.com [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China)

2012-07-29

Graphical abstract: Detection model of dc-CLEIA based on anti-RAC scFv-AP fusion protein. Highlights: Black-Right-Pointing-Pointer The scFv-AP fusion protein against ractopamine (RAC) was produced. Black-Right-Pointing-Pointer A dc-CLEIA for RAC was developed based on the purified scFv-AP fusion protein. Black-Right-Pointing-Pointer The sensitivity of dc-CLEIA was 10 times as sensitive as dc-ELISA for RAC. Black-Right-Pointing-Pointer Recovery tests from pork samples were studied. Black-Right-Pointing-Pointer Good accuracy was obtained. - Abstract: A rapid, sensitive chemiluminescent enzyme immunoassay (CLEIA) for ractopamine (RAC) based on a single-chain variable fragment (scFv)-alkaline phosphatase (AP) fusion protein was developed. The scFv gene was prepared by cloning the heavy- and light-chain variable region genes (V{sub H} and V{sub L}) from hybridoma cell line AC2, which secretes antibodies against RAC, and assembling V{sub H} and V{sub L} genes with a linker by means of splicing overlap extension polymerase chain reaction. The resulting scFv gene was inserted into the expression vector pLIP6/GN containing AP to produce the fusion protein in Escherichia coli strain BL21. The purified scFv-AP fusion protein was used to develop a direct competitive CLEIA (dcCLEIA) protocol for detection of RAC. The average concentration required for 50% inhibition of binding and the limit of detection of the assay were 0.25 {+-} 0.03 and 0.02 {+-} 0.004 ng mL{sup -1}, respectively, and the linear response range extended from 0.05 to 1.45 ng mL{sup -1}. The assay was 10 times as sensitive as the corresponding enzyme-linked immunosorbent assay based on the same fusion protein. Cross-reactivity studies showed that the fusion protein did not cross react with RAC analogs. DcCLEIA was used to analyze RAC spiked pork samples, and the validation was confirmed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS). The results showed a good correlation between

Production of recombinant proteins in Escherichia coli tagged with the fusion protein CusF3H.

Science.gov (United States)

Vargas-Cortez, Teresa; Morones-Ramirez, Jose Ruben; Balderas-Renteria, Isaias; Zarate, Xristo

2017-04-01

Recombinant protein expression in the bacterium Escherichia coli still is the number one choice for large-scale protein production. Nevertheless, many complications can arise using this microorganism, such as low yields, the formation of inclusion bodies, and the requirement for difficult purification steps. Most of these problems can be solved with the use of fusion proteins. Here, the use of the metal-binding protein CusF3H+ is described as a new fusion protein for recombinant protein expression and purification in E. coli. We have previously shown that CusF produces large amounts of soluble protein, with low levels of formation of inclusion bodies, and that proteins can be purified using IMAC resins charged with Cu(II) ions. CusF3H+ is an enhanced variant of CusF, formed by the addition of three histidine residues at the N-terminus. These residues then can bind Ni(II) ions allowing improved purity after affinity chromatography. Expression and purification of Green Fluorescent Protein tagged with CusF3H+ showed that the mutation did not alter the capacity of the fusion protein to increase protein expression, and purity improved considerably after affinity chromatography with immobilized nickel ions; high yields are obtained after tag-removal since CusF3H+ is a small protein of just 10 kDa. Furthermore, the results of experiments involving expression of tagged proteins having medium to large molecular weights indicate that the presence of the CusF3H+ tag improves protein solubility, as compared to a His-tag. We therefore endorse CusF3H+ as a useful alternative fusion protein/affinity tag for production of recombinant proteins in E. coli. Copyright © 2017 Elsevier Inc. All rights reserved.

Generation and Characterization of Novel Human IRAS Monoclonal Antibodies

Directory of Open Access Journals (Sweden)

Bo Wang

2009-01-01

Full Text Available Imidazoline receptors were first proposed by Bousquet et al., when they studied antihypertensive effect of clonidine. A strong candidate for I1R, known as imidazoline receptor antisera-selected protein (IRAS, has been cloned from human hippocampus. We reported that IRAS mediated agmatine-induced inhibition of opioid dependence in morphine-dependent cells. To elucidate the functional and structure properties of I1R, we developed the newly monoclonal antibody against the N-terminal hIRAS region including the PX domain (10–120aa through immunization of BALB/c mice with the NusA-IRAS fusion protein containing an IRAS N-terminal (10–120aa. Stable hybridoma cell lines were established and monoclonal antibodies specifically recognized full-length IRAS proteins in their native state by immunoblotting and immunoprecipitation. Monoclonal antibodies stained in a predominantly punctate cytoplasmic pattern when applied to IRAS-transfected HEK293 cells by indirect immunofluorescence assays and demonstrated excellent reactivity in flow immunocytometry. These monoclonal antibodies will provide powerful reagents for the further investigation of hIRAS protein functions.

Intracellular antibody capture: A molecular biology approach to inhibitors of protein-protein interactions.

Science.gov (United States)

Zhang, Jing; Rabbitts, Terence H

2014-11-01

Many proteins of interest in basic biology, translational research studies and for clinical targeting in diseases reside inside the cell and function by interacting with other macromolecules. Protein complexes control basic processes such as development and cell division but also abnormal cell growth when mutations occur such as found in cancer. Interfering with protein-protein interactions is an important aspiration in both basic and disease biology but small molecule inhibitors have been difficult and expensive to isolate. Recently, we have adapted molecular biology techniques to develop a simple set of protocols for isolation of high affinity antibody fragments (in the form of single VH domains) that function within the reducing environment of higher organism cells and can bind to their target molecules. The method called Intracellular Antibody Capture (IAC) has been used to develop inhibitory anti-RAS and anti-LMO2 single domains that have been used for target validation of these antigens in pre-clinical cancer models and illustrate the efficacy of the IAC approach to generation of drug surrogates. Future use of inhibitory VH antibody fragments as drugs in their own right (we term these macrodrugs to distinguish them from small molecule drugs) requires their delivery to target cells in vivo but they can also be templates for small molecule drug development that emulate the binding sites of the antibody fragments. This article is part of a Special Issue entitled: Recent advances in molecular engineering of antibody. Copyright © 2014 Elsevier B.V. All rights reserved.

Rapamycin-induced oligomer formation system of FRB-FKBP fusion proteins.

Science.gov (United States)

Inobe, Tomonao; Nukina, Nobuyuki

2016-07-01

Most proteins form larger protein complexes and perform multiple functions in the cell. Thus, artificial regulation of protein complex formation controls the cellular functions that involve protein complexes. Although several artificial dimerization systems have already been used for numerous applications in biomedical research, cellular protein complexes form not only simple dimers but also larger oligomers. In this study, we showed that fusion proteins comprising the induced heterodimer formation proteins FRB and FKBP formed various oligomers upon addition of rapamycin. By adjusting the configuration of fusion proteins, we succeeded in generating an inducible tetramer formation system. Proteins of interest also formed tetramers by fusing to the inducible tetramer formation system, which exhibits its utility in a broad range of biological applications. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Functional NifD-K fusion protein in Azotobacter vinelandii is a homodimeric complex equivalent to the native heterotetrameric MoFe protein

International Nuclear Information System (INIS)

Lahiri, Surobhi; Pulakat, Lakshmi; Gavini, Nara

2005-01-01

The MoFe protein of the complex metalloenzyme nitrogenase folds as a heterotetramer containing two copies each of the homologous α and β subunits, encoded by the nifD and the nifK genes respectively. Recently, the functional expression of a fusion NifD-K protein of nitrogenase was demonstrated in Azotobacter vinelandii, strongly implying that the MoFe protein is flexible as it could accommodate major structural changes, yet remain functional [M.H. Suh, L. Pulakat, N. Gavini, J. Biol. Chem. 278 (2003) 5353-5360]. This finding led us to further explore the type of interaction between the fused MoFe protein units. We aimed to determine whether an interaction exists between the two fusion MoFe proteins to form a homodimer that is equivalent to native heterotetrameric MoFe protein. Using the Bacteriomatch Two-Hybrid System, translationally fused constructs of NifD-K (fusion) with the full-length λCI of the pBT bait vector and also NifD-K (fusion) with the N-terminal α-RNAP of the pTRG target vector were made. To compare the extent of interaction between the fused NifD-K proteins to that of the β-β interactions in the native MoFe protein, we proceeded to generate translationally fused constructs of NifK with the α-RNAP of the pTRG vector and λCI protein of the pBT vector. The strength of the interaction between the proteins in study was determined by measuring the β-galactosidase activity and extent of ampicillin resistance of the colonies expressing these proteins. This analysis demonstrated that direct protein-protein interaction exists between NifD-K fusion proteins, suggesting that they exist as homodimers. As the interaction takes place at the β-interfaces of the NifD-K fusion proteins, we propose that these homodimers of NifD-K fusion protein may function in a similar manner as that of the heterotetrameric native MoFe protein. The observation that the extent of protein-protein interaction between the β-subunits of the native MoFe protein in Bacterio

The antibody response to well-defined malaria antigens after acute malaria in individuals living under continuous malaria transmission

DEFF Research Database (Denmark)

Petersen, E; Høgh, B; Dziegiel, M

1992-01-01

The IgG and IgM antibody responses to the C-terminal 783 amino acids of the P. falciparum glutamate-rich protein, GLURP489-1271, expressed as an E. coli fusion protein, the IgG response to a 18-mer synthetic peptide EDKNEKGQHEIVEVEEIL (GLURP899-916) representing the C-terminal repeats of GLURP......, and a synthetic peptide (EENV)6 representing the C-terminal repeats from Pf155/RESA, were investigated longitudinally in 13 children and 7 adults living under conditions of continuous, intense malaria transmission. Some subjects did not recognize the antigens after malaria infection, and in subjects recognizing...... the antigens, the responses were often short-lived. In adults, the antibody responses to the GLURP489-1271 fusion protein and the (EENV)6 peptide peaked after 2 weeks, and not all individuals responded to all antigens. The antibody response, even against large fragments of conserved antigens, is not uniformly...

Genetically engineered endostatin-lidamycin fusion proteins effectively inhibit tumor growth and metastasis

International Nuclear Information System (INIS)

Jiang, Wen-guo; Zhen, Yong-su; Lu, Xin-an; Shang, Bo-yang; Fu, Yan; Zhang, Sheng-hua; Zhou, Daifu; Li, Liang; Li, Yi; Luo, Yongzhang

2013-01-01

Endostatin (ES) inhibits endothelial cell proliferation, migration, invasion, and tube formation. It also shows antiangiogenesis and antitumor activities in several animal models. Endostatin specifically targets tumor vasculature to block tumor growth. Lidamycin (LDM), which consists of an active enediyne chromophore (AE) and a non-covalently bound apo-protein (LDP), is a member of chromoprotein family of antitumor antibiotics with extremely potent cytotoxicity to cancer cells. Therefore, we reasoned that endostatin-lidamycin (ES-LDM) fusion proteins upon energizing with enediyne chromophore may obtain the combined capability targeting tumor vasculature and tumor cell by respective ES and LDM moiety. In this study, we designed and obtained two new endostatin-based fusion proteins, endostatin-LDP (ES-LDP) and LDP-endostatin (LDP-ES). In vitro, the antiangiogenic effect of fusion proteins was determined by the wound healing assay and tube formation assay and the cytotoxicity of their enediyne-energized analogs was evaluated by CCK-8 assay. Tissue microarray was used to analyze the binding affinity of LDP, ES or ES-LDP with specimens of human lung tissue and lung tumor. The in vivo efficacy of the fusion proteins was evaluated with human lung carcinoma PG-BE1 xenograft and the experimental metastasis model of 4T1-luc breast cancer. ES-LDP and LDP-ES disrupted the formation of endothelial tube structures and inhibited endothelial cell migration. Evidently, ES-LDP accumulated in the tumor and suppressed tumor growth and metastasis. ES-LDP and ES show higher binding capability than LDP to lung carcinoma; in addition, ES-LDP and ES share similar binding capability. Furthermore, the enediyne-energized fusion protein ES-LDP-AE demonstrated significant efficacy against lung carcinoma xenograft in athymic mice. The ES-based fusion protein therapy provides some fundamental information for further drug development. Targeting both tumor vasculature and tumor cells by endostatin

Conservation of a proteinase cleavage site between an insect retrovirus (gypsy) Env protein and a baculovirus envelope fusion protein

International Nuclear Information System (INIS)

Pearson, Margot N.; Rohrmann, George F.

2004-01-01

The predicted Env protein of insect retroviruses (errantiviruses) is related to the envelope fusion protein of a major division of the Baculoviridae. The highest degree of homology is found in a region that contains a furin cleavage site in the baculovirus proteins and an adjacent sequence that has the properties of a fusion peptide. In this investigation, the homologous region in the Env protein of the gypsy retrovirus of Drosophila melanogaster (DmegypV) was investigated. Alteration of the predicted DmegypV Env proteinase cleavage site from RIAR to AIAR significantly reduced cleavage of Env in both Spodoptera frugiperda (Sf-9) and D. melanogaster (S2) cell lines. When the predicted DmegypV Env cleavage site RIAR was substituted for the cleavage sequence RRKR in the Lymantria dispar nucleopolyhedrovirus fusion protein (LD130) sequence, cleavage of the hybrid LD130 molecules still occurred, although at a reduced level. The conserved 21-amino acid sequence just downstream of the cleavage site, which is thought to be the fusion peptide in LD130, was also characterized. When this sequence from DmegypV Env was substituted for the homologous sequence in LD130, cleavage still occurred, but no fusion was observed in either cell type. In addition, although a DmegypV-Env-green fluorescent protein construct localized to cell membranes, no cell fusion was observed

Discovery of functional monoclonal antibodies targeting G-protein-coupled receptors and ion channels.

Science.gov (United States)

Wilkinson, Trevor C I

2016-06-15

The development of recombinant antibody therapeutics is a significant area of growth in the pharmaceutical industry with almost 50 approved monoclonal antibodies on the market in the US and Europe. Despite this growth, however, certain classes of important molecular targets have remained intractable to therapeutic antibodies due to complexity of the target molecules. These complex target molecules include G-protein-coupled receptors and ion channels which represent a large potential target class for therapeutic intervention with monoclonal antibodies. Although these targets have typically been addressed by small molecule approaches, the exquisite specificity of antibodies provides a significant opportunity to provide selective modulation of these target proteins. Given this opportunity, substantial effort has been applied to address the technical challenges of targeting these complex membrane proteins with monoclonal antibodies. In this review recent progress made in the strategies for discovery of functional monoclonal antibodies for these challenging membrane protein targets is addressed. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Anti-HmuY antibodies specifically recognize Porphyromonas gingivalis HmuY protein but not homologous proteins in other periodontopathogens.

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Michał Śmiga

Full Text Available Given the emerging evidence of an association between periodontal infections and systemic conditions, the search for specific methods to detect the presence of P. gingivalis, a principal etiologic agent in chronic periodontitis, is of high importance. The aim of this study was to characterize antibodies raised against purified P. gingivalis HmuY protein and selected epitopes of the HmuY molecule. Since other periodontopathogens produce homologs of HmuY, we also aimed to characterize responses of antibodies raised against the HmuY protein or its epitopes to the closest homologous proteins from Prevotella intermedia and Tannerella forsythia. Rabbits were immunized with purified HmuY protein or three synthetic, KLH-conjugated peptides, derived from the P. gingivalis HmuY protein. The reactivity of anti-HmuY antibodies with purified proteins or bacteria was determined using Western blotting and ELISA assay. First, we found homologs of P. gingivalis HmuY in P. intermedia (PinO and PinA proteins and T. forsythia (Tfo protein and identified corrected nucleotide and amino acid sequences of Tfo. All proteins were overexpressed in E. coli and purified using ion-exchange chromatography, hydrophobic chromatography and gel filtration. We demonstrated that antibodies raised against P. gingivalis HmuY are highly specific to purified HmuY protein and HmuY attached to P. gingivalis cells. No reactivity between P. intermedia and T. forsythia or between purified HmuY homologs from these bacteria and anti-HmuY antibodies was detected. The results obtained in this study demonstrate that P. gingivalis HmuY protein may serve as an antigen for specific determination of serum antibodies raised against this bacterium.

Novel immunotoxin: a fusion protein consisting of gelonin and an acetylcholine receptor fragment as a potential immunotherapeutic agent for the treatment of Myasthenia gravis.

Science.gov (United States)

Hossann, Martin; Li, Zhuoyu; Shi, Yawei; Kreilinger, Ulrike; Büttner, Jörn; Vogel, Pia D; Yuan, Jingming; Wise, John G; Trommer, Wolfgang E

2006-03-01

In continuation of our attempts for antigen-specific suppression of the immune system [I.L. Urbatsch, R.K.M. Sterz, K. Peper, W.E. Trommer, Eur. J. Immunol. 23(1993) 776-779] a novel fusion protein composed of amino acids 4-181 of the extracellular domain of the alpha-subunit of the human muscle acetylcholine receptor and the plant toxin gelonin was expressed in Escherichia coli. The fusion protein formed inclusion bodies but could be solubilized in the presence of guanidinium hydrochloride. After a simple two step purification and refolding procedure, it exhibited a native structure at least in the main immunogenic region as shown by antibodies recognizing a conformational epitope. Half maximal inhibition of translation was achieved at 46 ng/ml as compared to 4.6 ng/ml for native and 2.4 for recombinant gelonin. Its use as therapeutic agent for the treatment of Myasthenia gravis was investigated in an animal model. Female Lewis rats were immunized with complete acetylcholine receptor from the electric ray Torpedo californica and developed thereafter experimental autoimmune M. gravis. Quantitative assessment of the disease was achieved by repetitive stimulation of the Nervus tibialis. Rats showed no symptoms of M. gravis, neither visually nor electrophysiologically after treatment with the fusion protein as determined one and seven weeks after the second application. This approach may also be useful for the therapy of further autoimmune diseases by substituting other autoantigens for the AchR fragment in the fusion protein.

Production of unnaturally linked chimeric proteins using a combination of sortase-catalyzed transpeptidation and click chemistry

NARCIS (Netherlands)

Witte, Martin D.; Theile, Christopher S.; Wu, Tongfei; Guimaraes, Carla P.; Blom, Annet E. M.; Ploegh, Hidde L.

Chimeric proteins, including bispecific antibodies, are biological tools with therapeutic applications. Genetic fusion and ligation methods allow the creation of N-to-C and C-to-N fused recombinant proteins, but not unnaturally linked N-to-N and C-to-C fusion proteins. This protocol describes a

Mycobacterium tuberculosis HspX/EsxS Fusion Protein: Gene Cloning, Protein Expression, and Purification in Escherichia coli.

Science.gov (United States)

Khademi, Farzad; Yousefi-Avarvand, Arshid; Derakhshan, Mohammad; Meshkat, Zahra; Tafaghodi, Mohsen; Ghazvini, Kiarash; Aryan, Ehsan; Sankian, Mojtaba

2017-10-01

The purpose of this study was to clone, express, and purify a novel multidomain fusion protein of Micobacterium tuberculosis (Mtb) in a prokaryotic system. An hspX/esxS gene construct was synthesized and ligated into a pGH plasmid, E. coli TOP10 cells were transformed, and the vector was purified. The vector containing the construct and pET-21b (+) plasmid were digested with the same enzymes and the construct was ligated into pET-21b (+). The accuracy of cloning was confirmed by colony PCR and sequencing. E. coli BL21 cells were transformed with the pET-21b (+)/hspX/esxS expression vector and protein expression was evaluated. Finally, the expressed fusion protein was purified on a Ni-IDA column and verified by SDS-PAGE and western blotting. The hspX/esxS gene construct was inserted into pET-21b (+) and recombinant protein expression was induced with IPTG in E. coli BL21 cells. Various concentrations of IPTG were tested to determine the optimum concentration for expression induction. The recombinant protein was expressed in insoluble inclusion bodies. Three molar guanidine HCl was used to solubilize the insoluble protein. An HspX/EsxS Mtb fusion protein was expressed in E. coli and the recombinant protein was purified. After immunological analysis, the HspX/EsxS fusion protein might be an anti-tuberculosis vaccine candidate in future clinical trial studies.

Intramuscular Immunisation with Chlamydial Proteins Induces Chlamydia trachomatis Specific Ocular Antibodies.

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Alexander Badamchi-Zadeh

Full Text Available Ocular infection with Chlamydia trachomatis can cause trachoma, which is the leading cause of blindness due to infection worldwide. Despite the large-scale implementation of trachoma control programmes in the majority of countries where trachoma is endemic, there remains a need for a vaccine. Since C. trachomatis infects the conjunctival epithelium and stimulates an immune response in the associated lymphoid tissue, vaccine regimens that enhance local antibody responses could be advantageous. In experimental infections of non-human primates (NHPs, antibody specificity to C. trachomatis antigens was found to change over the course of ocular infection. The appearance of major outer membrane protein (MOMP specific antibodies correlated with a reduction in ocular chlamydial burden, while subsequent generation of antibodies specific for PmpD and Pgp3 correlated with C. trachomatis eradication.We used a range of heterologous prime-boost vaccinations with DNA, Adenovirus, modified vaccinia Ankara (MVA and protein vaccines based on the major outer membrane protein (MOMP as an antigen, and investigated the effect of vaccine route, antigen and regimen on the induction of anti-chlamydial antibodies detectable in the ocular lavage fluid of mice.Three intramuscular vaccinations with recombinant protein adjuvanted with MF59 induced significantly greater levels of anti-MOMP ocular antibodies than the other regimens tested. Intranasal delivery of vaccines induced less IgG antibody in the eye than intramuscular delivery. The inclusion of the antigens PmpD and Pgp3, singly or in combination, induced ocular antigen-specific IgG antibodies, although the anti-PmpD antibody response was consistently lower and attenuated by combination with other antigens.If translatable to NHPs and/or humans, this investigation of the murine C. trachomatis specific ocular antibody response following vaccination provides a potential mouse model for the rapid and high throughput

Conformational Heterogeneity in Antibody-Protein Antigen Recognition IMPLICATIONS FOR HIGH AFFINITY PROTEIN COMPLEX FORMATION

Czech Academy of Sciences Publication Activity Database

Addis, P. W.; Hall, c. J.; Bruton, S.; Veverka, Václav; Wilkinson, I. C.; Muskett, F. W.; Renshaw, P. S.; Prosser, C. E.; Carrington, B.; Lawson, A. D. G.; Griffin, R.; Taylor, R. J.; Waters, L. C.; Henry, A. J.; Carr, M. D.

2014-01-01

Roč. 289, č. 10 (2014), s. 7200-7210 ISSN 0021-9258 Institutional support: RVO:61388963 Keywords : NMR * antibody * protein-protein interaction * protein conformation Subject RIV: CE - Biochemistry Impact factor: 4.573, year: 2014

A simple vector system to improve performance and utilisation of recombinant antibodies

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Vincent Karen J

2006-12-01

Full Text Available Abstract Background Isolation of recombinant antibody fragments from antibody libraries is well established using technologies such as phage display. Phage display vectors are ideal for efficient display of antibody fragments on the surface of bacteriophage particles. However, they are often inefficient for expression of soluble antibody fragments, and sub-cloning of selected antibody populations into dedicated soluble antibody fragment expression vectors can enhance expression. Results We have developed a simple vector system for expression, dimerisation and detection of recombinant antibody fragments in the form of single chain Fvs (scFvs. Expression is driven by the T7 RNA polymerase promoter in conjunction with the inducible lysogen strain BL21 (DE3. The system is compatible with a simple auto-induction culture system for scFv production. As an alternative to periplasmic expression, expression directly in the cytoplasm of a mutant strain with a more oxidising cytoplasmic environment (Origami 2™ (DE3 was investigated and found to be inferior to periplasmic expression in BL21 (DE3 cells. The effect on yield and binding activity of fusing scFvs to the N terminus of maltose binding protein (a solubility enhancing partner, bacterial alkaline phosphatase (a naturally dimeric enzymatic reporter molecule, or the addition of a free C-terminal cysteine was determined. Fusion of scFvs to the N-terminus of maltose binding protein increased scFv yield but binding activity of the scFv was compromised. In contrast, fusion to the N-terminus of bacterial alkaline phosphatase led to an improved performance. Alkaline phosphatase provides a convenient tag allowing direct enzymatic detection of scFv fusions within crude extracts without the need for secondary reagents. Alkaline phosphatase also drives dimerisation of the scFv leading to an improvement in performance compared to monovalent constructs. This is illustrated by ELISA, western blot and

Comparison of immune responses against foot-and-mouth disease virus induced by fusion proteins using the swine IgG heavy chain constant region or β-galactosidase as a carrier of immunogenic epitopes

International Nuclear Information System (INIS)

Li Guangjin; Chen Weizao; Yan Weiyao; Zhao Kai; Liu Mingqiu; Zhang Jun; Fei Liang; Xu Quanxing; Sheng Zutian; Lu Yonggan; Zheng Zhaoxin

2004-01-01

Previously, we demonstrated that a fusion protein (Gal-FMDV) consisting of β-galactosidase and an immunogenic peptide, amino acids (141-160)-(21-40)-(141-160), of foot-and-mouth disease virus (FMDV) VP1 protein induced protective immune responses in guinea pigs and swine. We now designed a new potential recombinant protein vaccine against FMDV in swine. The immunogenic peptide, amino acids (141-160)-(21-40)-(141-160) from the VP1 protein of serotype O FMDV, was fused to the carboxy terminus of a swine immunoglobulin G single heavy chain constant region and expressed in Escherichia coli. The expressed fusion protein (IgG-FMDV) was purified and emulsified with oil adjuvant. Vaccination twice at an interval of 3 weeks with the emulsified IgG-FMDV fusion protein induced an FMDV-specific spleen proliferative T-cell response in guinea pigs and elicited high levels of neutralizing antibody in guinea pigs and swine. All of the immunized animals were efficiently protected against FMDV challenge. There was no significant difference between IgG-FMDV and Gal-FMDV in eliciting immunity after vaccination twice in swine. However, when evaluating the efficacy of a single inoculation of the fusion proteins, we found that IgG-FMDV could elicit a protective immune response in swine, while Gal-FMDV only elicited a weak neutralizing activity and could not protect the swine against FMDV challenge. Our results suggest that the IgG-FMDV fusion protein is a promising vaccine candidate for FMD in swine

Novel fusion protein approach for efficient high-throughput screening of small molecule-mediating protein-protein interactions in cells and living animals.

Science.gov (United States)

Paulmurugan, Ramasamy; Gambhir, Sanjiv S

2005-08-15

Networks of protein interactions execute many different intracellular pathways. Small molecules either synthesized within the cell or obtained from the external environment mediate many of these protein-protein interactions. The study of these small molecule-mediated protein-protein interactions is important in understanding abnormal signal transduction pathways in a variety of disorders, as well as in optimizing the process of drug development and validation. In this study, we evaluated the rapamycin-mediated interaction of the human proteins FK506-binding protein (FKBP12) rapamycin-binding domain (FRB) and FKBP12 by constructing a fusion of these proteins with a split-Renilla luciferase or a split enhanced green fluorescent protein (split-EGFP) such that complementation of the reporter fragments occurs in the presence of rapamycin. Different linker peptides in the fusion protein were evaluated for the efficient maintenance of complemented reporter activity. This system was studied in both cell culture and xenografts in living animals. We found that peptide linkers with two or four EAAAR repeat showed higher protein-protein interaction-mediated signal with lower background signal compared with having no linker or linkers with amino acid sequences GGGGSGGGGS, ACGSLSCGSF, and ACGSLSCGSFACGSLSCGSF. A 9 +/- 2-fold increase in signal intensity both in cell culture and in living mice was seen compared with a system that expresses both reporter fragments and the interacting proteins separately. In this fusion system, rapamycin induced heterodimerization of the FRB and FKBP12 moieties occurred rapidly even at very lower concentrations (0.00001 nmol/L) of rapamycin. For a similar fusion system employing split-EGFP, flow cytometry analysis showed significant level of rapamycin-induced complementation.

Identification of two Th1 cell epitopes on the Babesia bovis-encoded 77-kilodalton merozoite protein (Bb-1) by use of truncated recombinant fusion proteins.

Science.gov (United States)

Brown, W C; Zhao, S; Woods, V M; Tripp, C A; Tetzlaff, C L; Heussler, V T; Dobbelaere, D A; Rice-Ficht, A C

1993-01-01

Previous studies have demonstrated the serologic and T-cell immunogenicity for cattle of a recombinant form of the apical complex-associated 77-kDa merozite protein of Babesia bovis, designated Bb-1. The present study characterizes the immunogenic epitopes of the Bb-1 protein. A series of recombinant truncated fusion proteins spanning the majority of the Bb-1 protein were expressed in Escherichia coli, and their reactivities with bovine peripheral blood mononuclear cells and T-cell clones derived from B. bovis-immune cattle and with rabbit antibodies were determined. Lymphocytes from two immune cattle were preferentially stimulated by the N-terminal half of the Bb-1 protein (amino acids 23 to 266, termed Bb-1A), localizing the T-cell epitopes to the Bb-1A portion of the molecule. CD4+ T-cell clones derived by stimulation with the intact Bb-1 fusion protein were used to identify two T-cell epitopes in the Bb-1A protein, consisting of amino acids SVVLLSAFSGN VWANEAEVSQVVK and FSDVDKTKSTEKT (residues 23 to 46 and 82 to 94). In contrast, rabbit antiserum raised against the intact fusion protein reacted only with the C-terminal half of the protein (amino acids 267 to 499, termed Bb-1B), which contained 28 tandem repeats of the tetrapeptide PAEK or PAET. Biological assays and Northern (RNA) blot analyses for cytokines revealed that following activation with concanavalin A, T-cell clones reactive against the two Bb-1A epitopes produced interleukin-2, gamma interferon, and tumor necrosis factors beta and alpha, but not interleukin-4, suggesting that the Bb-1 antigen preferentially stimulates the Th1 subset of CD4+ T cells in cattle. The studies described here report for the first time the characterization, by cytokine production, of the Th1 subset of bovine T cells and show that, as in mice, protozoal antigens can induce Th1 cells in ruminants. This first demonstration of B. bovis-encoded Th1 cell epitopes provides a rationale for incorporation of all or part of the Bb-1

Clinical spectrum and diagnostic value of antibodies against the potassium channel-related protein complex☆

Science.gov (United States)

Montojo, M.T.; Petit-Pedrol, M.; Graus, F.; Dalmau, J.

2016-01-01

Introduction Antibodies against a protein complex that includes voltage-gated potassium channels (VGKC) have been reported in patients with limbic encephalitis, peripheral nerve hyperexcitability, Morvan's syndrome, and a large variety of neurological syndromes. Review summary In this article, a review is presented of the syndromes associated with antibodies against VGKC-related proteins and the main antigens of this protein complex, the proteins LGI1 (leucine rich glioma inactivated protein 1) and Caspr2 (contactin-associated protein-like 2). The conceptual problems and clinical implications of the description of antibodies against VGKC-related proteins other than LGI1 and Caspr2 are also discussed. Although initial studies indicated the occurrence of antibodies against VGKC, recent investigations have shown that the main antigens are a neuronal secreted protein known as LGI1 which modulates synaptic excitability, and a protein called Caspr2 located on the cell surface and processes of neurons of different brain regions, and at the juxtaparanodal region of myelinated axons. While antibodies against LGI1 preferentially associate with classical limbic encephalitis, antibodies against Caspr2 associate with a wider spectrum of symptoms, including Morvan's syndrome, peripheral nerve hyperexcitability or neuromyotonia, and limbic or more extensive encephalitis. In addition there are reports of patients with antibodies against VGKC-related proteins that are different from LGI1 or Caspr2. In these cases, the identity and location of the antigens are unknown, the syndrome association is not specific, and the response to treatment uncertain. Conclusions The discovery of antigens such as LGI1 and Caspr2 has resulted in a clinical and molecular definition of the broad group of diseases previously attributed to antibodies against VGKC. Considering the literature that describes the presence of antibodies against VGKC other than LGI1 and Caspr2 proteins, we propose a practical

Regulation of Exocytotic Fusion Pores by SNARE Protein Transmembrane Domains

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Zhenyong Wu

2017-10-01

Full Text Available Calcium-triggered exocytotic release of neurotransmitters and hormones from neurons and neuroendocrine cells underlies neuronal communication, motor activity and endocrine functions. The core of the neuronal exocytotic machinery is composed of soluble N-ethyl maleimide sensitive factor attachment protein receptors (SNAREs. Formation of complexes between vesicle-attached v- and plasma-membrane anchored t-SNAREs in a highly regulated fashion brings the membranes into close apposition. Small, soluble proteins called Complexins (Cpx and calcium-sensing Synaptotagmins cooperate to block fusion at low resting calcium concentrations, but trigger release upon calcium increase. A growing body of evidence suggests that the transmembrane domains (TMDs of SNARE proteins play important roles in regulating the processes of fusion and release, but the mechanisms involved are only starting to be uncovered. Here we review recent evidence that SNARE TMDs exert influence by regulating the dynamics of the fusion pore, the initial aqueous connection between the vesicular lumen and the extracellular space. Even after the fusion pore is established, hormone release by neuroendocrine cells is tightly controlled, and the same may be true of neurotransmitter release by neurons. The dynamics of the fusion pore can regulate the kinetics of cargo release and the net amount released, and can determine the mode of vesicle recycling. Manipulations of SNARE TMDs were found to affect fusion pore properties profoundly, both during exocytosis and in biochemical reconstitutions. To explain these effects, TMD flexibility, and interactions among TMDs or between TMDs and lipids have been invoked. Exocytosis has provided the best setting in which to unravel the underlying mechanisms, being unique among membrane fusion reactions in that single fusion pores can be probed using high-resolution methods. An important role will likely be played by methods that can probe single fusion pores

Antibody response to the lipopolysaccharide and protein antigens of Salmonella typhi during typhoid infection

International Nuclear Information System (INIS)

Tsang, R.S.W.; Chau, P.Y.; Lam, S.K.

1981-01-01

Serum antibody responses to the lipopolysaccharide and protein antigens of S. typhi in typhoid patients were studied using a solid-phase radioimmunoassay technique with 125 I labelled anti-immunoglobulin antibody. Sera from 24 adult typhoid patients and 20 non-typhoid adult controls were compared. As a group, sera from typhoid patients showed increased IgA, IgG and IgM immunoglobulin levels and gave significantly higher anti-LPS and anti-protein antibody titres in all three major immunoglobulin classes than did non-typhoid controls. Levels of antibodies against LPS or protein in sera of typhoid patients were highly variable with a skew distribution. A good correlation was found between antibody titres to the LPS antigen and those to a protein antigen. No correlation, however, was found between the anti-LPS antibody titres measured by radioimmunoassay and the anti-O antibody titres measured by the Widal agglutination test. Titration of anti-LPS or anti-protein antibodies by radioimmunoassay was found to be more sensitive and specific than Widal test for the serological diagnosis of typhoid fever. The advantages of measuring antibody response by radioimmunoassay over conventional Widal test are discussed. (author)

Produksi dan Karakterisasi Antibodi Monoklonal Anti-Cysticercus cellulosae (PRODUCTION AND CHRACTERIZATION OF MONOCLONAL ANTIBODIES AGAINST CYSTICERCUS CELLULOSAE

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Ida Bagus Ngurah Swacita

2015-10-01

Full Text Available The purpose of this study is to make a monoclonal antibody against- Cysticercus cellulosae and itscharacterization. Samples antigen prepared from T. solium larvae (C. cellulosae was then used to immunizeBalb/c. The immune response of mice assessed by ELISA test, then the lymphocytes of mice used for theproduction of monoclonal antibodies (MoAb. Origin lymphocytes of mice that produce antibodies againstC. cellulosae antigen, fused with myeloma cells (NS1. Results fusion of two cells produces hybrid cellscalled hybridomas; cells are then screened by ELISA test. Hybridoma cells that produce only MoAb, usedto produce large quantities in vitro. Characterization of MoAb against-C.cellulosae was tested by usingELISA and Western blotting. Mice were immunized with C.cellulosae antigen showed an immune responseproducing antibodies to C.cellulosae. Based on the results of fusion, produced a total of 51 hybridoma cellclones and after being screened, only three clones of hybridoma cells that produced MoAb against–C.cellulosae. MoAb produced, named after the hole where the growth of the ELISA micro plate, the BE6,BE7, and EE9. Characteristics of this MoAb capable of tracking cellulosae of fluid larvae and recognizeantigen protein bands with molecular weight 78kDa.

Fusion proteins useful for producing pinene

Energy Technology Data Exchange (ETDEWEB)

Peralta-Yahya, Pamela P.; Keasling, Jay D

2016-06-28

The present invention provides for a modified host cell comprising a heterologous pinene synthase (PS), or enzymatically active fragment or variant thereof, and optionally a geranyl pyrophosphate synthase (GPPS), or enzymatically active fragment or variant thereof, or a fusion protein comprising: (a) a PS and (b) a GPPS linked by a linker.

Antibodies to watch in 2014.

Science.gov (United States)

Reichert, Janice M

2014-01-01

Since 2010, mAbs has documented the biopharmaceutical industry's progress in transitioning antibody therapeutics to first Phase 3 clinical studies and regulatory review, and its success at gaining first marketing approvals for antibody-based products. This installment of the "Antibodies to watch" series outlines events anticipated to occur between December 2013 and the end of 2014, including first regulatory actions on marketing applications for vedolizumab, siltuximab, and ramucirumab, as well as the Fc fusion proteins Factor IX-Fc and Factor VIII-Fc; and the submission of first marketing applications for up to five therapeutics (secukinumab, ch14.18, onartuzumab, necitumumab, gevokizumab). Antibody therapeutics in Phase 3 studies are described, with an emphasis on those with study completion dates in 2014, including antibodies targeting interleukin-17a or the interleukin-17a receptor (secukinumab, ixekizumab, brodalumab), proprotein convertase subtilisin/kexin type 9 (alirocumab, evolocumab, bococizumab), and programmed death 1 receptor (lambrolizumab, nivolumab). Five antibodies with US Food and Drug Administration's Breakthrough Therapy designation (obinutuzumab, ofatumumab, lambrolizumab, bimagrumab, daratumumab) are also discussed.

Characterization of the fusion core in zebrafish endogenous retroviral envelope protein

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Shi, Jian [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072 (China); State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Zhang, Huaidong [CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Gong, Rui, E-mail: gongr@wh.iov.cn [CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Xiao, Gengfu, E-mail: xiaogf@wh.iov.cn [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072 (China); State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China)

2015-05-08

Zebrafish endogenous retrovirus (ZFERV) is the unique endogenous retrovirus in zebrafish, as yet, containing intact open reading frames of its envelope protein gene in zebrafish genome. Similarly, several envelope proteins of endogenous retroviruses in human and other mammalian animal genomes (such as syncytin-1 and 2 in human, syncytin-A and B in mouse) were identified and shown to be functional in induction of cell–cell fusion involved in placental development. ZFERV envelope protein (Env) gene appears to be also functional in vivo because it is expressible. After sequence alignment, we found ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes, especially in the regions of N- and C-terminal heptad repeats (NHR and CHR) which were crucial for membrane fusion. We expressed the regions of N + C protein in the ZFERV Env (residues 459–567, including predicted NHR and CHR) to characterize the fusion core structure. We found N + C protein could form a stable coiled-coil trimer that consists of three helical NHR regions forming a central trimeric core, and three helical CHR regions packing into the grooves on the surface of the central core. The structural characterization of the fusion core revealed the possible mechanism of fusion mediated by ZFERV Env. These results gave comprehensive explanation of how the ancient virus infects the zebrafish and integrates into the genome million years ago, and showed a rational clue for discovery of physiological significance (e.g., medicate cell–cell fusion). - Highlights: • ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes. • The fusion core of ZFERV Env forms stable coiled-coil trimer including three NHRs and three CHRs. • The structural mechanism of viral entry mediated by ZFERV Env is disclosed. • The results are helpful for further discovery of physiological function of ZFERV Env in zebrafish.

A Protein Disulfide Isomerase Gene Fusion Expression System That Increases the Extracellular Productivity of Bacillus brevis

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Kajino, Tsutomu; Ohto, Chikara; Muramatsu, Masayoshi; Obata, Shusei; Udaka, Shigezo; Yamada, Yukio; Takahashi, Haruo

2000-01-01

We have developed a versatile Bacillus brevis expression and secretion system based on the use of fungal protein disulfide isomerase (PDI) as a gene fusion partner. Fusion with PDI increased the extracellular production of heterologous proteins (light chain of immunoglobulin G, 8-fold; geranylgeranyl pyrophosphate synthase, 12-fold). Linkage to PDI prevented the aggregation of the secreted proteins, resulting in high-level accumulation of fusion proteins in soluble and biologically active forms. We also show that the disulfide isomerase activity of PDI in a fusion protein is responsible for the suppression of the aggregation of the protein with intradisulfide, whereas aggregation of the protein without intradisulfide was prevented even when the protein was fused to a mutant PDI whose two active sites were disrupted, suggesting that another PDI function, such as chaperone-like activity, synergistically prevented the aggregation of heterologous proteins in the PDI fusion expression system. PMID:10653729

Antibody proteases: induction of catalytic response.

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Gabibov, A G; Friboulet, A; Thomas, D; Demin, A V; Ponomarenko, N A; Vorobiev, I I; Pillet, D; Paon, M; Alexandrova, E S; Telegin, G B; Reshetnyak, A V; Grigorieva, O V; Gnuchev, N V; Malishkin, K A; Genkin, D D

2002-10-01

Most of the data accumulated throughout the years on investigation of catalytic antibodies indicate that their production increases on the background of autoimmune abnormalities. The different approaches to induction of catalytic response toward recombinant gp120 HIV-1 surface protein in mice with various autoimmune pathologies are described. The peptidylphosphonate conjugate containing structural part of gp120 molecule is used for reactive immunization of NZB/NZW F1, MRL, and SJL mice. The specific modification of heavy and light chains of mouse autoantibodies with Val-Ala-Glu-Glu-Glu-Val-PO(OPh)2 reactive peptide was demonstrated. Increased proteolytic activity of polyclonal antibodies in SJL mice encouraged us to investigate the production of antigen-specific catalytic antibodies on the background of induced experimental autoimmune encephalomyelitis (EAE). The immunization of autoimmune-prone mice with the engineered fusions containing the fragments of gp120 and encephalitogenic epitope of myelin basic protein (MBP(89-104)) was made. The proteolytic activity of polyclonal antibodies isolated from the sera of autoimmune mice immunized by the described antigen was shown. Specific immune response of SJL mice to these antigens was characterized. Polyclonal antibodies purified from sera of the immunized animals revealed proteolytic activity. The antiidiotypic approach to raise the specific proteolytic antibody as an "internal image" of protease is described. The "second order" monoclonal antibodies toward subtilisin Carlsberg revealed pronounced proteolytic activity.

The yeast cell fusion protein Prm1p requires covalent dimerization to promote membrane fusion.

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Alex Engel

2010-05-01

Full Text Available Prm1p is a multipass membrane protein that promotes plasma membrane fusion during yeast mating. The mechanism by which Prm1p and other putative regulators of developmentally controlled cell-cell fusion events facilitate membrane fusion has remained largely elusive. Here, we report that Prm1p forms covalently linked homodimers. Covalent Prm1p dimer formation occurs via intermolecular disulfide bonds of two cysteines, Cys-120 and Cys-545. PRM1 mutants in which these cysteines have been substituted are fusion defective. These PRM1 mutants are normally expressed, retain homotypic interaction and can traffic to the fusion zone. Because prm1-C120S and prm1-C545S mutants can form covalent dimers when coexpressed with wild-type PRM1, an intermolecular C120-C545 disulfide linkage is inferred. Cys-120 is adjacent to a highly conserved hydrophobic domain. Mutation of a charged residue within this hydrophobic domain abrogates formation of covalent dimers, trafficking to the fusion zone, and fusion-promoting activity. The importance of intermolecular disulfide bonding informs models regarding the mechanism of Prm1-mediated cell-cell fusion.

Detection of Human Epididymis Protein 4 (HE4) in Human Serum Samples Using a Specific Monoclonal Antibody-Based Sandwich Enzyme-Linked Immunosorbent Assay (ELISA).

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Zhou, Lijun; Lv, Zhiqiang; Shao, Jing; Xu, Ying; Luo, Xiaohong; Zhang, Yuming; Hu, Yang; Zhang, Wenji; Luo, Shuhong; Fang, Jianmin; Wang, Ying; Duan, Chaohui; Huang, Ruopan

2016-09-01

The human epididymis protein 4 (HE4) may have high specificity in the detection of malignant diseases, making the development of an immunoassay for HE4 essential. In our study, a fusion gene was constructed encoded with the HE4 protein. This protein was then produced in the bacterial cells (Escherichia coli) and used to immunize mice in order to eventually generate hybridomas specific to HE4. The hybridoma supernatants were then screened, and four positive anti-HE4 cell lines were selected. These cell lines produce monoclonal antibodies against HE4 epitopes, as demonstrated in the Western blot as well as by direct enzyme-linked immunosorbent assay (ELISA). Using the developed antibodies, we successfully identified several good antibody pairs from the hybridomas, which allowed for the development of a sandwich ELISA to measure HE4 levels. By using the HE4 ELISA, we measured HE4 levels of 60 clinical human serum samples. Compared with the Food and Drug Administration (FDA) approved kit (Roche), our results showed a strong positive correlation to those of the FDA-approved kit. In summary, highly sensitive antibody pairs were screened against HE4, and a sandwich ELISA was developed as an accurate analytical tool for the detection of HE4 in human serum, which could be especially valuable for diagnosing ovarian carcinomas. © 2015 Wiley Periodicals, Inc.

Studies to Prevent Degradation of Recombinant Fc-Fusion Protein Expressed in Mammalian Cell Line and Protein Characterization

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Sanjukta Chakrabarti

2016-06-01

Full Text Available Clipping of recombinant proteins is a major issue in animal cell cultures. A recombinant Fc-fusion protein, VEGFR1(D1–D3-Fc expressed in CHOK1SV GS-KO cells was observed to be undergoing clippings in lab scale cultures. Partial cleaving of expressed protein initiated early on in cell culture and was observed to increase over time in culture and also on storage. In this study, a few parameters were explored in a bid to inhibit clipping in the fusion protein The effects of culture temperature, duration of culture, the addition of an anti-clumping agent, ferric citrate and use of protease inhibitor cocktail on inhibition of proteolysis of the Fc fusion were studied. Lowering of culture temperature from 37 to 30 °C alone appears to be the best solution for reducing protein degradation from the quality, cost and regulatory points of view. The obtained Fc protein was characterized and found to be in its stable folded state, exhibiting a high affinity for its ligand and also biological and functional activities.

Importance of neonatal FcR in regulating the serum half-life of therapeutic proteins containing the Fc domain of human IgG1: a comparative study of the affinity of monoclonal antibodies and Fc-fusion proteins to human neonatal FcR.

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Suzuki, Takuo; Ishii-Watabe, Akiko; Tada, Minoru; Kobayashi, Tetsu; Kanayasu-Toyoda, Toshie; Kawanishi, Toru; Yamaguchi, Teruhide

2010-02-15

The neonatal FcR (FcRn) binds to the Fc domain of IgG at acidic pH in the endosome and protects IgG from degradation, thereby contributing to the long serum half-life of IgG. To date, more than 20 mAb products and 5 Fc-fusion protein products have received marketing authorization approval in the United States, the European Union, or Japan. Many of these therapeutic proteins have the Fc domain of human IgG1; however, the serum half-lives differ in each protein. To elucidate the role of FcRn in the pharmacokinetics of Fc domain-containing therapeutic proteins, we evaluated the affinity of the clinically used human, humanized, chimeric, or mouse mAbs and Fc-fusion proteins to recombinant human FcRn by surface plasmon resonance analysis. The affinities of these therapeutic proteins to FcRn were found to be closely correlated with the serum half-lives reported from clinical studies, suggesting the important role of FcRn in regulating their serum half-lives. The relatively short serum half-life of Fc-fusion proteins was thought to arise from the low affinity to FcRn. The existence of some mAbs having high affinity to FcRn and a short serum half-life, however, suggested the involvement of other critical factor(s) in determining the serum half-life of such Abs. We further investigated the reason for the relatively low affinity of Fc-fusion proteins to FcRn and suggested the possibility that the receptor domain of Fc-fusion protein influences the structural environment of the FcRn binding region but not of the FcgammaRI binding region of the Fc domain.

Clinical spectrum and diagnostic value of antibodies against the potassium channel related protein complex.

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Montojo, M T; Petit-Pedrol, M; Graus, F; Dalmau, J

2015-06-01

Antibodies against a protein complex that includes voltage-gated potassium channels (VGKC) have been reported in patients with limbic encephalitis, peripheral nerve hyperexcitability, Morvan's syndrome, and a large variety of neurological syndromes. In this article, a review is presented of the syndromes associated with antibodies against VGKC-related proteins and the main antigens of this protein complex, the proteins LGI1 (leucine rich glioma inactivated protein 1) and Caspr2 (contactin-associated protein-like 2). The conceptual problems and clinical implications of the description of antibodies against VGKC-related proteins other than LGI1 and Caspr2 are also discussed. Although initial studies indicated the occurrence of antibodies against VGKC, recent investigations have shown that the main antigens are a neuronal secreted protein known as LGI1 which modulates synaptic excitability, and a protein called Caspr2 located on the cell surface and processes of neurons of different brain regions, and at the juxtaparanodal region of myelinated axons. While antibodies against LGI1 preferentially associate with classical limbic encephalitis, antibodies against Caspr2 associate with a wider spectrum of symptoms, including Morvan's syndrome, peripheral nerve hyperexcitability or neuromyotonia, and limbic or more extensive encephalitis. In addition there are reports of patients with antibodies against VGKC-related proteins that are different from LGI1 or Caspr2. In these cases, the identity and location of the antigens are unknown, the syndrome association is not specific, and the response to treatment uncertain. The discovery of antigens such as LGI1 and Caspr2 has resulted in a clinical and molecular definition of the broad group of diseases previously attributed to antibodies against VGKC. Considering the literature that describes the presence of antibodies against VGKC other than LGI1 and Caspr2 proteins, we propose a practical algorithm for the diagnosis and treatment

Antibody-mediated delivery of interleukin 4 to the neo-vasculature reduces chronic skin inflammation.

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Hemmerle, Teresa; Zgraggen, Silvana; Matasci, Mattia; Halin, Cornelia; Detmar, Michael; Neri, Dario

2014-11-01

The antibody-mediated delivery of cytokines ("immunocytokines") to sites of pathological angiogenesis represents an attractive strategy for the development of innovative biopharmaceuticals, capable of modulating the activity of the immune system in cancer and in chronic inflammatory conditions. Recombinant IL4 has previously been shown to be therapeutically active in patients with psoriasis. The antibody-mediated delivery of this cytokine to sites of chronic skin inflammatory conditions should lead to an improved potency and selectivity, compared to non-targeted IL4. The therapeutic activity of F8-IL4, a fusion protein of the F8 antibody (specific to the alternatively-spliced EDA domain of fibronectin) with murine IL4, was investigated in three immunocompetent mouse models of skin inflammation: two induced by the TLR7/8 ligand imiquimod (in Balb/c and C57BL/6) and one mediated by the over-expression of VEGF-A. The EDA domain of fibronectin, a marker for angiogenesis, is expressed in the inflamed skin in all three models and F8-IL4 selectively localized to inflamed skin lesions following intravenous administration. The F8-IL4 fusion protein mediated a therapeutic benefit, which was superior to the one of a non-targeted version of IL4 and led to increased levels of key regulatory cytokines (including IL5, IL10, IL13, and IL27) in the inflamed skin, while IL2 levels were not affected in all treatment groups. A murine version of etanercept and a murine anti-IL17 antibody were used as positive control in the therapy experiments. Skin inflammatory lesions can be selectively targeted using anti-EDA antibody-cytokine fusion proteins and the pharmacodelivery of IL4 confers a therapeutic benefit by shifting the cytokine balance. Copyright © 2014 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Production and characterization of polyclonal antibody against a synthetic peptide from β-actin protein

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Nazila Amini

2014-06-01

Full Text Available Objective(s:Antibodies against actin, as one of the most widely studied structural and multifunctional housekeeping proteins in eukaryotic cells, are used as internal loading controls in western blot analyses. The aim of this study was to produce polyclonal antibody against a synthetic peptide derived from N-terminal region of β-actin protein to be used as a protein loading control in western blot and other assay systems. Materials and Methods: A synthetic peptide derived from β-actin protein was designed and conjugated to Keyhole limpet hemocyanin (KLH (and used to immunize a white New Zealand rabbit. The antibody was purified from serum by affinity chromatography column. The purity of the antibody was determined by SDS-PAGE and its ability to recognize the immunizing peptide was measured by ELISA. The reactivity of the antibody with β-actin protein in a panel of different cell lysates was then evaluated by western blot. In addition, the reactivity of the antibody with the corresponding protein was also evaluated by Immunocytochemistry and Immunohistochemistry in different samples. Results: The antibody could recognize the immunizing peptide in ELISA. It could also recognize            β-actin protein in western blot as well as in immunocytochemistry and immunohistochemistry. Conclusion: Our data suggest that this antibody may be used as an internal control in western blot analyses as well as in other immunological applications such as ELISA,immunocytochemistry and immunohistochemistry.

Characterization of the stability and bio-functionality of tethered proteins on bioengineered scaffolds: implications for stem cell biology and tissue repair.

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Wang, Ting-Yi; Bruggeman, Kiara A F; Sheean, Rebecca K; Turner, Bradley J; Nisbet, David R; Parish, Clare L

2014-05-23

Various engineering applications have been utilized to deliver molecules and compounds in both innate and biological settings. In the context of biological applications, the timely delivery of molecules can be critical for cellular and organ function. As such, previous studies have demonstrated the superiority of long-term protein delivery, by way of protein tethering onto bioengineered scaffolds, compared with conventional delivery of soluble protein in vitro and in vivo. Despite such benefits little knowledge exists regarding the stability, release kinetics, longevity, activation of intracellular pathway, and functionality of these proteins over time. By way of example, here we examined the stability, degradation and functionality of a protein, glial-derived neurotrophic factor (GDNF), which is known to influence neuronal survival, differentiation, and neurite morphogenesis. Enzyme-linked immunosorbent assays (ELISA) revealed that GDNF, covalently tethered onto polycaprolactone (PCL) electrospun nanofibrous scaffolds, remained present on the scaffold surface for 120 days, with no evidence of protein leaching or degradation. The tethered GDNF protein remained functional and capable of activating downstream signaling cascades, as revealed by its capacity to phosphorylate intracellular Erk in a neural cell line. Furthermore, immobilization of GDNF protein promoted cell survival and differentiation in culture at both 3 and 7 days, further validating prolonged functionality of the protein, well beyond the minutes to hours timeframe observed for soluble proteins under the same culture conditions. This study provides important evidence of the stability and functionality kinetics of tethered molecules. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Development of microLIPS (Luciferase Immunoprecipitation Systems): a novel microfluidic assay for rapid serum antibody detection

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Chandrangsu, Matt; Burbelo, Peter D.; Iadarola, Michael J.; Smith, Paul D.; Morgan, Nicole Y.

2012-06-01

There is considerable interest in the development of rapid, point-of-care antibody detection for the diagnosis of infectious and auto-immune diseases. In this paper, we present work on the development of a self-contained microfluidic format for the Luciferase Immunoprecipitation Systems (LIPS) assay. Whereas the majority of immunoassays for antigen-specific antibodies employ either bacteria- or yeast-expressed proteins and require the use of secondary antibodies, the LIPS technique uses a fusion protein comprised of a Renilla luciferase reporter and the antigen of interest produced via mammalian cell culture, ensuring the addition of mammalian post-translational modifications. Patient serum is mixed with the fusion protein and passed over immobilized Protein A/G; after washing, the only remaining luciferase-tagged antigens are those retained by specific antibodies. These can be quantitatively measured using chemiluminescence upon the introduction of coelenterazine. The assay has been successfully employed for a wide variety of diseases in a microwell format. We report on a recent demonstration of rapid HSV-2 diagnosis with the LIPS assay in a microfluidic format, using one microliter of serum and obtaining results in under ten minutes. We will also discuss recent progress on two fronts, both aimed at the deployment of this technology in the field: first, simplifying assay operation through the automation of flow control using power-free means; and second, efforts to increase signal levels, primarily through strategies to increase antibody binding capacity, in order to move towards portable battery powered electronics.

Enterotoxigenic Escherichia coli Adhesin-Toxoid Multiepitope Fusion Antigen CFA/I/II/IV-3xSTaN12S-mnLTG192G/L211A-Derived Antibodies Inhibit Adherence of Seven Adhesins, Neutralize Enterotoxicity of LT and STa Toxins, and Protect Piglets against Diarrhea.

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Nandre, Rahul; Ruan, Xiaosai; Lu, Ti; Duan, Qiangde; Sack, David; Zhang, Weiping

2018-03-01

Enterotoxigenic Escherichia coli (ETEC) strains are a leading cause of children's diarrhea and travelers' diarrhea. Vaccines inducing antibodies to broadly inhibit bacterial adherence and to neutralize toxin enterotoxicity are expected to be effective against ETEC-associated diarrhea. 6×His-tagged adhesin-toxoid fusion proteins were shown to induce neutralizing antibodies to several adhesins and LT and STa toxins (X. Ruan, D. A. Sack, W. Zhang, PLoS One 10:e0121623, 2015, https://doi.org/10.1371/journal.pone.0121623). However, antibodies derived from His-tagged CFA/I/II/IV-2xSTa A14Q -dmLT or CFA/I/II/IV-2xSTa N12S -dmLT protein were less effective in neutralizing STa enterotoxicity and were not evaluated in vivo for efficacy against ETEC diarrhea. Additionally, His-tagged proteins are considered less desirable for human vaccines. In this study, we produced a tagless adhesin-toxoid MEFA (multiepitope fusion antigen) protein, enhanced anti-STa immunogenicity by including a third copy of STa toxoid STa N12S , and examined antigen immunogenicity in a murine model. Moreover, we immunized pregnant pigs with the tagless adhesin-toxoid MEFA protein and evaluated passive antibody protection against STa + or LT + ETEC infection in a pig challenge model. Results showed that tagless adhesin-toxoid MEFA CFA/I/II/IV-3xSTa N12S -mnLT R192G/L211A induced broad antiadhesin and antitoxin antibody responses in the intraperitoneally immunized mice and the intramuscularly immunized pigs. Mouse and pig serum antibodies significantly inhibited adherence of seven colonization factor antigen (CFA) adhesins (CFA/I and CS1 to CS6) and effectively neutralized both toxins. More importantly, suckling piglets born to the immunized mothers acquired antibodies and were protected against STa + ETEC and LT + ETEC diarrhea. These results indicated that tagless CFA/I/II/IV-3xSTa N12S -mnLT R192G/L211A induced broadly protective antiadhesin and antitoxin antibodies and demonstrate that this adhesin

Binding of monoclonal antibody to protein antigen in fluid phase or bound to solid supports

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Kennel, S J

1982-01-01

Rat monoclonal antibody (MoAb) to fragment D (FgD) of human fibrinogen was used to characterize the direct binding of antibody to protein in solution or bound to solid supports. Purified IgG, F(ab')/sub 2/ and Fab' were prepared from ascites fluid of hybridoma 104-14B which is a fusion product of spleen cells from a rat immunized with FgD and the mouse myeloma cell line, P3-X63-Ag8. Two-dimensional electrophoresis of radioiodinated antibody preparations demonstrated the presence of hybrid immunoglobulin molecules, but only structures having rat heavy and rat light chains had active antibody combinig sites. The affinity constant for IgG as well as F(ab')/sub 2/ and Fab', 6x10/sup 9/ M/sup -1/, was identical when tested using fluid phase antigen (/sup 125/I-labeled FgD). Affinity constants determined for direct binding of iodinated IgG using FgD immobilized on solid supports showed a slight dependence on the antigen concentration used in the measurement. These values ranged from 0.5x10/sup 9/ M/sup -1/ at high antigen concentrations (1.3x10/sup -7/ M) to 9x10/sup 9/ M/sup -1/ at low antigen concentration (1.3x10/sup -10/ M). Binding constants for F(ab')/sub 2/ and Fab' gave similar results indicating that binding was homogeneous and univalent. The capacity of solid state antigen to bind antibody varied with the method used to bind FgD to the solid support. FgD bound directly to polystyrene plates was least efficient at binding labeled antibody; FgD bound to plates through intermediate carriers poly(L-lysine) was only slightly more efficient, while antigen bound to Sepharose beads by cyanogen bromide activation was the most active.

Immunogenicity of Recombinant Proteins Consisting of Plasmodium vivax Circumsporozoite Protein Allelic Variant-Derived Epitopes Fused with Salmonella enterica Serovar Typhimurium Flagellin

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Leal, Monica Teixeira Andrade; Camacho, Ariane Guglielmi Ariza; Teixeira, Laís Helena; Bargieri, Daniel Youssef; Soares, Irene Silva; Tararam, Cibele Aparecida

2013-01-01

A Plasmodium falciparum circumsporozoite protein (CSP)-based recombinant fusion vaccine is the first malaria vaccine to reach phase III clinical trials. Resistance to infection correlated with the production of antibodies to the immunodominant central repeat region of the CSP. In contrast to P. falciparum, vaccine development against the CSP of Plasmodium vivax malaria is far behind. Based on this gap in our knowledge, we generated a recombinant chimeric protein containing the immunodominant central repeat regions of the P. vivax CSP fused to Salmonella enterica serovar Typhimurium-derived flagellin (FliC) to activate the innate immune system. The recombinant proteins that were generated contained repeat regions derived from each of the 3 different allelic variants of the P. vivax CSP or a fusion of regions derived from each of the 3 allelic forms. Mice were subcutaneously immunized with the fusion proteins alone or in combination with the Toll-like receptor 3 (TLR-3) agonist poly(I·C), and the anti-CSP serum IgG response was measured. Immunization with a mixture of the 3 recombinant proteins, each containing immunodominant epitopes derived from a single allelic variant, rather than a single recombinant protein carrying a fusion of regions derived from each of 3 allelic forms elicited a stronger immune response. This response was independent of TLR-4 but required TLR-5/MyD88 activation. Antibody titers significantly increased when poly(I·C) was used as an adjuvant with a mixture of the 3 recombinant proteins. These recombinant fusion proteins are novel candidates for the development of an effective malaria vaccine against P. vivax. PMID:23863502

Activated microglia induce bone marrow mesenchymal stem cells to produce glial cell-derived neurotrophic factor and protect neurons against oxygen-glucose deprivation injury

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Bingke Lv

2016-12-01

Full Text Available In this study, we investigated interactions among microglia (MG, bone marrow mesenchymal stem cells (BMSCs and neurons in cerebral ischemia and the potential mechanisms using an in vitro oxygen-glucose deprivation (OGD model. Rat BMSCs were incubated with conditioned medium (CM from in vitro cultures of OGD-activated rat MG and murine BV2 MG cells. Effects of glial cell-derived neurotrophic factor (GDNF on rat neuron viability, apoptosis, lactate dehydrogenase (LDH leakage and mitochondrial membrane potential (MMP were analyzed in this model. OGD-activated MG promoted GDNF production by BMSCs (P < 0.01. TNFα, but not IL6 or IL1β, promoted GDNF production by BMSCs (P < 0.001. GDNF or CM pre-treated BMSCs elevated neuronal viability and suppressed apoptosis (P < 0.05 or P < 0.01; these effects were inhibited by the RET antibody. GDNF activated MEK/ERK and PI3K/AKT signaling but not JNK/c-JUN. Furthermore, GDNF upregulated B cell lymphoma 2 (BCL2 and heat shock 60 kDa protein 1 (HSP60 levels, suppressed LDH leakage, and promoted MMP. Thus, activated MG produce TNFα to stimulate GDNF production by BMSCs, which prevents and repairs OGD-induced neuronal injury, possibly via regulating MEK/ERK and PI3K/AKT signaling. These findings will facilitate the prevention and treatment of neuronal injury by cerebral ischemia.

Targeting to cells of fluorescent liposomes covalently coupled with monoclonal antibody or protein A

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Leserman, Lee D.; Barbet, Jacques; Kourilsky, François; Weinstein, John N.

1980-12-01

Many applications envisioned for liposomes in cell biology and chemotherapy require their direction to specific cellular targets1-3. The ability to use antibody as a means of conferring specificity to liposomes would markedly increase their usefulness. We report here a method for covalently coupling soluble proteins, including monoclonal antibody and Staphylococcus aureus protein A (ref. 4), to small sonicated liposomes, by using the heterobifunctional cross-linking reagent N-hydroxysuccinimidyl 3-(2-pyridyldithio)propionate (SPDP, Pharmacia). Liposomes bearing covalently coupled mouse monoclonal antibody against human β2-microglobulin [antibody B1.1G6 (IgG2a, κ) (B. Malissen et al., in preparation)] bound specifically to human, but not to mouse cells. Liposomes bearing protein A became bound to human cells previously incubated with the B1.1G6 antibody, but not to cells incubated without antibody. The coupling method results in efficient binding of protein to the liposomes without aggregation and without denaturation of the coupled ligand; at least 60% of liposomes bound functional protein. Further, liposomes did not leak encapsulated carboxyfluorescein (CF) as a consequence of the reaction.

A Halotyrosine Antibody that Detects Increased Protein Modifications in Asthma Patients

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Jin, Hongjun; Hallstrand, Teal S.; Daly, Don S.; Matzke, Melissa M.; Nair, Parameswaran; Bigelow, Diana J.; Pounds, Joel G.; Zangar, Richard C.

2014-01-31

Background-Airway inflammation plays an important pathophysiological role in asthma. Eosinophils produce hypobromite and bromotyrosine while neutrophils produce hypochlorite and chlorotyrosine. Objective-To evaluate halotyrosine modifications of individual airway proteins as a marker of inflammation in asthma using an antibody-based assay. Methods-We developed a novel monoclonal antibody (BTK-94C) that binds halogenated tyrosine residues, and used this antibody in a custom enzyme-linked immunosorbent assay (ELISA) microarray platform to examine halotyrosine levels in 23 proteins in three independent sets of sputum samples (52 samples total). Results-In 15 subjects with either no asthma, or with asthma characterized by high or low sputum eosinophil counts, we found associations between increased halotyrosine levels of at least three proteins and severity of airway hyperresponsiveness (AHR). Treatment with mepolizumab in 17 patients with sputum eosinophilia markedly reduced the sputum eosinophilia and significantly reduced halotyrosine levels in one sputum protein. Further analysis of 10 subjects with neutrophilic asthma and 10 health controls demonstrated a broad increase in halotyrosine in the patients with airway neutrophilia. Conclusions-Significantly higher levels of halotyrosine are associated with asthma in the asthma phenotypes we examined. The halotyrosine levels correlated with indirect AHR in the form of exercise-induced bronchoconstriction. Clinical Implication-An antibody-based assay for tyrosine halogenation in specific proteins may prove useful for assessing airway inflammation in asthma. Capsule Summary-An antibody to measure protein monobrominated tyrosine and other halotyrosine modifications was developed and used to evaluate halogenation in specific proteins in the airways for the first time. Associations were found between levels of halotyrosine and exercise-induced bronchoconstriction, and eosinophil and neutrophil inflammation in sputum from

Induction of protein body formation in plant leaves by elastin-like polypeptide fusions

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Joensuu Jussi J

2009-08-01

Full Text Available Abstract Background Elastin-like polypeptides are synthetic biopolymers composed of a repeating pentapeptide 'VPGXG' sequence that are valuable for the simple non-chromatographic purification of recombinant proteins. In addition, elastin-like polypeptide fusions have been shown to enhance the accumulation of a range of different recombinant proteins in plants, thus addressing the major limitation of plant-based expression systems, which is a low production yield. This study's main objectives were to determine the general utility of elastin-like polypeptide protein fusions in various intracellular compartments and to elucidate elastin-like polypeptide's mechanism of action for increasing recombinant protein accumulation in the endoplasmic reticulum of plants. Results The effect of elastin-like polypeptide fusions on the accumulation of green fluorescent protein targeted to the cytoplasm, chloroplasts, apoplast, and endoplasmic reticulum was evaluated. The endoplasmic reticulum was the only intracellular compartment in which an elastin-like polypeptide tag was shown to significantly enhance recombinant protein accumulation. Interestingly, endoplasmic reticulum-targeted elastin-like polypeptide fusions induced the formation of a novel type of protein body, which may be responsible for elastin-like polypeptide's positive effect on recombinant protein accumulation by excluding the heterologous protein from normal physiological turnover. Although expressed in the leaves of plants, these novel protein bodies appeared similar in size and morphology to the prolamin-based protein bodies naturally found in plant seeds. The elastin-like polypeptide-induced protein bodies were highly mobile organelles, exhibiting various dynamic patterns of movement throughout the cells, which were dependent on intact actin microfilaments and a functional actomyosin motility system. Conclusion An endoplasmic reticulum-targeted elastin-like polypeptide fusion approach

Analyses of functions of an anti-PD-L1/TGFβR2 bispecific fusion protein (M7824).

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Jochems, Caroline; Tritsch, Sarah R; Pellom, Samuel Troy; Su, Zhen; Soon-Shiong, Patrick; Wong, Hing C; Gulley, James L; Schlom, Jeffrey

2017-09-26

M7824 (MSB0011359C) is a novel first-in-class bifunctional fusion protein consisting of a fully human IgG1 anti-PD-L1 monoclonal antibody (with structural similarities to avelumab) linked to the extracellular domain of two TGFβ receptor 2 (TGFβR2) molecules serving as a TGFβ Trap. Avelumab has demonstrated clinical activity in a range of human cancers and has been approved by the Food and Drug Administration for the therapy of Merkel cell and bladder carcinomas. Preclinical studies have shown this anti-PD-L1 is capable of mediating antibody-dependent cell-mediated cytotoxicity (ADCC). In the studies reported here, it is shown that M7824 is also capable of mediating ADCC of a wide range of human carcinoma cells in vitro , employing natural killer (NK) cells as effectors, albeit not as potent as anti-PD-L1 employing some tumor cells as targets. The addition of the IL-15 superagonist fusion protein complex ALT-803 enhanced the ADCC capacity of both anti-PD-L1 and M7824, and to levels that both agents now demonstrated similar levels of ADCC of tumor cells. TGFβ is a known immunosuppressive entity. Studies reported here show TGFβ1 induced reduction of several NK activation markers as well as reduction of endogenous NK lytic activity and NK-mediated ADCC of tumor cells. These phenomena could be reduced or mitigated, however, by M7824, but not by anti-PD-L1. M7824, but not anti-PD-L1, was also shown to reduce the immunosuppressive activity of regulatory T cells on human CD4 + T-cell proliferation. These studies thus demonstrate the dual functionalities of M7824 and provide the rationale for its further clinical development.

Rational design of an EGF-IL18 fusion protein: Implication for developing tumor therapeutics

International Nuclear Information System (INIS)

Lu Jianxin; Peng Ying; Meng Zhefeng; Jin Liqin; Lu Yongsui; Guan Minxin

2005-01-01

Interleukin-18 (IL-18) is a proinflammatory cytokine. This protein has a role in regulating immune responses and exhibits significant anti-tumor activities. Epidermal growth factor (EGF) is an important growth factor that plays a central role in the regulation of cell cycle and differentiation. It was proposed that a targeted delivery of IL-18 by generation of IL-18-EGF fusion protein might decrease adverse effects and result in enhancing cytotoxic and antitumor activities. In the present study, a fusion protein, consisting of EGFR binding domain fused to human IL-18 mature peptide via a linker peptide of (Gly 4 Ser) 3, was constructed and expressed in the insect cell line Sf9 using Bac-to-Bac baculovirus expression system. We showed that the purified recombinant fusion protein induced similar levels of IFN-γ to that of native IL-18 protein in human PBMC in the presence of ConA. Furthermore, EGF receptor competitive test in human epithelial cancer A431 cell line showed that EGF-IL18 fusion protein can specifically bind with EGFR by competing with native EGF protein. These suggest that this rationally designed protein can be further developed as novel tumor therapeutics

Elevated temperature triggers human respiratory syncytial virus F protein six-helix bundle formation

International Nuclear Information System (INIS)

Yunus, Abdul S.; Jackson, Trent P.; Crisafi, Katherine; Burimski, Irina; Kilgore, Nicole R.; Zoumplis, Dorian; Allaway, Graham P.; Wild, Carl T.; Salzwedel, Karl

2010-01-01

Human respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infection in infants, immunocompromised patients, and the elderly. The RSV fusion (F) protein mediates fusion of the viral envelope with the target cell membrane during virus entry and is a primary target for antiviral drug and vaccine development. The F protein contains two heptad repeat regions, HR1 and HR2. Peptides corresponding to these regions form a six-helix bundle structure that is thought to play a critical role in membrane fusion. However, characterization of six-helix bundle formation in native RSV F protein has been hindered by the fact that a trigger for F protein conformational change has yet to be identified. Here we demonstrate that RSV F protein on the surface of infected cells undergoes a conformational change following exposure to elevated temperature, resulting in the formation of the six-helix bundle structure. We first generated and characterized six-helix bundle-specific antibodies raised against recombinant peptides modeling the RSV F protein six-helix bundle structure. We then used these antibodies as probes to monitor RSV F protein six-helix bundle formation in response to a diverse array of potential triggers of conformational changes. We found that exposure of 'membrane-anchored' RSV F protein to elevated temperature (45-55 deg. C) was sufficient to trigger six-helix bundle formation. Antibody binding to the six-helix bundle conformation was detected by both flow cytometry and cell-surface immunoprecipitation of the RSV F protein. None of the other treatments, including interaction with a number of potential receptors, resulted in significant binding by six-helix bundle-specific antibodies. We conclude that native, untriggered RSV F protein exists in a metastable state that can be converted in vitro to the more stable, fusogenic six-helix bundle conformation by an increase in thermal energy. These findings help to better define the mechanism of

Axon Guidance of Sympathetic Neurons to Cardiomyocytes by Glial Cell Line-Derived Neurotrophic Factor (GDNF)

NARCIS (Netherlands)

Miwa, Keiko; Lee, Jong-Kook; Takagishi, Yoshiko; Opthof, Tobias; Fu, Xianming; Hirabayashi, Masumi; Watabe, Kazuhiko; Jimbo, Yasuhiko; Kodama, Itsuo; Komuro, Issei

2013-01-01

Molecular signaling of cardiac autonomic innervation is an unresolved issue. Here, we show that glial cell line-derived neurotrophic factor (GDNF) promotes cardiac sympathetic innervation in vitro and in vivo. In vitro, ventricular myocytes (VMs) and sympathetic neurons (SNs) isolated from neonatal

A fluorescent cassette-based strategy for engineering multiple domain fusion proteins

Directory of Open Access Journals (Sweden)

Khorchid Ahmad

2003-07-01

Full Text Available Abstract Background The engineering of fusion proteins has become increasingly important and most recently has formed the basis of many biosensors, protein purification systems, and classes of new drugs. Currently, most fusion proteins consist of three or fewer domains, however, more sophisticated designs could easily involve three or more domains. Using traditional subcloning strategies, this requires micromanagement of restriction enzymes sites that results in complex workaround solutions, if any at all. Results Therefore, to aid in the efficient construction of fusion proteins involving multiple domains, we have created a new expression vector that allows us to rapidly generate a library of cassettes. Cassettes have a standard vector structure based on four specific restriction endonuclease sites and using a subtle property of blunt or compatible cohesive end restriction enzymes, they can be fused in any order and number of times. Furthermore, the insertion of PCR products into our expression vector or the recombination of cassettes can be dramatically simplified by screening for the presence or absence of fluorescence. Conclusions Finally, the utility of this new strategy was demonstrated by the creation of basic cassettes for protein targeting to subcellular organelles and for protein purification using multiple affinity tags.

Fusion protein-based biofilm fabrication composed of recombinant azurin–myoglobin for dual-level biomemory application

Energy Technology Data Exchange (ETDEWEB)

Lee, Taek [Research Institute for Basic Science, Sogang University, Heukseok-dong, Dongjak-gu, Seoul 156-756 (Korea, Republic of); Chung, Yong-Ho; Yoon, Jinho [Department of Chemical and Biomolecular Engineering, Sogang University, Heukseok-dong, Dongjak-gu, 35 Baekbeom-ro (Sinsu-dong), Mapo-gu, Seoul 121-742 (Korea, Republic of); Min, Junhong [School of Integrative Engineering, Chung-Ang University, Heukseok-dong, Dongjak-gu, Seoul 156-756 (Korea, Republic of); Choi, Jeong-Woo, E-mail: jwchoi@sogang.ac.kr [Department of Chemical and Biomolecular Engineering, Sogang University, Heukseok-dong, Dongjak-gu, 35 Baekbeom-ro (Sinsu-dong), Mapo-gu, Seoul 121-742 (Korea, Republic of)

2014-11-30

Graphical abstract: - Highlights: • We developed the fusion protein-based biofilm on the inorganic surface. • For making the fusion protein, the recombinant azurin and the myoglobin was conjugated by the native chemical ligation method. • The developed fusion protein shows unique electrochemical property. • The proposed fusion protein biofilm appears to be a good method for dual-level biomemory device. - Abstract: In the present study, a fusion protein-based biofilm composed of a recombinant azurin–myoglobin (Azu-Myo) has been developed and confirmed its original electrochemical property for dual-level biomemory device application. For this purpose, the azurin was modified with cysteine residues for direct immobilization and conjugation. Then, the recombinant azurin was conjugated with the myoglobin via a sulfo-SMCC bifunctional linker using the chemical ligation method (CLM). The SDS-PAGE and UV–vis spectroscopy were performed to examine the fusion protein conjugates. The prepared Azu-Myo fusion protein was self-assembled onto Au substrate for the biofilm fabrication. Then, the atomic force microscopy (AFM) was used to confirm the immobilization and the surface-enhanced Raman spectroscopy (SERS) was carried out to the surface analysis. Also, the cyclic voltammetry (CV) was carried out to observe an electrochemical property of fabricated biofilm. As a result, the two pair of redox potential values was obtained for dual-level biomemory device application. Then, the dual-level biomemory function was verified by the multi-potential chronoamperometry (MPCA). The results indicate a new fabrication method and material combination for advances in bioelectronic device development.

Fusion protein-based biofilm fabrication composed of recombinant azurin–myoglobin for dual-level biomemory application

International Nuclear Information System (INIS)

Lee, Taek; Chung, Yong-Ho; Yoon, Jinho; Min, Junhong; Choi, Jeong-Woo

2014-01-01

Graphical abstract: - Highlights: • We developed the fusion protein-based biofilm on the inorganic surface. • For making the fusion protein, the recombinant azurin and the myoglobin was conjugated by the native chemical ligation method. • The developed fusion protein shows unique electrochemical property. • The proposed fusion protein biofilm appears to be a good method for dual-level biomemory device. - Abstract: In the present study, a fusion protein-based biofilm composed of a recombinant azurin–myoglobin (Azu-Myo) has been developed and confirmed its original electrochemical property for dual-level biomemory device application. For this purpose, the azurin was modified with cysteine residues for direct immobilization and conjugation. Then, the recombinant azurin was conjugated with the myoglobin via a sulfo-SMCC bifunctional linker using the chemical ligation method (CLM). The SDS-PAGE and UV–vis spectroscopy were performed to examine the fusion protein conjugates. The prepared Azu-Myo fusion protein was self-assembled onto Au substrate for the biofilm fabrication. Then, the atomic force microscopy (AFM) was used to confirm the immobilization and the surface-enhanced Raman spectroscopy (SERS) was carried out to the surface analysis. Also, the cyclic voltammetry (CV) was carried out to observe an electrochemical property of fabricated biofilm. As a result, the two pair of redox potential values was obtained for dual-level biomemory device application. Then, the dual-level biomemory function was verified by the multi-potential chronoamperometry (MPCA). The results indicate a new fabrication method and material combination for advances in bioelectronic device development

The equine herpesvirus-1 IR3 gene that lies antisense to the sole immediate-early (IE) gene is trans-activated by the IE protein, and is poorly expressed to a protein

International Nuclear Information System (INIS)

Ahn, Byung Chul; Breitenbach, Jonathan E.; Kim, Seong K.; O'Callaghan, Dennis J.

2007-01-01

The unique IR3 gene of equine herpesvirus 1 (EHV-1) is expressed as a late 1.0-kb transcript. Previous studies confirmed the IR3 transcription initiation site and tentatively identified other cis-acting elements specific to IR3 such as a TATA box, a 443 base pair 5'untranslated region (UTR), a 285 base pair open reading frame (ORF), and a poly adenylation (A) signal [Holden, V.R., Harty, R.N., Yalamanchili, R.R., O'Callaghan, D.J., 1992. The IR3 gene of equine herpesvirus type 1: a unique gene regulated by sequences within the intron of the immediate-early gene. DNA Seq. 3, 143-152]. Transient transfection assays revealed that the IR3 promoter is strongly trans-activated by the IE protein (IEP) and that coexpression of the IEP with the early EICP0 and IR4 regulatory proteins results in maximal trans-activation of the IR3 promoter. Gel shift assays revealed that the IEP directly binds to the IR3 promoter region. Western blot analysis showed that the IR3 protein produced in E. coli was detected by antibodies to IR3 synthetic peptides; however, the IR3 protein was not detected in EHV-1 infected cell extracts by these same anti-IR3 antibodies, even though the IR3 transcript was detected by northern blot. These findings suggest that the IR3 may not be expressed to a protein. Expression of an IR3/GFP fusion gene was not observed, but expression of a GFP/IR3 fusion gene was detected by fluorescent microscopy. In further attempts to detect the IR3/GFP fusion protein using anti-GFP antibody, western blot analysis showed that the IR3/GFP fusion protein was not detected in vivo. Interestingly, a truncated form of the GFP/IR3 protein was synthesized from the GFP/IR3 fusion gene. However, GFP/IR3 and IR3/GFP fusion proteins of the predicted sizes were synthesized by in vitro coupled transcription and translation of the fusion genes, suggesting poor expression of the IR3 protein in vivo. The possible role of the IR3 transcript in EHV-1 infection is discussed

In vivo immobilization of fusion proteins on bioplastics by the novel tag BioF.

Science.gov (United States)

Moldes, Cristina; García, Pedro; García, José L; Prieto, María A

2004-06-01

A new protein immobilization and purification system has been developed based on the use of polyhydroxyalkanoates (PHAs, or bioplastics), which are biodegradable polymers accumulated as reserve granules in the cytoplasm of certain bacteria. The N-terminal domain of the PhaF phasin (a PHA-granule-associated protein) from Pseudomonas putida GPo1 was used as a polypeptide tag (BioF) to anchor fusion proteins to PHAs. This tag provides a novel way to immobilize proteins in vivo by using bioplastics as supports. The granules carrying the BioF fusion proteins can be isolated by a simple centrifugation step and used directly for some applications. Moreover, when required, a practically pure preparation of the soluble BioF fusion protein can be obtained by a mild detergent treatment of the granule. The efficiency of this system has been demonstrated by constructing two BioF fusion products, including a functional BioF-beta-galactosidase. This is the first example of an active bioplastic consisting of a biodegradable matrix carrying an active enzyme.

Effects of a superantigen-antibody recombinant fusion protein (r-C242 Fab-SEA) on toxicological responses in the anaesthetised rabbit

International Nuclear Information System (INIS)

Ilbaeck, Nils-Gunnar; Gunnarsson, Kjell; Persson, Robert; Lindh, Ulf; Staaalhandske, Torbjoern

2003-01-01

The objective was to study toxin-induced effects on physiological parameters in the rabbit and whether these parameters show dose-response and co-variation after administration of a recombinant fusion protein between staphylococcal enterotoxin (SE) and the Fab fragment of an antibody. Rabbits are very sensitive to SE toxins and the cardiovascular and immune effects are similar to those observed in septic shock in man. The test compound, r-C242 Fab-SEA, was administered intravenously to anaesthetised New Zealand white rabbits at doses in the range of 0.00005-50 μg/kg. All rabbits were checked for titres of anti-SEA antibodies before entering the experiment, since they could neutralise the effect of the test compound. Heart rate, blood pressure and body temperature were continuously monitored before and during 6 h after dosing. Immediately before the start of administration and 3 and 6 h during the experiment, blood gases (pO 2 and pCO 2 ), pH, haematology, clinical chemistry, cytokine response (TNF-α) and trace elements (Mn, Cu, Zn, Se, Ag, Cd, Hg and Pb) were measured. No mortality occurred, but at 50 μg/kg severe adverse clinical signs developed. The decrease in blood pressure was weakly dose-related. Heart rate, ECG, body temperature, pCO 2 and pH were not affected by the treatment. pO 2 tended to increase as a function of time, but not in relation to dose. WBC and PLT decreased dose dependently. TNF-α was not affected by the treatment. The major effects on clinical chemistry were a dose-dependent increase in AST and creatinine. Potassium and urea showed dose dependent increases, mainly at higher doses, though these changes were of less value for drug selection purposes. Trace element changes were observed, including an increase in Mn and a decrease of Zn at all doses. The Cu/Zn ratio decreased below normal at low doses, whereas at high doses in which adverse effects developed, it increased above normal. Post mortem examination revealed minimal to moderate

Spatiotemporal dynamics of membrane remodeling and fusion proteins during endocytic transport.

Science.gov (United States)

Arlt, Henning; Auffarth, Kathrin; Kurre, Rainer; Lisse, Dominik; Piehler, Jacob; Ungermann, Christian

2015-04-01

Organelles of the endolysosomal system undergo multiple fission and fusion events to combine sorting of selected proteins to the vacuole with endosomal recycling. This sorting requires a consecutive remodeling of the organelle surface in the course of endosomal maturation. Here we dissect the remodeling and fusion machinery on endosomes during the process of endocytosis. We traced selected GFP-tagged endosomal proteins relative to exogenously added fluorescently labeled α-factor on its way from the plasma membrane to the vacuole. Our data reveal that the machinery of endosomal fusion and ESCRT proteins has similar temporal localization on endosomes, whereas they precede the retromer cargo recognition complex. Neither deletion of retromer nor the fusion machinery with the vacuole affects this maturation process, although the kinetics seems to be delayed due to ESCRT deletion. Of importance, in strains lacking the active Rab7-like Ypt7 or the vacuolar SNARE fusion machinery, α-factor still proceeds to late endosomes with the same kinetics. This indicates that endosomal maturation is mainly controlled by the early endosomal fusion and remodeling machinery but not the downstream Rab Ypt7 or the SNARE machinery. Our data thus provide important further understanding of endosomal biogenesis in the context of cargo sorting. © 2015 Arlt et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Production of Hev b5 as a fluorescent biotin-binding tripartite fusion protein in insect cells

International Nuclear Information System (INIS)

Nordlund, Henri R.; Laitinen, Olli H.; Uotila, Sanna T.H.; Kulmala, Minna; Kalkkinen, Nisse; Kulomaa, Markku S.

2005-01-01

The presented green fluorescent protein and streptavidin core-based tripartite fusion system provides a simple and efficient way for the production of proteins fused to it in insect cells. This fusion protein forms a unique tag, which serves as a multipurpose device enabling easy optimization of production, one-step purification via streptavidin-biotin interaction, and visualization of the fusion protein during downstream processing and in applications. In the present study, we demonstrate the successful production, purification, and detection of a natural rubber latex allergen Hev b5 with this system. We also describe the production of another NRL allergen with the system, Hev b1, which formed large aggregates and gave small yields in purification. The aggregates were detected at early steps by microscopical inspection of the infected insect cells producing this protein. Therefore, this fusion system can also be utilized as a fast indicator of the solubility of the expressed fusion proteins and may therefore be extremely useful in high-throughput expression approaches

Production of Hev b5 as a fluorescent biotin-binding tripartite fusion protein in insect cells.

Science.gov (United States)

Nordlund, Henri R; Laitinen, Olli H; Uotila, Sanna T H; Kulmala, Minna; Kalkkinen, Nisse; Kulomaa, Markku S

2005-10-14

The presented green fluorescent protein and streptavidin core-based tripartite fusion system provides a simple and efficient way for the production of proteins fused to it in insect cells. This fusion protein forms a unique tag, which serves as a multipurpose device enabling easy optimization of production, one-step purification via streptavidin-biotin interaction, and visualization of the fusion protein during downstream processing and in applications. In the present study, we demonstrate the successful production, purification, and detection of a natural rubber latex allergen Hev b5 with this system. We also describe the production of another NRL allergen with the system, Hev b1, which formed large aggregates and gave small yields in purification. The aggregates were detected at early steps by microscopical inspection of the infected insect cells producing this protein. Therefore, this fusion system can also be utilized as a fast indicator of the solubility of the expressed fusion proteins and may therefore be extremely useful in high-throughput expression approaches.

Immunochemical characterization of rhesus proteins with antibodies raised against synthetic peptides.

Science.gov (United States)

Hermand, P; Mouro, I; Huet, M; Bloy, C; Suyama, K; Goldstein, J; Cartron, J P; Bailly, P

1993-07-15

Rabbit polyclonal antibodies were raised against synthetic peptides corresponding to hydrophilic regions of the human Rhesus (Rh) IX cDNA-encoded polypeptide predicted to be extracellularly or intracellularly exposed in the topologic model of the Rh blood group protein. Four antibodies encompassing residues 33-45 (MPC1), 224-233 (MPC4), 390-404 (MPC6), and 408-416 (MPC8) were characterized and compared with a polyclonal anti-Rh protein obtained by immunization with purified Rh proteins. All antibodies had specificity for authentic Rh polypeptides and reacted on Western blot with Rh proteins immunoprecipitated with human monoclonal anti-RhD, -c, and -E. MPC1, but not the other antibodies, agglutinated all human erythrocytes except Rhnull and Rhmod cells, which either lack totally or are severely deficient in Rh proteins, respectively. Immunoblotting analysis with membrane proteins from common and rare variants showed that MPC1 and MPC8 reacted in Western blot with 32-Kd Rh polypeptides from all common red blood cells except those from Rhnull and Rhmod, indicating that peptide regions 33-45 and 408-416 may be common to several if not all Rh proteins, whatever the Rh blood group specificity. MPC4 reacted only with membrane preparations from cells carrying the E antigen, whereas MPC6 recognized preferentially the Rh proteins from E and Ee preparations, suggesting that the protein encoded by the RhIXb cDNA carries the E and/or e antigen(s). Immunoadsorption experiments using inside-out or right-side-out sealed vesicules from DccEE red blood cells as competing antigen showed that the MPC6 and MPC8 antibodies bound only to the cytoplasmic side of the erythrocyte membrane, thus providing evidence for the intracellular orientation of the C-terminal 27 residues of the Rh polypeptides. Attempts to transiently or stably express the Rh polypeptides. Attempts to transiently or stably express the Rh cDNA in eukaryotic cells were largely unsuccessful, suggesting that Rh antigen

Fusion protein is the main determinant of metapneumovirus host tropism.

Science.gov (United States)

de Graaf, Miranda; Schrauwen, Eefje J A; Herfst, Sander; van Amerongen, Geert; Osterhaus, Albert D M E; Fouchier, Ron A M

2009-06-01

Human metapneumovirus (HMPV) and avian metapneumovirus subgroup C (AMPV-C) infect humans and birds, respectively. This study confirmed the difference in host range in turkey poults, and analysed the contribution of the individual metapneumovirus genes to host range in an in vitro cell-culture model. Mammalian Vero-118 cells supported replication of both HMPV and AMPV-C in contrast to avian quail fibroblast (QT6) cells in which only AMPV-C replicated to high titres. Inoculation of Vero-118 and QT6 cells with recombinant HMPV in which genes were exchanged with those of AMPV-C revealed that the metapneumovirus fusion (F) protein is the main determinant for host tropism. Chimeric viruses in which polymerase complex proteins were exchanged between HMPV and AMPV-C replicated less efficiently compared with HMPV in QT6 cells. Using mini-genome systems, it was shown that exchanging these polymerase proteins resulted in reduced replication and transcription efficiency in QT6 cells. Examination of infected Vero-118 and QT6 cells revealed that viruses containing the F protein of AMPV-C yielded larger syncytia compared with viruses containing the HMPV F protein. Cell-content mixing assays revealed that the F protein of AMPV-C was more fusogenic compared with the F protein of HMPV, and that the F2 region is responsible for the difference observed between AMPV-C and HMPV F-promoted fusion in QT6 and Vero-118 cells. This study provides insight into the determinants of host tropism and membrane fusion of metapneumoviruses.

Brain stem slice conditioned medium contains endogenous BDNF and GDNF that affect neural crest boundary cap cells in co-culture.

Science.gov (United States)

Kaiser, Andreas; Kale, Ajay; Novozhilova, Ekaterina; Siratirakun, Piyaporn; Aquino, Jorge B; Thonabulsombat, Charoensri; Ernfors, Patrik; Olivius, Petri

2014-05-30

Conditioned medium (CM), made by collecting medium after a few days in cell culture and then re-using it to further stimulate other cells, is a known experimental concept since the 1950s. Our group has explored this technique to stimulate the performance of cells in culture in general, and to evaluate stem- and progenitor cell aptitude for auditory nerve repair enhancement in particular. As compared to other mediums, all primary endpoints in our published experimental settings have weighed in favor of conditioned culture medium, where we have shown that conditioned culture medium has a stimulatory effect on cell survival. In order to explore the reasons for this improved survival we set out to analyze the conditioned culture medium. We utilized ELISA kits to investigate whether brain stem (BS) slice CM contains any significant amounts of brain-derived neurotrophic factor (BDNF) and glial cell derived neurotrophic factor (GDNF). We further looked for a donor cell with progenitor characteristics that would be receptive to BDNF and GDNF. We chose the well-documented boundary cap (BC) progenitor cells to be tested in our in vitro co-culture setting together with cochlear nucleus (CN) of the BS. The results show that BS CM contains BDNF and GDNF and that survival of BC cells, as well as BC cell differentiation into neurons, were enhanced when BS CM were used. Altogether, we conclude that BC cells transplanted into a BDNF and GDNF rich environment could be suitable for treatment of a traumatized or degenerated auditory nerve. Copyright © 2014 Elsevier B.V. All rights reserved.

Tumour auto-antibody screening: performance of protein microarrays using SEREX derived antigens

International Nuclear Information System (INIS)

Stempfer, René; Weinhäusel, Andreas; Syed, Parvez; Vierlinger, Klemens; Pichler, Rudolf; Meese, Eckart; Leidinger, Petra; Ludwig, Nicole; Kriegner, Albert; Nöhammer, Christa

2010-01-01

The simplicity and potential of minimal invasive testing using serum from patients make auto-antibody based biomarkers a very promising tool for use in diagnostics of cancer and auto-immune disease. Although several methods exist for elucidating candidate-protein markers, immobilizing these onto membranes and generating so called macroarrays is of limited use for marker validation. Especially when several hundred samples have to be analysed, microarrays could serve as a good alternative since processing macro membranes is cumbersome and reproducibility of results is moderate. Candidate markers identified by SEREX (serological identification of antigens by recombinant expression cloning) screenings of brain and lung tumour were used for macroarray and microarray production. For microarray production recombinant proteins were expressed in E. coli by autoinduction and purified His-tag (histidine-tagged) proteins were then used for the production of protein microarrays. Protein arrays were hybridized with the serum samples from brain and lung tumour patients. Methods for the generation of microarrays were successfully established when using antigens derived from membrane-based selection. Signal patterns obtained by microarrays analysis of brain and lung tumour patients' sera were highly reproducible (R = 0.92-0.96). This provides the technical foundation for diagnostic applications on the basis of auto-antibody patterns. In this limited test set, the assay provided high reproducibility and a broad dynamic range to classify all brain and lung samples correctly. Protein microarray is an efficient means for auto-antibody-based detection when using SEREX-derived clones expressing antigenic proteins. Protein microarrays are preferred to macroarrays due to the easier handling and the high reproducibility of auto-antibody testing. Especially when using only a few microliters of patient samples protein microarrays are ideally suited for validation of auto-antibody

Measles Virus Fusion Protein: Structure, Function and Inhibition

Directory of Open Access Journals (Sweden)

Philippe Plattet

2016-04-01

Full Text Available Measles virus (MeV, a highly contagious member of the Paramyxoviridae family, causes measles in humans. The Paramyxoviridae family of negative single-stranded enveloped viruses includes several important human and animal pathogens, with MeV causing approximately 120,000 deaths annually. MeV and canine distemper virus (CDV-mediated diseases can be prevented by vaccination. However, sub-optimal vaccine delivery continues to foster MeV outbreaks. Post-exposure prophylaxis with antivirals has been proposed as a novel strategy to complement vaccination programs by filling herd immunity gaps. Recent research has shown that membrane fusion induced by the morbillivirus glycoproteins is the first critical step for viral entry and infection, and determines cell pathology and disease outcome. Our molecular understanding of morbillivirus-associated membrane fusion has greatly progressed towards the feasibility to control this process by treating the fusion glycoprotein with inhibitory molecules. Current approaches to develop anti-membrane fusion drugs and our knowledge on drug resistance mechanisms strongly suggest that combined therapies will be a prerequisite. Thus, discovery of additional anti-fusion and/or anti-attachment protein small-molecule compounds may eventually translate into realistic therapeutic options.

[Research progress in hirudin fusion protein--review].

Science.gov (United States)

Zhang, Chuan-Ling; Yu, Ai-Ping; Jin, Ji-De; Wu, Chu-Tse

2007-02-01

Natural hirudin extracted from the secretion of medical leech salivary gland is a single-chain peptide containing 65 aminoacid residues with molecular weight of 7000 D, and exists in three isomers of HV1, HV2 and HV3. Hirudin possesses three disulfide bridges forming the structure of core cyclic peptides, which binds to the catalytic site of thrombin so as to inhibit the catalysis of thrombin. Its c-terminus rich in acidic aminoacid residues possesses hydrophilicity, and is free on the molecular surface, and can bind with fibrin recognition site of hirudin. The minimal segment of 12 - 16 C-terminal acidic residues keeps the minimal activity of anti-thrombosis. Thus, hirudin, as a potent and specific inhibitor of thrombin, can be used to protect from and to treat clinically thrombosis. As it has some disadvantages such as short half-life, bleeding side-effect and mono-function, and so on, hirudin has been fused with some other functional proteins in recent years. The obtained fusion proteins can prolong the half life of hirudin, or relieve it bleeding side effect, or bring new functions, such as thrombolysis, inhibiting the platelet aggregation, targeting specifically. The research progress in hirudin fusion protein was summarized in this review.

Delayed administration of glial cell line-derived neurotrophic factor (GDNF) protects retinal ganglion cells in a pig model of acute retinal ischemia

DEFF Research Database (Denmark)

Kyhn, Maria Voss; Klassen, Henry; Johansson, Ulrica Englund

2009-01-01

electroretinography (mfERG), quantification of NeuN positive cells and evaluation of the degree of retinal perivasculitis and inflammation 6 weeks after the insult. In the post-injection eyes (days 14, 28 and 42), the ratios of the iN1 and the iP2 amplitudes were 0.10 (95% CI: 0.05-0.15) and 0.09 (95% CI: 0.......04-0.16) in eyes treated with blank microspheres, and 0.24 (95% CI: 0.18-0.32) and 0.23 (95% CI: 0.15-0.33) in eyes treated with GDNF microspheres. These differences were statistically significant (P eyes...... injected with GDNF microspheres compared to eyes injected with blank microspheres. In eyes injected with GDNF microspheres the ganglion cell count was 9.5/field (s.e.m.: 2.1, n = 8), in eyes injected with blank microspheres it was 3.5/field (s.e.m.: 1.2, n = 7). This difference was statistically...

The MARVEL domain protein, Singles Bar, is required for progression past the pre-fusion complex stage of myoblast fusion.

Science.gov (United States)

Estrada, Beatriz; Maeland, Anne D; Gisselbrecht, Stephen S; Bloor, James W; Brown, Nicholas H; Michelson, Alan M

2007-07-15

Multinucleated myotubes develop by the sequential fusion of individual myoblasts. Using a convergence of genomic and classical genetic approaches, we have discovered a novel gene, singles bar (sing), that is essential for myoblast fusion. sing encodes a small multipass transmembrane protein containing a MARVEL domain, which is found in vertebrate proteins involved in processes such as tight junction formation and vesicle trafficking where--as in myoblast fusion--membrane apposition occurs. sing is expressed in both founder cells and fusion competent myoblasts preceding and during myoblast fusion. Examination of embryos injected with double-stranded sing RNA or embryos homozygous for ethane methyl sulfonate-induced sing alleles revealed an identical phenotype: replacement of multinucleated myofibers by groups of single, myosin-expressing myoblasts at a stage when formation of the mature muscle pattern is complete in wild-type embryos. Unfused sing mutant myoblasts form clusters, suggesting that early recognition and adhesion of these cells are unimpaired. To further investigate this phenotype, we undertook electron microscopic ultrastructural studies of fusing myoblasts in both sing and wild-type embryos. These experiments revealed that more sing mutant myoblasts than wild-type contain pre-fusion complexes, which are characterized by electron-dense vesicles paired on either side of the fusing plasma membranes. In contrast, embryos mutant for another muscle fusion gene, blown fuse (blow), have a normal number of such complexes. Together, these results lead to the hypothesis that sing acts at a step distinct from that of blow, and that sing is required on both founder cell and fusion-competent myoblast membranes to allow progression past the pre-fusion complex stage of myoblast fusion, possibly by mediating fusion of the electron-dense vesicles to the plasma membrane.

Expression and the antigenicity of recombinant coat proteins of tungro viruses expressed in Escherichia coli.

Science.gov (United States)

Yee, Siew Fung; Chu, Chia Huay; Poili, Evenni; Sum, Magdline Sia Henry

2017-02-01

Rice tungro disease (RTD) is a recurring disease affecting rice farming especially in the South and Southeast Asia. The disease is commonly diagnosed by visual observation of the symptoms on diseased plants in paddy fields and by polymerase chain reaction (PCR). However, visual observation is unreliable and PCR can be costly. High-throughput as well as relatively cheap detection methods are important for RTD management for screening large number of samples. Due to this, detection by serological assays such as immunoblotting assays and enzyme-linked immunosorbent assay are preferred. However, these serological assays are limited by lack of continuous supply of antibodies as reagents due to the difficulty in preparing sufficient purified virions as antigens. This study aimed to generate and evaluate the reactivity of the recombinant coat proteins of Rice tungro bacilliform virus (RTBV) and Rice tungro spherical virus (RTSV) as alternative antigens to generate antibodies. The genes encoding the coat proteins of both viruses, RTBV (CP), and RTSV (CP1, CP2 and CP3) were cloned and expressed as recombinant fusion proteins in Escherichia coli. All of the recombinant fusion proteins, with the exception of the recombinant fusion protein of the CP2 of RTSV, were reactive against our in-house anti-tungro rabbit serum. In conclusion, our study showed the potential use of the recombinant fusion coat proteins of the tungro viruses as alternative antigens for production of antibodies for diagnostic purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

Anti-protein C antibodies are associated with resistance to endogenous protein C activation and a severe thrombotic phenotype in antiphospholipid syndrome.

Science.gov (United States)

Arachchillage, D R J; Efthymiou, M; Mackie, I J; Lawrie, A S; Machin, S J; Cohen, H

2014-11-01

Antiphospholipid antibodies may interfere with the anticoagulant activity of activated protein C (APC) to induce acquired APC resistance (APCr). To investigate the frequency and characteristics of APCr by using recombinant human APC (rhAPC) and endogenous protein C activation in antiphospholipid syndrome (APS). APCr was assessed in APS and non-APS venous thromboembolism (VTE) patients on warfarin and normal controls with rhAPC or Protac by thrombin generation. IgG anti-protein C and anti-protein S antibodies and avidity were assessed by ELISA. APS patients showed greater resistance to both rhAPC and Protac than non-APS patients and normal controls (median normalized endogenous thrombin potential inhibition): APS patients with rhAPC, 81.3% (95% confidence interval [CI] 75.2-88.3%; non-APS patients with rhAPC, 97.7% (95% CI 93.6-101.8%; APS patients with Protac, 66.0% (95% CI 59.5-72.6%); and non-APS patients with Protac, 80.7 (95% CI 74.2-87.2%). APS patients also had a higher frequency and higher levels of anti-protein C antibodies, with 60% (15/25) high-avidity antibodies. High-avidity anti-protein C antibodies were associated with greater APCr and with a severe thrombotic phenotype (defined as the development of recurrent VTE while patients were receiving therapeutic anticoagulation or both venous and arterial thrombosis). Twelve of 15 (80%) patients with high-avidity anti-protein C antibodies were classified as APS category I. Thrombotic APS patients showed greater APCr to both rhAPC and activation of endogenous protein C by Protac. High-avidity anti-protein C antibodies, associated with greater APCr, may provide a marker for a severe thrombotic phenotype in APS. However, in patients with category I APS, it remains to be established whether anti-protein C or anti-β2 -glycoprotein I antibodies are responsible for APCr. © 2014 International Society on Thrombosis and Haemostasis.

High-level expression of soluble recombinant proteins in Escherichia coli using an HE-maltotriose-binding protein fusion tag.

Science.gov (United States)

Han, Yingqian; Guo, Wanying; Su, Bingqian; Guo, Yujie; Wang, Jiang; Chu, Beibei; Yang, Guoyu

2018-02-01

Recombinant proteins are commonly expressed in prokaryotic expression systems for large-scale production. The use of genetically engineered affinity and solubility enhancing fusion proteins has increased greatly in recent years, and there now exists a considerable repertoire of these that can be used to enhance the expression, stability, solubility, folding, and purification of their fusion partner. Here, a modified histidine tag (HE) used as an affinity tag was employed together with a truncated maltotriose-binding protein (MBP; consisting of residues 59-433) from Pyrococcus furiosus as a solubility enhancing tag accompanying a tobacco etch virus protease-recognition site for protein expression and purification in Escherichia coli. Various proteins tagged at the N-terminus with HE-MBP(Pyr) were expressed in E. coli BL21(DE3) cells to determine expression and solubility relative to those tagged with His6-MBP or His6-MBP(Pyr). Furthermore, four HE-MBP(Pyr)-fused proteins were purified by immobilized metal affinity chromatography to assess the affinity of HE with immobilized Ni 2+ . Our results showed that HE-MBP(Pyr) represents an attractive fusion protein allowing high levels of soluble expression and purification of recombinant protein in E. coli. Copyright © 2017 Elsevier Inc. All rights reserved.

Targeting the Conserved Fusion Loop of HAP2 Inhibits the Transmission of Plasmodium berghei and falciparum

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Fiona Angrisano

2017-12-01

Full Text Available Summary: Inhibiting transmission of Plasmodium is a central strategy in malarial eradication, and the biological process of gamete fusion during fertilization is a proven target for this approach. The lack of a structure or known molecular function of current anti-malarial vaccine targets has previously been a hindrance in the development of transmission-blocking vaccines. Structure/function studies have indicated that the conserved gamete membrane fusion protein HAP2 is a class II viral fusion protein. Here, we demonstrate that targeting a function-critical site of the fusion/cd loop with species-specific antibodies reduces Plasmodium berghei transmission in vivo by 58.9% and in vitro fertilization by up to 89.9%. A corresponding reduction in P. falciparum transmission (75.5%/36.4% reductions in intensity/prevalence is observed in complimentary field studies. These results emphasize conserved mechanisms of fusion in Apicomplexa, while highlighting an approach to design future anti-malarial transmission-blocking vaccines. : Angrisano et al. find that the HAP2 cd-loop can be targeted as an anti-malarial intervention, is immunogenic across multiple plasmodial species, can induce antibodies that specifically recognize the sexual stages of the parasitic life cycle, and can mediate transmission-blocking immunity in the lab and the field. Keywords: HAP2, malaria, transmission, fusion, vaccine

Myeloma-Derived Light Chain Paired with a Diagnostic Monoclonal Antibody Hinders Immunoassay Performance.

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Tu, Bailin; Tieman, Bryan; Moore, Jeffrey; Pan, You; Muerhoff, A Scott

2017-06-01

Monoclonal antibodies are widely used as the capture and detection reagents in diagnostic immunoassays. In the past, myeloma fusion partners expressing endogenous heavy and/or light chains were often used to generate hybridoma cell lines. As a result, mixed populations of antibodies were produced that can cause inaccurate test results, poor antibody stability, and significant lot-to-lot variability. We describe one such scenario where the P3U1 (P3X63Ag8U.1) myeloma fusion partner was used in the generation of a hybridoma producing protein induced vitamin K absence/antagonist-II (PIVKA II) antibody. The hybridoma produces three subpopulations of immunoglobulin as determined by ion exchange (IEx) chromatography that exhibit varying degrees of immunoreactivity (0%, 50%, or 100%) to the target antigen as determined by Surface Plasmon Resonance. To produce an antibody with the highest possible sensitivity and specificity, the antigen-specific heavy and light chain variable domains (VH and VL) were cloned from the hybridoma and tethered to murine IgG1 and kappa scaffolds. The resulting recombinant antibody was expressed in Chinese hamster ovary cells and is compatible for use in a diagnostic immunoassay.

Referencing cross-reactivity of detection antibodies for protein array experiments [version 1; referees: 1 approved, 2 approved with reservations

Directory of Open Access Journals (Sweden)

Darragh Lemass

2016-01-01

Full Text Available Protein arrays are frequently used to profile antibody repertoires in humans and animals. High-throughput protein array characterisation of complex antibody repertoires requires a platform-dependent, lot-to-lot validation of secondary detection antibodies. This article details the validation of an affinity-isolated anti-chicken IgY antibody produced in rabbit and a goat anti-rabbit IgG antibody conjugated with alkaline phosphatase using protein arrays consisting of 7,390 distinct human proteins. Probing protein arrays with secondary antibodies in absence of chicken serum revealed non-specific binding to 61 distinct human proteins. The cross-reactivity of the tested secondary detection antibodies points towards the necessity of platform-specific antibody characterisation studies for all secondary immunoreagents. Secondary antibody characterisation using protein arrays enables generation of reference lists of cross-reactive proteins, which can be then excluded from analysis in follow-up experiments. Furthermore, making such cross-reactivity lists accessible to the wider research community may help to interpret data generated by the same antibodies in applications not related to protein arrays such as immunoprecipitation, Western blots or other immunoassays.

Bioluminescent Antibodies for Point-of-Care Diagnostics.

Science.gov (United States)

Xue, Lin; Yu, Qiuliyang; Griss, Rudolf; Schena, Alberto; Johnsson, Kai

2017-06-12

We introduce a general method to transform antibodies into ratiometric, bioluminescent sensor proteins for the no-wash quantification of analytes. Our approach is based on the genetic fusion of antibody fragments to NanoLuc luciferase and SNAP-tag, the latter being labeled with a synthetic fluorescent competitor of the antigen. Binding of the antigen, here synthetic drugs, by the sensor displaces the tethered fluorescent competitor from the antibody and disrupts bioluminescent resonance energy transfer (BRET) between the luciferase and fluorophore. The semisynthetic sensors display a tunable response range (submicromolar to submillimolar) and large dynamic range (ΔR max >500 %), and they permit the quantification of analytes through spotting of the samples onto paper followed by analysis with a digital camera. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Oral vaccine of Lactococcus lactis harbouring pandemic H1N1 2009 haemagglutinin1 and nisP anchor fusion protein elevates anti-HA1 sIgA levels in mice.

Science.gov (United States)

Joan, Stella Siaw Xiu; Pui-Fong, Jee; Song, Adelene Ai-Lian; Chang, Li-Yen; Yusoff, Khatijah; AbuBakar, Sazaly; Rahim, Raha Abdul

2016-05-01

An oral lactococcal-based vaccine which haboured the haemagglutinin1 (HA1) antigen fused to nisP anchor protein for the purpose of surface displaying the HA1 antigen was developed against H1N1 virus. Recombinant L. lactis strains expressed HA1-nisP fusion proteins when induced with nisin, as confirmed through western blotting. However, immunofluorescense did not detect any surface-displayed proteins, suggesting that the protein was either unsuccessfully translocated or improperly displayed. Despite this, oral administration of recombinant L. lactis strains to BALB/c mice revealed that significant levels of anti-HA1 sIgA antibodies were detected in mice fecal suspension samples of mice group NZ9000 (pNZ:HN) when compared to the negative control NZ9000 (pNZ8048) group. Specific anti-HA1 sIgA antibodies were locally produced and live recombinant lactococcal vaccine was able to elicit humoral response of BALB/c mice despite unsuccessful surface display of the HA1 epitope.

Immune response in mice to ingested soya protein: antibody production, oral tolerance and maternal transfer

DEFF Research Database (Denmark)

Christensen, Hanne Risager; Pedersen, Susanne Brix; Frøkiær, Hanne

2004-01-01

antibody response in the offspring, bat in this case in the absence of oral tolerance. This indicates that, under certain conditions, factors involved in spontaneous antibody production can be transmitted from mother to offspring. Understanding the immune response to soya protein ingested under healthy...... by ELISA, and to the presence of oral tolerance detected as a suppressed antibody and cell-proliferation response upon immunisation with soya protein. F0 mice generated soya-specific antibodies, while oral tolerance to the same soya proteins was also clearly induced. When F0 dams were transferred to soya...

Purification of CD47-streptavidin fusion protein from bacterial lysate using biotin-agarose affinity chromatography.

Science.gov (United States)

Salehi, Nasrin; Peng, Ching-An

2016-07-08

CD47 is a widely expressed transmembrane glycoprotein that modulates the activity of a plethora of immune cells via its extracellular domain. Therefore, CD47 plays important roles in the regulation of immune responses and may serve as targets for the development of immunotherapeutic agents. To make sure CD47 functionality is intact under the process of protein conjugation, CD47-streptavidin fusion protein was expressed and purified because it can easily bind to biotin-tagged materials via the unique biotin-streptavidin affinity. In this study, gene sequences of CD47 extracellular domain (CD47ECD) and core streptavidin (coreSA) with a total 834 bp were inserted into pET20b plasmid to construct recombinant plasmid encoding CD47-SA fusion gene. After bacteria transformation, the CD47-SA fusion protein was expressed by isopropyl-β-d-thiogalactopyranoside (IPTG) induction. The collected bacteria lysate was loaded on biotinylated agarose to proceed the purification of CD47-SA fusion protein. Due to the unexpected high affinity between biotin and coreSA, standard washing and elution approaches (e.g., varying pH, using biotin, and applying guanidine hydrochloride) reported for biotin-streptavidin affinity chromatography were not able to separate the target fusion protein. Instead, using low concentration of the non-ionic detergent Triton X-100 followed with alkaline buffer could efficiently weaken the binding between biotin and coreSA, thereby eluting out CD47-SA fusion protein from the biotin agarose column. The purified CD47-SA fusion protein was further characterized by molecular biology methods and its antiphagocytic functionality was confirmed by the phagocytosis assay. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:949-958, 2016. © 2016 American Institute of Chemical Engineers.

Antibody Response is More Likely to Pneumococcal Proteins Than to Polysaccharide After HIV-associated Invasive Pneumococcal Disease

DEFF Research Database (Denmark)

Kantsø, Bjørn; Green, Nicola; Goldblatt, David

2015-01-01

to at least 1 protein compared to 51% of non-IPD controls. HIV IPD cases responded to more proteins than non-IPD controls (8.6 ± 8.4 vs 4.2 ± 7.6 proteins; P = .01), and had a significantly higher probability of yielding an antibody response to the proteins PiaA, PsaA, and PcpA. Twenty-two percent of HIV......-infected individuals with IPD had a serotype-specific antibody response. Younger age at the time of IPD was the only predictor of a serotype-specific pneumococcal antibody response, whereas we did not identify predictors of a protein-specific antibody response. CONCLUSIONS: Antibody responses occurred more frequently...

Development and Characterization of Mouse Monoclonal Antibodies Reactive with Chicken CD83

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This study was carried out to develop and characterize mouse monoclonal antibodies (mAbs) against chicken CD83 (chCD83), a membrane-bound glycoprotein belonging to the immunoglobulin superfamily that is primarily expressed on mature dendritic cells (DCs). A recombinant chCD83/IgG4 fusion protein con...

Protein-tyrosine phosphatase SHP2 contributes to GDNF neurotrophic activity through direct binding to phospho-Tyr687 in the RET receptor tyrosine kinase.

Science.gov (United States)

Perrinjaquet, Maurice; Vilar, Marçal; Ibáñez, Carlos F

2010-10-08

The signaling mechanisms by which neurotrophic receptors regulate neuronal survival and axonal growth are still incompletely understood. In the receptor tyrosine kinase RET, a receptor for GDNF (glial cell line-derived neurotrophic factor), the functions of the majority of tyrosine residues that become phosphorylated are still unknown. Here we have identified the protein-tyrosine phosphatase SHP2 as a novel direct interactor of RET and the first effector known to bind to phosphorylated Tyr(687) in the juxtamembrane region of the receptor. We show that SHP2 is recruited to RET upon ligand binding in a cooperative fashion, such that both interaction with Tyr(687) and association with components of the Tyr(1062) signaling complex are required for stable recruitment of SHP2 to the receptor. SHP2 recruitment contributes to the ability of RET to activate the PI3K/AKT pathway and promote survival and neurite outgrowth in primary neurons. Furthermore, we find that activation of protein kinase A (PKA) by forskolin reduces the recruitment of SHP2 to RET and negatively affects ligand-mediated neurite outgrowth. In agreement with this, mutation of Ser(696), a known PKA phosphorylation site in RET, enhances SHP2 binding to the receptor and eliminates the effect of forskolin on ligand-induced outgrowth. Together, these findings establish SHP2 as a novel positive regulator of the neurotrophic activities of RET and reveal Tyr(687) as a critical platform for integration of RET and PKA signals. We anticipate that several other phosphotyrosines of unknown function in neuronal receptor tyrosine kinases will also support similar regulatory functions.

Selecting highly structure-specific antibodies using structured synthetic mimics of the cystine knot protein sclerostin

NARCIS (Netherlands)

Back, J.W.; Frisch, C.; Van Pee, K.; Boschert, V.; van Vught, R.; Puijk, W.; Mueller, T. D.; Knappik, A.; Timmerman, P.

2012-01-01

Antibodies directed against specific regions of a protein have traditionally been raised against full proteins, protein domains or simple unstructured peptides, containing contiguous stretches of primary sequence. We have used a new approach of selecting antibodies against restrained peptides

Evaluation of antibodies against feline coronavirus 7b protein for diagnosis of feline infectious peritonitis in cats.

Science.gov (United States)

Kennedy, Melissa A; Abd-Eldaim, Mohamed; Zika, Sarah E; Mankin, Joseph M; Kania, Stephen A

2008-09-01

To determine whether expression of feline coronavirus (FCoV) 7b protein, as indicated by the presence of specific serum antibodies, consistently correlated with occurrence of feline infectious peritonitis (FIP) in cats. 95 serum samples submitted for various diagnostic assays and 20 samples from specific-pathogen-free cats tested as negative control samples. The 7b gene from a virulent strain of FCoV was cloned into a protein expression vector. The resultant recombinant protein was produced and used in antibody detection assays via western blot analysis of serum samples. Results were compared with those of an immunofluorescence assay (IFA) for FCoV-specific antibody and correlated with health status. Healthy IFA-seronegative cats were seronegative for antibodies against the 7b protein. Some healthy cats with detectable FCoV-specific antibodies as determined via IFA were seronegative for antibodies against the 7b protein. Serum from cats with FIP had antibodies against the 7b protein, including cats with negative results via conventional IFA. However, some healthy cats, as well as cats with conditions other than FIP that were seropositive to FCoV via IFA, were also seropositive for the 7b protein. Expression of the 7b protein, as indicated by detection of antibodies against the protein, was found in most FCoV-infected cats. Seropositivity for this protein was not specific for the FCoV virulent biotype or a diagnosis of FIP.

Antibody-mediated Prevention of Fusarium Mycotoxins in the Field

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Yu-Cai Liao

2008-10-01

Full Text Available Fusarium mycotoxins directly accumulated in grains during the infection of wheat and other cereal crops by Fusarium head blight (FHB pathogens are detrimental to humans and domesticated animals. Prevention of the mycotoxins via the development of FHB-resistant varieties has been a challenge due to the scarcity of natural resistance against FHB pathogens. Various antibodies specific to Fusarium fungi and mycotoxins are widely used in immunoassays and antibody-mediated resistance in planta against Fusarium pathogens has been demonstrated. Antibodies fused to antifungal proteins have been shown to confer a very significantly enhanced Fusarium resistance in transgenic plants. Thus, antibody fusions hold great promise as an effective tool for the prevention of mycotoxin contaminations in cereal grains. This review highlights the utilization of protective antibodies derived from phage display to increase endogenous resistance of wheat to FHB pathogens and consequently to reduce mycotoxins in field. The role played by Fusarium-specific antibody in the resistance is also discussed.

Analyzing Protein Changes in Guinea Pig Tissue Lysates Using Non-guinea Pig Specific Antibodies: Procedures for Western Blotting and Examples Using 16 Individual Antibodies for Common CNS Proteins

National Research Council Canada - National Science Library

Johnson, Erik A; Daugherty, Kelly S

2006-01-01

... behavioral and protein changes due to the absence of guinea pig-specific antibodies. We have developed a procedure to determine the specificity of commercially available, non-guinea pig-specific antibodies in guinea pig lysates...

Immunization with FSHβ fusion protein antigen prevents bone loss in a rat ovariectomy-induced osteoporosis model

Energy Technology Data Exchange (ETDEWEB)

Geng, Wenxin; Yan, Xingrong; Du, Huicong; Cui, Jihong; Li, Liwen, E-mail: liven@nwu.edu.cn; Chen, Fulin, E-mail: chenfl@nwu.edu.cn

2013-05-03

Highlights: •A GST-FSH fusion protein was successfully expressed in E. coli. •Immunization with GST-FSH antigen can raise high-titer anti-FSH polyclonal sera. •Anti-FSH polyclonal sera can neutralize osteoclastogenic effect of FSH in vitro. •FSH immunization can prevent bone loss in a rat osteoporosis model. -- Abstract: Osteoporosis, a metabolic bone disease, threatens postmenopausal women globally. Hormone replacement therapy (HTR), especially estrogen replacement therapy (ERT), is used widely in the clinic because it has been generally accepted that postmenopausal osteoporosis is caused by estrogen deficiency. However, hypogonadal α and β estrogen receptor null mice were only mildly osteopenic, and mice with either receptor deleted had normal bone mass, indicating that estrogen may not be the only mediator that induces osteoporosis. Recently, follicle-stimulating hormone (FSH), the serum concentration of which increases from the very beginning of menopause, has been found to play a key role in postmenopausal osteoporosis by promoting osteoclastogenesis. In this article, we confirmed that exogenous FSH can enhance osteoclast differentiation in vitro and that this effect can be neutralized by either an anti-FSH monoclonal antibody or anti-FSH polyclonal sera raised by immunizing animals with a recombinant GST-FSHβ fusion protein antigen. Moreover, immunizing ovariectomized rats with the GST-FSHβ antigen does significantly prevent trabecular bone loss and thereby enhance the bone strength, indicating that a FSH-based vaccine may be a promising therapeutic strategy to slow down bone loss in postmenopausal women.

Recombinant fragment of an antibody tailored for direct radioiodination

Czech Academy of Sciences Publication Activity Database

Sedláček, Juraj; Fábry, Milan; Sieglová, Irena; Král, Vlastimil; Uhnáková, Bronislava; Mudra, M.; Kronrád, L.; Sawicka, A.; Mikolajczak, R.; Řezáčová, Pavlína

2012-01-01

Roč. 55, č. 1 (2012), s. 52-56 ISSN 0362-4803 R&D Projects: GA MPO 2A-2TP1/076; GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z50520514 Keywords : I125 labelling * single-chain antibody variable fragment * tyrosine-rich polypeptide segment * fusion protein Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.240, year: 2012

Prm3p is a pheromone-induced peripheral nuclear envelope protein required for yeast nuclear fusion.

Science.gov (United States)

Shen, Shu; Tobery, Cynthia E; Rose, Mark D

2009-05-01

Nuclear membrane fusion is the last step in the mating pathway of the yeast Saccharomyces cerevisiae. We adapted a bioinformatics approach to identify putative pheromone-induced membrane proteins potentially required for nuclear membrane fusion. One protein, Prm3p, was found to be required for nuclear membrane fusion; disruption of PRM3 caused a strong bilateral defect, in which nuclear congression was completed but fusion did not occur. Prm3p was localized to the nuclear envelope in pheromone-responding cells, with significant colocalization with the spindle pole body in zygotes. A previous report, using a truncated protein, claimed that Prm3p is localized to the inner nuclear envelope. Based on biochemistry, immunoelectron microscopy and live cell microscopy, we find that functional Prm3p is a peripheral membrane protein exposed on the cytoplasmic face of the outer nuclear envelope. In support of this, mutations in a putative nuclear localization sequence had no effect on full-length protein function or localization. In contrast, point mutations and deletions in the highly conserved hydrophobic carboxy-terminal domain disrupted both protein function and localization. Genetic analysis, colocalization, and biochemical experiments indicate that Prm3p interacts directly with Kar5p, suggesting that nuclear membrane fusion is mediated by a protein complex.

Electrostatic Architecture of the Infectious Salmon Anemia Virus (ISAV) Core Fusion Protein Illustrates a Carboxyl-Carboxylate pH Sensor.

Science.gov (United States)

Cook, Jonathan D; Soto-Montoya, Hazel; Korpela, Markus K; Lee, Jeffrey E

2015-07-24

Segment 5, ORF 1 of the infectious salmon anemia virus (ISAV) genome, encodes for the ISAV F protein, which is responsible for viral-host endosomal membrane fusion during a productive ISAV infection. The entry machinery of ISAV is composed of a complex of the ISAV F and ISAV hemagglutinin esterase (HE) proteins in an unknown stoichiometry prior to receptor engagement by ISAV HE. Following binding of the receptor to ISAV HE, dissociation of the ISAV F protein from HE, and subsequent endocytosis, the ISAV F protein resolves into a fusion-competent oligomeric state. Here, we present a 2.1 Å crystal structure of the fusion core of the ISAV F protein determined at low pH. This structure has allowed us to unambiguously demonstrate that the ISAV entry machinery exhibits typical class I viral fusion protein architecture. Furthermore, we have determined stabilizing factors that accommodate the pH-dependent mode of ISAV transmission, and our structure has allowed the identification of a central coil that is conserved across numerous and varied post-fusion viral glycoprotein structures. We then discuss a mechanistic model of ISAV fusion that parallels the paramyxoviral class I fusion strategy wherein attachment and fusion are relegated to separate proteins in a similar fashion to ISAV fusion. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Expression of Leukemia-Associated Nup98 Fusion Proteins Generates an Aberrant Nuclear Envelope Phenotype.

Science.gov (United States)

Fahrenkrog, Birthe; Martinelli, Valérie; Nilles, Nadine; Fruhmann, Gernot; Chatel, Guillaume; Juge, Sabine; Sauder, Ursula; Di Giacomo, Danika; Mecucci, Cristina; Schwaller, Jürg

2016-01-01

Chromosomal translocations involving the nucleoporin NUP98 have been described in several hematopoietic malignancies, in particular acute myeloid leukemia (AML). In the resulting chimeric proteins, Nup98's N-terminal region is fused to the C-terminal region of about 30 different partners, including homeodomain (HD) transcription factors. While transcriptional targets of distinct Nup98 chimeras related to immortalization are relatively well described, little is known about other potential cellular effects of these fusion proteins. By comparing the sub-nuclear localization of a large number of Nup98 fusions with HD and non-HD partners throughout the cell cycle we found that while all Nup98 chimeras were nuclear during interphase, only Nup98-HD fusion proteins exhibited a characteristic speckled appearance. During mitosis, only Nup98-HD fusions were concentrated on chromosomes. Despite the difference in localization, all tested Nup98 chimera provoked morphological alterations in the nuclear envelope (NE), in particular affecting the nuclear lamina and the lamina-associated polypeptide 2α (LAP2α). Importantly, such aberrations were not only observed in transiently transfected HeLa cells but also in mouse bone marrow cells immortalized by Nup98 fusions and in cells derived from leukemia patients harboring Nup98 fusions. Our findings unravel Nup98 fusion-associated NE alterations that may contribute to leukemogenesis.

Premature activation of the paramyxovirus fusion protein before target cell attachment with corruption of the viral fusion machinery.

Science.gov (United States)

Farzan, Shohreh F; Palermo, Laura M; Yokoyama, Christine C; Orefice, Gianmarco; Fornabaio, Micaela; Sarkar, Aurijit; Kellogg, Glen E; Greengard, Olga; Porotto, Matteo; Moscona, Anne

2011-11-04

Paramyxoviruses, including the childhood pathogen human parainfluenza virus type 3, enter host cells by fusion of the viral and target cell membranes. This fusion results from the concerted action of its two envelope glycoproteins, the hemagglutinin-neuraminidase (HN) and the fusion protein (F). The receptor-bound HN triggers F to undergo conformational changes that render it competent to mediate fusion of the viral and cellular membranes. We proposed that, if the fusion process could be activated prematurely before the virion reaches the target host cell, infection could be prevented. We identified a small molecule that inhibits paramyxovirus entry into target cells and prevents infection. We show here that this compound works by an interaction with HN that results in F-activation prior to receptor binding. The fusion process is thereby prematurely activated, preventing fusion of the viral membrane with target cells and precluding viral entry. This first evidence that activation of a paramyxovirus F can be specifically induced before the virus contacts its target cell suggests a new strategy with broad implications for the design of antiviral agents.

Enhanced SUMOylation of proteins containing a SUMO-interacting motif by SUMO-Ubc9 fusion

International Nuclear Information System (INIS)

Kim, Eui Tae; Kim, Kyeong Kyu; Matunis, Mike J.; Ahn, Jin-Hyun

2009-01-01

Identifying new targets for SUMO and understanding the function of protein SUMOylation are largely limited by low level of SUMOylation. It was found recently that Ubc9, the SUMO E2 conjugating enzyme, is covalently modified by SUMO at a lysine 14 in the N-terminal alpha helix, and that SUMO-modified Ubc9 has enhanced conjugation activity for certain target proteins containing a SUMO-interacting motif (SIM). Here, we show that, compared to intact Ubc9, the SUMO-Ubc9 fusion protein has higher conjugating activity for SIM-containing targets such as Sp100 and human cytomegalovirus IE2. Assays using an IE2 SIM mutant revealed the requirement of SIM for the enhanced IE2 SUMOylation by SUMO-Ubc9. In pull-down assays with cell extracts, the SUMO-Ubc9 fusion protein bound to more diverse cellular proteins and interacted with some SIM-containing proteins with higher affinities than Ubc9. Therefore, the devised SUMO-Ubc9 fusion will be useful for identifying SIM-containing SUMO targets and producing SUMO-modified proteins.

The TIP30 protein complex, arachidonic acid and coenzyme A are required for vesicle membrane fusion.

Directory of Open Access Journals (Sweden)

Chengliang Zhang

Full Text Available Efficient membrane fusion has been successfully mimicked in vitro using artificial membranes and a number of cellular proteins that are currently known to participate in membrane fusion. However, these proteins are not sufficient to promote efficient fusion between biological membranes, indicating that critical fusogenic factors remain unidentified. We have recently identified a TIP30 protein complex containing TIP30, acyl-CoA synthetase long-chain family member 4 (ACSL4 and Endophilin B1 (Endo B1 that promotes the fusion of endocytic vesicles with Rab5a vesicles, which transport endosomal acidification enzymes vacuolar (H⁺-ATPases (V-ATPases to the early endosomes in vivo. Here, we demonstrate that the TIP30 protein complex facilitates the fusion of endocytic vesicles with Rab5a vesicles in vitro. Fusion of the two vesicles also depends on arachidonic acid, coenzyme A and the synthesis of arachidonyl-CoA by ACSL4. Moreover, the TIP30 complex is able to transfer arachidonyl groups onto phosphatidic acid (PA, producing a new lipid species that is capable of inducing close contact between membranes. Together, our data suggest that the TIP30 complex facilitates biological membrane fusion through modification of PA on membranes.

Structure of the cleavage-activated prefusion form of the parainfluenza virus 5 fusion protein.

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Welch, Brett D; Liu, Yuanyuan; Kors, Christopher A; Leser, George P; Jardetzky, Theodore S; Lamb, Robert A

2012-10-09

The paramyxovirus parainfluenza virus 5 (PIV5) enters cells by fusion of the viral envelope with the plasma membrane through the concerted action of the fusion (F) protein and the receptor binding protein hemagglutinin-neuraminidase. The F protein folds initially to form a trimeric metastable prefusion form that is triggered to undergo large-scale irreversible conformational changes to form the trimeric postfusion conformation. It is thought that F refolding couples the energy released with membrane fusion. The F protein is synthesized as a precursor (F0) that must be cleaved by a host protease to form a biologically active molecule, F1,F2. Cleavage of F protein is a prerequisite for fusion and virus infectivity. Cleavage creates a new N terminus on F1 that contains a hydrophobic region, known as the FP, which intercalates target membranes during F protein refolding. The crystal structure of the soluble ectodomain of the uncleaved form of PIV5 F is known; here we report the crystal structure of the cleavage-activated prefusion form of PIV5 F. The structure shows minimal movement of the residues adjacent to the protease cleavage site. Most of the hydrophobic FP residues are buried in the uncleaved F protein, and only F103 at the newly created N terminus becomes more solvent-accessible after cleavage. The conformational freedom of the charged arginine residues that compose the protease recognition site increases on cleavage of F protein.

Expression, purification and characterization of hepatitis B virus X protein BH3-like motif-linker-Bcl-xL fusion protein for structural studies

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Hideki Kusunoki

2017-03-01

Full Text Available Hepatitis B virus X protein (HBx is a multifunctional protein that interacts directly with many host proteins. For example, HBx interacts with anti-apoptotic proteins, Bcl-2 and Bcl-xL, through its BH3-like motif, which leads to elevated cytosolic calcium levels, efficient viral DNA replication and the induction of apoptosis. To facilitate sample preparation and perform detailed structural characterization of the complex between HBx and Bcl-xL, we designed and purified a recombinant HBx BH3-like motif-linker-Bcl-xL fusion protein produced in E. coli. The fusion protein was characterized by size exclusion chromatography, circular dichroism and nuclear magnetic resonance experiments. Our results show that the fusion protein is a monomer in aqueous solution, forms a stable intramolecular complex, and likely retains the native conformation of the complex between Bcl-xL and the HBx BH3-like motif. Furthermore, the HBx BH3-like motif of the intramolecular complex forms an α-helix. These observations indicate that the fusion protein should facilitate structural studies aimed at understanding the interaction between HBx and Bcl-xL at the atomic level.

Site-specific modification of genome with cell-permeable Cre fusion protein in preimplantation mouse embryo

International Nuclear Information System (INIS)

Kim, Kyoungmi; Kim, Hwain; Lee, Daekee

2009-01-01

Site-specific recombination (SSR) by Cre recombinase and its target sequence, loxP, is a valuable tool in genetic analysis of gene function. Recently, several studies reported successful application of Cre fusion protein containing protein transduction peptide for inducing gene modification in various mammalian cells including ES cell as well as in the whole animal. In this study, we show that a short incubation of preimplantation mouse embryos with purified cell-permeable Cre fusion protein results in efficient SSR. X-Gal staining of preimplantation embryos, heterozygous for Gtrosa26 tm1Sor , revealed that treatment of 1-cell or 2-cell embryos with 3 μM of Cre fusion protein for 2 h leads to Cre-mediated excision in 70-85% of embryos. We have examined the effect of the concentration of the Cre fusion protein and the duration of the treatment on embryonic development, established a condition for full term development and survival to adulthood, and demonstrated the germ line transmission of excised Gtrosa26 allele. Potential applications and advantages of the highly efficient technique described here are discussed.

Distinctive serum protein profiles involving abundant proteins in lung cancer patients based upon antibody microarray analysis

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Rom William N

2005-08-01

Full Text Available Abstract Background Cancer serum protein profiling by mass spectrometry has uncovered mass profiles that are potentially diagnostic for several common types of cancer. However, direct mass spectrometric profiling has a limited dynamic range and difficulties in providing the identification of the distinctive proteins. We hypothesized that distinctive profiles may result from the differential expression of relatively abundant serum proteins associated with the host response. Methods Eighty-four antibodies, targeting a wide range of serum proteins, were spotted onto nitrocellulose-coated microscope slides. The abundances of the corresponding proteins were measured in 80 serum samples, from 24 newly diagnosed subjects with lung cancer, 24 healthy controls, and 32 subjects with chronic obstructive pulmonary disease (COPD. Two-color rolling-circle amplification was used to measure protein abundance. Results Seven of the 84 antibodies gave a significant difference (p Conclusion Our results suggest that a distinctive serum protein profile involving abundant proteins may be observed in lung cancer patients relative to healthy subjects or patients with chronic disease and may have utility as part of strategies for detecting lung cancer.

Characterization of hapten-protein conjugates: antibody generation and immunoassay development for chlorophenoxyacetic acid pesticides.

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Boro, Robin C; Singh, K Vikas; Suri, C Raman

2009-01-01

The generation of specific and sensitive antibodies against small molecules is greatly dependent upon the characteristics of the hapten-protein conjugates. In this study, we report a new fluorescence-based method for the characterization of hapten-protein conjugates. The method is based on an effect promoted by hapten-protein conjugation density upon the fluorescence intensity of the intrinsic tryptophan chromophore molecules of the protein. The proposed methodology is applied to quantify the hapten-protein conjugation density for two different chlorophenoxyacetic acid pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenoxybutyric acid (2,4-DB), coupled to carrier protein. Highly sensitive anti-2,4-D and anti-2,4-DB antibodies were obtained using these well-characterized hapten-protein conjugates. The generated antibodies were used in an immunoassay format demonstrating inhibitory concentration (IC50) values equal to 30 and 7 ng/mL for 2,4-D and 2,4-DB, respectively. Linearity was observed in the concentration range between 0.1-500 nglmL with LODs around 4 and 3 ng/mL for 2,4-D and 2,4-DB, respectively, in standard water samples. The proposed method was successfully applied for the determination of the extent of hapten-protein conjugation to produce specific antibodies for immunoassay development against pesticides.

Photocleavable DNA Barcoding Antibodies for Multiplexed Protein Analysis in Single Cells.

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Ullal, Adeeti V; Weissleder, Ralph

2015-01-01

We describe a DNA-barcoded antibody sensing technique for single cell protein analysis in which the barcodes are photocleaved and digitally detected without amplification steps (Ullal et al., Sci Transl Med 6:219, 2014). After photocleaving the unique ~70 mer DNA barcodes we use a fluorescent hybridization technology for detection, similar to what is commonly done for nucleic acid readouts. This protocol offers a simple method for multiplexed protein detection using 100+ antibodies and can be performed on clinical samples as well as single cells.

γ-Synuclein antibodies have neuroprotective potential on neuroretinal cells via proteins of the mitochondrial apoptosis pathway.

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Corina Wilding

Full Text Available The family of synuclein proteins (α, β and γ are related to neurodegenerative disease e.g. Parkinson disease and Morbus Alzheimer. Additionally, a connection between γ-synuclein and glaucoma, a neurodegenerative disease characterized by a progressive loss of retinal ganglion cells, which finally leads to blindness, exists. The reason for the development of glaucoma is still unknown. Recent studies evaluating the participation of immunological components, demonstrate complex changed antibody reactivities in glaucoma patients in comparison to healthy people, showing not only up-regulations (e.g. alpha-fodrin antibody but also down-regulations (e.g. γ-synuclein antibody of antibodies in glaucoma patients. Up-regulated antibodies could be auto-aggressive, but the role of down-regulated antibodies is still unclear. Previous studies show a significant influence of the serum and the antibodies of glaucoma patients on protein expression profiles of neuroretinal cells. The aim of this study was to investigate the effect of γ-synuclein antibody on the viability and reactive oxygen species levels of a neuroretinal cell line (RGC-5 as well as their interaction with cellular proteins. We found a protective effect of γ-synuclein antibody resulting in an increased viability (up to 15% and decreased reactive oxygen species levels (up to -12% of glutamate and oxidative stressed RGC-5. These can be traced back to anti-apoptotic altered protein expressions in the mitochondrial apoptosis pathway indicated by mass spectrometry and validated by microarray analysis such as active caspase 3, bcl-2 associated-x-protein, S100A4, voltage-dependent anion channel, extracellular-signal-regulated-kinase (down-regulated and baculoviral IAP repeat-containing protein 6, phosphorylated extracellular-signal-regulated-kinase (up-regulated. These changed protein expression are triggered by the γ-synuclein antibody internalization of RGC-5 we could see in immunohistochemical

Oral Administration of Recombinant Saccharomyces boulardii Expressing Ovalbumin-CPE Fusion Protein Induces Antibody Response in Mice.

Science.gov (United States)

Bagherpour, Ghasem; Ghasemi, Hosnie; Zand, Bahare; Zarei, Najmeh; Roohvand, Farzin; Ardakani, Esmat M; Azizi, Mohammad; Khalaj, Vahid

2018-01-01

Saccharomyces boulardii , a subspecies of Saccharomyces cerevisiae , is a well-known eukaryotic probiotic with many benefits for human health. In the present study, a recombinant strain of S. boulardii was prepared to use as a potential oral vaccine delivery vehicle. In this sense, a ura3 auxotroph strain of S. boulardii CNCM I-745 (known as S. cerevisiae HANSEN CBS 5926, Yomogi ® ) was generated using CRISPR/Cas9 methodology. Then a gene construct encoding a highly immunogenic protein, ovalbumin (OVA), was prepared and transformed into the ura3 - S. boulardii . To facilitate the transport of the recombinant immunogen across the intestinal barrier, a claudin-targeting sequence from Clostridium perfringens enterotoxin (CPE) was added to the C-terminus of the expression cassette. The recombinant S. boulardii strain expressing the OVA-CPE fusion protein was then administered orally to a group of mice, and serum IgG and fecal IgA levels were evaluated by ELISA. Our results demonstrated that anti-OVA IgG in serum significantly increased in test group ( P boulardii or PBS), and the fecal IgA titer was significantly higher in test group ( P boulardii strain expressing the similar construct lacking C-terminal CPE was also administered orally. The result showed an increased level of serum IgG in group receiving yeasts expressing the CPE negative construct compared to control groups; however, the fecal IgA levels did not increase significantly. In conclusion, our findings indicated that the yeast S. boulardii , as a delivery vehicle with possible immunomodulatory effects, and c-CPE, as a targeting tag, synergistically assist to stimulate systemic and local immunity. This proposed recombinant S. boulardii system might be useful in the expression of other antigenic peptides, making it as a promising tool for oral delivery of vaccines or therapeutic proteins.

Trophoblast cell fusion and differentiation are mediated by both the protein kinase C and a pathways.

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Waka Omata

Full Text Available The syncytiotrophoblast of the human placenta is an epithelial barrier that interacts with maternal blood and is a key for the transfer of nutrients and other solutes to the developing fetus. The syncytiotrophoblast is a true syncytium and fusion of progenitor cytotrophoblasts is the cardinal event leading to the formation of this layer. BeWo cells are often used as a surrogate for cytotrophoblasts, since they can be induced to fuse, and then express certain differentiation markers associated with trophoblast syncytialization. Dysferlin, a syncytiotrophoblast membrane repair protein, is up-regulated in BeWo cells induced to fuse by treatment with forskolin; this fusion is thought to occur through cAMP/protein kinase A-dependent mechanisms. We hypothesized that dysferlin may also be up-regulated in response to fusion through other pathways. Here, we show that BeWo cells can also be induced to fuse by treatment with an activator of protein kinase C, and that this fusion is accompanied by increased expression of dysferlin. Moreover, a dramatic synergistic increase in dysferlin expression is observed when both the protein kinase A and protein kinase C pathways are activated in BeWo cells. This synergy in fusion is also accompanied by dramatic increases in mRNA for the placental fusion proteins syncytin 1, syncytin 2, as well as dysferlin. Dysferlin, however, was shown to be dispensable for stimulus-induced BeWo cell syncytialization, since dysferlin knockdown lines fused to the same extent as control cells. The classical trophoblast differentiation marker human chorionic gonadotropin was also monitored and changes in the expression closely parallel that of dysferlin in all of the experimental conditions employed. Thus different biochemical markers of trophoblast fusion behave in concert supporting the hypothesis that activation of both protein kinase C and A pathways lead to trophoblastic differentiation.

Structural and kinetic analysis of the unnatural fusion protein 4-coumaroyl-CoA ligase::stilbene synthase

Energy Technology Data Exchange (ETDEWEB)

Wang, Yechun; Yi, Hankuil; Wang, Melissa; Yu, Oliver; Jez, Joseph M. (WU); (Danforth)

2012-10-24

To increase the biochemical efficiency of biosynthetic systems, metabolic engineers have explored different approaches for organizing enzymes, including the generation of unnatural fusion proteins. Previous work aimed at improving the biosynthesis of resveratrol, a stilbene associated a range of health-promoting activities, in yeast used an unnatural engineered fusion protein of Arabidopsis thaliana (thale cress) 4-coumaroyl-CoA ligase (At4CL1) and Vitis vinifera (grape) stilbene synthase (VvSTS) to increase resveratrol levels 15-fold relative to yeast expressing the individual enzymes. Here we present the crystallographic and biochemical analysis of the 4CL::STS fusion protein. Determination of the X-ray crystal structure of 4CL::STS provides the first molecular view of an artificial didomain adenylation/ketosynthase fusion protein. Comparison of the steady-state kinetic properties of At4CL1, VvSTS, and 4CL::STS demonstrates that the fusion protein improves catalytic efficiency of either reaction less than 3-fold. Structural and kinetic analysis suggests that colocalization of the two enzyme active sites within 70 {angstrom} of each other provides the basis for enhanced in vivo synthesis of resveratrol.

Collaborative enhancement of antibody binding to distinct PECAM-1 epitopes modulates endothelial targeting.

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Ann-Marie Chacko

Full Text Available Antibodies to platelet endothelial cell adhesion molecule-1 (PECAM-1 facilitate targeted drug delivery to endothelial cells by "vascular immunotargeting." To define the targeting quantitatively, we investigated the endothelial binding of monoclonal antibodies (mAbs to extracellular epitopes of PECAM-1. Surprisingly, we have found in human and mouse cell culture models that the endothelial binding of PECAM-directed mAbs and scFv therapeutic fusion protein is increased by co-administration of a paired mAb directed to an adjacent, yet distinct PECAM-1 epitope. This results in significant enhancement of functional activity of a PECAM-1-targeted scFv-thrombomodulin fusion protein generating therapeutic activated Protein C. The "collaborative enhancement" of mAb binding is affirmed in vivo, as manifested by enhanced pulmonary accumulation of intravenously administered radiolabeled PECAM-1 mAb when co-injected with an unlabeled paired mAb in mice. This is the first demonstration of a positive modulatory effect of endothelial binding and vascular immunotargeting provided by the simultaneous binding a paired mAb to adjacent distinct epitopes. The "collaborative enhancement" phenomenon provides a novel paradigm for optimizing the endothelial-targeted delivery of therapeutic agents.

Membrane fusion and exocytosis.

Science.gov (United States)

Jahn, R; Südhof, T C

1999-01-01

Membrane fusion involves the merger of two phospholipid bilayers in an aqueous environment. In artificial lipid bilayers, fusion proceeds by means of defined transition states, including hourglass-shaped intermediates in which the proximal leaflets of the fusing membranes are merged whereas the distal leaflets are separate (fusion stalk), followed by the reversible opening of small aqueous fusion pores. Fusion of biological membranes requires the action of specific fusion proteins. Best understood are the viral fusion proteins that are responsible for merging the viral with the host cell membrane during infection. These proteins undergo spontaneous and dramatic conformational changes upon activation. In the case of the paradigmatic fusion proteins of the influenza virus and of the human immunodeficiency virus, an amphiphilic fusion peptide is inserted into the target membrane. The protein then reorients itself, thus forcing the fusing membranes together and inducing lipid mixing. Fusion of intracellular membranes in eukaryotic cells involves several protein families including SNAREs, Rab proteins, and Sec1/Munc-18 related proteins (SM-proteins). SNAREs form a novel superfamily of small and mostly membrane-anchored proteins that share a common motif of about 60 amino acids (SNARE motif). SNAREs reversibly assemble into tightly packed helical bundles, the core complexes. Assembly is thought to pull the fusing membranes closely together, thus inducing fusion. SM-proteins comprise a family of soluble proteins that bind to certain types of SNAREs and prevent the formation of core complexes. Rab proteins are GTPases that undergo highly regulated GTP-GDP cycles. In their GTP form, they interact with specific proteins, the effector proteins. Recent evidence suggests that Rab proteins function in the initial membrane contact connecting the fusing membranes but are not involved in the fusion reaction itself.

Binding induced conformational changes of proteins correlate with their intrinsic fluctuations: a case study of antibodies

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Keskin Ozlem

2007-05-01

Full Text Available Abstract Background How antibodies recognize and bind to antigens can not be totally explained by rigid shape and electrostatic complimentarity models. Alternatively, pre-existing equilibrium hypothesis states that the native state of an antibody is not defined by a single rigid conformation but instead with an ensemble of similar conformations that co-exist at equilibrium. Antigens bind to one of the preferred conformations making this conformation more abundant shifting the equilibrium. Results Here, two antibodies, a germline antibody of 36–65 Fab and a monoclonal antibody, SPE7 are studied in detail to elucidate the mechanism of antibody-antigen recognition and to understand how a single antibody recognizes different antigens. An elastic network model, Anisotropic Network Model (ANM is used in the calculations. Pre-existing equilibrium is not restricted to apply to antibodies. Intrinsic fluctuations of eight proteins, from different classes of proteins, such as enzymes, binding and transport proteins are investigated to test the suitability of the method. The intrinsic fluctuations are compared with the experimentally observed ligand induced conformational changes of these proteins. The results show that the intrinsic fluctuations obtained by theoretical methods correlate with structural changes observed when a ligand is bound to the protein. The decomposition of the total fluctuations serves to identify the different individual modes of motion, ranging from the most cooperative ones involving the overall structure, to the most localized ones. Conclusion Results suggest that the pre-equilibrium concept holds for antibodies and the promiscuity of antibodies can also be explained this hypothesis: a limited number of conformational states driven by intrinsic motions of an antibody might be adequate to bind to different antigens.

Intracellular delivery of cell-penetrating peptide-transcriptional factor fusion protein and its role in selective osteogenesis

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Suh, Jin Sook; Lee, Jue Yeon; Choi, Yoon Jung; You, Hyung Keun; Hong, Seong-Doo; Chung, Chong Pyoung; Park, Yoon Jeong

2014-01-01

Protein-transduction technology has been attempted to deliver macromolecular materials, including protein, nucleic acids, and polymeric drugs, for either diagnosis or therapeutic purposes. Herein, fusion protein composed of an arginine-rich cell-penetrating peptide, termed low-molecular-weight protamine (LMWP), and a transcriptional coactivator with a PDZ-binding motif (TAZ) protein was prepared and applied in combination with biomaterials to increase bone-forming capacity. TAZ has been recently identified as a specific osteogenic stimulating transcriptional coactivator in human mesenchymal stem cell (hMSC) differentiation, while simultaneously blocking adipogenic differentiation. However, TAZ by itself cannot penetrate the cells, and thus needs a transfection tool for translocalization. The LMWP-TAZ fusion proteins were efficiently translocalized into the cytosol of hMSCs. The hMSCs treated with cell-penetrating LMWP-TAZ exhibited increased expression of osteoblastic genes and protein, producing significantly higher quantities of mineralized matrix compared to free TAZ. In contrast, adipogenic differentiation of the hMSCs was blocked by treatment of LMWP-TAZ fusion protein, as reflected by reduced marker-protein expression, adipocyte fatty acid-binding protein 2, and peroxisome proliferator-activated receptor-γ messenger ribonucleic acid levels. LMWP-TAZ was applied in alginate gel for the purpose of localization and controlled release. The LMWP-TAZ fusion protein-loaded alginate gel matrix significantly increased bone formation in rabbit calvarial defects compared with alginate gel matrix mixed with free TAZ protein. The protein transduction of TAZ fused with cell-penetrating LMWP peptide was able selectively to stimulate osteogenesis in vitro and in vivo. Taken together, this fusion protein-transduction technology for osteogenic protein can thus be applied in combination with biomaterials for tissue regeneration and controlled release for tissue

Viral membrane fusion

International Nuclear Information System (INIS)

Harrison, Stephen C.

2015-01-01

Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. - Highlights: • Viral fusion proteins overcome the high energy barrier to lipid bilayer merger. • Different molecular structures but the same catalytic mechanism. • Review describes properties of three known fusion-protein structural classes. • Single-virion fusion experiments elucidate mechanism

Viral membrane fusion

Energy Technology Data Exchange (ETDEWEB)

Harrison, Stephen C., E-mail: harrison@crystal.harvard.edu

2015-05-15

Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. - Highlights: • Viral fusion proteins overcome the high energy barrier to lipid bilayer merger. • Different molecular structures but the same catalytic mechanism. • Review describes properties of three known fusion-protein structural classes. • Single-virion fusion experiments elucidate mechanism.

Low Resolution Structure of RAR1-GST-Tag Fusion Protein in Solution

International Nuclear Information System (INIS)

Taube, M.; Kozak, M.; Jarmolowski, A.

2010-01-01

RAR1 is a protein required for resistance mediated by many R genes and function upstream of signaling pathways leading to H 2 O 2 accumulation. The structure and conformation of RAR1-GST-Tag fusion protein from barley (Hordeum vulgare) in solution was studied by the small angle scattering of synchrotron radiation. It was found that the dimer of RAR1-GST-Tag protein is characterized in solution by radius of gyration R G = 6.19 nm and maximal intramolecular vector D max = 23 nm. On the basis of the small angle scattering of synchrotron radiation SAXS data two bead models obtained by ab initio modeling are proposed. Both models show elongated conformations. We also concluded that molecules of fusion protein form: dimers in solution via interaction of GST domains. (authors)

A recombinant bivalent fusion protein rVE confers active and passive protection against Yersinia enterocolitica infection in mice.

Science.gov (United States)

Singh, Amit Kumar; Kingston, Joseph Jeyabalaji; Murali, Harishchandra Sripathy; Batra, Harsh Vardhan

2014-03-05

In the present study, a bivalent chimeric protein rVE comprising immunologically active domains of Yersinia pestis LcrV and YopE was assessed for its prophylactic abilities against Yersinia enterocolitica O:8 infection in murine model. Mice immunized with rVE elicited significantly higher antibody titers with substantial contribution from the rV component (3:1 ratio). Robust and significant resistance to Y. enterocolitica infection with 100% survival (Penterocolitica O:8 against the 75%, 60% and 75% survival seen in mice immunized with rV, rE, rV+rE, respectively. Macrophage monolayer supplemented with anti-rVE polysera illustrated efficient protection (89.41% survival) against challenge of Y. enterocolitica O:8. In contrast to sera from sham-immunized mice, immunization with anti-rVE polysera provided complete protection to BALB/c mice against I.P. challenge with 10(8)CFU of Y. enterocolitica O:8 and developed no conspicuous signs of infection in necropsy. The histopathological analysis of microtome sections confirmed significantly reduced lesion size or no lesion in liver and intestine upon infection in anti-rVE immunized mice. The findings from this study demonstrated the fusion protein rVE as a potential candidate subunit vaccine and showed the functional role of antibodies in protection against Y. enterocolitica infections. Copyright © 2014 Elsevier Ltd. All rights reserved.

The involvement of BDNF, NGF and GDNF in aging and Alzheimer’s disease

OpenAIRE

Budni, Josiane; Bellettini-Santos, Tatiani; Mina, Francielle; Garcez, Michelle Lima; Zugno, Alexandra Ioppi

2015-01-01

Aging is a normal physiological process accompanied by cognitive decline. This aging process has been the primary risk factor for development of aging-related diseases such as Alzheimer’s disease (AD). Cognitive deficit is related to alterations of neurotrophic factors level such as brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and glial cell-derived neurotrophic factor (GDNF). These strong relationship between aging and AD is important to investigate the time which they...

Protein-tyrosine Phosphatase SHP2 Contributes to GDNF Neurotrophic Activity through Direct Binding to Phospho-Tyr687 in the RET Receptor Tyrosine Kinase*

Science.gov (United States)

Perrinjaquet, Maurice; Vilar, Marçal; Ibáñez, Carlos F.

2010-01-01

The signaling mechanisms by which neurotrophic receptors regulate neuronal survival and axonal growth are still incompletely understood. In the receptor tyrosine kinase RET, a receptor for GDNF (glial cell line-derived neurotrophic factor), the functions of the majority of tyrosine residues that become phosphorylated are still unknown. Here we have identified the protein-tyrosine phosphatase SHP2 as a novel direct interactor of RET and the first effector known to bind to phosphorylated Tyr687 in the juxtamembrane region of the receptor. We show that SHP2 is recruited to RET upon ligand binding in a cooperative fashion, such that both interaction with Tyr687 and association with components of the Tyr1062 signaling complex are required for stable recruitment of SHP2 to the receptor. SHP2 recruitment contributes to the ability of RET to activate the PI3K/AKT pathway and promote survival and neurite outgrowth in primary neurons. Furthermore, we find that activation of protein kinase A (PKA) by forskolin reduces the recruitment of SHP2 to RET and negatively affects ligand-mediated neurite outgrowth. In agreement with this, mutation of Ser696, a known PKA phosphorylation site in RET, enhances SHP2 binding to the receptor and eliminates the effect of forskolin on ligand-induced outgrowth. Together, these findings establish SHP2 as a novel positive regulator of the neurotrophic activities of RET and reveal Tyr687 as a critical platform for integration of RET and PKA signals. We anticipate that several other phosphotyrosines of unknown function in neuronal receptor tyrosine kinases will also support similar regulatory functions. PMID:20682772

Engineering of a parainfluenza virus type 5 fusion protein (PIV-5 F): development of an autonomous and hyperfusogenic protein by a combinational mutagenesis approach.

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Terrier, O; Durupt, F; Cartet, G; Thomas, L; Lina, B; Rosa-Calatrava, M

2009-12-01

The entry of enveloped viruses into host cells is accomplished by fusion of the viral envelope with the target cell membrane. For the paramyxovirus parainfluenza virus type 5 (PIV-5), this fusion involves an attachment protein (HN) and a class I viral fusion protein (F). We investigated the effect of 20 different combinations of 12 amino-acid substitutions within functional domains of the PIV-5 F glycoprotein, by performing cell surface expression measurements, quantitative fusion and syncytia assays. We found that combinations of mutations conferring an autonomous phenotype with mutations leading to an increased fusion activity were compatible and generated functional PIV-5 F proteins. The addition of mutations in the heptad-repeat domains led to both autonomous and hyperfusogenic phenotypes, despite the low cell surface expression of the corresponding mutants. Such engineering approach may prove useful not only for deciphering the fundamental mechanism behind viral-mediated membrane fusion but also in the development of potential therapeutic applications.

[Construction and application of prokaryotic expression system of Leptospira interrogans lipL32/1-lipL41/1 fusion gene].

Science.gov (United States)

Luo, Dong-jiao; Yan, Jie; Mao, Ya-fei; Li, Shu-ping; Luo, Yi-hui; Li, Li-wei

2005-01-01

To construct lipL32/1-lipL41/1 fusion gene and its prokaryotic expression system and to determine frequencies of carrying and expression of lipL32 and lipL41 genes in L.interrogans wild strains and specific antibody levels in sera from leptospirosis patients. lipL32/1-lipL41/1 fusion gene was constructed using linking primer PCR method and the prokaryotic expression system of the fusion gene done with routine techniques. SDS-PAGE was used to examine expression of the target recombinant protein rLipL32/1-rLipL41/1. Immunogenicity of rLipL32/1-rLipL41/1 was identified by Western blot. PCR and MAT were performed to detect carrying and expression of lipL32 and lipL41 genes in 97 wild L.interrogans strains. Antibodies against products of lipL32 and lipL41 genes in serum samples from 228 leptospirosis patients were detected by ELISA method. The homogeneity of nucleotide and putative amino acid sequence of lipL32/1-lipL41/1 fusion gene were 99.9 % and 99.8 % in comparison with the reported sequences. Expression output of the target recombinant protein rLipL32/1-rLipL41/1, mainly present in inclusion body, accounted for 10 % of the total bacterial proteins. Both the rabbit antisera against rLipL32/1 and rLipL41/1 could combine to rLipL32/1-rLipL41/1. 97.9 % and 87.6 % of the L.interrogans wild strains had lipL32 and lipL41 genes, respectively. 95.9 % and 84.5 % of the wild strains were positive for MAT with titers of 1:4 - 1:128 using rabbit anti-rLipL32s or anti-rLipL41s sera, respectively. 94.7 % - 97.4 % of the patients'serum samples were positive for rLipL32s antibodies, while 78.5 % - 84.6 % of them were rLipL41s antibodies detectable. lipL32/1-jlipL41/1 fusion gene and its prokaryotic expression system were successfully constructed. The expressed fusion protein had qualified immunogenicity. Both the lipL32 and lipL41 genes are extensively carried and frequently expressed by different serogroups of L.interrogans, and their expression products exhibit cross-antigenicity.

Analyzing Protein Changes in Guinea Pig Tissue Lysates Using Non-guinea Pig Specific Antibodies: Procedures for Western Blotting and Examples Using 16 Individual Antibodies for Common CNS Proteins

Science.gov (United States)

2006-05-01

guinea pig model does present a significant problem...trying to correlate behavioral and protein changes due to the absence of guinea pig -specific antibodies. We...have developed a procedure to determine the specificity of commercially available, non- guinea pig -specific antibodies in guinea pig lysates.

Dual-color bioluminescent sensor proteins for therapeutic drug monitoring of antitumor antibodies

NARCIS (Netherlands)

van Rosmalen, M.; Ni, Y.; Vervoort, D.F.M.; Arts, R.; Ludwig, S.K.J.; Merkx, M.

2018-01-01

Monitoring the levels of therapeutic antibodies in individual patients would allow patient-specific dose optimization, with the potential for major therapeutic and financial benefits. Our group recently developed a new platform of bioluminescent sensor proteins (LUMABS; LUMinescent AntiBody Sensor)

Respiratory syncytial virus fusion glycoprotein expressed in insect cells form protein nanoparticles that induce protective immunity in cotton rats.

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Gale Smith

Full Text Available Respiratory Syncytial Virus (RSV is an important viral agent causing severe respiratory tract disease in infants and children as well as in the elderly and immunocompromised individuals. The lack of a safe and effective RSV vaccine represents a major unmet medical need. RSV fusion (F surface glycoprotein was modified and cloned into a baculovirus vector for efficient expression in Sf9 insect cells. Recombinant RSV F was glycosylated and cleaved into covalently linked F2 and F1 polypeptides that formed homotrimers. RSV F extracted and purified from insect cell membranes assembled into 40 nm protein nanoparticles composed of multiple RSV F oligomers arranged in the form of rosettes. The immunogenicity and protective efficacy of purified RSV F nanoparticles was compared to live and formalin inactivated RSV in cotton rats. Immunized animals induced neutralizing serum antibodies, inhibited virus replication in the lungs, and had no signs of disease enhancement in the respiratory track of challenged animals. RSV F nanoparticles also induced IgG competitive for binding of palivizumab neutralizing monoclonal antibody to RSV F antigenic site II. Antibodies to this epitope are known to protect against RSV when passively administered in high risk infants. Together these data provide a rational for continued development a recombinant RSV F nanoparticle vaccine candidate.

Combining random gene fission and rational gene fusion to discover near-infrared fluorescent protein fragments that report on protein-protein interactions.

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Pandey, Naresh; Nobles, Christopher L; Zechiedrich, Lynn; Maresso, Anthony W; Silberg, Jonathan J

2015-05-15

Gene fission can convert monomeric proteins into two-piece catalysts, reporters, and transcription factors for systems and synthetic biology. However, some proteins can be challenging to fragment without disrupting function, such as near-infrared fluorescent protein (IFP). We describe a directed evolution strategy that can overcome this challenge by randomly fragmenting proteins and concomitantly fusing the protein fragments to pairs of proteins or peptides that associate. We used this method to create libraries that express fragmented IFP as fusions to a pair of associating peptides (IAAL-E3 and IAAL-K3) and proteins (CheA and CheY) and screened for fragmented IFP with detectable near-infrared fluorescence. Thirteen novel fragmented IFPs were identified, all of which arose from backbone fission proximal to the interdomain linker. Either the IAAL-E3 and IAAL-K3 peptides or CheA and CheY proteins could assist with IFP fragment complementation, although the IAAL-E3 and IAAL-K3 peptides consistently yielded higher fluorescence. These results demonstrate how random gene fission can be coupled to rational gene fusion to create libraries enriched in fragmented proteins with AND gate logic that is dependent upon a protein-protein interaction, and they suggest that these near-infrared fluorescent protein fragments will be suitable as reporters for pairs of promoters and protein-protein interactions within whole animals.

Anti-Diabetic Effects of CTB-APSL Fusion Protein in Type 2 Diabetic Mice

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Yunlong Liu

2014-03-01

Full Text Available To determine whether cholera toxin B subunit and active peptide from shark liver (CTB-APSL fusion protein plays a role in treatment of type 2 diabetic mice, the CTB-APSL gene was cloned and expressed in silkworm (Bombyx mori baculovirus expression vector system (BEVS, then the fusion protein was orally administrated at a dose of 100 mg/kg for five weeks in diabetic mice. The results demonstrated that the oral administration of CTB-APSL fusion protein can effectively reduce the levels of both fasting blood glucose (FBG and glycosylated hemoglobin (GHb, promote insulin secretion and improve insulin resistance, significantly improve lipid metabolism, reduce triglycerides (TG, total cholesterol (TC and low density lipoprotein (LDL levels and increase high density lipoprotein (HDL levels, as well as effectively improve the inflammatory response of type 2 diabetic mice through the reduction of the levels of inflammatory cytokines tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6. Histopathology shows that the fusion protein can significantly repair damaged pancreatic tissue in type 2 diabetic mice, significantly improve hepatic steatosis and hepatic cell cloudy swelling, reduce the content of lipid droplets in type 2 diabetic mice, effectively inhibit renal interstitial inflammatory cells invasion and improve renal tubular epithelial cell nucleus pyknosis, thus providing an experimental basis for the development of a new type of oral therapy for type 2 diabetes.

Purification, crystallization and X-ray diffraction analysis of human dynamin-related protein 1 GTPase-GED fusion protein

International Nuclear Information System (INIS)

Klinglmayr, Eva; Wenger, Julia; Mayr, Sandra; Bossy-Wetzel, Ella; Puehringer, Sandra

2012-01-01

The crystallization and initial diffraction analysis of human Drp1 GTPase-GED fusion protein are reported. The mechano-enzyme dynamin-related protein 1 plays an important role in mitochondrial fission and is implicated in cell physiology. Dysregulation of Drp1 is associated with abnormal mitochondrial dynamics and neuronal damage. Drp1 shares structural and functional similarities with dynamin 1 with respect to domain organization, ability to self-assemble into spiral-like oligomers and GTP-cycle-dependent membrane scission. Structural studies of human dynamin-1 have greatly improved the understanding of this prototypical member of the dynamin superfamily. However, high-resolution structural information for full-length human Drp1 covering the GTPase domain, the middle domain and the GTPase effector domain (GED) is still lacking. In order to obtain mechanistic insights into the catalytic activity, a nucleotide-free GTPase-GED fusion protein of human Drp1 was expressed, purified and crystallized. Initial X-ray diffraction experiments yielded data to 2.67 Å resolution. The hexagonal-shaped crystals belonged to space group P2 1 2 1 2, with unit-cell parameters a = 53.59, b = 151.65, c = 43.53 Å, one molecule per asymmetric unit and a solvent content of 42%. Expression of selenomethionine-labelled protein is currently in progress. Here, the expression, purification, crystallization and X-ray diffraction analysis of the Drp1 GTPase-GED fusion protein are presented, which form a basis for more detailed structural and biophysical analysis

[Construction of cTnC-linker-TnI (P) Genes, Expression of Fusion Protein and Preparation of Lyophilized Protein].

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Song, Xiaoli; Liu, Xiaoyun; Cai, Lei; Wu, Jianwei; Wang, Jihua

2015-12-01

In order to construct and express human cardiac troponin C-linker-troponin I(P) [ cTnC-linker-TnI(P)] fusion protein, detect its activity and prepare lyophilized protein, we searched the CDs of human cTnC and cTnI from GenBank, synthesized cTnC and cTnI(30-110aa) into cloning vector by a short DNA sequence coding for 15 neutral amino acid residues. pCold I-cTnC-linker-TnI(P) was constructed and transformed into E. coli BL21(DE3). Then, cTnC-linker-TnI(P) fusion protein was induced by isopropyl-β-D-thiogalactopyranoside (IPTG). Soluable expression of cTnC-linker-TnI(P) in prokaryotic system was successfully obtained. The fusion protein was purified by Ni²⁺ Sepharose 6 Fast Flow affinity chromatography with over 95% purity and prepared into lyophilized protein. The activity of purified cTnC-linker-TnI(P) and its lyophilized protein were detected by Wondfo Finecare™ cTnI Test. Lyophilized protein of cTnC-linker-TnI(P) was stable for 10 or more days at 37 °C and 4 or more months at 25 °C and 4 °C. The expression system established in this research is feasible and efficient. Lyophilized protein is stable enough to be provided as biological raw materials for further research.

Coating Nanoparticles with Plant-Produced Transferrin-Hydrophobin Fusion Protein Enhances Their Uptake in Cancer Cells

DEFF Research Database (Denmark)

Reuter, Lauri J.; Shahbazi, Mohammad-Ali; Makila, Ermei M.

2017-01-01

can be expressed in Nicotiana benthamiana plants as a fusion with Trichoderma reesei hydrophobins HFBI, HFBII, or HFBIV. Transferrin-HFBIV was further expressed in tobacco BY-2 suspension cells. Both partners of the fusion protein retained their functionality; the hydrophobin moiety enabled migration...... to a surfactant phase in an aqueous two-phase system, and the transferrin moiety was able to reversibly bind iron. Coating porous silicon nanoparticles with the fusion protein resulted in uptake of the nanoparticles in human cancer cells. This study provides a proof-of concept for the functionalization...

Evidence for participation of GCS1 in fertilization of the starlet sea anemone Nematostella vectensis: Implication of a common mechanism of sperm–egg fusion in plants and animals

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Ebchuqin, Eerdundagula; Yokota, Naoto; Yamada, Lixy [Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Sugashima, Toba 517-0004 (Japan); Yasuoka, Yuuri [Marine Genomics Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495 (Japan); Akasaka, Mari [Laboratory of Molecular Genetics, Graduate School of Science, Nagoya University, Chikusa-ku, Furo-cho, Nagoya 464-8602 (Japan); Arakawa, Mio; Deguchi, Ryusaku [Department of Biology, Miyagi University of Education, Sendai, Miyagi 980-0845 (Japan); Mori, Toshiyuki [Waseda Institute for Advanced Study, Waseda University, Shinjuku, Tokyo 169-8050 (Japan); Sawada, Hitoshi, E-mail: hsawada@bio.nagoya-u.ac.jp [Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Sugashima, Toba 517-0004 (Japan)

2014-09-05

Highlights: • GCS1 is a sperm transmembrane protein that is essential for gamete fusion in flowering plants. • The GCS1 gene is present not only in angiosperms but also in unicellular organisms and animals. • NvGCS1 gene is expressed in the testis and GCS1 protein exists in sperm of a sea anemone. • Anti-GCS1 antibodies inhibited the fertilization, showing the participation in fertilization. - Abstract: It has been reported that GCS1 (Generative Cell Specific 1) is a transmembrane protein that is exclusively expressed in sperm cells and is essential for gamete fusion in flowering plants. The GCS1 gene is present not only in angiosperms but also in unicellular organisms and animals, implying the occurrence of a common or ancestral mechanism of GCS1-mediated gamete fusion. In order to elucidate the common mechanism, we investigated the role of GCS1 in animal fertilization using a sea anemone (Cnidaria), Nematostella vectensis. Although the existence of the GCS1 gene in N. vectensis has been reported, the expression of GCS1 in sperm and the role of GCS1 in fertilization are not known. In this study, we showed that the GCS1 gene is expressed in the testis and that GCS1 protein exists in sperm by in situ hybridization and proteomic analysis, respectively. Then we made four peptide antibodies against the N-terminal extracellular region of NvGCS1. These antibodies specifically reacted to NvGCS1 among sperm proteins on the basis of Western analysis and potently inhibited fertilization in a concentration-dependent manner. These results indicate that sperm GCS1 plays a pivotal role in fertilization, most probably in sperm–egg fusion, in a starlet sea anemone, suggesting a common gamete-fusion mechanism shared by eukaryotic organisms.

Xerophthalmia of Sjogren's Syndrome Diagnosed with Anti-Salivary Gland Protein 1 Antibodies

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Sahana Vishwanath

2014-06-01

Full Text Available Purpose: The purpose of this report is to describe 2 patients with persistent severe dry eyes, positive Schirmer tests for Sjogren's syndrome (SS but lacking antibodies to either Ro or La. These patients were diagnosed to have SS by detecting antibodies to salivary gland protein 1 (Sp1 and parotid secretory protein (PSP. This report emphasizes the existence of patients with SS who lack antibodies to either Ro or La and may therefore be misdiagnosed. Detection of novel autoantibodies, including antibodies to Sp1 and PSP, are helpful in identifying these patients. Initial presentation may simply be dry eyes. Methods: Two patients who presented to our ophthalmology clinic are described. One of the patients underwent multiple procedures over a period of 10 years for severe xerophthalmia. The other patient had rheumatoid arthritis and xerophthalmia. However, in both patients, chronic xerophthalmia had been considered to be idiopathic because antibodies Ro and La were negative. Further serologic testing revealed antibodies to Sp1 and PSP. Results: Two patients who lacked antibodies to Ro and La but not to Sp1 and PSP were diagnosed as having SS. Conclusion: Patients presenting with unexplained dry eyes may not always show the serology markers in the current criteria for SS, anti-Ro and anti-La. In these cases, investigation for novel, early antibodies to Sp1 and PSP is of importance in the diagnosis of SS.

[Eukaryotic Expression and Immunogenic Research of Recombination Ebola Virus Membrane Protein Gp-Fc].

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Zhang, Xiaoguang; Yang, Ren; Wang, Jiao; Wang, Xuan; Hou, Mieling; An, Lina; Zhu, Ying; Cao, Yuxi; Zeng, Yi

2016-01-01

We used 293 cells to express the recombinant membrane protein of the Ebola virus. Then, the immunogenicity of the recombinant protein was studied by immunized BALB/c mice. According to the codon use frequency of humans, the gene encoding the extracellular domain of the Ebola virus membrane protein was optimized, synthesized, and inserted into the eukaryotic expression plasmid pXG-Fc to construct the human IgG Fc and Ebola GP fusion protein expression plasmid pXG-modGP-Fc. To achieve expression, the fusion protein expression vector was transfected into high-density 293 cells using transient transfection technology. The recombinant protein was purified by protein A affinity chromatography. BALB/c mice were immunized with the purified fusion protein, and serum antibody titers evaluated by an indirect enzyme-linked immunosorbent assay (ELISA). Purification and analyses of the protein revealed that the eukaryotic expression vector could express the recombinant protein GP-Fc effectively, and that the recombinant protein in the supernatant of the cell culture was present as a dimer. After immunization with the purified recombinant protein, a high titer of antigen-specific IgG could be detected in the serum of immunized mice by indirect ELISA, showing that the recombinant protein had good immunogenicity. These data suggest that we obtained a recombinant protein with good immunogenicity. Our study is the basis for development of a vaccine against the Ebola virus and for screening of monoclonal antibodies.

Simplifying complex sequence information: a PCP-consensus protein binds antibodies against all four Dengue serotypes.

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Bowen, David M; Lewis, Jessica A; Lu, Wenzhe; Schein, Catherine H

2012-09-14

Designing proteins that reflect the natural variability of a pathogen is essential for developing novel vaccines and drugs. Flaviviruses, including Dengue (DENV) and West Nile (WNV), evolve rapidly and can "escape" neutralizing monoclonal antibodies by mutation. Designing antigens that represent many distinct strains is important for DENV, where infection with a strain from one of the four serotypes may lead to severe hemorrhagic disease on subsequent infection with a strain from another serotype. Here, a DENV physicochemical property (PCP)-consensus sequence was derived from 671 unique sequences from the Flavitrack database. PCP-consensus proteins for domain 3 of the envelope protein (EdomIII) were expressed from synthetic genes in Escherichia coli. The ability of the purified consensus proteins to bind polyclonal antibodies generated in response to infection with strains from each of the four DENV serotypes was determined. The initial consensus protein bound antibodies from DENV-1-3 in ELISA and Western blot assays. This sequence was altered in 3 steps to incorporate regions of maximum variability, identified as significant changes in the PCPs, characteristic of DENV-4 strains. The final protein was recognized by antibodies against all four serotypes. Two amino acids essential for efficient binding to all DENV antibodies are part of a discontinuous epitope previously defined for a neutralizing monoclonal antibody. The PCP-consensus method can significantly reduce the number of experiments required to define a multivalent antigen, which is particularly important when dealing with pathogens that must be tested at higher biosafety levels. Copyright © 2012 Elsevier Ltd. All rights reserved.

TALE-PvuII fusion proteins--novel tools for gene targeting.

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Yanik, Mert; Alzubi, Jamal; Lahaye, Thomas; Cathomen, Toni; Pingoud, Alfred; Wende, Wolfgang

2013-01-01

Zinc finger nucleases (ZFNs) consist of zinc fingers as DNA-binding module and the non-specific DNA-cleavage domain of the restriction endonuclease FokI as DNA-cleavage module. This architecture is also used by TALE nucleases (TALENs), in which the DNA-binding modules of the ZFNs have been replaced by DNA-binding domains based on transcription activator like effector (TALE) proteins. Both TALENs and ZFNs are programmable nucleases which rely on the dimerization of FokI to induce double-strand DNA cleavage at the target site after recognition of the target DNA by the respective DNA-binding module. TALENs seem to have an advantage over ZFNs, as the assembly of TALE proteins is easier than that of ZFNs. Here, we present evidence that variant TALENs can be produced by replacing the catalytic domain of FokI with the restriction endonuclease PvuII. These fusion proteins recognize only the composite recognition site consisting of the target site of the TALE protein and the PvuII recognition sequence (addressed site), but not isolated TALE or PvuII recognition sites (unaddressed sites), even at high excess of protein over DNA and long incubation times. In vitro, their preference for an addressed over an unaddressed site is > 34,000-fold. Moreover, TALE-PvuII fusion proteins are active in cellula with minimal cytotoxicity.