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Sample records for antigen mimicking peptides

  1. Antibodies against a class II HLA-peptide complex raised by active immunization of mice with antigen mimicking peptides

    DEFF Research Database (Denmark)

    Dam-Tuxen, R; Riise, Erik Skjold

    2009-01-01

    Multiple sclerosis (MS) is an autoimmune disease linked to the human leucocyte antigen (HLA) class II genes DRB1*1501, DRB5*0101 and DQB1*0602. T cells reactive towards the DRB1*1501 in complex with various peptides derived from myelin basic protein (MBP), which is the major component of myelin......, have been found in the peripheral blood of MS patients. These autoreactive T cells are believed to play a role in the pathogenesis of MS. In this article, antibodies against the HLA complex DR2b (DRA1*0101/DRB1*1501) in complex with the MBP-derived peptide MBP(85-99) have been generated by immunization...

  2. A Peptide mimicking a region in proliferating cell nuclear antigen specific to key protein interactions is cytotoxic to breast cancer.

    Science.gov (United States)

    Smith, Shanna J; Gu, Long; Phipps, Elizabeth A; Dobrolecki, Lacey E; Mabrey, Karla S; Gulley, Pattie; Dillehay, Kelsey L; Dong, Zhongyun; Fields, Gregg B; Chen, Yun-Ru; Ann, David; Hickey, Robert J; Malkas, Linda H

    2015-02-01

    Proliferating cell nuclear antigen (PCNA) is a highly conserved protein necessary for proper component loading during the DNA replication and repair process. Proteins make a connection within the interdomain connector loop of PCNA, and much of the regulation is a result of the inherent competition for this docking site. If this target region of PCNA is modified, the DNA replication and repair process in cancer cells is potentially altered. Exploitation of this cancer-associated region has implications for targeted breast cancer therapy. In the present communication, we characterize a novel peptide (caPeptide) that has been synthesized to mimic the sequence identified as critical to the cancer-associated isoform of PCNA. This peptide is delivered into cells using a nine-arginine linking mechanism, and the resulting peptide (R9-cc-caPeptide) exhibits cytotoxicity in a triple-negative breast cancer cell line, MDA-MB-436, while having less of an effect on the normal counterparts (MCF10A and primary breast epithelial cells). The novel peptide was then evaluated for cytotoxicity using various in vivo techniques, including ATP activity assays, flow cytometry, and clonogenetic assays. This cytotoxicity has been observed in other breast cancer cell lines (MCF7 and HCC1937) and other forms of cancer (pancreatic and lymphoma). R9-cc-caPeptide has also been shown to block the association of PCNA with chromatin. Alanine scanning of the peptide sequence, combined with preliminary in silico modeling, gives insight to the disruptive ability and the molecular mechanism of action of the therapeutic peptide in vivo. PMID:25480843

  3. A Peptide Mimicking a Region in Proliferating Cell Nuclear Antigen Specific to Key Protein Interactions Is Cytotoxic to Breast Cancer

    OpenAIRE

    Smith, Shanna J.; Gu, Long; Phipps, Elizabeth A.; Lacey E Dobrolecki; Mabrey, Karla S.; Gulley, Pattie; Dillehay, Kelsey L; Dong, Zhongyun; Fields, Gregg B.; Chen, Yun-Ru; Ann, David; Hickey, Robert J.; Malkas, Linda H.

    2015-01-01

    Proliferating cell nuclear antigen (PCNA) is a highly conserved protein necessary for proper component loading during the DNA replication and repair process. Proteins make a connection within the interdomain connector loop of PCNA, and much of the regulation is a result of the inherent competition for this docking site. If this target region of PCNA is modified, the DNA replication and repair process in cancer cells is potentially altered. Exploitation of this cancer-associated region has imp...

  4. Selection of a peptide mimicking neutralization epitope of hepatitis E virus with phage peptide display technology

    Institute of Scientific and Technical Information of China (English)

    Ying Gu; Jun Zhang; Ying-Bing Wang; Shao-Wei Li; Hai-Jie Yang; Wen-Xin Luo; Ning-Shao Xia

    2004-01-01

    AIM: To select the peptide mimicking the neutralization epitope of hepatitis E virus which bound to non-type-specific and conformational monoclonal antibodies (mAbs) 8C11 and 8H3 fromed 7-peptide phage display library, and expressed the peptide recombinant with HBcAg in E.coli, and to observe whether the recombinant HBcAg could still form virus like particle (VLP) and to test the activation of the recombinant polyprotein and chemo-synthesized peptide that was selected by mAb 8H3.METHODS: 8C11 and 8H3 were used to screen for binding peptides through a 7-peptide phage display library. After 4rounds of panning, monoclonal phages were selected and sequenced. The obtained dominant peptide coding sequences was then synthesized and inserted into amino acid 78 to 83 of hepatitis B core antigen (HBcAg), and then expressed in E. coli. Activity of the recombinant proteins was detected by Western blotting, VLPs of the recombinant polyproteins were tested by transmission electron microscopy and binding activity of the chemo-synthesized peptide was confirmed by BIAcore biosensor.RESULTS: Twenty-one positive monoclonal phages (10for 8CL1, and 11 for 8H3) were selected and the inserted fragments were sequenced. The DNA sequence coding for the obtained dominant peptides 8C11 (N′-His-Pro-Thr-LeuLeu-Arg-Ile-C′, named 8C11A) and 8H3 (N′-Ser-Ile-LeuPro- Tyr-Pro-Tyr-C′, named 8H3A) were then synthesized and cloned to the HBcAg vector, then expressed in E. coli.The recombinant proteins aggregated into homodimer or polymer on SDS-PAGE, and could bind to mAb 8C11 and 8H3 in Western blotting. At the same time, the recombinant polyprotein could form virus like particles (VLPs), which could be visualized on electron micrograph. The dominant peptide 8H3A selected by mAb 8H3 was further chemosynthesized, and its binding to mAb 8H3 could be detected by BIAcore biosensor.CONCLUSION: These results implicate that conformational neutralizing epitope can be partially modeled by a short

  5. Self-assembled light-harvesting peptide nanotubes for mimicking natural photosynthesis.

    Science.gov (United States)

    Kim, Jae Hong; Lee, Minah; Lee, Joon Seok; Park, Chan Beum

    2012-01-01

    Light-harvesting peptide nanotubes are synthesized by the self-assembly of diphenylalanine with THPP and platinum nanoparticles (nPt; see picture; TEOA = triethanolamine). The light-harvesting peptide nanotubes are suitable for mimicking photosynthesis because of their structure and electrochemical properties that are similar to the ones of photosystem I in natural photosynthesis. PMID:21976303

  6. Oxidative stress can alter the antigenicity of immunodominant peptides

    DEFF Research Database (Denmark)

    Weiskopf, Daniela; Schwanninger, Angelika; Weinberger, Birgit; Almanzar, Giovanni; Parson, Walther; Buus, Søren; Lindner, Herbert; Grubeck-Loebenstein, Beatrix

    2010-01-01

    APCs operate frequently under oxidative stress induced by aging, tissue damage, pathogens, or inflammatory responses. Phagocytic cells produce peroxides and free-radical species that facilitate pathogen clearance and can in the case of APCs, also lead to oxidative modifications of antigenic...... proteins and peptides. Little information is available presently about the consequences of such modifications on the immune response. To model oxidative modification of an immunodominant antigenic peptide, we oxidized the methionine residue of the human CMV pp65(495-503) (NLVPMVATV) peptide. Such...... modifications of an antigenic peptide can affect MHC binding or TCR recognition. Using binding and dissociation assays, we demonstrate that oxidative modification of the CMVpp65(495-503) peptide leads to a decreased binding of the pMHC complex to the TCR, whereas binding of the peptide to the MHC class I...

  7. Autologous peptides constitutively occupy the antigen binding site on Ia

    DEFF Research Database (Denmark)

    Buus, S; Sette, A; Colon, S M;

    1988-01-01

    Low molecular weight material associated with affinity-purified class II major histocompatibility complex (MHC) molecules of mouse (Ia) had the expected properties of peptides bound to the antigen binding site of Ia. Thus, the low molecular weight material derived from the I-Ad isotype was...

  8. Synthetic peptides with antigenic specificity for bacterial toxins.

    Science.gov (United States)

    Sela, M; Arnon, R; Jacob, C O

    1986-01-01

    The attachment of a diphtheria toxin-specific synthetic antigenic determinant and a synthetic adjuvant to a synthetic polymeric carrier led to production of a totally synthetic macromolecule which provoked protective antibodies against diphtheria when administered in aqueous solution. When peptides related to the B subunit of cholera toxin were synthesized and attached to tetanus toxoid, antibodies produced against the conjugate reacted in some but not all cases with intact cholera toxin and (especially with peptide CTP 3, residues 50-64) neutralized toxin reactivity, as tested by permeability in rabbit skin, fluid accumulation in ligated small intestinal loops and adenylate cyclase activation. Polymerization of the peptide without any external carrier, or conjugation with the dipalmityl lysine group, had as good an effect in enhancing the immune response as its attachment to tetanus toxoid. Prior exposure to the carrier suppressed the immune response to the epitope attached to it, whereas prior exposure to the synthetic peptide had a good priming effect when the intact toxin was given; when two different peptides were attached to the same carrier, both were expressed. Antisera against peptide CTP 3 were highly cross-reactive with the heat-labile toxin of Escherichia coli and neutralized it to the same extent as cholera toxin, which is not surprising in view of the great homology between the two proteins. A synthetic oligonucleotide coding for CTP 3 has been used to express the peptide in a form suitable for immunization. It led to a priming effect against the intact cholera toxin. PMID:2426052

  9. Identification of a peptide binding protein that plays a role in antigen presentation.

    OpenAIRE

    Lakey, E K; Margoliash, E.; Pierce, S K

    1987-01-01

    The helper T-cell response to globular proteins appears, in general, to require intracellular processing of the antigen, such that a peptide fragment containing the T-cell antigenic determinant is released and transported to and held on the surface of an Ia-expressing, antigen-presenting cell. However, the molecular details underlying these phenomena are largely unknown. The means by which antigenic peptides are anchored on the antigen-presenting cell surface was investigated. A cell surface ...

  10. Probing the S1 specificity pocket of the aminopeptidases that generate antigenic peptides

    OpenAIRE

    Zervoudi, Efthalia; Papakyriakou, Athanasios; Georgiadou, Dimitra; Evnouchidou, Irini; Gajda, Anna; Poreba, Marcin; Salvesen, Guy S.; Drag, Marcin; Hattori, Akira; Swevers, Luc; Vourloumis, Dionisios; Stratikos, Efstratios

    2011-01-01

    Abstract ER aminopeptidase 1 (ERAP1), ER aminopeptidase 2 (ERAP2) and Insulin Regulated aminopeptidase (IRAP) are three homologous enzymes that play critical roles in the generation of antigenic peptides. These aminopeptidases excise amino acids from N-terminally extended precursors of antigenic peptides in order to generate the correct length epitopes for binding onto MHC class I molecules. The specificity of these peptidases can affect antigenic peptide selection, but has not yet...

  11. Design, synthesis and DNA interactions of a chimera between a platinum complex and an IHF mimicking peptide.

    Science.gov (United States)

    Rao, Harita; Damian, Mariana S; Alshiekh, Alak; Elmroth, Sofi K C; Diederichsen, Ulf

    2015-12-28

    Conjugation of metal complexes with peptide scaffolds possessing high DNA binding affinity has shown to modulate their biological activities and to enhance their interaction with DNA. In this work, a platinum complex/peptide chimera was synthesized based on a model of the Integration Host Factor (IHF), an architectural protein possessing sequence specific DNA binding and bending abilities through its interaction with a minor groove. The model peptide consists of a cyclic unit resembling the minor grove binding subdomain of IHF, a positively charged lysine dendrimer for electrostatic interactions with the DNA phosphate backbone and a flexible glycine linker tethering the two units. A norvaline derived artificial amino acid was designed to contain a dimethylethylenediamine as a bidentate platinum chelating unit, and introduced into the IHF mimicking peptides. The interaction of the chimeric peptides with various DNA sequences was studied by utilizing the following experiments: thermal melting studies, agarose gel electrophoresis for plasmid DNA unwinding experiments, and native and denaturing gel electrophoresis to visualize non-covalent and covalent peptide-DNA adducts, respectively. By incorporation of the platinum metal center within the model peptide mimicking IHF we have attempted to improve its specificity and DNA targeting ability, particularly towards those sequences containing adjacent guanine residues. PMID:26477860

  12. Current status of multiple antigen-presenting peptide vaccine systems: Application of organic and inorganic nanoparticles

    Directory of Open Access Journals (Sweden)

    Taguchi Hiroaki

    2011-08-01

    Full Text Available Abstract Many studies are currently investigating the development of safe and effective vaccines to prevent various infectious diseases. Multiple antigen-presenting peptide vaccine systems have been developed to avoid the adverse effects associated with conventional vaccines (i.e., live-attenuated, killed or inactivated pathogens, carrier proteins and cytotoxic adjuvants. Recently, two main approaches have been used to develop multiple antigen-presenting peptide vaccine systems: (1 the addition of functional components, e.g., T-cell epitopes, cell-penetrating peptides, and lipophilic moieties; and (2 synthetic approaches using size-defined nanomaterials, e.g., self-assembling peptides, non-peptidic dendrimers, and gold nanoparticles, as antigen-displaying platforms. This review summarizes the recent experimental studies directed to the development of multiple antigen-presenting peptide vaccine systems.

  13. Immune response to immunodominant Mycobacterium tuberculosis antigen ESAT-6 derived peptide is HLA-haplotype dependent

    OpenAIRE

    Smart, Michele; Behrens, Marshall; David, Luckey; Conway, Catherine; Taneja, Veena

    2014-01-01

    The antigenic proteins of Mycobacterium tuberculosis (Mtb) have been defined. We used synthetic peptides of secreted antigens, early secreted antigenic target 6 (ESAT-6) and cultural filtrate protein-10 (CFP-10), of Mtb and characterized the immune response in context of HLA genes. Humanized mice lacking endogenous class II molecules but expressing various human DR and DQ HLA transgenes singly or as a haplotype were used to study the HLA-mediated immune response to peptides. Our observations ...

  14. Identification of a peptide binding protein that plays a role in antigen presentation

    International Nuclear Information System (INIS)

    The helper T-cell response to globular proteins appears, in general, to require intracellular processing of the antigen, such that a peptide fragment containing the T-cell antigenic determinant is released and transported to and held on the surface of an Ia-expressing, antigen-presenting cell. However, the molecular details underlying these phenomena are largely unknown. The means by which antigenic peptides are anchored on the antigen-presenting cell surface was investigated. A cell surface protein is identified that was isolated by it ability to bind to a 24-amino acid peptide fragment of pigeon cytochrome c, residues 81-104, containing the major antigenic determinant for B10.A mouse T cells. This peptide binding protein, purified from [35S]methionine-labeled cells, appears as two discrete bands of ≅72 and 74 kDa after NaDodSO4/PAGE. The protein can be eluted from the peptide affinity column with equivalent concentrations of either the antigenic pigeon cytochrome c peptide or the corresponding nonantigenic peptide of mouse cytochrome c. However, it does not bind to the native cytochromes c, either of pigeon or mouse, and thus the protein appears to recognize some structure available only in the free peptides. This protein plays a role in antigen presentation. Its expression is not major histocompatibility complex-restricted in that the blocking activity of the antisera can be absorbed on spleen cells from mice of different haplotypes. This peptide binding protein can be isolated from a variety of cell types, including B cells, T cells, and fibroblasts. The anchoring of processed peptides on the cell surface by such a protein may play a role in antigen presentation

  15. MHC-restricted antigen presentation and recognition: constraints on gene, recombinant and peptide vaccines in humans

    Directory of Open Access Journals (Sweden)

    Cunha-Neto E.

    1999-01-01

    Full Text Available The target of any immunization is to activate and expand lymphocyte clones with the desired recognition specificity and the necessary effector functions. In gene, recombinant and peptide vaccines, the immunogen is a single protein or a small assembly of epitopes from antigenic proteins. Since most immune responses against protein and peptide antigens are T-cell dependent, the molecular target of such vaccines is to generate at least 50-100 complexes between MHC molecule and the antigenic peptide per antigen-presenting cell, sensitizing a T cell population of appropriate clonal size and effector characteristics. Thus, the immunobiology of antigen recognition by T cells must be taken into account when designing new generation peptide- or gene-based vaccines. Since T cell recognition is MHC-restricted, and given the wide polymorphism of the different MHC molecules, distinct epitopes may be recognized by different individuals in the population. Therefore, the issue of whether immunization will be effective in inducing a protective immune response, covering the entire target population, becomes an important question. Many pathogens have evolved molecular mechanisms to escape recognition by the immune system by variation of antigenic protein sequences. In this short review, we will discuss the several concepts related to selection of amino acid sequences to be included in DNA and peptide vaccines.

  16. Novel selective inhibitors of aminopeptidases that generate antigenic peptides.

    Science.gov (United States)

    Papakyriakou, Athanasios; Zervoudi, Efthalia; Theodorakis, Emmanuel A; Saveanu, Loredana; Stratikos, Efstratios; Vourloumis, Dionisios

    2013-09-01

    Endoplasmic reticulum aminopeptidases, ERAP1 and ERAP2, as well as Insulin regulated aminopeptidase (IRAP) play key roles in antigen processing, and have recently emerged as biologically important targets for manipulation of antigen presentation. Taking advantage of the available structural and substrate-selectivity data for these enzymes, we have rationally designed a new series of inhibitors that display low micromolar activity. The selectivity profile for these three highly homologous aminopeptidases provides a promising avenue for modulating intracellular antigen processing. PMID:23916253

  17. INDUCEMENT OF ANTITUMOR-IMMUNITY BY DC ACTIVATED BY HSP70-H22 TUMOR ANTIGEN PEPTIDE

    Institute of Scientific and Technical Information of China (English)

    冯作化; 黄波; 张桂梅; 李东; 王洪涛

    2003-01-01

    Objective: To investigate the feasibility of decreasing the dosage of tumor antigen peptides by dendritic cell (DC)-presenting and the characteristics of modification of DC by heat shock protein (Hsp70) and antigen peptides. Methods: Peptides were bound to Hsp70 and used to modify DC in vitro. The metabolism of the modified DC and the cytokines secreted by the modified DC were determined. The activation of lymphocytes by the modified DC and Hsp70-H22 peptides was tested. The cytotoxicity of the activated lymphocytes to H22 tumor cells was analyzed. The inhibitory effect of tumor in mice by the injection of DC and Hsp70-H22 peptides was tested. Results: 0.15μg of H22 peptides bound with Hsp70 could make 2×105 DC mature. 4×103 matured DC could activate 2×106 lymphocytes. The same amount of lymphocytes could be activated to produce similar cytotoxicity to tumor cells by either DC modified by 0.003μg of peptides bound with Hsp70 or by direct stimulation with 0.15μg of peptides bound with Hsp70. The dosage of peptides could be reduced by about 50 folds if the modified DC was used for injection instead of Hsp70-peptides. Peptides from normal hepatocytes, bound with Hsp70, could not make DC mature, nor activate lymphocytes through DC. Conclusion: The dosage of Hsp70-H22 peptides can be reduced significantly by DC-presenting to activate lymphocytes. Peptides from normal cells could not activate lymphocytes by either Hsp70-presenting or DC-presenting and they have little chance to induce autoimmunity.

  18. Turnover of Ia-peptide complexes is facilitated in viable antigen-presenting cells: biosynthetic turnover of Ia vs. peptide exchange.

    OpenAIRE

    Harding, C V; Roof, R W; Unanue, E R

    1989-01-01

    Macrophages and B cells process antigens to produce antigenic peptides that associate with class II major histocompatibility complex molecules (e.g., Ia molecules); these Ia-peptide complexes are recognized by CD4+ T lymphocytes. Processing of the antigen hen egg white lysozyme was inhibited by cycloheximide in peritoneal exudate cells (PECs, largely macrophages), but not in TA3 B-lymphoma cells. The uptake and metabolism of hen egg white lysozyme was largely intact in cycloheximide-treated P...

  19. Antigenic peptide trimming by ER aminopeptidases – insights from structural studies

    OpenAIRE

    Stratikos, Efstratios; Stern, Lawrence J.

    2013-01-01

    Generation and destruction of antigenic peptides by ER resident aminopeptidases ERAP1 and ERAP2 have been shown in the last few years to be important for the correct functioning and regulation of the adaptive immune response. These two highly homologous aminopeptidases appear to have evolved complex mechanisms well suited for their biological role in antigen presentation. Furthermore, polymorphic variability in these enzymes appears to affect their function and predispose individuals to disea...

  20. Evasion of peptide, but not lipid antigen presentation, through pathogen-induced dendritic cell maturation

    OpenAIRE

    Hava, David L.; van der Wel, Nicole ,; Cohen, Nadia; Dascher, Christopher C.; Houben, Diane; León, Luis; Agarwal, Sandeep; Sugita, Masahiko; van Zon, Maaike; Kent, Sally C.; Shams, Homayoun; Peters, Peter J.; Brenner, Michael B.

    2008-01-01

    Dendritic cells (DC) present lipid and peptide antigens to T cells on CD1 and MHC Class II (MHCII), respectively. The relative contribution of these systems during the initiation of adaptive immunity after microbial infection is not characterized. MHCII molecules normally acquire antigen and rapidly traffic from phagolysosomes to the plasma membrane as part of DC maturation, whereas CD1 molecules instead continually recycle between these sites before, during, and after DC maturation. We find ...

  1. Chagas disease-specific antigens: characterization of epitopes in CRA/FRA by synthetic peptide mapping and evaluation by ELISA-peptide assay

    OpenAIRE

    Bottino, Carolina G; Gomes, Luciano P; Pereira, José B; José R. Coura; Provance, David William; De-Simone, Salvatore G

    2013-01-01

    Background The identification of epitopes in proteins recognized by medically relevant antibodies is useful for the development of peptide-based diagnostics and vaccines. In this study, epitopes in the cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA) proteins from Trypanosoma cruzi were identified using synthetic peptide techniques and pooled sera from Chagasic patients. The epitopes were further assayed with an ELISA assay based on synthetic peptides. Methods Twent...

  2. Structural Basis For Antigenic Peptide Precursor Processing by the Endoplasmic Reticulum Aminopeptidase ERAP1

    OpenAIRE

    Nguyen, Tina T.; Chang, Shih-Chung; Evnouchidou, Irini; Ian A York; Zikos, Christos; Rock, Kenneth L.; Goldberg, Alfred L.; Stratikos, Efstratios; Stern, Lawrence J.

    2011-01-01

    ERAP1 trims antigen precursors to fit into MHC class I proteins. To perform this function, ERAP1 has unique substrate preferences, trimming long peptides while sparing shorter ones. To identify the structural basis for ERAP1's unusual properties, we determined the X-ray crystal structure of human ERAP1 bound to bestatin. The structure reveals an open conformation with a large interior compartment. An extended groove originating from the enzyme's catalytic center can accommodate long peptides ...

  3. Conformation and dynamics of the hinge peptide: a potential carrier for antigenic sequences

    Czech Academy of Sciences Publication Activity Database

    Maloň, Petr; Urbanová, M.; Buděšínský, Miloš; Gut, Vladimír; Hlaváček, Jan; Niederhafner, Petr; Dlouhá, Helena; Palivec, L.; Jankovská, Vendula; Wünsch, E.

    Geneva : Kenes International, 2005 - (Flegl, M.; Fridkin, M.; Gilon, C.; Slaninová, J.), s. 1039-1040 ISBN 965-90833-0-0. [Peptides 2004. International and European Peptide Symposium /3./ /29./. Praha (CZ), 05.09.2004-10.09.2004] R&D Projects: GA ČR(CZ) GA203/02/0328 Institutional research plan: CEZ:AV0Z40500505 Keywords : conformation * dynamics * antigenic sequences * VCD Subject RIV: CE - Biochemistry

  4. Optimized tumor cryptic peptides: the basis for universal neo-antigen-like tumor vaccines.

    Science.gov (United States)

    Menez-Jamet, Jeanne; Gallou, Catherine; Rougeot, Aude; Kosmatopoulos, Kostas

    2016-07-01

    The very impressive clinical results recently obtained in cancer patients treated with immune response checkpoint inhibitors boosted the interest in immunotherapy as a therapeutic choice in cancer treatment. However, these inhibitors require a pre-existing tumor specific immune response and the presence of tumor infiltrating T cells to be efficient. This immune response can be triggered by cancer vaccines. One of the main issues in tumor vaccination is the choice of the right antigen to target. All vaccines tested to date targeted tumor associated antigens (TAA) that are self-antigens and failed to show a clinical efficacy because of the immune self-tolerance to TAA. A new class of tumor antigens has recently been described, the neo-antigens that are created by point mutations of tumor expressing proteins and are recognized by the immune system as non-self. Neo-antigens exhibit two main properties: they are not involved in the immune self-tolerance process and are immunogenic. However, the majority of the neo-antigens are patient specific and their use as cancer vaccines requires their previous identification in each patient individualy that can be done only in highly specialized research centers. It is therefore evident that neo-antigens cannot be used for patient vaccination worldwide. This raises the question of whether we can find neo-antigen like vaccines, which would not be patient specific. In this review we show that optimized cryptic peptides from TAA are neo-antigen like peptides. Optimized cryptic peptides are recognized by the immune system as non-self because they target self-cryptic peptides that escape self-tolerance; in addition they are strongly immunogenic because their sequence is modified in order to enhance their affinity for the HLA molecule. The first vaccine based on the optimized cryptic peptide approach, Vx-001, which targets the widely expressed tumor antigen telomerase reverse transcriptase (TERT), has completed a large phase I clinical

  5. A chemically synthesized peptide which elicits humoral and cellular immune responses to mycobacterial antigens.

    OpenAIRE

    Minden, P; Houghten, R A; Spear, J R; Shinnick, T M

    1986-01-01

    Monoclonal antibodies directed to Mycobacterium bovis BCG (BCG) and to M. tuberculosis H37Rv (H37Rv) were used in conjunction with affinity chromatography to prepare a mycobacterial component which was designated BCG-a. A synthetic peptide antigen was prepared based on the amino acid sequence of BCG-a and was designated BCG-a-P. Significant immunological similarities were found between BCG-a-P and antigens in extracts of BCG and H37Rv but not between BCG-a-P and antigens of nontuberculous myc...

  6. Molecular characterization of antigen-peptide pulsed dendritic cells: immature dendritic cells develop a distinct molecular profile when pulsed with antigen peptide.

    Directory of Open Access Journals (Sweden)

    Amy X Yang

    Full Text Available As dendritic cells (DCs are the most potent professional antigen-presenting cells, they are being tested as cancer vaccines for immunotherapy of established cancers. Although numerous studies have characterized DCs by their phenotype and function, few have identified potential molecular markers of antigen presentation prior to vaccination of host. In this study we generated pre-immature DC (piDC, immature DC (iDC, and mature DC (mDC from human peripheral blood monocytes (PBMC obtained from HLA-A2 healthy donors, and pulsed them with human papillomavirus E7 peptide (p11-20, a class I HLA-A2 binding antigen. We then characterized DCs for cell surface phenotype and gene expression profile by microarray technology. We identified a set of 59 genes that distinguished three differentiation stages of DCs (piDC, iDC and mDC. When piDC, iDC and mDC were pulsed with E7 peptide for 2 hrs, the surface phenotype did not change, however, iDCs rather than mDCs showed transcriptional response by up-regulation of a set of genes. A total of 52 genes were modulated in iDC upon antigen pulsing. Elongation of pulse time for iDCs to 10 and 24 hrs did not significantly bring further changes in gene expression. The E7 peptide up-modulated immune response (KPNA7, IGSF6, NCR3, TREM2, TUBAL3, IL8, NFKBIA, pro-apoptosis (BTG1, SEMA6A, IGFBP3 and SRGN, anti-apoptosis (NFKBIA, DNA repair (MRPS11, RAD21, TXNRD1, and cell adhesion and cell migration genes (EPHA1, PGF, IL8 and CYR61 in iDCs. We confirmed our results by Q-PCR analysis. The E7 peptide but not control peptide (PADRE induced up-regulation of NFKB1A gene only in HLA-A2 positive iDCs and not in HLA-A2 negative iDCs. These results suggest that E7 up-regulation of genes is specific and HLA restricted and that these genes may represent markers of antigen presentation and help rapidly assess the quality of dendritic cells prior to administration to the host.

  7. Synthetic peptide vaccines: palmitoylation of peptide antigens by a thioester bond increases immunogenicity

    DEFF Research Database (Denmark)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Tesser, G.I.;

    1997-01-01

    amide bond. It was found that these S-palmitoylated peptides were much more immunogenic than N-palmitoylated peptides and at least similar to KLH-conjugated peptides with respect to appearance and magnitude of induced antibodies (canine parvovirus) or immunocastration effect (gonadotropin...

  8. Enhanced T cell responses to antigenic peptides targeted to B cell surface Ig, Ia, or class I molecules

    OpenAIRE

    1988-01-01

    The helper T cell recognition of soluble globular protein antigens requires that the proteins be processed by an APC, releasing a peptide that is transported to and held on the APC surface where it is recognized by the specific T cell in conjunction with Ia. When cellular processing functions are blocked, APC lose their ability to present native antigens while retaining the capacity to activate T cells when provided with a cognate peptide fragment that contains the T cell antigenic determinan...

  9. Structural requirements for the interaction between class II MHC molecules and peptide antigens

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Appella, E; Adorini, L; Grey, H M

    1990-01-01

    Previous work from our and other laboratories indicates that T cells recognize a complex between the MHC restriction element and peptide antigen fragments. This paper reviews the structural characteristics of the formation of such a complex. By analyzing in detail the interactions between purified...

  10. Structural Basis for Antigenic Peptide Recognition and Processing by Endoplasmic Reticulum (ER) Aminopeptidase 2.

    Science.gov (United States)

    Mpakali, Anastasia; Giastas, Petros; Mathioudakis, Nikolas; Mavridis, Irene M; Saridakis, Emmanuel; Stratikos, Efstratios

    2015-10-23

    Endoplasmic reticulum (ER) aminopeptidases process antigenic peptide precursors to generate epitopes for presentation by MHC class I molecules and help shape the antigenic peptide repertoire and cytotoxic T-cell responses. To perform this function, ER aminopeptidases have to recognize and process a vast variety of peptide sequences. To understand how these enzymes recognize substrates, we determined crystal structures of ER aminopeptidase 2 (ERAP2) in complex with a substrate analogue and a peptidic product to 2.5 and 2.7 Å, respectively, and compared them to the apo-form structure determined to 3.0 Å. The peptides were found within the internal cavity of the enzyme with no direct access to the outside solvent. The substrate analogue extends away from the catalytic center toward the distal end of the internal cavity, making interactions with several shallow pockets along the path. A similar configuration was evident for the peptidic product, although decreasing electron density toward its C terminus indicated progressive disorder. Enzymatic analysis confirmed that visualized interactions can either positively or negatively impact in vitro trimming rates. Opportunistic side-chain interactions and lack of deep specificity pockets support a limited-selectivity model for antigenic peptide processing by ERAP2. In contrast to proposed models for the homologous ERAP1, no specific recognition of the peptide C terminus by ERAP2 was evident, consistent with functional differences in length selection and self-activation between these two enzymes. Our results suggest that ERAP2 selects substrates by sequestering them in its internal cavity and allowing opportunistic interactions to determine trimming rates, thus combining substrate permissiveness with sequence bias. PMID:26381406

  11. PLGA nanoparticle-mediated delivery of tumor antigenic peptides elicits effective immune responses

    Directory of Open Access Journals (Sweden)

    Ma W

    2012-03-01

    Full Text Available Wenxue Ma1, Mingshui Chen1, Sharmeela Kaushal1,2, Michele McElroy1,2, Yu Zhang3, Cengiz Ozkan3, Michael Bouvet1,2, Carol Kruse4, Douglas Grotjahn5, Thomas Ichim6, Boris Minev1,7,81Moores Cancer Center, University of California San Diego, 2Department of Surgery, University of California San Diego, 3Laboratory of Biomaterials and Nanotechnology, University of California Riverside, 4UCLA Division of Neurosurgery, Los Angeles, 5Chemistry Department, San Diego State University, San Diego, 6MediStem Inc. San Diego, 7UCSD Division of Neurosurgery, San Diego, 8Genelux Corporation, San Diego, CA, USA Abstract: The peptide vaccine clinical trials encountered limited success because of difficulties associated with stability and delivery, resulting in inefficient antigen presentation and low response rates in patients with cancer. The purpose of this study was to develop a novel delivery approach for tumor antigenic peptides in order to elicit enhanced immune responses using poly(DL-lactide-co-glycolide nanoparticles (PLGA-NPs encapsulating tumor antigenic peptides. PLGA-NPs were made using the double emulsion-solvent evaporation method. Artificial antigen-presenting cells were generated by human dendritic cells (DCs loaded with PLGA-NPs encapsulating tumor antigenic peptide(s. The efficiency of the antigen presentation was measured by interferon-γ ELISpot assay (Vector Laboratories, Burlingame, CA. Antigen-specific cytotoxic T lymphocytes (CTLs were generated and evaluated by CytoTox 96® Non-Radioactive Cytotoxicity Assay (Promega, Fitchburg, WI. The efficiency of the peptide delivery was compared between the methods of emulsification in incomplete Freund’s adjuvant and encapsulation in PLGA-NPs. Our results showed that most of the PLGA-NPs were from 150 nm to 500 nm in diameter, and were negatively charged at pH 7.4 with a mean zeta potential of -15.53 ± 0.71 mV; the PLGA-NPs could be colocalized in human DCs in 30 minutes of incubation. Human DCs

  12. Analysis of protective antigen peptide binding motifs using bacterial display technology

    Science.gov (United States)

    Sarkes, Deborah A.; Dorsey, Brandi L.; Stratis-Cullum, Dimitra N.

    2015-05-01

    In today's fast-paced world, a new biological threat could emerge at any time, necessitating a prompt, reliable, inexpensive detection reagent in each case. Combined with magnetic-activated cell sorting (MACS), bacterial display technology makes it possible to isolate selective, high affinity peptide reagents in days to weeks. Utilizing the eCPX display scaffold is also a rapid way to screen potential peptide reagents. Peptide affinity reagents for protective antigen (PA) of the biothreat Bacillus anthracis were previously discovered using bacterial display. Bioinformatics analysis resulted in the consensus sequence WXCFTC. Additionally, we have discovered PA binding peptides with a WW motif, one of which, YGLHPWWKNAPIGQR, can pull down PA from 1% human serum. The strength of these two motifs combined, to obtain a WWCFTC consensus, is assessed here using Fluorescence Activated Cell Sorting (FACS). While monitoring binding to PA, overall expression of the display scaffold was assessed using the YPet Mona expression control tag (YPet), and specificity was assessed by binding to Streptavidin R-Phycoerythrin (SAPE). The importance of high YPet binding is highlighted as many of the peptides in one of the three replicate experiments fell below our 80% binding threshold. We demonstrate that it is preferable to discard this experiment, due to questionable expression of the peptide itself, than to try to normalize for relative expression. The peptides containing the WWCFTC consensus were of higher affinity and greater specificity than the peptides containing the WW consensus alone, validating further investigation to optimize known PA binders.

  13. Analysis of endogenous peptides bound by soluble MHC class I molecules: a novel approach for identifying tumor-specific antigens.

    Science.gov (United States)

    Barnea, Eilon; Beer, Ilan; Patoka, Renana; Ziv, Tamar; Kessler, Ofra; Tzehoval, Esther; Eisenbach, Lea; Zavazava, Nicholas; Admon, Arie

    2002-01-01

    The Human MHC Project aims at comprehensive cataloging of peptides presented within the context of different human leukocyte antigens (HLA) expressed by cells of various tissue origins, both in health and in disease. Of major interest are peptides presented on cancer cells, which include peptides derived from tumor antigens that are of interest for immunotherapy. Here, HLA-restricted tumor-specific antigens were identified by transfecting human breast, ovarian and prostate tumor cell lines with truncated genes of HLA-A2 and HLA-B7. Soluble HLA secreted by these cell lines were purified by affinity chromatography and analyzed by nano-capillary electrospray ionization-tandem mass spectrometry. Typically, a large peptide pool was recovered and sequenced including peptides derived from MAGE-B2 and mucin and other new tumor-derived antigens that may serve as potential candidates for immunotherapy. PMID:11782012

  14. Miniaturizing VEGF: Peptides mimicking the discontinuous VEGF receptor-binding site modulate the angiogenic response

    Science.gov (United States)

    De Rosa, Lucia; Finetti, Federica; Diana, Donatella; di Stasi, Rossella; Auriemma, Sara; Romanelli, Alessandra; Fattorusso, Roberto; Ziche, Marina; Morbidelli, Lucia; D’Andrea, Luca Domenico

    2016-08-01

    The angiogenic properties of VEGF are mediated through the binding of VEGF to its receptor VEGFR2. The VEGF/VEGFR interface is constituted by a discontinuous binding region distributed on both VEGF monomers. We attempted to reproduce this discontinuous binding site by covalently linking into a single molecular entity two VEGF segments involved in receptor recognition. We designed and synthesized by chemical ligation a set of peptides differing in length and flexibility of the molecular linker joining the two VEGF segments. The biological activity of the peptides was characterized in vitro and in vivo showing a VEGF-like activity. The most biologically active mini-VEGF was further analyzed by NMR to determine the atomic details of its interaction with the receptor.

  15. Antigenic peptide trimming by ER aminopeptidases--insights from structural studies.

    Science.gov (United States)

    Stratikos, Efstratios; Stern, Lawrence J

    2013-10-01

    Generation and destruction of antigenic peptides by ER resident aminopeptidases ERAP1 and ERAP2 have been shown in the last few years to be important for the correct functioning and regulation of the adaptive immune response. These two highly homologous aminopeptidases appear to have evolved complex mechanisms well suited for their biological role in antigen presentation. Furthermore, polymorphic variability in these enzymes appears to affect their function and predispose individuals to disease. This review discusses our current understanding of the molecular mechanisms behind ERAP1/2 function as suggested by several recently determined crystallographic structures of these enzymes. PMID:23545452

  16. PLAP efficiently generates mature antigenic peptides in vitro but in patterns distinct from ERAP11

    OpenAIRE

    Georgiadou, Dimitra; Hearn, Arron; Evnouchidou, Irini; Chroni, Angeliki; Leondiadis, Leondios; Ian A York; Rock, Kenneth L.; Stratikos, Efstratios

    2010-01-01

    All three members of the oxytocinase sub-family of M1 aminopeptidases, ERAP1 (ERAAP), ERAP2 and PLAP (IRAP), have been implicated in the generation of MHC class I-presented peptides. ERAP1 and 2 trim peptides in the endoplasmic reticulum for direct presentation whereas PLAP has been recently implicated in cross presentation. The best characterized member of the family, ERAP1, has unique enzymatic properties that fit well with its role in antigen processing. ERAP1 can trim a large variety of l...

  17. Construction and characterization of an HCV-derived multi-epitope peptide antigen containing B-cell HVR1 mimotopes and T-cell conserved epitopes

    Institute of Scientific and Technical Information of China (English)

    GAO; Jun; GONG; Yuping; ZHAO; Ping; ZHU; Qing; YANG; Xiaoping; QI; Zhongtian

    2006-01-01

    Hepatitis C (HCV) genome is highly variable, particularly in the hypervariable region 1(HVR1) of its E2 envelope gene. The variability of HCV genome has been a major obstacle for developing HCV vaccines. Due to B-cell HVR1 mimotopes mimicking the antigenicity of natural HVR1 epitopes and some T-cell epitopes from the consensus sequence of HCV genes conserving among the different HCV genotypes, we synthesized an minigene of HCV-derived multi-epitope peptide antigen (CMEP), which contains 9 B-cell HVR1 mimotopes in E2, 2 conserved CTL epitopes in C, 1conserved CTL epitope in NS3 and 1 conserved Th epitope in NS3. This minigene was cloned into a GST expression vector to generate a fusion protein GST-CMER The immunogenic properties of CEMP were characterized by HCV infected patients' sera, and found that the reactivity frequency reached 75%. The cross reactivity of anti-CEMP antibody with different natural HVR1 variants was up to 90%. Meanwhile, we constructed an HCV DNA vaccine candidate, plasmid pVAX1.0-st-CMEP carrying the recombinant gene (st) of a secretion signal peptide and PADRE universal Th cell epitope sequence in front of the CMEP minigene. Immunization of rabbits with pVAX1.0-st-CMEP resulted in the production of antibody, which was of the same cross reactivity as the fusion protein GST-CMEP.Our findings indicate that the HCV-derived multi-epitope peptide antigen in some degree possessed the characteristics of neutralizing HCV epitopes, and would be of the value as a candidate for the development of HCV vaccines.

  18. Multiple antigen peptide dendrimer elicits antibodies for detecting rat and mouse growth hormone binding proteins

    OpenAIRE

    Aguilar, Roberto M.; Talamantes, Frank J.; Bustamante, Juan J.; Muñoz, Jesus; Treviño, Lisa R.; Martinez, Andrew O.; Haro, Luis S.

    2009-01-01

    The membrane-bound rat growth hormone receptor (GH-R) and an alternatively spliced isoform, the soluble rat GH binding protein (GH-BP), are comprised of identical N-terminal GH binding domains, however, their C-terminal sequences differ. Immunological reagents are needed to distinguish between the two isoforms in order to understand their respective roles in mediating the actions of GH. Accordingly, a tetravalent multiple antigen peptide (MAP) dendrimer with four identical branches of a C-ter...

  19. Structural Basis For Antigenic Peptide Precursor Processing by the Endoplasmic Reticulum Aminopeptidase ERAP1

    Energy Technology Data Exchange (ETDEWEB)

    T Nguyen; S Chang; I Evnouchidou; I York; C Zikos; K Rock; A Goldberg; E Stratikos; L Stern

    2011-12-31

    ERAP1 trims antigen precursors to fit into MHC class I proteins. To fulfill this function, ERAP1 has unique substrate preferences, trimming long peptides but sparing shorter ones. To identify the structural basis for ERAP1's unusual properties, we determined the X-ray crystal structure of human ERAP1 bound to bestatin. The structure reveals an open conformation with a large interior compartment. An extended groove originating from the enzyme's catalytic center can accommodate long peptides and has features that explain ERAP1's broad specificity for antigenic peptide precursors. Structural and biochemical analyses suggest a mechanism for ERAP1's length-dependent trimming activity, whereby binding of long rather than short substrates induces a conformational change with reorientation of a key catalytic residue toward the active site. ERAP1's unique structural elements suggest how a generic aminopeptidase structure has been adapted for the specialized function of trimming antigenic precursors.

  20. Developing Peptide Mimotopes of Capsular Polysaccharides and Lipopolysaccharides Protective Antigens of Pathogenic Burkholderia Bacteria.

    Science.gov (United States)

    Guo, Pengfei; Zhang, Jing; Tsai, Shien; Li, Bingjie; Lo, Shyh-Ching

    2016-06-01

    Burkholderia pseudomallei (BP) and Burkholderia mallei (BM) are two species of pathogenic Burkholderia bacteria. Our laboratory previously identified four monoclonal antibodies (MAbs) that reacted against Burkholderia capsular polysaccharides (PS) and lipopolysaccharides (LPS) and effectively protected against a lethal dose of BP/BM infections in mice. In this study, we used phage display panning against three different phage peptide libraries to select phage clones specifically recognized by each of the four protective MAbs. After sequencing a total of 179 candidate phage clones, we examined in detail six selected phage clones carrying different peptide inserts for the specificity of binding by the respective target MAbs. Chemically synthesized peptides corresponding to those displayed by the six phage clones were conjugated to keyhole limpet hemocyanin carrier protein and tested for their binding specificity to the respective protective MAbs. The study revealed that four of the six peptides, all derived from the library displaying dodecapeptides, functioned well as "mimotopes" of Burkholderia PS and LPS as demonstrated by a high degree of specific competition against the binding of three protective MAbs to BP and BM. Our results suggest that the four selected peptide mimics corresponding to PS/LPS protective antigens of BP and BM could potentially be developed into peptide vaccines against pathogenic Burkholderia bacteria. PMID:27328059

  1. A modern approach for epitope prediction: identification of foot-and-mouth disease virus peptides binding bovine leukocyte antigen (BoLA) class I molecules

    Science.gov (United States)

    Major histocompatibility complex (MHC) class I molecules regulate adaptive immune responses through the presentation of antigenic peptides to CD8positive T-cells. Polymorphisms in the peptide binding region of class I molecules determine peptide binding affinity and stability during antigen presenta...

  2. Linkage of bacterial protein synthesis and presentation of MHC class I-restricted Listeria monocytogenes-derived antigenic peptides.

    Directory of Open Access Journals (Sweden)

    Silke Grauling-Halama

    Full Text Available The processing and MHC class I-restricted presentation of antigenic peptides derived from the p60 protein of the facultative intracellular bacterium Listeria monocytogenes is tightly linked to bacterial protein synthesis. We used non-linear regression analysis to fit a mathematical model of bacterial antigen processing to a published experimental data set showing the accumulation and decay of p60-derived antigenic peptides in L. monocytogenes-infected cells. Two alternative models equally describe the experimental data. The simulation accounting for a stable and a hypothetical rapidly degraded form of antigen predicts that the antigenic peptides p60 217-225 and p60 449-457 are derived from a putative instable form of p60 with an average intracellular half-life of approximately 3 minutes accounting for approximately 31% of all p60 molecules synthesized. The alternative model predicts that both antigenic peptides are processed from p60 degraded intracellularly with a half-life of 109 min and that antigen processing only occurs as long as bacterial protein synthesis is not inhibited. In order to decide between both models the intracellular accumulation of p60 in infected cells was studied experimentally and compared with model predictions. Inhibition of p60 degradation by the proteasome inhibitor epoxomicin revealed that during the first 3 h post infection approximately 30% of synthesized p60 molecules were degraded. This value is significantly lower than the approximately 50% degradation of p60 that would be expected in the presence of the predicted putative short-lived state of p60 and also fits precisely with the predictions of the alternative model, indicating that the tight connection of bacterial protein biosynthesis and antigen processing and presentation of L. monocyctogenes-derived antigenic peptides is not caused by the presence of a highly instable antigenic substrate.

  3. Synthetic Peptide Ligands of the Antigen Binding Receptor Induce Programmed Cell Death in a Human B-Cell Lymphoma

    Science.gov (United States)

    Renschler, Markus F.; Bhatt, Ramesh R.; Dower, William J.; Levy, Ronald

    1994-04-01

    Peptide ligands for the antigen binding site of the surface immunoglobulin receptor of a human B-cell lymphoma cell line were identified with the use of filamentous phage libraries displaying random 8- and 12-amino acid peptides. Corresponding synthetic peptides bound specifically to the antigen binding site of this immunoglobulin receptor and blocked the binding of an anti-idiotype antibody. The ligands, when conjugated to form dimers or tetramers, induced cell death by apoptosis in vitro with an IC50 between 40 and 200 nM. This effect was associated with specific stimulation of intracellular protein tyrosine phosphorylation.

  4. Antigen-oriented T cell migration contributes to myelin peptide induced-EAE and immune tolerance.

    Science.gov (United States)

    Zheng, Peiguo; Fu, Hanxiao; Wei, Gaohui; Wei, Zhongwei; Zhang, Junhua; Ma, Xuehan; Rui, Dong; Meng, Xianchun; Ming, Liang

    2016-08-01

    Treatment with soluble myelin peptide can efficiently and specifically induce tolerance to demyelination autoimmune diseases including multiple sclerosis, however the mechanism underlying this therapeutic effect remains to be elucidated. In actively induced mouse model of experimental autoimmune encephalomyelitis (EAE) we analyzed T cell and innate immune cell responses in the central nervous system (CNS) and spleen after intraperitoneal (i.p.) infusion of myelin oligodendrocyte glycoprotein (MOG). We found that i.p. MOG infusion blocked effector T cell recruitment to the CNS and protected mice from EAE and lymphoid organ atrophy. Innate immune CD11b(+) cells preferentially recruited MOG-specific effector T cells, particularly when activated to become competent antigen presenting cells (APCs). During EAE development, mature APCs were enriched in the CNS rather than in the spleen, attracting effector T cells to the CNS. Increased myelin antigen exposure induced CNS-APC maturation, recruiting additional effector T cells to the CNS, causing symptoms of disease. MOG triggered functional maturation of splenic APCs. MOG presenting APCs interacted with MOG-specific T cells in the spleen, aggregating to cluster around CD11b(+) cells, and were trapped in the periphery. This process was MHC II dependent as an MHC II directed antibody blocked CD4(+) T cell cluster formation. These findings highlight the role of myelin peptide-loaded APCs in myelin peptide-induced EAE and immune tolerance. PMID:27327113

  5. IMMUNOLOGICAL CHARACTERISTIC OF SYNTHETIC PEPTIDES SIMILAR TO ACTUAL HIV ANTIGEN DETERMINANTS

    Directory of Open Access Journals (Sweden)

    S. V. Korobova

    2016-01-01

    Full Text Available The development of HIV vaccine remains an important goal in prophylaxis and therapy of HIV/ AIDS epidemics. There are various approaches for development of а candidate vaccine based on induction of neutralizing antibodies and cell-mediated immunity. Synthetic peptides are considered promising vaccine antigens since they are capable of activating both humoral and cellular immune response. HIV-1 envelope gp120 is the target for neutralizing antiviral antibodies. The V3 region of the HIV-1 gp120 is highly immunogenic and important for the virus-coreceptor interaction. In a RV144 vaccine trial, the levels of vaccine-induced IgG antibodies recognizing V1V2 regions from multiple HIV-1 subtypes show inverse correlations with a risk for HIV-1 infection. Meanwhile, HIV is characterized by high diversity. The consensus and mosaic immunogens are complete but artificial proteins, which are computationally designed to elicit immune responses with improved cross-reactive broadness. We have been studied immunogenic properties of synthetic peptides derived from V1, V2, V3 loop regions of the consensus M HIV1 (CON-S sequence group of the gp 120 envelope protein and V3 loop derived from a Russian RUA022a2 isolate. These peptides specifically reacted to HIV-positive sera in ELISA, thus indicating their similarity to appropriate HIV proteins. The peptides proved to be weakly immunogenic. Therefore, Freund complete adjuvant was used to enhance peptide immunogenicity. To assess the immunogenicity, the mice were immunized with a peptide mixture. Antibodies have been developed to every peptide from the mixture, being, predominantly, of IgG isotype. The antibody titers depended on the length of peptide sequences. However, the sera from immunized mice did not have a HIV neutralizing activity. The serum neutralization was assessed by pseudovirus-based assay, using a molecular clone of virus isolates CAP 45.2.00.G3 and QH.209.14.M.EnvA2. The virus neutralization is a

  6. Probing the S1 specificity pocket of the aminopeptidases that generate antigenic peptides: S1 specificity of ERAP1, ERAP2 and IRAP

    OpenAIRE

    Zervoudi, Efthalia; Papakyriakou, Athanasios; Georgiadou, Dimitra; Evnouchidou, Irini; Gajda, Anna; Poreba, Marcin; Salvesen, Guy S.; Drag, Marcin; Hattori, Akira; Swevers, Luc; Vourloumis, Dionisios; Stratikos, Efstratios

    2011-01-01

    ER aminopeptidase 1 (ERAP1), ER aminopeptidase 2 (ERAP2) and Insulin Regulated aminopeptidase (IRAP) are three homologous enzymes that play critical roles in the generation of antigenic peptides. These aminopeptidases excise amino acids from N-terminally extended precursors of antigenic peptides in order to generate the correct length epitopes for binding onto MHC class I molecules. The specificity of these peptidases can affect antigenic peptide selection, but has not yet been investigated i...

  7. Characterization of antigen processing and presentation by peptide-linked MHC class I molecules

    OpenAIRE

    Tiwari, Neeraj

    2005-01-01

    MHC-Klasse-I-Moleküle präsentieren gewöhnlich Peptide, die aus zytosolischen Antigenproteinen durch proteasomalen Verdau generiert und anschließend vom TAP-Peptidtransporter ins endoplasmatische Retikulum transportiert werden. Es können jedoch auch endozytierte Antigene für die MHC-Klasse-I-vermittelten Antigenpräsentation prozessiert werden, wobei dieser alternative Weg entweder in einer Proteasom/TAP-abhängigen oder unabhängigen Weise abläuft. Während diese so genannte „Kreuzpräsentation“ f...

  8. Mapping the antigenic structure of porcine parvovirus at the level of peptides

    DEFF Research Database (Denmark)

    Kamstrup, Søren; Langeveld, Jan; Bøtner, Anette;

    1998-01-01

    The antigenic structure of the capsid proteins of porcine parvovirus (PPV) was investigated. A total of nine linear epitopes were identified by Pepscan using porcine or rabbit anti-PPV antisera. No sites were identified with a panel of neutralising monoclonal antibodies (MAbs). All epitopes were...... located in the region corresponding to the major capsid protein VP2. Based on this information, and on analogy to other autonomous parvoviruses, 24 different peptides were synthesised, coupled to keyhole limpet haemocyanin (KLH) and used to immunise rabbits. Most antisera were able to bind viral protein...

  9. Identification of an erythrocyte binding peptide from the erythrocyte binding antigen, EBA-175, which blocks parasite multiplication and induces peptide-blocking antibodies

    DEFF Research Database (Denmark)

    Jakobsen, P.H.; Heegaard, Peter M. H.; Koch, C.; Wasniowska, K.; Lemnge, M.M.; Jensen, J.B.; Sim, B.K.L.

    1998-01-01

    A biotinylated peptide covering a sequence of 21 amino acids (aa) from the erythrocyte binding antigen (EBA-175) of Plasmodium falciparum bound to human glycophorin A, an erythrocyte receptor for merozoites, as demonstrated by enzyme-linked immunosorbent assay (ELISA) and to erythrocytes as...... the binding of a range of truncated peptides to immobilized glycophorin A. Our data indicate that EBA(aa1085-96) is part of a ligand on the merozoite for binding to erythrocyte receptors. This binding suggests that the EBA(aa1085-96) peptide is involved in a second binding step, independent of sialic...

  10. Calcium Binding by Ro 60 Multiple Antigenic Peptides on PVDF Membrane.

    Science.gov (United States)

    Kurien, Biji T; Bachmann, Michael P

    2015-01-01

    Antibodies directed against ribonucleoprotein (RNP) particles are observed in systemic lupus erythematosus. Ro RNP particle is one such target. It is composed of a 60 kDa protein (Ro 60 or SS-A) that is non-covalently associated with at least one of the four short uridine-rich RNAs (the hY RNAs). Previously, we showed that multiple antigenic peptides (MAPs) made from the sequence of the Ro 60 autoantigen could be used, using double-immunodiffusion studies, enzyme-linked immunosorbant assay, affinity chromatography, and surface plasmon resonance, to show intramolecular and intermolecular protein-protein interaction within the Ro 60 RNP particle. We also observed that calcium is important in mediating this interaction. We hypothesized, therefore, that 60 kDa Ro is a calcium-binding protein. To investigate this, we electrophoresed 60 kDa Ro MAPs, transferred them to PVDF membrane, and assayed calcium binding using the Quin-2 system. Several Ro 60 MAPs were found to bind calcium using this assay, as well as bovine serum albumin, another calcium-binding protein. However, a MAP constructed from the Sm autoantigen did not bind to calcium. These data, along with our observation regarding the involvement of calcium in protein-protein interaction occurring between Ro 60 antigen and Ro 60 MAPs, makes us propose that Ro 60 antigen is a calcium-binding protein. PMID:26139264

  11. Identification of an erythrocyte binding peptide from the erythrocyte binding antigen, EBA-175, which blocks parasite multiplication and induces peptide-blocking antibodies

    DEFF Research Database (Denmark)

    Jakobsen, P.H.; Heegaard, Peter M. H.; Koch, C.; Wasniowska, K.; Lemnge, M.M.; Jensen, J.B.; Sim, B.K.L.

    1998-01-01

    A biotinylated peptide covering a sequence of 21 amino acids (aa) from the erythrocyte binding antigen (EBA-175) of Plasmodium falciparum bound to human glycophorin A, an erythrocyte receptor for merozoites, as demonstrated by enzyme-linked immunosorbent assay (ELISA) and to erythrocytes as...... the binding of a range of truncated peptides to immobilized glycophorin A. Our data indicate that EBA(aa1085-96) is part of a ligand on the merozoite for binding to erythrocyte receptors. This binding suggests that the EBA(aa1085-96) peptide is involved in a second binding step, independent of sialic...... acid, Antibody recognition of this peptide sequence may protect against merozoite invasion, but only a small proportion of sera from adults from different areas of malaria transmission showed antibody reactivities to the EBA(aa1076-96! peptide, indicating that this sequence is only weakly immunogenic...

  12. Identification of an erythrocyte binding peptide from the erythrocyte binding antigen, EBA-175, which blocks parasite multiplication and induces peptide-blocking antibodies

    DEFF Research Database (Denmark)

    Jakobsen, P H; Heegaard, P M; Koch, C; Wasniowska, K; Lemnge, M M; Jensen, J B; Sim, B K

    1998-01-01

    A biotinylated peptide covering a sequence of 21 amino acids (aa) from the erythrocyte binding antigen (EBA-175) of Plasmodium falciparum bound to human glycophorin A, an erythrocyte receptor for merozoites, as demonstrated by enzyme-linked immunosorbent assay (ELISA) and to erythrocytes as...... the binding of a range of truncated peptides to immobilized glycophorin A. Our data indicate that EBA(aa1085-96) is part of a ligand on the merozoite for binding to erythrocyte receptors. This binding suggests that the EBA(aa1085-96) peptide is involved in a second binding step, independent of sialic...... acid. Antibody recognition of this peptide sequence may protect against merozoite invasion, but only a small proportion of sera from adults from different areas of malaria transmission showed antibody reactivities to the EBA(aa1076-96) peptide, indicating that this sequence is only weakly immunogenic...

  13. Beta-Hemolytic, Multi-Lancefield Antigen-Agglutinating Enterococcus durans from a Pregnant Woman, Mimicking Streptococcus agalactiae

    OpenAIRE

    Savini, Vincenzo; Franco, Alessia; Gherardi, Giovanni; Marrollo, Roberta; Argentieri, Angela Valentina; Pimentel de Araujo, Fernanda; Amoruso, Roberta; Battisti, Antonio; Fazii, Paolo; Carretto, Edoardo

    2014-01-01

    A beta-hemolytic Lancefield antigen A-, B-, C-, D-, F-, and G-positive Enterococcus durans strain was cultivated from the rectovaginal swab of a pregnant woman who underwent antenatal screening for Streptococcus agalactiae. The isolate raised concern as to what extent similar strains are misrecognized and lead to false diagnosis of group B streptococci.

  14. Small molecule and peptide-mediated inhibition of Epstein-Barr virus nuclear antigen 1 dimerization

    International Nuclear Information System (INIS)

    Highlights: ► Evidence that targeting EBNA1 dimer, an EBV onco-antigen, can be achievable. ► A small molecule and a peptide as EBNA1 dimerization inhibitors identified. ► Both inhibitors associated with EBNA1 and blocked EBNA1 DNA binding activity. ► Also, prevented its dimerization, and repressed viral gene transcription. -- Abstract: Latent Epstein-Barr virus (EBV) infection is associated with human B cell lymphomas and certain carcinomas. EBV episome persistence, replication, and gene expression are dependent on EBV-encoded nuclear antigen 1 (EBNA1)’s DNA binding domain (DBD)/dimerization domain (DD)-mediated sequence-specific DNA binding activity. Homodimerization of EBNA1 is essential for EBNA1 DNA binding and transactivation. In this study, we characterized a novel small molecule EBNA1 inhibitor EiK1, screened from the previous high throughput screening (HTS). The EiK1 compound specifically inhibited the EBNA1-dependent, OriP-enhanced transcription, but not EBNA1-independent transcription. A Surface Plasmon Resonance Biacore assay revealed that EiK1 associates with EBNA1 amino acid 459–607 DBD/DD. Consistent with the SPR data, in vitro gel shift assays showed that EiK1 suppressed the activity of EBNA1 binding to the cognate familial repeats (FR) sequence, but not control RBP-Jκ binding to the Jκ site. Subsequently, a cross-linker-mediated in vitro multimerization assay and EBNA1 homodimerization-dependent yeast two-hybrid assay showed that EiK1 significantly inhibited EBNA1 dimerization. In an attempt to identify more highly specific peptide inhibitors, small peptides encompassing the EBNA1 DBD/DD were screened for inhibition of EBNA1 DBD-mediated DNA binding function. The small peptide P85, covering EBNA1 a.a. 560–574, significantly blocked EBNA1 DNA binding activity in vitro, prevented dimerization in vitro and in vivo, associated with EBNA1 in vitro, and repressed EBNA1-dependent transcription in vivo. Collectively, this study describes two

  15. Small molecule and peptide-mediated inhibition of Epstein-Barr virus nuclear antigen 1 dimerization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Young; Song, Kyung-A [Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Samsung Biomedical Research Institute (SBRI), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kieff, Elliott [Department of Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States); Kang, Myung-Soo, E-mail: mkang@skku.edu [Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Samsung Biomedical Research Institute (SBRI), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Department of Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States)

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer Evidence that targeting EBNA1 dimer, an EBV onco-antigen, can be achievable. Black-Right-Pointing-Pointer A small molecule and a peptide as EBNA1 dimerization inhibitors identified. Black-Right-Pointing-Pointer Both inhibitors associated with EBNA1 and blocked EBNA1 DNA binding activity. Black-Right-Pointing-Pointer Also, prevented its dimerization, and repressed viral gene transcription. -- Abstract: Latent Epstein-Barr virus (EBV) infection is associated with human B cell lymphomas and certain carcinomas. EBV episome persistence, replication, and gene expression are dependent on EBV-encoded nuclear antigen 1 (EBNA1)'s DNA binding domain (DBD)/dimerization domain (DD)-mediated sequence-specific DNA binding activity. Homodimerization of EBNA1 is essential for EBNA1 DNA binding and transactivation. In this study, we characterized a novel small molecule EBNA1 inhibitor EiK1, screened from the previous high throughput screening (HTS). The EiK1 compound specifically inhibited the EBNA1-dependent, OriP-enhanced transcription, but not EBNA1-independent transcription. A Surface Plasmon Resonance Biacore assay revealed that EiK1 associates with EBNA1 amino acid 459-607 DBD/DD. Consistent with the SPR data, in vitro gel shift assays showed that EiK1 suppressed the activity of EBNA1 binding to the cognate familial repeats (FR) sequence, but not control RBP-J{kappa} binding to the J{kappa} site. Subsequently, a cross-linker-mediated in vitro multimerization assay and EBNA1 homodimerization-dependent yeast two-hybrid assay showed that EiK1 significantly inhibited EBNA1 dimerization. In an attempt to identify more highly specific peptide inhibitors, small peptides encompassing the EBNA1 DBD/DD were screened for inhibition of EBNA1 DBD-mediated DNA binding function. The small peptide P85, covering EBNA1 a.a. 560-574, significantly blocked EBNA1 DNA binding activity in vitro, prevented dimerization in vitro and in vivo, associated

  16. Immunogenicity of multiple antigen peptides containing Plasmodium vivax CS epitopes in BALB/c mice

    Directory of Open Access Journals (Sweden)

    Myriam A. Herrera

    1994-01-01

    Full Text Available Multiple antigen peptide systems (MAPs allow the incorporation of various epitopes in to a single synthetic peptide immunogen. We have characterized the immune response of BALB/c mice to a series of MAPs assembled with different B and T cell epitopes derived from the Plasmodium vivax circumsporozoite (CS protein. A B-cell epitope from the central repeat domain and two T-cell epitopes from the amino and carboxyl flanking regions were used to assembled eight different MAPs. An additional universal T cell epitope (ptt-30 from tetanus toxin protein was included. Immunogenicity in terms of antibody responses and in vitro T lymphocyte proliferation was evaluated. MAPs containing B and T cell epitopes induced high titers of anti-peptides antibodies, which recognized the native protein on sporozoites as determined by IFAT. The antibody specificity was also determined by a competitive inhibition assay with different MAPs. A MAP containing the B cell epitope (p11 and the universal epitope ptt-30 together with another composed of p11 and the promiscuous T cell epitope (p25 proved to be the most immunogenic. The strong antibody response and specificity for the cognate protein indicates that further studies designed to assess the potential of these proteins as human malaria vaccine candidates are warranted.

  17. Presenting a foreign antigen on live attenuated Edwardsiella tarda using twin-arginine translocation signal peptide as a multivalent vaccine.

    Science.gov (United States)

    Wang, Yamin; Yang, Weizheng; Wang, Qiyao; Qu, Jiangbo; Zhang, Yuanxing

    2013-12-01

    The twin-arginine translocation (Tat) system is a major pathway for transmembrane translocation of fully folded proteins. In this study, a multivalent vaccine to present foreign antigens on live attenuated vaccine Edwardsiella tarda WED using screened Tat signal peptide was constructed. Because the Tat system increases the yields of folded antigens in periplasmic space or extracellular milieu, it is expected to contribute to the production of conformational epitope-derived specific antibodies. E. tarda Tat signal peptides fused with the green fluorescent protein (GFP) was constructed under the control of an in vivo inducible dps promoter. The resulting plasmids were electroporated into WED and the subcellular localizations of GFP were analyzed with Western blotting. Eight signal peptides with optimized GFP translocation efficiency were further fused to a protective antigen glyceraldehyde-3-phosphate dehydrogenase (GapA) from a fish pathogen Aeromonas hydrophila. Signal peptides of DmsA, NapA, and SufI displayed high efficiency for GapA translocation. The relative percent survival (RPS) of turbot was measured with a co-infection of E. tarda and A. hydrophila, and the strain with DmsA signal peptide showed the maximal protection. This study demonstrated a new platform to construct multivalent vaccines using optimized Tat signal peptide in E. tarda. PMID:23994481

  18. Loss of T Cell Antigen Recognition Arising from Changes in Peptide and Major Histocompatibility Complex Protein Flexibility: Implications for Vaccine Design

    Energy Technology Data Exchange (ETDEWEB)

    Insaidoo, Francis K.; Borbulevych, Oleg Y.; Hossain, Moushumi; Santhanagopolan, Sujatha M.; Baxter, Tiffany K.; Baker, Brian M. (Notre)

    2012-05-08

    Modification of the primary anchor positions of antigenic peptides to improve binding to major histocompatibility complex (MHC) proteins is a commonly used strategy for engineering peptide-based vaccine candidates. However, such peptide modifications do not always improve antigenicity, complicating efforts to design effective vaccines for cancer and infectious disease. Here we investigated the MART-1{sub 27-35} tumor antigen, for which anchor modification (replacement of the position two alanine with leucine) dramatically reduces or ablates antigenicity with a wide range of T cell clones despite significantly improving peptide binding to MHC. We found that anchor modification in the MART-1{sub 27-35} antigen enhances the flexibility of both the peptide and the HLA-A*0201 molecule. Although the resulting entropic effects contribute to the improved binding of the peptide to MHC, they also negatively impact T cell receptor binding to the peptide {center_dot} MHC complex. These results help explain how the 'anchor-fixing' strategy fails to improve antigenicity in this case, and more generally, may be relevant for understanding the high specificity characteristic of the T cell repertoire. In addition to impacting vaccine design, modulation of peptide and MHC flexibility through changes to antigenic peptides may present an evolutionary strategy for the escape of pathogens from immune destruction.

  19. Antigen

    Science.gov (United States)

    An antigen is any substance that causes your immune system to produce antibodies against it. This means your immune ... and is trying to fight it off. An antigen may be a substance from the environment, such ...

  20. Enzymatic hydrolysis of heated whey: iron-binding ability of peptides and antigenic protein fractions.

    Science.gov (United States)

    Kim, S B; Seo, I S; Khan, M A; Ki, K S; Lee, W S; Lee, H J; Shin, H S; Kim, H S

    2007-09-01

    This study evaluated the influence of various enzymes on the hydrolysis of whey protein concentrate (WPC) to reduce its antigenic fractions and to quantify the peptides having iron-binding ability in its hydrolysates. Heated (for 10 min at 100 degrees C) WPC (2% protein solution) was incubated with 2% each of Alcalase, Flavourzyme, papain, and trypsin for 30, 60, 90, 120, 150, 180, and 240 min at 50 degrees C. The highest hydrolysis of WPC was observed after 240 min of incubation with Alcalase (12.4%), followed by Flavourzyme (12.0%), trypsin (10.4%), and papain (8.53%). The nonprotein nitrogen contents of WPC hydrolysate followed the hydrolytic pattern of whey. The major antigenic fractions (beta-lactoglobulin) in WPC were degraded within 60 min of its incubation with Alcalase, Flavourzyme, or papain. Chromatograms of enzymatic hydrolysates of heated WPC also indicated complete degradation of beta-lactoglobulin, alpha-lactalbumin, and BSA. The highest iron solubility was noticed in hydrolysates derived with Alcalase (95%), followed by those produced with trypsin (90%), papain (87%), and Flavourzyme (81%). Eluted fraction 1 (F-1) and fraction 2 (F-2) were the respective peaks for the 0.25 and 0.5 M NaCl chromatographic step gradient for analysis of hydrolysates. Iron-binding ability was noticeably higher in F-1 than in F-2 of all hydrolysates of WPC. The highest iron contents in F-1 were observed in WPC hydrolysates derived with Alcalase (0.2 mg/kg), followed by hydrolysates derived with Flavourzyme (0.14 mg/kg), trypsin (0.14 mg/kg), and papain (0.08 mg/kg). Iron concentrations in the F-2 fraction of all enzymatic hydrolysates of WPC were low and ranged from 0.03 to 0.05 mg/kg. Fraction 1 may describe a new class of iron chelates based on the reaction of FeSO4 x 7 H2O with a mixture of peptides obtained by the enzymatic hydrolysis of WPC. The chromatogram of Alcalase F-1 indicated numerous small peaks of shorter wavelengths, which probably indicated a variety of

  1. Expression of HSV-1 ICP0 Antigen Peptide in Prokaryotic Cells and Preparation of Specific Antibody

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As an immediate-early protein of herpes simplex virus, infected-cell polypeptide 0 (ICP0) exhibits complicated interactions with host cells, and its regulatory function on gene expression is of great importance. Since the ICP0 encoding sequence contains many rare codons which are absent in E.coli, and ICP0 is highly unstable in prokaryotic cells, expression of entire ICP0 in prokaryotic cells has never been reported. In order to further investigate the function of ICP0, a recombinant plasmid was constructed by subcloning a cDNA fragment encoding an amino-terminal of 105 residues of the ICP0 protein into pGEX-5x-1 vector. The resulting GST-105 fusion antigen peptide was expressed with high efficiency in E.coli. Antibodies prepared after the immunization of mice with purified fusion protein can recognize not only the denatured ICP0 protein, but also the native ICP0 protein with normal biological conformation.

  2. A novel strategy to improve antigen presentation for active immunotherapy in cancer. Fusion of the human papillomavirus type 16 E7 antigen to a cell penetrating peptide

    International Nuclear Information System (INIS)

    Facilitating the delivery of exogenous antigens to antigen-presenting cells, ensuing processing and presentation via the major histocompatibility complex class I and induction of an effective immune response are fundamental for an effective therapeutic cancer vaccine. In this regard, we propose the use of cell-penetrating peptides fused to a tumor antigen. To demonstrate this concept we designed a fusion protein comprising a novel cell-penetrating and immunostimulatory peptide corresponding to residues 32 to 51 of the Limulus anti-lipopolysaccharide factor protein (LALF32-51) linked to human papillomavirus 16 E7 antigen (LALF32-51-E7). In this work, we demonstrated that the immunization with LALF32-51-E7 using the TC-1 mouse model induces a potent and long-lasting anti-tumor response supported on an effective E7-specific CD8+T-cell response. The finding that therapeutic immunization with LALF32-51 or E7 alone, or an admixture of LALF32-51 and E7, does not induce significant tumor reduction indicates that covalent linkage between LALF32-51 and E7 is required for the anti-tumor effect. These results support the use of this novel cell-penetrating peptide as an efficient means for delivering therapeutic targets into cellular compartments with the induction of a cytotoxic CD8+T lymphocyte immune response. This approach is promissory for the treatment of tumors associated with the human papillomavirus 16, which is responsible for the 50% of cervical cancer cases worldwide and other malignancies. Furthermore, protein-based vaccines can circumvent the major histocompatibility complex specificity limitation associated with peptide vaccines providing a greater extent in their application

  3. Development of 111In-labeled tumor-associated antigen peptides for monitoring dendritic-cell-based vaccination

    International Nuclear Information System (INIS)

    Dendritic cells (DC) are professional antigen-presenting cells capable of inducing potent immune responses. In our ongoing clinical trials, human leukocyte antigen (HLA)-A2.1+ melanoma patients are vaccinated with mature DC, presenting tumor-derived peptides in major histocompatibility complexes (MHC) to naive T cells. Previously, we have shown that both intradermally and intranodally injected 111In-labeled mature DC migrate to draining lymph nodes. However, little is known about the fate of the MHC-peptide complex after injection of these peptide-loaded DC. The aim of the present study was to develop radiolabeled, tumor-derived peptides to monitor their binding to MHC Class I. Methods: The HLA-A2.1 binding peptide gp100:154-162mod (gp100:154m) was conjugated with diethylenetriamine pentaacetic acid (DTPA) either at the N-terminus (α-DTPA-gp100:154m) or at the epsilon amino group of the Lys154 residue (ε-DTPA-gp100:154m) and labeled with 111In. Results: The maximum specific activity for both peptides was 13 GBq/μmol. The IC5 of the α-[111In]DTPA-gp100:154m peptide was >75 μM. The IC5 of the 111In-labeled ε-DTPA-gp100:154m was 3 μM, similar to the unconjugated peptide. MHC binding studies showed specific binding of the ε-[111In]DTPA-gp100:154m peptide to the JY cells at 4 deg. C. Interestingly, no specific binding was observed for the α-[111In]DTPA-gp100:154m peptide. In contrast to the α-[111In]DTPA-gp100:154m peptide, the ε-[111In]DTPA-gp100:154m peptide was recognized by cytotoxic T cells. Conclusion: When DTPA was conjugated to the epsilon NH2 group of the Lys154 residue, MHC binding of the peptide was preserved and could still be recognized by cytotoxic T cells. These studies allow the noninvasive determination of the behavior of MHC-peptide complexes on DC in vivo

  4. Protective efficacy of bacterial membranes containing surface-exposed BM95 antigenic peptides for the control of cattle tick infestations.

    Science.gov (United States)

    Canales, Mario; Labruna, Marcelo B; Soares, João F; Prudencio, Carlos R; de la Fuente, José

    2009-12-01

    The Rhipicephalus (Boophilus) microplus BM86 and BM95 glycoproteins are homologous proteins that protect cattle against tick infestations. In this study, we demonstrated that the recombinant chimeric protein comprising tick BM95 immunogenic peptides fused to the A. marginale MSP1a N-terminal region for presentation on the Escherichia coli membrane was protective against R. microplus infestations in rabbits. This system provides a novel and simple approach for the production of tick protective antigens by surface display of antigenic protein chimera on live E. coli and suggests the possibility of using recombinant bacterial membrane fractions for vaccination against cattle tick infestations. PMID:19835826

  5. A kinked antimicrobial peptide from Bombina maxima. I. Three-dimensional structure determined by NMR in membrane-mimicking environments.

    Science.gov (United States)

    Toke, Orsolya; Bánóczi, Zoltán; Király, Péter; Heinzmann, Ralf; Bürck, Jochen; Ulrich, Anne S; Hudecz, Ferenc

    2011-04-01

    Maximin-4 is a 27-residue cationic antimicrobial peptide exhibiting selectivity for bacterial cells. As part of the innate defense system in the Chinese red-belly toad, its mode of action is thought to be ion channel or pore formation and dissipation of the electrochemical gradient across the pathogenic cell membrane. Here we present the high-resolution structure of maximin-4 in two different membrane mimetics, sodium dodecyl sulfate micelles and 50% methanol, as determined by (1)H solution NMR spectroscopy. In both environments, the peptide chain adopts a helix-break-helix conformation following a highly disordered N-terminal segment. Despite the similarities in the overall topology of the two structures, major differences are observed in terms of the interactions stabilizing the kink region and the arrangement of the four lysine residues. This has a marked influence on the shape and charge distribution of the molecule and may have implications for the bacterial selectivity of the peptide. The solution NMR results are complemented by CD spectroscopy and solid-state NMR experiments in lipid bilayers, both confirming the predominantly helical conformation of the peptide. As a first step in elucidating the membrane interactions of maximin-4, our study contributes to a better understanding of the mode of action of antimicrobial peptides and the factors governing their selectivity. PMID:21234559

  6. sNebula, a network-based algorithm to predict binding between human leukocyte antigens and peptides

    Science.gov (United States)

    Luo, Heng; Ye, Hao; Ng, Hui Wen; Sakkiah, Sugunadevi; Mendrick, Donna L.; Hong, Huixiao

    2016-01-01

    Understanding the binding between human leukocyte antigens (HLAs) and peptides is important to understand the functioning of the immune system. Since it is time-consuming and costly to measure the binding between large numbers of HLAs and peptides, computational methods including machine learning models and network approaches have been developed to predict HLA-peptide binding. However, there are several limitations for the existing methods. We developed a network-based algorithm called sNebula to address these limitations. We curated qualitative Class I HLA-peptide binding data and demonstrated the prediction performance of sNebula on this dataset using leave-one-out cross-validation and five-fold cross-validations. This algorithm can predict not only peptides of different lengths and different types of HLAs, but also the peptides or HLAs that have no existing binding data. We believe sNebula is an effective method to predict HLA-peptide binding and thus improve our understanding of the immune system. PMID:27558848

  7. Surface bound VEGF mimicking peptide maintains endothelial cell proliferation in the absence of soluble VEGF in vitro.

    Science.gov (United States)

    Le Saux, Guillaume; Plawinski, Laurent; Parrot, Camila; Nlate, Sylvain; Servant, Laurent; Teichmann, Martin; Buffeteau, Thierry; Durrieu, Marie-Christine

    2016-06-01

    Continuous glucose monitoring is an efficient method for the management of diabetes and in limiting the complications induced by large fluctuations in glucose levels. For this, intravascular systems may assist in producing more reliable and accurate devices. However, neovascularization is a key factor to be addressed in improving their biocompatibility. In this scope, the perennial modification of the surface of an implant with the proangiogenic Vascular Endothelial Growth Factor mimic peptide (SVVYGLR peptide sequence) holds great promise. Herein, we report on the preparation of gold substrates presenting the covalently grafted SVVYGLR peptide sequence and their effect on HUVEC behavior. Effective coupling was demonstrated using XPS and PM-IRRAS. The produced surfaces were shown to be beneficial for HUVEC adhesion. Importantly, surface bound SVVYGLR is able to maintain HUVEC proliferation even in the absence of soluble VEGF. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1425-1436, 2016. PMID:26845245

  8. Evaluation of multiple antigenic peptides based on the Chikungunya E2 protein for improved serological diagnosis of infection.

    Science.gov (United States)

    Bhatnagar, Santwana; Kumar, Pradeep; Mohan, Teena; Verma, Priyanka; Parida, M M; Hoti, S L; Rao, D N

    2015-03-01

    In recent years, Chikungunya virus (CHIKV) reemerged and numerous outbreaks were reported all over the world. After screening CHIKV-positive sera, we had already reported many dominant epitopes within the envelope E2 protein of CHIKV. In the present study, we aimed at developing a highly sensitive immunodiagnostic assay for CHIKV based on a multiple antigenic peptide (MAP) approach using selective epitopes of the E2 protein. MAPs in four different E2 peptide combinations were screened with CHIKV-positive sera. The MAPs reacted with all CHIKV-positive sera and no reactivity was seen with healthy or dengue-positive sera. Our results indicate that MAP 1 seems to be an alternate antigen to full-length protein E2 for immunodiagnosis of CHIKV infections with high sensitivity and specificity. PMID:25412351

  9. Self-adjuvanted hyaluronate--antigenic peptide conjugate for transdermal treatment of muscular dystrophy.

    Science.gov (United States)

    Kong, Won Ho; Sung, Dong Kyung; Kim, Hyemin; Yang, Jeong-A; Ieronimakis, Nicholas; Kim, Ki Su; Lee, Jeehun; Kim, Deok-Ho; Yun, Seok Hyun; Hahn, Sei Kwang

    2016-03-01

    Duchenne's muscular dystrophy (DMD) is a neuromuscular disorder accompanied with muscle weakness and wasting. Since myostatin was reported to be a key regulator of muscle wasting, myostatin inhibitors have been investigated as therapeutic candidates for the treatment of muscular diseases. Here, we report an antigenic peptide of myostatin fragment (MstnF) conjugated to hyaluronate (HA) with a low molecular weight (MW, 17 kDa) for transdermal immunotherapy of DMD. Facilitating the transdermal delivery, the low MW HA showed a boosting effect on the immunization of MstnF possibly by engaging both toll-like receptors and cluster of differentiation 44 (CD44). In vivo two-photon microscopy clearly visualized the effective transdermal penetration of HA-MstnF conjugates into deep intact skin layers. The transdermal immunization of mdx mice significantly increased antibody titers against myostatin. Furthermore, the mdx mice immunized with HA-MstnF conjugates resulted in statistically significant improvement in the biochemical and pathological status of skeletal musculature as well as functional behaviors. PMID:26724457

  10. Cutting Edge: Coding Single Nucleotide Polymorphisms of Endoplasmic Reticulum Aminopeptidase 1 Can Affect Antigenic Peptide Generation In Vitro by Influencing Basic Enzymatic Properties of the Enzyme

    OpenAIRE

    Evnouchidou, Irini; Kamal, Ram P.; Seregin, Sergey S.; Goto, Yoshikuni; Tsujimoto, Masafumi; Hattori, Akira; Voulgari, Paraskevi V; Drosos, Alexandros A.; Amalfitano, Andrea; Ian A York; Stratikos, Efstratios

    2011-01-01

    ER aminopeptidase 1 (ERAP1) customizes antigenic peptide precursors for MHC class I presentation and edits the antigenic peptide repertoire. Coding single nucleotide polymorphisms (SNPs) in ERAP1 were recently linked with predisposition to autoimmune disease, suggesting a link between pathogenesis of autoimmunity and ERAP1-mediated Ag processing. To investigate this possibility, we analyzed the effect that disease-linked SNPs have on Ag processing by ERAP1 in vitro. Michaelis–Menten analysis ...

  11. Synthesis of a peptide-universal nucleotide antigen: towards next-generation antibodies to detect topoisomerase I-DNA covalent complexes.

    Science.gov (United States)

    Perkins, Angela L; Peterson, Kevin L; Beito, Thomas G; Flatten, Karen S; Kaufmann, Scott H; Harki, Daniel A

    2016-04-26

    The topoisomerase (topo) I-DNA covalent complex represents an attractive target for developing diagnostic antibodies to measure responsiveness to drugs. We report a new antigen, peptide , and four murine monoclonal antibodies raised against that exhibit excellent specificity for recognition of in comparison to structurally similar peptides by enzyme-linked immunosorbent assays. Although topo I-DNA complex detection was not achieved in cellular samples by these new antibodies, a new strategy for antigen design is reported. PMID:27113574

  12. ERAP1 functions override the intrinsic selection of specific antigens as immunodominant peptides, thereby altering the potency of antigen-specific cytolytic and effector memory T-cell responses.

    Science.gov (United States)

    Rastall, David P W; Aldhamen, Yasser A; Seregin, Sergey S; Godbehere, Sarah; Amalfitano, Andrea

    2014-12-01

    Endoplasmic reticulum aminopeptidase 1 (ERAP1) is a critical component of the adaptive immune system that has been shown to increase or decrease the presentation of specific peptides on MHC class I molecules. Here, we have demonstrated that ERAP1 functions are not only important during the presentation of antigen-derived peptides, but these functions can also completely change which antigen-derived peptides ultimately become selected as immunodominant T-cell epitopes. Our results suggest that ERAP1 may do this by destroying epitopes that would otherwise become immunodominant in the absence of adequate ERAP1 functionality. We further establish that ERAP1-mediated influences on T-cell functions are both qualitative and quantitative, by demonstrating that loss of ERAP1 function redirects CTL killing toward a different set of antigen-derived epitopes and increases the percent of antigen-specific memory T cells elicited by antigen exposure. As a result, our studies suggest that normal ERAP1 activity can act to suppress the numbers of T effector memory cells that respond to a given antigen. This unique finding may shed light on why certain ERAP1 single nucleotide polymorphisms are associated with several autoimmune diseases, for example, by significantly altering the robustness and quality of CD8+ T-cell memory responses to antigen-derived peptides. PMID:25087231

  13. Definition of a physiologic aging autoantigen by using synthetic peptides of membrane protein band 3: localization of the active antigenic sites.

    Science.gov (United States)

    Kay, M M; Marchalonis, J J; Hughes, J; Watanabe, K; Schluter, S F

    1990-08-01

    Senescent cell antigen (SCA), an aging antigen, is a protein that appears on old cells and marks them for removal by the immune system in mammals. It is derived from band 3, a ubiquitous membrane transport protein found in diverse cell types and tissues. We have used synthetic peptides to identify aging antigenic sites on band 3, using a competitive inhibition assay and immunoblotting with IgG directed against the aging antigen on old cells. Results indicate that: (i) the active antigenic sites of the aging antigen reside on membrane protein band 3 residues that are extracellular regions implicated in anion transport (residues 538-554 and 788-827); (ii) a putative ankyrin-binding-region peptide is not involved in SCA activity; and (iii) carbohydrate moieties are not required for the antigenicity or recognition of SCA because synthetic peptides alone abolish binding of senescent cell IgG to erythrocytes. One of the putative transport sites that contributes to the aging antigen is located toward the carboxyl terminus. A model of band 3 is presented. Localization of the active antigenic site on the band 3 molecule facilitates definition of the molecular changes occurring during aging that initiate molecular as well as cellular degeneration. PMID:1696010

  14. Ceria/POMs hybrid nanoparticles as a mimicking metallopeptidase for treatment of neurotoxicity of amyloid-β peptide.

    Science.gov (United States)

    Guan, Yijia; Li, Meng; Dong, Kai; Gao, Nan; Ren, Jinsong; Zheng, Yongchen; Qu, Xiaogang

    2016-08-01

    Protein misfolding to amyloid aggregates is the hallmark for neurodegenerative disease. While much attention has been paid to screen natural proteases that can degrade amyloid-β peptides (Aβ), it is difficult to apply them in the clinics with the intractable problem of immunogenicity in living organisms. Herein, we rationally designed an artificial nanozyme, Ceria/Polyoxometalates hybrid (CeONP@POMs) with both proteolytic and superoxide dismutase (SOD) activities. Our results indicated that CeONP@POMs could efficiently degrade Aβ aggregates and reduce intracellular reactive oxygen species (ROS). More importantly, CeONP@POMD could not only promote PC12 cell proliferation and can cross blood-brain barrier (BBB), but also inhibit Aβ-induced BV2 microglial cell activation which was demonstrated by immunoluorescence assay and flow cytometry measurements. In vivo studies further indicated that CeONP@POMD as nanozyme possessed good biocompatibility, evidenced by a detailed study of their biodistribution, body weight change, and in vivo toxicology. Therefore, our results pave the way for design of multifunctional artificial nanozyme for treatment of neurotoxicity of amyloid-β peptide. PMID:27179436

  15. FULL-LENGTH PEPTIDE ASSAY OF ANTIGENIC PROFILE OF ENVELOPE PROTEINS FROM SIBERIAN ISOLATES OF HEPATITIS C VIRUS

    Directory of Open Access Journals (Sweden)

    A. A. Grazhdantseva

    2014-07-01

    Full Text Available Antigenic profiles of envelope glycoproteins of hepatitis C virus presented by three genotypes 1b, 2a/2c and 3a, which are most widespread in the territory of Russia and, in particular, in Novosibirsk, were studied using a panel of overlapping synthetic peptides. It was shown that highly immunogenic peptide epitopes of Е1 and Е2 proteins common for all HCV genotypes, are located in amino acid positions 250-260, 315-325 (Е1 protein, 390-400 (hypervariable region 1, 430-440, and 680-690 (Е2 protein. The greatest inter-genotypic differences were recorded in positions 280-290, 410-430 and 520-540. A novel antigenic determinant was detected in the region of aa 280-290 of the Е1 protein which was typical only for HCV 2a/2c genotype. A broad variation in the boundaries for the most epitopes suggests a high variability of the Е1 and Е2 viral proteins; however, a similar repertoire of antibodies induced by different HCV genotypes indicates to an opportunity of designing a new generation of cross-reactive HCV vaccines based on mapping of the E1 and E2 antigenic regions.

  16. Proteolytic activity of prostate-specific antigen (PSA towards protein substrates and effect of peptides stimulating PSA activity.

    Directory of Open Access Journals (Sweden)

    Johanna M Mattsson

    Full Text Available Prostate-specific antigen (PSA or kallikrein-related peptidase-3, KLK3 exerts chymotrypsin-like proteolytic activity. The main biological function of PSA is the liquefaction of the clot formed after ejaculation by cleavage of semenogelins I and II in seminal fluid. PSA also cleaves several other substrates, which may explain its putative functions in prostate cancer and its antiangiogenic activity. We compared the proteolytic efficiency of PSA towards several protein and peptide substrates and studied the effect of peptides stimulating the activity of PSA with these substrates. An endothelial cell tube formation model was used to analyze the effect of PSA-degraded protein fragments on angiogenesis. We showed that PSA degrades semenogelins I and II much more efficiently than other previously identified protein substrates, e.g., fibronectin, galectin-3 and IGFBP-3. We identified nidogen-1 as a new substrate for PSA. Peptides B2 and C4 that stimulate the activity of PSA towards small peptide substrates also enhanced the proteolytic activity of PSA towards protein substrates. Nidogen-1, galectin-3 or their fragments produced by PSA did not have any effect on endothelial cell tube formation. Although PSA cleaves several other protein substrates, in addition to semenogelins, the physiological importance of this activity remains speculative. The PSA levels in prostate are very high, but several other highly active proteases, such as hK2 and trypsin, are also expressed in the prostate and may cleave protein substrates that are weakly cleaved by PSA.

  17. Grafting of a peptide probe for Prostate-Specific Antigen detection using diazonium electroreduction and click chemistry.

    Science.gov (United States)

    Strzemińska, I; Sainte Rose Fanchine, S; Anquetin, G; Reisberg, S; Noël, V; Pham, M C; Piro, B

    2016-07-15

    The main objective of this work was to validate a label-free electrochemical method of protein detection using peptides as capture probes. As a proof-of-concept, we used a 7 amino acids sequence (HSSKLQL) specific for Prostate Specific Antigen. We investigated various electrografting conditions of two anilines (2-[(4-aminophenyl)sulfanyl]-8-hydroxy-1,4-naphthoquinone and 4-azidoaniline) further converted in situ into their corresponding diazonium salts on glassy carbon electrodes. It was demonstrated that the best method to obtain a mixed layer is the simultaneous electroreduction of the two diazonium salts. 4-azidoaniline was used to covalently immobilize the ethynyl-functionalized peptide probe by click coupling, and the hydroxynaphthoquinone derivative plays the role of electrochemical transducer of the peptide-protein recognition. The proteolytic activity of PSA towards a small peptide substrate carrying streptavidin at its distal end was also investigated to design an original sensing architecture leading to a reagentless, label free, and "signal-on" PSA sensor. Without optimization, the limit of quantification can be estimated in the nM to pM range. PMID:26938492

  18. Presentation of peptides from Bacillus anthracis protective antigen on Tobacco Mosaic Virus as an epitope targeted anthrax vaccine.

    Science.gov (United States)

    McComb, Ryan C; Ho, Chi-Lee; Bradley, Kenneth A; Grill, Laurence K; Martchenko, Mikhail

    2015-11-27

    The current anthrax vaccine requires improvements for rapidly invoking longer-lasting neutralizing antibody responses with fewer doses from a well-defined formulation. Designing antigens that target neutralizing antibody epitopes of anthrax protective antigen, a component of anthrax toxin, may offer a solution for achieving a vaccine that can induce strong and long lasting antibody responses with fewer boosters. Here we report implementation of a strategy for developing epitope focused virus nanoparticle vaccines against anthrax by using immunogenic virus particles to present peptides derived from anthrax toxin previously identified in (1) neutralizing antibody epitope mapping studies, (2) toxin crystal structure analyses to identify functional regions, and (3) toxin mutational analyses. We successfully expressed two of three peptide epitopes from anthrax toxin that, in previous reports, bound antibodies that were partially neutralizing against toxin activity, discovered cross-reactivity between vaccine constructs and toxin specific antibodies raised in goats against native toxin and showed that antibodies induced by our vaccine constructs also cross-react with native toxin. While protection against intoxication in cellular and animal studies were not as effective as in previous studies, partial toxin neutralization was observed in animals, demonstrating the feasibility of using plant-virus nanoparticles as a platform for epitope defined anthrax vaccines. PMID:26514421

  19. Hematopoietic stem cells and progenitors of chronic myeloid leukemia express leukemia-associated antigens: implications for the graft-versus-leukemia effect and peptide vaccine-based immunotherapy

    OpenAIRE

    Yong, Agnes S.M.; Keyvanfar, Keyvan; Eniafe, Rhoda; Savani, Bipin N.; Rezvani, Katayoun; Sloand, Elaine M.; Goldman, John M.; Barrett, A. John

    2008-01-01

    The cure of chronic myeloid leukemia (CML) patients following allogeneic stem cell transplantation (SCT) is attributed to graft-versus-leukemia (GVL) effects targeting alloantigens and/or leukemia-associated antigens (LAA) on leukemia cells. To assess the potential of LAA-peptide vaccines in eliminating leukemia in CML patients, we measured WT1, PR3, ELA2 and PRAME expression in CD34+ progenitor subpopulations in CML patients and compared them with minor histocompatibility antigens (mHAgs) HA...

  20. Dendritic cells engineered to express defined allo-HLA peptide complexes induce antigen-specific cytotoxic T cells efficiently killing tumour cells

    DEFF Research Database (Denmark)

    Stronen, E; Abrahamsen, I W; Gaudernack, G; Wälchli, S; Munthe, E; Buus, S; Johansen, F-E; Lund-Johansen, F; Olweus, J

    2009-01-01

    , efficiently present externally loaded peptides from the antigen, Melan-A/MART-1 to T cells from HLA-A*0201-negative donors. CD8(+) T cells binding HLA-A*0201/MART-1 pentamers were detected already after 12 days of co-culture in 11/11 donors. The majority of cells from pentamer(+) cell lines were CTL and...... efficiently killed HLA-A*0201(+) melanoma cells, whilst sparing HLA-A*0201(+) B-cells. Allo-restricted CTL specific for peptides from the leukaemia-associated antigens CD33 and CD19 were obtained with comparable efficiency. Collectively, the results show that dendritic cells engineered to express defined allo...

  1. Personalized peptide vaccination for advanced biliary tract cancer: IL-6, nutritional status and pre-existing antigen-specific immunity as possible biomarkers for patient prognosis

    OpenAIRE

    Yoshitomi, Munehiro; Yutani, Shigeru; Matsueda, Satoko; IOJI, TETSUYA; Komatsu, Nobukazu; SHICHIJO, SHIGEKI; Yamada, Akira; ITOH, KYOGO; SASADA, TETSURO; Kinoshita, Hisafumi

    2011-01-01

    Considering that the prognosis of patients with advanced biliary tract cancer (BTC) remains very poor, with a median survival of less than 1 year, new therapeutic approaches need to be developed. In the present study, a phase II clinical trial of personalized peptide vaccination (PPV) was conducted in advanced BTC patients to evaluate the feasibility of this treatment and to identify potential biomarkers. A maximum of 4 human leukocyte antigen-matched peptides, which were selected based on th...

  2. Proof of concept: A bioinformatic and serological screening method for identifying new peptide antigens for Chlamydia trachomatis related sequelae in women☆

    OpenAIRE

    Stansfield, Scott H.; Patel, Pooja; Debattista, Joseph; Charles W Armitage; Cunningham, Kelly; Timms, Peter; Allan, John; Mittal, Aruna; Huston, Wilhelmina M.

    2013-01-01

    This study aimed to identify new peptide antigens from Chlamydia (C.) trachomatis in a proof of concept approach which could be used to develop an epitope-based serological diagnostic for C. trachomatis related infertility in women. A bioinformatics analysis was conducted examining several immunodominant proteins from C. trachomatis to identify predicted immunoglobulin epitopes unique to C. trachomatis. A peptide array of these epitopes was screened against participant sera. The participants ...

  3. Redefining an epitope of a malaria vaccine candidate, with antibodies against the N-terminal MSA-2 antigen of Plasmodium harboring non-natural peptide bonds

    OpenAIRE

    Lozano, José Manuel; Guerrero, Yuly Andrea; Alba, Martha Patricia; Lesmes, Liliana Patricia; Escobar, José Oswaldo; Patarroyo, Manuel Elkin

    2013-01-01

    The aim of obtaining novel vaccine candidates against malaria and other transmissible diseases can be partly based on selecting non-polymorphic peptides from relevant antigens of pathogens, which have to be then precisely modified for inducing a protective immunity against the disease. Bearing in mind the high degree of the MSA-221–40 peptide primary structure’s genetic conservation among malaria species, and its crucial role in the high RBC binding ability of Plasmodium falciparum (the main ...

  4. Characterization of the Antigen Processing Machinery and Endogenous Peptide Presentation of a Bat MHC Class I Molecule.

    Science.gov (United States)

    Wynne, James W; Woon, Amanda P; Dudek, Nadine L; Croft, Nathan P; Ng, Justin H J; Baker, Michelle L; Wang, Lin-Fa; Purcell, Anthony W

    2016-06-01

    Bats are a major reservoir of emerging and re-emerging infectious diseases, including severe acute respiratory syndrome-like coronaviruses, henipaviruses, and Ebola virus. Although highly pathogenic to their spillover hosts, bats harbor these viruses, and a large number of other viruses, with little or no clinical signs of disease. How bats asymptomatically coexist with these viruses is unknown. In particular, little is known about bat adaptive immunity, and the presence of functional MHC molecules is mostly inferred from recently described genomes. In this study, we used an affinity purification/mass spectrometry approach to demonstrate that a bat MHC class I molecule, Ptal-N*01:01, binds antigenic peptides and associates with peptide-loading complex components. We identified several bat MHC class I-binding partners, including calnexin, calreticulin, protein disulfide isomerase A3, tapasin, TAP1, and TAP2. Additionally, endogenous peptide ligands isolated from Ptal-N*01:01 displayed a relatively broad length distribution and an unusual preference for a C-terminal proline residue. Finally, we demonstrate that this preference for C-terminal proline residues was observed in Hendra virus-derived peptides presented by Ptal-N*01:01 on the surface of infected cells. To our knowledge, this is the first study to identify endogenous and viral MHC class I ligands for any bat species and, as such, provides an important avenue for monitoring and development of vaccines against major bat-borne viruses both in the reservoir and spillover hosts. Additionally, it will provide a foundation to understand the role of adaptive immunity in bat antiviral responses. PMID:27183594

  5. Immunization with antigenic peptides complexed with β-glucan induces potent cytotoxic T-lymphocyte activity in combination with CpG-ODNs.

    Science.gov (United States)

    Mochizuki, Shinichi; Morishita, Hiromi; Kobiyama, Kouji; Aoshi, Taiki; Ishii, Ken J; Sakurai, Kazuo

    2015-12-28

    The induction of antigen-specific immune responses requires immunization with not only antigens, but also adjuvants. CpG oligonucleotides (CpG-ODNs) are well-known ligands for Toll-like receptor 9 and a potent adjuvant that induces both Th1-type humoral and cellular immune responses including cytotoxic T-lymphocyte responses. We previously demonstrated that β-glucan schizophyllan (SPG) can form complexes with CpG-ODNs with attached dA40 (CpG-dA/SPG), which can accumulate in macrophages in the draining inguinal lymph nodes and induce strong immune responses by co-administration of antigenic proteins, namely ovalbumin (OVA). Immunization with antigenic peptides, OVA257-264, did not induce these antigen-specific immune responses even in combination with CpG-dA/SPG, indicating that peptides require a carrier to antigen presenting cells. In this study, we prepared conjugates comprising OVA257-264 and dA40, and made complexes with SPG. Immunization with OVA257-264-dA/SPG induced peptide-specific immune responses in combination with CpG-dA regardless of complexation with SPG both in vitro and in vivo. When splenocytes from immunized mice were incubated with E.G7-OVA tumor model cells presenting OVA peptides, the number of cells drastically decreased after 24h. Furthermore, mice pre-immunized with OVA257-264-dA/SPG and CpG-ODNs exhibited a long delay in tumor growth after tumor inoculation. Therefore, these peptide-dA/SPG and CpG-dA/SPG complexes could be used as a potent vaccine for the treatment of cancers and infectious diseases. PMID:26562685

  6. Activated human γδ T cells induce peptide-specific CD8+ T-cell responses to tumor-associated self-antigens.

    Science.gov (United States)

    Altvater, Bianca; Pscherer, Sibylle; Landmeier, Silke; Kailayangiri, Sareetha; Savoldo, Barbara; Juergens, Heribert; Rossig, Claudia

    2012-03-01

    Specific cellular immunotherapy of cancer requires efficient generation and expansion of cytotoxic T lymphocytes (CTLs) that recognize tumor-associated self-antigens. Here, we investigated the capacity of human γδ T cells to induce expansion of CD8+ T cells specific for peptides derived from the weakly immunogenic tumor-associated self-antigens PRAME and STEAP1. Coincubation of aminobisphosphonate-stimulated human peripheral blood-derived γδ T cells (Vγ9+Vδ2+), loaded with HLA-A*02-restricted epitopes of PRAME, with autologous peripheral blood CD8+ T cells stimulated the expansion of peptide-specific cytolytic effector memory T cells. Moreover, peptide-loaded γδ T cells efficiently primed antigen-naive CD45RA+ CD8+ T cells against PRAME peptides. Direct comparisons with mature DCs revealed equal potency of γδ T cells and DCs in inducing primary T-cell responses and peptide-specific T-cell activation and expansion. Antigen presentation by γδ T-APCs was not able to overcome the limited capacity of peptide-specific T cells to interact with targets expressing full-length antigen. Importantly, T cells with regulatory phenotype (CD4+ CD25hiFoxP3+) were lower in cocultures with γδ T cells compared to DCs. In summary, bisphosphonate-activated γδ T cells permit generation of CTLs specific for weakly immunogenic tumor-associated epitopes. Exploiting this strategy for effective immunotherapy of cancer requires strategies that enhance the avidity of CTL responses to allow for efficient targeting of cancer. PMID:21928126

  7. I-Ad-binding peptides derived from unrelated protein antigens share a common structural motif

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Colon, S;

    1988-01-01

    represent a mechanism to achieve a very permissive type of interaction that yet retained some degree of specificity. In the present set of experiments we analyzed the I-Ad binding pattern of a series of overlapping peptides derived from sperm whale myoglobin (residues 102-125) and influenza hemagglutinin...

  8. Structural analysis of peptides capable of binding to more than one Ia antigen

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Colon, S;

    1989-01-01

    The Ia binding regions were analyzed for three unrelated peptide Ag (sperm whale myoglobin 106-118, influenza hemagglutinin 130-142, and lambda repressor protein 12-26) for which binding to more than one Ia molecule has previously been demonstrated. By determining the binding profile of three...

  9. Purification, crystallization and preliminary X-ray diffraction analysis of the human major histocompatibility antigen HLA-B*2703 complexed with a viral peptide and with a self-peptide

    International Nuclear Information System (INIS)

    The product of the human leukocyte antigen (HLA) gene HLA-B*2703 differs from that of the prototypical subtype HLA-B*2705 by a single amino acid at heavy-chain residue 59 that is involved in anchoring the peptide N-terminus within the A pocket of the molecule. Two B*2703–peptide complexes were crystallized using the hanging-drop vapour-diffusion method using PEG 8000 as a precipitant. A pocket of the molecule, two HLA-B*2703–peptide complexes were crystallized and data sets were collected to high resolution using synchrotron radiation. The product of the human leukocyte antigen (HLA) gene HLA-B*2703 differs from that of the prototypical subtype HLA-B*2705 by a single amino acid at heavy-chain residue 59 that is involved in anchoring the peptide N-terminus within the A pocket of the molecule. Two B*2703–peptide complexes were crystallized using the hanging-drop vapour-diffusion method using PEG 8000 as a precipitant. The crystals belong to space group P21 (pVIPR peptide) or P212121 (pLMP2 peptide). Data sets were collected to 1.55 Å (B*2703–pVIPR) or 2.0 Å (B*2703–pLMP2) resolution using synchrotron radiation. With B*2705–pVIPR as a search model, a clear molecular-replacement solution was found for both B*2703 complexes

  10. Characterization of desmoglein-3 epitope region peptides as synthetic antigens: analysis of their in vitro T cell stimulating efficacy, cytotoxicity, stability, and their conformational features.

    Science.gov (United States)

    Szabados, Hajnalka; Uray, Katalin; Majer, Zsuzsa; Silló, Pálma; Kárpáti, Sarolta; Hudecz, Ferenc; Bősze, Szilvia

    2015-09-01

    Desmoglein-3 (Dsg3) adhesion protein is the main target of autoantibodies and autoreactive T cells in Pemphigus vulgaris (PV) autoimmune skin disorder. Several mapping studies of Dsg3 T cell epitope regions were performed, and based on those data, we designed and synthesized four peptide series corresponding to Dsg3 T cell epitope regions. Each peptide series consists of a 17mer full-length peptide (Dsg3/189-205, Dsg3/206-222, Dsg3/342-358, and Dsg3/761-777) and its N-terminally truncated derivatives, resulting in 15 peptides altogether. The peptides were prepared on solid phase and were chemically characterized. In order to establish a structure-activity relationship, the solution conformation of the synthetic peptides has been investigated using electronic circular dichroism spectroscopy. The in vitro T cell stimulating efficacy of the peptides has been determined on peripheral blood mononuclear cells isolated from whole blood of PV patients and also from healthy donors. After 20 h of stimulation, the interferon (IFN)-γ content of the supernatants was measured by enzyme-linked immunosorbent assay. In the in vitro conditions, peptides were stable and non-cytotoxic. The in vitro IFN-γ production profile of healthy donors and PV patients, induced by peptides as synthetic antigens, was markedly different. The most unambiguous differences were observed after stimulation with 17mer peptide Dsg3/342-358, and three truncated derivatives from two other peptide series, namely, peptides Dsg3/192-205, Dsg3/763-777, and Dsg3/764-777. Comparative analysis of in vitro activity and the capability of oligopeptides to form ordered or unordered secondary structure showed that peptides bearing high solvent sensibility and backbone flexibility were the most capable to distinguish between healthy and PV donors. PMID:26250896

  11. Mapping of T cell epitopes using recombinant antigens and synthetic peptides.

    OpenAIRE

    Lamb, J R; Ivanyi, J.; Rees, A D; Rothbard, J B; Howland, K; Young, R. A.; Young, D B

    1987-01-01

    Two complementary approaches were used to determine the epitope specificity of clonal and polyclonal human T lymphocytes reactive with the 65-kd antigen of Mycobacterium leprae. A recombinant DNA sublibrary constructed from portions of the 65-kd gene was used to map T cell determinants within amino acid sequences 101-146 and 409-526. Independently, potential T cell epitopes within the protein were predicted based on an empirical analysis of specific patterns in the amino acid sequence. Of six...

  12. Synthesis of linear comb-like tetrameric peptide and glycopeptide dendrimers with Tn antigen

    Czech Academy of Sciences Publication Activity Database

    Vepřek, Pavel; Knytlová, K.; Hajdúch, M.; Trnka, T.; Sejbal, J.; Ježek, Jan

    Kingswinford : Mayflower Worldwide Ltd, 2003 - (Epton, R.), s. 267-270 ISBN 0-9515735-4-3. [Inovation and Perspectives in Solid Phase Synthesis & Combinatorial Libraries. Southampton (GB), 18.09.2001-22.09.2001] R&D Projects: GA ČR GA303/01/0690 Institutional research plan: CEZ:AV0Z4055905 Keywords : glycopeptide dendrimers * Tn antigen Subject RIV: CC - Organic Chemistry

  13. In vitro cytotoxic effects of CTL activated by dendritic cells loaded with esophageal cancer antigen peptide by 51Cr release assay

    International Nuclear Information System (INIS)

    Objective: RIT plays an important role in the targeted therapy for tumors. The aim of the paper was to study cytotoxic effects of the cytotoxic T lymphocytes (CTL) to human esophageal cancer cell line TE-1, activated by dendritic cells (DC) loaded with esophageal cancer antigen peptide. Methods: Esophageal cancer TE-1 cell antigen peptide was obtained by citrate phosphate buffer elution. DC were induced and proliferated in vitro and were loaded with the esophageal cancer antigen peptide. The tumor antigen specific CTL were generated from the DC. And the cytotoxicity of CTL to TE-1 was assessed by 51Cr release assay. Results: The killing rate of CTL activated by loaded DC[(81.12±2.93)%] was higher than that of CTL activated by DC unloaded [(11.16±3.07)%]. The killing rate of CTL activated by loaded DC in TE-1 pretreated with interferon (IFN)-γ [(89.15±3.62)%] was higher than that in cells without IFN-γ [(61.19±5.17)%]. The killing rate of CTL was higher than that in TE-1 with acid elution [(9.18±2.52)%]. The killing rate of CTL activated by loaded DC diminished in order in Eta-109, human adenocarcinoma cell line K59 and human suprarenal epithelioma cell line 786-0. Conclusions: Acid elution could get effective esophageal cancer antigen peptide from TE-1 cell membrane. The CTL activated by DC loaded with that peptide had specific cytotoxic effects to TE-1 cells. (authors)

  14. Phage displayed peptides and anti-idiotype antibodies recognised by a monoclonal antibody directed against a diagnostic antigen of Mycoplasma capricolum subsp. capripneumoniae.

    Science.gov (United States)

    Bengurić, D R; Dungu, B; Thiaucourt, F; du Plessis, D H

    2001-07-26

    A monoclonal antibody (Mab 4.52) raised against Mycoplasma capricolum subsp. capripneumoniae (Mccp) cell lysate was used as a template to obtain substitute antigens recognised by its paratope. Two approaches were investigated: a 17-mer random peptide library displayed on the surface of a filamentous phage was screened by panning on the immobilised Mab 4.52 and anti-idiotype antibodies were generated by immunising a chicken with the F(ab')(2) fragments of the antibody. Analysis of the peptide sequences displayed by the isolated phages identified two peptides. Both contained two cysteine residues and had identical or similar amino acids in positions 5 (P), 8 (I/L) and 13 (L). The fusion phages were also recognised by Mab 4.52 in enzyme-linked immunosorbent assay (ELISA) and binding was shown by surface plasmon resonance. One of the peptides was a markedly better inhibitor (67%) of the binding of Mab 4.52 to its original antigen than the other (20%) at 1mg/ml. After absorption, to remove isotypic and allotypic reactivities, the anti-idiotype IgY was specifically recognised by Mab 4.52 in ELISA and was able to inhibit its binding to the original antigen, whereas anti-idiotype antibodies raised against a bluetongue virus-specific antibody had no effect. In spite of unequivocal binding of the anti-idiotype antibodies and the fusion phages to the paratope of Mab 4.52, goat antisera appeared not to react with either of the surrogate antigens. In contrast, the test sera bound to the original antigen suggesting that Mab 4.52 does not recognise exactly the same antigenic site as antibodies in the goat antisera. PMID:11376960

  15. Improved serodiagnosis of hepatitis C virus infection with synthetic peptide antigen from capsid protein.

    OpenAIRE

    Hosein, B; Fang, C T; Popovsky, M A; J. Ye; Zhang, M; WANG, C. Y.

    1991-01-01

    Cloning and expression of hepatitis C virus have allowed the development of immunoassays to detect hepatitis C virus infection. However, currently available recombinant fusion protein C100-3 assays, based on a nonstructural protein of the virus, are limited in sensitivity, particularly for detecting acute infection. In this report seroconversion panels showed that an assay based on synthetic peptides, derived from immunodominant regions of both capsid and nonstructural proteins, accelerated h...

  16. Polyclonal anti-idiotypic antibodies mimicking the small cell lung carcinoma antigen cluster-5A interact with a panel of antibodies and induce specific immune response in animals.

    OpenAIRE

    Zwicky, C.; Stahel, R A; Jaksche, H.; Waibel, R.; Lehmann, H. P.; Loibner, H

    1991-01-01

    Polyclonal anti-idiotypic antibodies (ab2) were generated by immunising goats with the murine IgG2a monoclonal antibody SWA20 which recognises the SCLC antigen cluster-5A, a tumour-associated sialoglycoprotein. Ab2 was shown to bind specifically to antibody SWA20, but not to isotype matched control antibodies. Pre-incubation with ab2 completely inhibited target cell binding of antibody SWA20 and of four other antibodies to cluster-5A antigen, while no effect was seen with antibodies to cluste...

  17. Coupling Peptide Antigens to Virus-Like Particles or to Protein Carriers Influences the Th1/Th2 Polarity of the Resulting Immune Response

    Directory of Open Access Journals (Sweden)

    Rattanaruji Pomwised

    2016-05-01

    Full Text Available We have conjugated the S9 peptide, a mimic of the group B streptococcal type III capsular polysaccharide, to different carriers in an effort to elicit an optimal immune response. As carriers, we utilized the soluble protein keyhole limpet hemocyanin and virus-like particles (VLPs from two plant viruses, Cowpea Chlorotic Mottle Virus and Cowpea Mosaic Virus. We have found that coupling the peptide to the soluble protein elicits a Th2 immune response, as evidenced by the production of the peptide-specific IgG1 antibody and IL-4/IL-10 production in response to antigen stimulation, whereas the peptide conjugated to VLPs elicited a Th1 response (IgG2a, IFN-γ. Because the VLPs used as carriers package RNA during the assembly process, we hypothesize that this effect may result from the presence of nucleic acid in the immunogen, which affects the Th1/Th2 polarity of the response.

  18. Proof of concept: A bioinformatic and serological screening method for identifying new peptide antigens for Chlamydia trachomatis related sequelae in women.

    Science.gov (United States)

    Stansfield, Scott H; Patel, Pooja; Debattista, Joseph; Armitage, Charles W; Cunningham, Kelly; Timms, Peter; Allan, John; Mittal, Aruna; Huston, Wilhelmina M

    2013-01-01

    This study aimed to identify new peptide antigens from Chlamydia (C.) trachomatis in a proof of concept approach which could be used to develop an epitope-based serological diagnostic for C. trachomatis related infertility in women. A bioinformatics analysis was conducted examining several immunodominant proteins from C. trachomatis to identify predicted immunoglobulin epitopes unique to C. trachomatis. A peptide array of these epitopes was screened against participant sera. The participants (all female) were categorized into the following cohorts based on their infection and gynecological history; acute (single treated infection with C. trachomatis), multiple (more than one C. trachomatis infection, all treated), sequelae (PID or tubal infertility with a history of C. trachomatis infection), and infertile (no history of C. trachomatis infection and no detected tubal damage). The bioinformatics strategy identified several promising epitopes. Participants who reacted positively in the peptide 11 ELISA were found to have an increased likelihood of being in the sequelae cohort compared to the infertile cohort with an odds ratio of 16.3 (95% c.i. 1.65-160), with 95% specificity and 46% sensitivity (0.19-0.74). The peptide 11 ELISA has the potential to be further developed as a screening tool for use during the early IVF work up and provides proof of concept that there may be further peptide antigens which could be identified using bioinformatics and screening approaches. PMID:24600556

  19. Proof of concept: A bioinformatic and serological screening method for identifying new peptide antigens for Chlamydia trachomatis related sequelae in women☆

    Science.gov (United States)

    Stansfield, Scott H.; Patel, Pooja; Debattista, Joseph; Armitage, Charles W.; Cunningham, Kelly; Timms, Peter; Allan, John; Mittal, Aruna; Huston, Wilhelmina M.

    2013-01-01

    This study aimed to identify new peptide antigens from Chlamydia (C.) trachomatis in a proof of concept approach which could be used to develop an epitope-based serological diagnostic for C. trachomatis related infertility in women. A bioinformatics analysis was conducted examining several immunodominant proteins from C. trachomatis to identify predicted immunoglobulin epitopes unique to C. trachomatis. A peptide array of these epitopes was screened against participant sera. The participants (all female) were categorized into the following cohorts based on their infection and gynecological history; acute (single treated infection with C. trachomatis), multiple (more than one C. trachomatis infection, all treated), sequelae (PID or tubal infertility with a history of C. trachomatis infection), and infertile (no history of C. trachomatis infection and no detected tubal damage). The bioinformatics strategy identified several promising epitopes. Participants who reacted positively in the peptide 11 ELISA were found to have an increased likelihood of being in the sequelae cohort compared to the infertile cohort with an odds ratio of 16.3 (95% c.i. 1.65–160), with 95% specificity and 46% sensitivity (0.19–0.74). The peptide 11 ELISA has the potential to be further developed as a screening tool for use during the early IVF work up and provides proof of concept that there may be further peptide antigens which could be identified using bioinformatics and screening approaches. PMID:24600556

  20. IgE ELISA using antisera derived from epsilon chain antigenic peptides detects allergen-specific IgE in allergic horses.

    Science.gov (United States)

    Kalina, Warren V; Pettigrew, Howard D; Gershwin, Laurel J

    2003-05-12

    Equine disease with an allergic etiology is common. Environmental antigens most often implicated as allergens in horses include molds, dusty hay, grass pollen, hay dust mites, and insect saliva. Although intradermal testing with allergen is a useful diagnostic tool for some species, skin testing frequently produces false positive results in horses. Allergen deprivation as a diagnostic tool is often impossible and at best it is ineffective at diagnosing the specific allergic reactivity. Synthesis of IgE after exposure to allergen is the instigator of the allergic process. While IgE exerts its effect after binding strongly to mast cell Fc receptors, the presence of free IgE in the serum can be used to quantify and determine the allergen specificity of the allergic disease. A lack of widely available reagents for detection of equine IgE has limited this approach in horses. We have used the nucleotide sequence of equine IgE to prepare a peptide-based immunogen to elicit equine epsilon chain-specific antisera. Selection of peptides was based on antigenic attributes of the deduced amino acid sequence of the equine epsilon chain. Six peptides were selected for conjugation to carrier molecules and rabbit immunization. Of these, one peptide elicited antisera that was successfully used in enzyme linked immunosorbant assay (ELISA) to screen horse serum from 64 allergic horses for allergen-specific IgE. Twenty-four of the 64 horses showed positive reactivity to one or more of the following allergens: grass, grain mill dust, mosquito, and horsefly. This study demonstrates the usefulness of peptide-based immunogens for development of antisera to rare or difficult to purify antigens such as IgE. Resultant antisera has great usefulness in diagnostic assays for equine allergy and as a research tool. PMID:12730014

  1. Expression and Immunogenicity of the Mycobacterial Ag85B/ESAT-6 Antigens Produced in Transgenic Plants by Elastin-Like Peptide Fusion Strategy

    Directory of Open Access Journals (Sweden)

    Doreen Manuela Floss

    2010-01-01

    Full Text Available This study explored a novel system combining plant-based production and the elastin-like peptide (ELP fusion strategy to produce vaccinal antigens against tuberculosis. Transgenic tobacco plants expressing the mycobacterial antigens Ag85B and ESAT-6 fused to ELP (TBAg-ELP were generated. Purified TBAg-ELP was obtained by the highly efficient, cost-effective, inverse transition cycling (ICT method and tested in mice. Furthermore, safety and immunogenicity of the crude tobacco leaf extracts were assessed in piglets. Antibodies recognizing mycobacterial antigens were produced in mice and piglets. A T-cell immune response able to recognize the native mycobacterial antigens was detected in mice. These findings showed that the native Ag85B and ESAT-6 mycobacterial B- and T-cell epitopes were conserved in the plant-expressed TBAg-ELP. This study presents the first results of an efficient plant-expression system, relying on the elastin-like peptide fusion strategy, to produce a safe and immunogenic mycobacterial Ag85B-ESAT-6 fusion protein as a potential vaccine candidate against tuberculosis.

  2. Peptide dendrimers

    Czech Academy of Sciences Publication Activity Database

    Niederhafner, Petr; Šebestík, Jaroslav; Ježek, Jan

    2005-01-01

    Roč. 11, - (2005), 757-788. ISSN 1075-2617 R&D Projects: GA ČR(CZ) GA203/03/1362 Institutional research plan: CEZ:AV0Z40550506 Keywords : multiple antigen peptides * peptide dendrimers * synthetic vaccine * multipleantigenic peptides Subject RIV: CC - Organic Chemistry Impact factor: 1.803, year: 2005

  3. Characterisation of peptide microarrays for studying antibody-antigen binding using surface plasmon resonance imagery.

    Directory of Open Access Journals (Sweden)

    Claude Nogues

    Full Text Available BACKGROUND: Non-specific binding to biosensor surfaces is a major obstacle to quantitative analysis of selective retention of analytes at immobilized target molecules. Although a range of chemical antifouling monolayers has been developed to address this problem, many macromolecular interactions still remain refractory to analysis due to the prevalent high degree of non-specific binding. We describe how we use the dynamic process of the formation of self assembling monolayers and optimise physical and chemical properties thus reducing considerably non-specific binding and allowing analysis of specific binding of analytes to immobilized target molecules. METHODOLOGY/PRINCIPAL FINDINGS: We illustrate this approach by the production of specific protein arrays for the analysis of interactions between the 65kDa isoform of human glutamate decarboxylase (GAD65 and a human monoclonal antibody. Our data illustrate that we have effectively eliminated non-specific interactions with the surface containing the immobilised GAD65 molecules. The findings have several implications. First, this approach obviates the dubious process of background subtraction and gives access to more accurate kinetic and equilibrium values that are no longer contaminated by multiphase non-specific binding. Second, an enhanced signal to noise ratio increases not only the sensitivity but also confidence in the use of SPR to generate kinetic constants that may then be inserted into van't Hoff type analyses to provide comparative DeltaG, DeltaS and DeltaH values, making this an efficient, rapid and competitive alternative to ITC measurements used in drug and macromolecular-interaction mechanistic studies. Third, the accuracy of the measurements allows the application of more intricate interaction models than simple Langmuir monophasic binding. CONCLUSIONS: The detection and measurement of antibody binding by the type 1 diabetes autoantigen GAD65 represents an example of an antibody-antigen

  4. Chimeric peptide containing both B and T cells epitope of tumor-associated antigen L6 enhances anti-tumor effects in HLA-A2 transgenic mice.

    Science.gov (United States)

    Lin, Su-I; Huang, Ming-Hsi; Chang, Yu-Wen; Chen, I-Hua; Roffler, Steve; Chen, Bing-Mae; Sher, Yuh-Pyng; Liu, Shih-Jen

    2016-07-28

    Synthetic peptides are attractive for cancer immunotherapy because of their safety and flexibility. In this report, we identified a new B cell epitope of tumor-associated antigen L6 (TAL6) that could induce antibody-dependent cellular cytotoxicity (ADCC) in vivo. We incorporated the B cell epitope with a cytotoxic T lymphocyte (CTL) and a helper T (Th) epitope to form a chimeric long peptide. We formulated the chimeric peptide with different adjuvants to immunize HLA-A2 transgenic mice and evaluate their immunogenicity. The chimeric peptide formulated with an emulsion type nanoparticle (PELC) adjuvant and a toll-like receptor 9 agonist (CpG ODN) (PELC/CpG) induced the greatest ADCC and CTL responses. The induced anti-tumor immunity inhibited the growth of TAL6-positive cancer cells. Moreover, we observed that immunization with the chimeric peptide inhibited cancer cell migration in vitro and metastasis in vivo. These data suggest that a chimeric peptide containing both B and T cell epitopes of TAL6 formulated with PELC/CpG adjuvant is feasible for cancer immunotherapy. PMID:27130449

  5. Identification of peptides fromm foot-and-mouth disease virus structural proteins bound by class I swine leucocyte antigen (SLA) alleles, SLA-1*0401 and SLA-2*0401

    Science.gov (United States)

    The analysis of peptide binding to porcine major histocompatibility complex (MHC) class I molecules has not been extensively performed. Critical to understanding the adaptive immune response of swine to infection is characterization of Swine Leucocyte Antigens (SLA) class I and class II peptide bind...

  6. Phage displaying peptides mimic schistosoma antigenic epitopes selected by rat natural antibodies and protective immunity induced by their immunization in mice

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Xin-Yuan Yi; Xian-Ping Li; Dong-Ming Zhou; McReynolds Larry; Xian-Fang Zeng

    2005-01-01

    AIM: To obtain the short peptides mimic antigenic epitopes selected by rat natural antibodies to schistosomes, and to explore their immunoprotection against schistosomiasis in mice.METHODS: Adults worm antigens (AWA) were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked transferred immunoblotting methods with normal SD rat sera (NRS). The killing effects on schistosomula with fresh and heat-inactivated sera from SD rats were observed. Then the purified IgG from sera of SD rats was used to biopan a phage random peptide library and 20 randomly selected positive clones were detected by ELISA and 2 of them were sequenced.Sixty female mice were immunized thrice with positive phage clones (0, 2nd, 4th wk). Each mouse was challenged with 40 cercariae, and all mice were killed 42 d after challenge. The worms and the liver eggs were counted. RESULTS: NRS could specifically react to the molecules of 75 000, 47 000, 34 500 and 23 000 of AWA. Sera from SD rats showed that the mortality rate of schistosomula was 76.2%, and when the sera were heat-inactivated in vitro, the mortality rate was decreased to 41.0% after being cultured for 48 h. The specific phages bound to IgG were enriched about 300-folds after three rounds of biopanning. Twenty clones were detected by ELISA, 19 of them bound to the specific IgG of rat sera. Immunization with these epitopes was carried out in mice. Compared with the control groups, the mixture of two mimic peptides could induce 34.9% (P = 0.000) worm reduction and 67.6% (P = 0.000) total liver egg reduction in mice. Two different mimic peptides could respectively induce 31.0% (P = 0.001), 14.5% (P = 0.074) worm reduction and 61.2% (P = 0.000), 35.7% (P = 0.000) total liver egg reduction. The specific antibody could be induced by immunization of the mimic peptides, and the antibody titer in immunized mice reached more than 1:6 400 as detected by ELISA.CONCLUSION: Specific peptides mimic antigenic

  7. Effect of different hapten-carrier conjugation ratios and molecular orientations on antibody affinity against a peptide antigen

    DEFF Research Database (Denmark)

    Pedersen, M. K.; Sørensen, Nanna Skall; Heegaard, Peter M. H.;

    2006-01-01

    affinity and titre of antibodies raised against the hapten using different conjugation ratios and orientations. The peptide was coupled to ovalbumin in four Conjugation ratios and two molecular orientations - terminal and central - and the Conjugates were verified by mass spectrometry. Mice were immunised....... Furthermore, the molecular orientation of the Coupled peptide has a major effect on the anti-peptide antibody titres induced....

  8. Primary structure of the 175K Plasmodium falciparum erythrocyte binding antigen and identification of a peptide which elicits antibodies that inhibit malaria merozoite invasion.

    Science.gov (United States)

    Sim, B K; Orlandi, P A; Haynes, J D; Klotz, F W; Carter, J M; Camus, D; Zegans, M E; Chulay, J D

    1990-11-01

    The Plasmodium falciparum gene encoding erythrocyte binding antigen-175 (EBA-175), a putative receptor for red cell invasion (Camus, D., and T. J. Hadley. 1985. Science (Wash. DC). 230:553-556.), has been isolated and characterized. DNA sequencing demonstrated a single open reading frame encoding a translation product of 1,435 amino acid residues. Peptides corresponding to regions on the deduced amino acid sequence predicted to be B cell epitopes were assessed for immunogenicity. Immunization of mice and rabbits with EBA-peptide 4, a synthetic peptide encompassing amino acid residues 1,062-1,103, produced antibodies that recognized P. falciparum merozoites in an indirect fluorescent antibody assay. When compared to sera from rabbits immunized with the same adjuvant and carrier protein, sera from rabbits immunized with EBA-peptide 4 inhibited merozoite invasion of erythrocytes in vitro by 80% at a 1:5 dilution. Furthermore, these sera inhibited the binding of purified, authentic EBA-175 to erythrocytes, suggesting that their activity in inhibiting merozoite invasion of erythrocytes is mediated by blocking the binding of EBA-175 to erythrocytes. Since the nucleotide sequence of EBA-peptide 4 is conserved among seven strains of P. falciparum from throughout the world (Sim, B. K. L. 1990. Mol. Biochem. Parasitol. 41:293-296.), these data identify a region of the protein that should be a focus of vaccine development efforts. PMID:2229177

  9. Interaction of a peptide derived from C-terminus of human TRPA1 channel with model membranes mimicking the inner leaflet of the plasma membrane

    Czech Academy of Sciences Publication Activity Database

    Witschas, Katja; Jobin, M.-L.; Korkut, D. N.; Vladan, M. M.; Salgado, G.; Lecomte, S.; Vlachová, Viktorie; Alves, I. D.

    2015-01-01

    Roč. 1848, č. 5 (2015), s. 1147-1159. ISSN 0005-2736 R&D Projects: GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : TRP channels * peptide -lipid intractions * secondary structure Subject RIV: ED - Physiology Impact factor: 3.836, year: 2014

  10. Association analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope and smoking status in Brazilian patients with rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Michel Alexandre Yazbek

    2011-01-01

    Full Text Available INTRODUCTION: Epstein-Barr virus exposure appears to be an environmental trigger for rheumatoid arthritis that interacts with other risk factors. Relationships among anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status have been observed in patients with rheumatoid arthritis from different populations. OBJECTIVE: To perform an association analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status in Brazilian patients with rheumatoid arthritis. METHODS: In a case-control study, 140 rheumatoid arthritis patients and 143 healthy volunteers who were matched for age, sex, and ethnicity were recruited. Anti-Epstein-Barr nuclear antigen-1 antibodies and anti-cyclic citrullinated peptide antibodies were examined using an enzyme-linked immunosorbent assay, and shared epitope alleles were identified by genotyping. Smoking information was collected from all subjects. A comparative analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status was performed in the patient group. Logistic regression analysis models were used to analyze the risk of rheumatoid arthritis. RESULTS: Anti-Epstein-Barr nuclear antigen-1 antibodies were not associated with anti-cyclic citrullinated peptide antibodies, shared epitope alleles, or smoking status. Anti-cyclic citrullinated peptide antibody positivity was significantly higher in smoking patients with shared epitope alleles (OR = 3.82. In a multivariate logistic regression analysis using stepwise selection, only anti-cyclic citrullinated peptide antibodies were found to be independently associated with rheumatoid arthritis (OR = 247.9. CONCLUSION: Anti-Epstein-Barr nuclear antigen-1 antibodies did not increase the risk of rheumatoid arthritis and were not associated with the rheumatoid arthritis risk factors studied. Smoking

  11. Association analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope and smoking status in Brazilian patients with rheumatoid arthritis

    Science.gov (United States)

    Yazbek, Michel Alexandre; de Barros-Mazon, Silvia; Rossi, Cláudio Lúcio; Londe, Ana Carolina; Costallat, Lilian Tereza Lavras; Bértolo, Manoel Barros

    2011-01-01

    INTRODUCTION: Epstein-Barr virus exposure appears to be an environmental trigger for rheumatoid arthritis that interacts with other risk factors. Relationships among anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status have been observed in patients with rheumatoid arthritis from different populations. OBJECTIVE: To perform an association analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status in Brazilian patients with rheumatoid arthritis. METHODS: In a case-control study, 140 rheumatoid arthritis patients and 143 healthy volunteers who were matched for age, sex, and ethnicity were recruited. Anti-Epstein-Barr nuclear antigen-1 antibodies and anti-cyclic citrullinated peptide antibodies were examined using an enzyme-linked immunosorbent assay, and shared epitope alleles were identified by genotyping. Smoking information was collected from all subjects. A comparative analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status was performed in the patient group. Logistic regression analysis models were used to analyze the risk of rheumatoid arthritis. RESULTS: Anti-Epstein-Barr nuclear antigen-1 antibodies were not associated with anti-cyclic citrullinated peptide antibodies, shared epitope alleles, or smoking status. Anti-cyclic citrullinated peptide antibody positivity was significantly higher in smoking patients with shared epitope alleles (OR = 3.82). In a multivariate logistic regression analysis using stepwise selection, only anti-cyclic citrullinated peptide antibodies were found to be independently associated with rheumatoid arthritis (OR = 247.9). CONCLUSION: Anti-Epstein-Barr nuclear antigen-1 antibodies did not increase the risk of rheumatoid arthritis and were not associated with the rheumatoid arthritis risk factors studied. Smoking and

  12. Vesicular Stomatitis Virus glycoprotein G carrying a tandem dimer of Foot and Mouth Disease Virus antigenic site A can be used as DNA and peptide vaccine for cattle.

    Science.gov (United States)

    Capozzo, Alejandra V; Wilda, Maximiliano; Bucafusco, Danilo; de los Ángeles Lavoria, María; Franco-Mahecha, Olga L; Mansilla, Florencia C; Pérez-Filgueira, Daniel M; Grigera, Pablo R

    2011-11-01

    Effective Foot and Mouth Disease Virus (FMDV) peptide vaccines for cattle have two major constraints: resemblance of one or more of the multiple conformations of the major VP1 antigenic sites to induce neutralizing antibodies, and stimulation of T cells despite the variable bovine-MHC polymorphism. To overcome these limitations, a chimeric antigen was developed, using Vesicular Stomatitis Virus glycoprotein (VSV-G) as carrier protein of an in tandem-dimer of FMDV antigenic site A (ASA), the major epitope on the VP1 capsid protein (aa 139-149, FMDV-C3 serotype). The G-ASA construct was expressed in the Baculovirus system to produce a recombinant protein (DEL BAC) (cloned in pCDNA 3.1 plasmid) (Invitrogen Corporation, Carlsbad, CA) and was also prepared as a DNA vaccine (pC DEL). Calves vaccinated with both immunogens elicited antibodies that recognized the ASA in whole virion and were able to neutralize FMDV infectivity in vitro. After two vaccine doses, DEL BAC induced serum neutralizing titers compatible with an "expected percentage of protection" above 90%. Plasmid pC DEL stimulated FMDV specific humoral responses earlier than DEL BAC, though IgG1 to IgG2 ratios were lower than those induced by both DEL BAC and inactivated FMDV-C3 after the second dose. DEL BAC induced FMDV-specific secretion of IFN-γ in peripheral blood mononuclear cells of outbred cattle immunized with commercial FMDV vaccine, suggesting its capacity to recall anamnestic responses mediated by functional T cell epitopes. The results show that exposing FMDV-VP1 major neutralizing antigenic site in the context of N-terminal sequences of the VSV G protein can overcome the immunological limitations of FMDV-VP1 peptides as effective protein and DNA vaccines for cattle. PMID:21889542

  13. Use of chimeric proteins to investigate the role of transporter associated with antigen processing (TAP) structural domains in peptide binding and translocation

    OpenAIRE

    Arora, Shikha; Lapinski, Philip Edward; Raghavan, Malini

    2001-01-01

    The transporter associated with antigen processing (TAP) comprises two subunits, TAP1 and TAP2, each containing a hydrophobic membrane-spanning region (MSR) and a nucleotide binding domain (NBD). The TAP1/TAP2 complex is required for peptide translocation across the endoplasmic reticulum membrane. To understand the role of each structural unit of the TAP1/TAP2 complex, we generated two chimeras containing TAP1 MSR and TAP2 NBD (T1MT2C) or TAP2 MSR and TAP1 NBD (T2MT1C). We show that TAP1/T2MT...

  14. The C-terminal fragment of prostate-specific antigen, a 2331 Da peptide, as a new urinary pathognomonic biomarker candidate for diagnosing prostate cancer.

    Directory of Open Access Journals (Sweden)

    Kenji Nakayama

    Full Text Available BACKGROUND AND OBJECTIVES: Prostate cancer (PCa is one of the most common cancers and leading cause of cancer-related deaths in men. Mass screening has been carried out since the 1990s using prostate-specific antigen (PSA levels in the serum as a PCa biomarker. However, although PSA is an excellent organ-specific marker, it is not a cancer-specific marker. Therefore, the aim of this study was to discover new biomarkers for the diagnosis of PCa. MATERIALS AND METHODS: We focused on urine samples voided following prostate massage (digital rectal examination [DRE] and conducted a peptidomic analysis of these samples using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS(n. Urinary biomaterials were concentrated and desalted using CM-Sepharose prior to the following analyses being performed by MALDI-TOF/MS(n: 1 differential analyses of mass spectra; 2 determination of amino acid sequences; and 3 quantitative analyses using a stable isotope-labeled internal standard. RESULTS: Multivariate analysis of the MALDI-TOF/MS mass spectra of urinary extracts revealed a 2331 Da peptide in urine samples following DRE. This peptide was identified as a C-terminal PSA fragment composed of 19 amino acid residues. Moreover, quantitative analysis of the relationship between isotope-labeled synthetic and intact peptides using MALDI-TOF/MS revealed that this peptide may be a new pathognomonic biomarker candidate that can differentiate PCa patients from non-cancer subjects. CONCLUSION: The results of the present study indicate that the 2331 Da peptide fragment of PSA may become a new pathognomonic biomarker for the diagnosis of PCa. A further large-scale investigation is currently underway to assess the possibility of using this peptide in the early detection of PCa.

  15. Tapasin discriminates peptide-human leukocyte antigen-A*02:01 complexes formed with natural ligands

    DEFF Research Database (Denmark)

    Røder, Gustav Andreas; Geironson, Linda; Rasmussen, Michael;

    2011-01-01

    and one consisting of medium to high affinity non-SYFPEITHI ligands, were studied in the context of HLA-A*02:01 binding and stability. We show that the SYFPEITHI peptides induced more stable HLA-A*02:01 molecules than the other ligands, although affinities were similar. Remarkably, Tpn(1-87) could...... functionally discriminate the selected SYFPEITHI peptides from the other peptide binders with high sensitivity and specificity. We suggest that this HLA-I- and peptide-specific function, together with the functions exerted by the more C-terminal parts of tapasin, are major features of tapasin-mediated HLA...

  16. Structures of MART-126/27-35Peptide/HLA-A2 Complexes Reveal a Remarkable Disconnect between Antigen Structural Homology and T Cell Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Borbulevych, Oleg Y; Insaidoo, Francis K; Baxter, Tiffany K; Powell, Jr., Daniel J.; Johnson, Laura A; Restifo, Nicholas P; Baker, Brian M [NIH; (Notre)

    2008-09-17

    Small structural changes in peptides presented by major histocompatibility complex (MHC) molecules often result in large changes in immunogenicity, supporting the notion that T cell receptors are exquisitely sensitive to antigen structure. Yet there are striking examples of TCR recognition of structurally dissimilar ligands. The resulting unpredictability of how T cells will respond to different or modified antigens impacts both our understanding of the physical bases for TCR specificity as well as efforts to engineer peptides for immunomodulation. In cancer immunotherapy, epitopes and variants derived from the MART-1/Melan-A protein are widely used as clinical vaccines. Two overlapping epitopes spanning amino acid residues 26 through 35 are of particular interest: numerous clinical studies have been performed using variants of the MART-1 26-35 decamer, although only the 27-35 nonamer has been found on the surface of targeted melanoma cells. Here, we show that the 26-35 and 27-35 peptides adopt strikingly different conformations when bound to HLA-A2. Nevertheless, clonally distinct MART-1{sub 26/27-35}-reactive T cells show broad cross-reactivity towards these ligands. Simultaneously, however, many of the cross-reactive T cells remain unable to recognize anchor-modified variants with very subtle structural differences. These dichotomous observations challenge our thinking about how structural information on unligated peptide/MHC complexes should be best used when addressing questions of TCR specificity. Our findings also indicate that caution is warranted in the design of immunotherapeutics based on the MART-1 26/27-35 epitopes, as neither cross-reactivity nor selectivity is predictable based on the analysis of the structures alone.

  17. Parasite Manipulation of the Invariant Chain and the Peptide Editor H2-DM Affects Major Histocompatibility Complex Class II Antigen Presentation during Toxoplasma gondii Infection.

    Science.gov (United States)

    Leroux, Louis-Philippe; Nishi, Manami; El-Hage, Sandy; Fox, Barbara A; Bzik, David J; Dzierszinski, Florence S

    2015-10-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite. This apicomplexan is the causative agent of toxoplasmosis, a leading cause of central nervous system disease in AIDS. It has long been known that T. gondii interferes with major histocompatibility complex class II (MHC-II) antigen presentation to attenuate CD4(+) T cell responses and establish persisting infections. Transcriptional downregulation of MHC-II genes by T. gondii was previously established, but the precise mechanisms inhibiting MHC-II function are currently unknown. Here, we show that, in addition to transcriptional regulation of MHC-II, the parasite modulates the expression of key components of the MHC-II antigen presentation pathway, namely, the MHC-II-associated invariant chain (Ii or CD74) and the peptide editor H2-DM, in professional antigen-presenting cells (pAPCs). Genetic deletion of CD74 restored the ability of infected dendritic cells to present a parasite antigen in the context of MHC-II in vitro. CD74 mRNA and protein levels were, surprisingly, elevated in infected cells, whereas MHC-II and H2-DM expression was inhibited. CD74 accumulated mainly in the endoplasmic reticulum (ER), and this phenotype required live parasites, but not active replication. Finally, we compared the impacts of genetic deletion of CD74 and H2-DM genes on parasite dissemination toward lymphoid organs in mice, as well as activation of CD4(+) T cells and interferon gamma (IFN-γ) levels during acute infection. Cyst burdens and survival during the chronic phase of infection were also evaluated in wild-type and knockout mice. These results highlight the fact that the infection is influenced by multiple levels of parasite manipulation of the MHC-II antigen presentation pathway. PMID:26195549

  18. Peptide-based biosensor for the prostate-specific antigen using magnetic particle-bound invertase and a personal glucose meter for readout

    International Nuclear Information System (INIS)

    We describe a highly sensitive and selective peptide-based biosensor for the prostate-specific antigen (PSA). The biotinylated peptide biotin-EHSSKLQKC served as a molecular recognition element. It was self-assembled on the surface of the wells of a 96-well microtiter plate modified with gold nanoparticles (AuNPs). In parallel, streptavidin-coated magnetic beads (strep-MBs) were modified with the enzyme invertase and then added to the peptide-modified wells upon which the modified strep-MBs bind to the peptide via biotin/streptavidin interaction. If a sample containing PSA is placed in the well, PSA will cause the cleavage of the peptide, and a respective quantity of invertase-modified strep-MBs will be released. The supernatant containing the invertase-modified strep-MBs is taken out and sucrose is added which is enzymatically cleaved by invertase. The concentration of the glucose formed after 1 h is quantified with a personal glucose meter. It is linearly related to the concentration of PSA in the range from 80 pg to 7 ng∙mL−1. The detection limit is 30 pg∙mL−1 and the relative standard deviation is 3.7 % (at a level of 500 pg∙mL−1 and for n = 7). The method was successfully applied to the determination of PSA in spiked real human urine. Due to its simplicity, sensitivity and selectivity, this bioassay offers a promising approach to the detection of PSA and other biomolecules. (author)

  19. Epitope mapping of anti-myelin oligodendrocyte glycoprotein (MOG) antibodies in a mouse model of multiple sclerosis: microwave-assisted synthesis of the peptide antigens and ELISA screening.

    Science.gov (United States)

    Pacini, Giulia; Ieronymaki, Matthaia; Nuti, Francesca; Sabatino, Giuseppina; Larregola, Maud; Aharoni, Rina; Papini, Anna Maria; Rovero, Paolo

    2016-01-01

    The role of pathologic auto-antibodies against myelin oligodendrocyte glycoprotein (MOG) in multiple sclerosis is a highly controversial matter. As the use of animal models may enable to unravel the molecular mechanisms of the human disorder, numerous studies on multiple sclerosis are carried out using experimental autoimmune encephalomyelitis (EAE). In particular, the most extensively used EAE model is obtained by immunizing C57BL/6 mice with the immunodominant peptide MOG(35-55). In this scenario, we analyzed the anti-MOG antibody response in this model using the recombinant refolded extracellular domain of the protein, MOG(1-117). To assess the presence of a B-cell intramolecular epitope spreading mechanism, we tested also five synthetic peptides mapping the 1-117 sequence of MOG, including MOG(35-55). For this purpose, we cloned, expressed in Escherichia coli and on-column refolded MOG(1-117), and we applied an optimized microwave-assisted solid-phase synthetic strategy to obtain the designed peptide sequences. Subsequently, we set up a solid-phase immunoenzymatic assay testing both naïve and EAE mice sera and using MOG protein and peptides as antigenic probes. The results obtained disclose an intense IgG antibody response against both the recombinant protein and the immunizing peptide, while no response was observed against the other synthetic fragments, thus excluding the presence of an intramolecular epitope spreading mechanism. Furthermore, as the properly refolded recombinant probe is able to bind antibodies with greater efficiency compared with MOG(35-55), we hypothesize the presence of both linear and conformational epitopes on MOG(35-55) sequence. PMID:26663200

  20. Electrostatic Modifications of the Human Leukocyte Antigen-DR P9 Peptide-Binding Pocket and Susceptibility to Primary Sclerosing Cholangitis

    Science.gov (United States)

    Hov, Johannes R; Kosmoliaptsis, Vasilis; Traherne, James A; Olsson, Marita; Boberg, Kirsten M; Bergquist, Annika; Schrumpf, Erik; Bradley, J Andrew; Taylor, Craig J; Lie, Benedicte A; Trowsdale, John; Karlsen, Tom H

    2011-01-01

    The strongest genetic risk factors for primary sclerosing cholangitis (PSC) are found in the human leukocyte antigen (HLA) complex at chromosome 6p21. Genes in the HLA class II region encode molecules that present antigen to T lymphocytes. Polymorphisms in these genes are associated with most autoimmune diseases, most likely because they contribute to the specificity of immune responses. The aim of this study was to analyze the structure and electrostatic properties of the peptide-binding groove of HLA-DR in relation to PSC. Thus, four-digit resolution HLA-DRB1 genotyping was performed in 356 PSC patients and 366 healthy controls. Sequence information was used to assign which amino acids were encoded at all polymorphic positions. In stepwise logistic regressions, variations at residues 37 and 86 were independently associated with PSC (P = 1.2 × 10−32 and P = 1.8 × 10−22 in single-residue models, respectively). Three-dimensional modeling was performed to explore the effect of these key residues on the HLA-DR molecule. This analysis indicated that residue 37 was a major determinant of the electrostatic properties of pocket P9 of the peptide-binding groove. Asparagine at residue 37, which was associated with PSC, induced a positive charge in pocket P9. Tyrosine, which protected against PSC, induced a negative charge in this pocket. Consistent with the statistical observations, variation at residue 86 also indirectly influenced the electrostatic properties of this pocket. DRB1*13:01, which was PSC-associated, had a positive P9 pocket and DRB1*13:02, protective against PSC, had a negative P9 pocket. Conclusion: The results suggest that in patients with PSC, residues 37 and 86 of the HLA-DRβ chain critically influence the electrostatic properties of pocket P9 and thereby the range of peptides presented. (Hepatology 2011;53:1967-1976) PMID:21413052

  1. Toll like receptor-3 ligand poly-ICLC promotes the efficacy of peripheral vaccinations with tumor antigen-derived peptide epitopes in murine CNS tumor models

    Directory of Open Access Journals (Sweden)

    Eguchi Junichi

    2007-02-01

    Full Text Available Abstract Background Toll-like receptor (TLR3 ligands serve as natural inducers of pro-inflammatory cytokines capable of promoting Type-1 adaptive immunity, and TLR3 is abundantly expressed by cells within the central nervous system (CNS. To improve the efficacy of vaccine strategies directed against CNS tumors, we evaluated whether administration of a TLR3 ligand, polyinosinic-polycytidylic (poly-IC stabilized with poly-lysine and carboxymethylcellulose (poly-ICLC would enhance the anti-CNS tumor effectiveness of tumor peptide-based vaccinations. Methods C57BL/6 mice bearing syngeneic CNS GL261 glioma or M05 melanoma received subcutaneous (s.c. vaccinations with synthetic peptides encoding CTL epitopes- mEphA2 (671–679, hgp100 (25–33 and mTRP-2 (180–188 for GL261, or ovalbumin (OVA: 257–264 for M05. The mice also received intramuscular (i.m. injections with poly-ICLC. Results The combination of subcutaneous (s.c. peptide-based vaccination and i.m. poly-ICLC administration promoted systemic induction of antigen (Ag-specific Type-1 CTLs expressing very late activation antigen (VLA-4, which confers efficient CNS-tumor homing of vaccine-induced CTLs based on experiments with monoclonal antibody (mAb-mediated blockade of VLA-4. In addition, the combination treatment allowed expression of IFN-γ by CNS tumor-infiltrating CTLs, and improved the survival of tumor bearing mice in the absence of detectable autoimmunity. Conclusion These data suggest that poly-ICLC, which has been previously evaluated in clinical trials, can be effectively combined with tumor Ag-specific vaccine strategies, thereby providing a greater index of therapeutic efficacy.

  2. Interleukin-21-dependent modulation of T cell antigen receptor reactivity towards low affinity peptide ligands in autoreactive CD8(+) T lymphocytes.

    Science.gov (United States)

    Bobbala, Diwakar; Orkhis, Sakina; Kandhi, Rajani; Ramanathan, Sheela; Ilangumaran, Subburaj

    2016-09-01

    IL-21 promotes autoimmune type-1 diabetes (T1D) in NOD mice by facilitating CD4(+) T cell help to CD8(+) T cells. IL-21 also enables autoreactive CD8(+) T cells to respond to weak TCR ligands and induce T1D. Here, we assessed whether IL-21 is essential for T1D induction in a mouse model where the disease can occur independently of CD4 help. In this model, which expresses lymphocytic choriomeningitis virus (LCMV) glycoprotein (GP) antigen under the rat insulin promoter (RIP-GP), LCMV infection activates CD8(+) T cells reactive to the GP-derived GP33 peptide that attack pancreatic islets and cause T1D. We show that IL-21 deficiency in RIP-GP mice did not impair T1D induction by LCMV expressing the wildtype GP33 peptide. Surprisingly, LCMV-L6F, expressing a weak peptide mimic of GP33, induced T1D more efficiently in Il21(-/-)RIP-GP mice than in controls. However, LCMV-C4Y expressing a very weak peptide mimic of GP33 did not induce T1D in Il21(-/-) mice, but T cells from the infected mice caused disease in lymphopenic RIP-GP mice upon adoptive transfer. Using Nur77(GFP) reporter mice, we show that CD8(+) T cells from Il21(-/-) mice expressing the GP33-specific transgenic P14 TCR showed increased reactivity towards low affinity TCR ligands. Collectively, our findings show that IL-21 is not always required for T1D induction by autoreactive CD8(+) T cells, and suggest that IL-21 may play an important role in regulating CD8(+) T cell reactivity towards low affinity TCR ligands. PMID:27300756

  3. Invasive breast cancer in Argentine women: association between risk and prognostic factors with antigens of a peptidic and carbohydrate nature

    Directory of Open Access Journals (Sweden)

    Croce MV

    2011-12-01

    Full Text Available Sandra O Demichelis, Marina T Isla-Larrain, Luciano Cermignani, Cecilio G Alberdi, Amada Segal-Eiras, María Virginia CroceCentre of Basic and Applied Immunological Research, Faculty of Medical Sciences, National University of La Plata, La Plata, ArgentinaObjective: In breast cancer, several tumor markers have been identified. The marker most extensively associated with breast cancer is MUC1. The objective of the study was to analyze prognostic and risk factors in relation to tumor markers in order to clarify breast cancer biology. A total of 349 primary tumor samples and lymph nodes from breast cancer patients were studied. Risk and prognostic factors were considered. An immunohistochemical approach was applied and an extensive statistical analysis was performed, including frequency analysis and analysis of variance. Correlation among variables was performed with principal component analysis.Results: All the antigens showed an increased expression according to tumor size increment; moreover, sialyl Lewis x expression showed a significant increase in relation to disease stage, whereas Tn and TF presented a positive tendency. Vascular invasion was related to sialyl Lewis x expression and number of metastatic lymph nodes. Taking into account risk factors, when a patient had at least one child, Lewis antigens diminished their expression. In relation to breastfeeding, sialyl Lewis x expression diminished, although its apical expression increased.Conclusion: Associations between MUC1 and carbohydrate antigens and risk and prognostic factors show the complexity of the cellular biological behavior that these antigens modulate in breast cancer.Keywords: breast cancer, Argentine women, risk factors, prognostic factors, antigenic expression

  4. A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro

    International Nuclear Information System (INIS)

    Highlights: → Adoptive immunotherapy depends on relevant numbers of cytolytic T lymphocytes. → An ideal artificial APCs system was successfully prepared in vivo. → Controlled release of IL-2 leads to much more T-cell expansion. → This system is better than general cellular APCs on T-cell expansion. -- Abstract: Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparation of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.

  5. A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Han, Hui [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Peng, Ji-Run, E-mail: pengjr@medmail.com.cn [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Chen, Peng-Cheng; Gong, Lei [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Qiao, Shi-Shi [Department of Hepatobiliary Surgery, The First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052 (China); Wang, Wen-Zhen; Cui, Zhu-Qingqing; Yu, Xin; Wei, Yu-Hua [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Leng, Xi-Sheng, E-mail: lengxs2003@yahoo.com.cn [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China)

    2011-08-05

    Highlights: {yields} Adoptive immunotherapy depends on relevant numbers of cytolytic T lymphocytes. {yields} An ideal artificial APCs system was successfully prepared in vivo. {yields} Controlled release of IL-2 leads to much more T-cell expansion. {yields} This system is better than general cellular APCs on T-cell expansion. -- Abstract: Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparation of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.

  6. Analysis of Swine Leukocyte Antigen Peptide Binding Profiles and the Identification of T cell Epitopes by Tetramer Staining

    DEFF Research Database (Denmark)

    Pedersen, Lasse Eggers

    of the specific CTL response elicited as a result of immunization against foot-and-mouth-disease virus (FMDV) and swine influenza A virus. These studies resulted in the identification of T cell epitopes from both viruses. As SLA:peptide binding data accumulates in these and similar studies, it becomes possible...

  7. Selection of glutamate-rich protein long synthetic peptides for vaccine development: antigenicity and relationship with clinical protection and immunogenicity

    DEFF Research Database (Denmark)

    Theisen, M; Dodoo, D; Toure-Balde, A; Soe, S; Corradin, G; Koram, K K; Kurtzhals, J A; Hviid, L; Theander, T; Akanmori, B; Ndiaye, M; Druilhe, P

    2001-01-01

    Antibodies against three long synthetic peptides (LSPs) derived from the glutamate-rich protein (GLURP) of Plasmodium falciparum were analyzed in three cohorts from Liberia, Ghana, and Senegal. Two overlapping LSPs, LR67 and LR68, are derived from the relatively conserved N-terminal nonrepeat reg...

  8. A High-avidity WT1-reactive T-Cell Receptor Mediates Recognition of Peptide and Processed Antigen but not Naturally Occurring WT1-positive Tumor Cells.

    Science.gov (United States)

    Jaigirdar, Adnan; Rosenberg, Steven A; Parkhurst, Maria

    2016-04-01

    Wilms tumor gene 1 (WT1) is an attractive target antigen for cancer immunotherapy because it is overexpressed in many hematologic malignancies and solid tumors but has limited, low-level expression in normal adult tissues. Multiple HLA class I and class II restricted epitopes have been identified in WT1, and multiple investigators are pursuing the treatment of cancer patients with WT1-based vaccines and adoptively transferred WT1-reactive T cells. Here we isolated an HLA-A*0201-restricted WT1-reactive T-cell receptor (TCR) by stimulating peripheral blood lymphocytes of healthy donors with the peptide WT1:126-134 in vitro. This TCR mediated peptide recognition down to a concentration of ∼0.1 ng/mL when pulsed onto T2 cells as well as recognition of HLA-A*0201 target cells transfected with full-length WT1 cDNA. However, it did not mediate consistent recognition of many HLA-A*0201 tumor cell lines or freshly isolated leukemia cells that endogeneously expressed WT1. We dissected this pattern of recognition further and observed that WT1:126-134 was more efficiently processed by immunoproteasomes compared with standard proteasomes. However, pretreatment of WT1 tumor cell lines with interferon gamma did not appreciably enhance recognition by our TCR. In addition, we highly overexpressed WT1 in several leukemia cell lines by electroporation with full-length WT1 cDNA. Some of these lines were still not recognized by our TCR suggesting possible antigen processing defects in some leukemias. These results suggest WT1:126-134 may not be a suitable target for T-cell based tumor immunotherapies. PMID:26938944

  9. Electrochemical immunoassay for the prostate specific antigen using a reduced graphene oxide functionalized with a high molecular-weight silk peptide

    International Nuclear Information System (INIS)

    High molecular-weight silk peptide (SP) was used to functionalize the surface of nanosheets of reduced graphene oxide (rGO). The SP-rGO nanocomposite was then mixed with mouse anti-human prostate specific antigen monoclonal antibody (anti-PSA) and coated onto a glassy carbon electrode to fabricate an immunosensor. By using the hexacyanoferrate redox system as electroactive probe, the immunosensor was characterized by voltammetry and electrochemical impedance spectroscopy. The peak current, measured at the potential of 0.24 V (vs. SCE), is distinctly reduced after binding prostate specific antigen (PSA). Response (measured by differential pulse voltammetry) is linearly related to PSA concentration in the range from 0.1 to 5.0 ng · mL−1 and from 5.0 to 80.0 ng∙mL−1, and the detection limit is 53 pg∙mL−1 (at an SNR of 3). The immunosensor was successfully applied to the determination of PSA in clinical serum samples, and the results were found to agree well with those obtained with an enzyme-linked immunosorbent assay. (author)

  10. Ubiquitin-hepatitis B core antigen-cytoplasmic transduction peptide enhances HBV-specific humoral and CTL immune responses in vivo.

    Science.gov (United States)

    Song, Linlin; Zhuo, Meng; Tang, Yuyan; Chen, Xiaohua; Tang, Zhenghao; Zang, Guoqing

    2014-11-01

    Therapeutic strategies based on an enhanced hepatitis B virus (HBV)-specific cytotoxic T lymphocyte (CTL) activity may eradicate HBV. We previously verified that a fusion protein ubiquitin (Ub)-hepatitis B core antigen (HBcAg)-cytoplasmic transduction peptide (CTP) can enter the cytoplasm of dendritic cells and enhance T cell response to generate HBV-specific CTLs efficiently in vitro. Ub, a marker of protein degradation, may promote the generation of peptides appropriate for major histocompatibility complex class I presentation. In the present study, the specific immune responses of the fusion protein Ub-HBcAg-CTP in BALB/c mice were evaluated and the underlying mechanisms were investigated. Results showed that Ub-HBcAg-CTP increased the anti-HBcAg titer and produced the cytokines IFN-γ and IL-2. This fusion protein also induced higher percentages of IFN-γ(+)CD8(+) cells and specific CTL responses. Ub-HBcAg-CTP could also upregulate the expressions of Jak2, Tyk2, STAT1, and STAT4 in T lymphocytes. In conclusion, Ub-HBcAg-CTP enhanced cellular and humoral immune responses and induced robust HBV-specific CTL activities in BALB/c mice. PMID:25135878

  11. Multicenter, phase II clinical trial of cancer vaccination for advanced esophageal cancer with three peptides derived from novel cancer-testis antigens

    Directory of Open Access Journals (Sweden)

    Kono Koji

    2012-07-01

    Full Text Available Abstract Background Since a phase I clinical trial using three HLA-A24-binding peptides from TTK protein kinase (TTK, lymphocyte antigen-6 complex locus K (LY6K, and insulin-like growth factor-II mRNA binding protein-3 (IMP3 had been shown to be promising for esophageal squamous cell carcinoma (ESCC, we further performed a multicenter, non-randomized phase II clinical trial. Patients and methods Sixty ESCC patients were enrolled to evaluate OS, PFS, immunological response employing ELISPOT and pentamer assays. Each of the three peptides was administered with IFA weekly. All patients received the vaccination without knowing an HLA-A type, and the HLA types were key-opened at the analysis point. Hence, the endpoints were set to evaluate differences between HLA-A*2402-positive (24(+ and -negative (24(− groups. Results The OS in the 24 (+ group (n = 35 tended to be better than that in the 24(− group (n = 25 (MST 4.6 vs. 2.6 month, respectively, p = 0.121, although the difference was not statistically significant. However, the PFS in the 24(+ group was significantly better than that in the 24(− group (p = 0.032. In the 24(+ group, ELISPOT assay indicated that the LY6K-, TTK-, and IMP3-specific CTL responses were observed after the vaccination in 63%, 45%, and 60% of the 24(+ group, respectively. The patients having LY6K-, TTK-, and IMP3-specific CTL responses revealed the better OS than those not having CTL induction, respectively. The patients showing the CTL induction for multiple peptides have better clinical responses. Conclusions The immune response induced by the vaccination could make the prognosis better for advanced ESCC patients. Trial registration ClinicalTrials.gov, number NCT00995358

  12. Selection of glutamate-rich protein long synthetic peptides for vaccine development: antigenicity and relationship with clinical protection and immunogenicity.

    Science.gov (United States)

    Theisen, M; Dodoo, D; Toure-Balde, A; Soe, S; Corradin, G; Koram, K K; Kurtzhals, J A; Hviid, L; Theander, T; Akanmori, B; Ndiaye, M; Druilhe, P

    2001-09-01

    Antibodies against three long synthetic peptides (LSPs) derived from the glutamate-rich protein (GLURP) of Plasmodium falciparum were analyzed in three cohorts from Liberia, Ghana, and Senegal. Two overlapping LSPs, LR67 and LR68, are derived from the relatively conserved N-terminal nonrepeat region (R0), and the third, LR70, is derived from the R2 repeat region. A high prevalence of antibody responses to each LSP was observed in all three areas of endemic infection. Levels of cytophilic immunoglobulin G (IgG) antibodies against both GLURP regions were significantly correlated with protection from clinical P. falciparum malaria. Protected children from the Ghana cohort possessed predominantly IgG1 antibodies against the nonrepeat epitope and IgG3 antibodies against the repeat epitope. T-cell proliferation responses, studied in the cohort from Senegal, revealed that T-helper-cell epitopes were confined to the nonrepeat region. When used as immunogens, the LR67 and LR68 peptides elicited strong IgG responses in outbred mice and LR67 also induced antibodies in mice of different H-2 haplotypes, confirming the presence of T-helper-cell epitopes in these constructs. Mouse antipeptide antisera recognized parasite proteins as determined by immunofluorescence and immunoblotting. This indicates that synthetic peptides derived from relatively conserved epitopes of GLURP might serve as useful immunogens for vaccination against P. falciparum malaria. PMID:11500389

  13. Structural features of class I H-2 antigens revealed by anti-peptide antibodies specific for intracytoplasmic determinants

    International Nuclear Information System (INIS)

    Rabbit antisera specific for synthetic peptides corresponding to each of the three intracytoplasmic exons (i.e. exons 6, 7 and 8) of the H-2K/sup b/ gene have been prepared and characterized in terms of their reactivity with class I H-2 molecules. Using lentil lectin-purified glycoproteins isolated from 125I-surface-labelled EL-4 (H-2/sup b/) cells, it has been possible to demonstrate that after clearance of the glycoprotein preparation with either anti-mouse β2-microglobulin, or alloantisera directed against H-2K/sup b/ and D/sup b/, there remains a non-β2-microglobulin-associated (i.e. free) class I heavy chain which can be immunoprecipitated by anti-peptide 8 antisera. This free class I heavy chain has the same 2D gel spot pattern as heavy chains from dimeric H-2K/sup b/, suggesting that conformational alterations resulting from the dissociation of β2-microglobulin, rather than chemical changes, are responsible for the loss of the alloantigenic determinants. Evidence has also been obtained indicating that the reaction of dimeric class I molecules with anti-peptide 6 induces the dissociation of β2-microglobulin, suggesting the potential for significant transmembrane conformational perturbations of the external domains as a result of interactions with the intracytoplasmic region

  14. Surfactant protein C peptides with salt-bridges (“ion-locks” promote high surfactant activities by mimicking the α-helix and membrane topography of the native protein

    Directory of Open Access Journals (Sweden)

    Frans J. Walther

    2014-07-01

    Full Text Available Background. Surfactant protein C (SP-C; 35 residues in lungs has a cationic N-terminal domain with two cysteines covalently linked to palmitoyls and a C-terminal region enriched in Val, Leu and Ile. Native SP-C shows high surface activity, due to SP-C inserting in the bilayer with its cationic N-terminus binding to the polar headgroup and its hydrophobic C-terminus embedded as a tilted, transmembrane α-helix. The palmitoylcysteines in SP-C act as ‘helical adjuvants’ to maintain activity by overriding the β-sheet propensities of the native sequences. Objective. We studied SP-C peptides lacking palmitoyls, but containing glutamate and lysine at 4-residue intervals, to assess whether SP-C peptides with salt-bridges (“ion-locks” promote surface activity by mimicking the α-helix and membrane topography of native SP-C. Methods. SP-C mimics were synthesized that reproduce native sequences, but without palmitoyls (i.e., SP-Css or SP-Cff, with serines or phenylalanines replacing the two cysteines. Ion-lock SP-C molecules were prepared by incorporating single or double Glu−–Lys+ into the parent SP-C’s. The secondary structures of SP-C mimics were studied with Fourier transform infrared (FTIR spectroscopy and PASTA, an algorithm that predicts β-sheet propensities based on the energies of the various β-sheet pairings. The membrane topography of SP-C mimics was investigated with orientated and hydrogen/deuterium (H/D exchange FTIR, and also Membrane Protein Explorer (MPEx hydropathy analysis. In vitro surface activity was determined using adsorption surface pressure isotherms and captive bubble surfactometry, and in vivo surface activity from lung function measures in a rabbit model of surfactant deficiency. Results. PASTA calculations predicted that the SP-Css and SP-Cff peptides should each form parallel β-sheet aggregates, with FTIR spectroscopy confirming high parallel β-sheet with ‘amyloid-like’ properties. The enhanced

  15. Selection of Glutamate-Rich Protein Long Synthetic Peptides for Vaccine Development: Antigenicity and Relationship with Clinical Protection and Immunogenicity

    OpenAIRE

    Theisen, Michael; Dodoo, Daniel; Toure-Balde, Aissatou; Soe, Soe; Corradin, Giampietro; Koram, Kwadwo K.; Kurtzhals, Jørgen A. L.; Hviid, Lars; Theander, Thor; Akanmori, Bartholomew; Ndiaye, Mohamadou; Druilhe, Pierre

    2001-01-01

    Antibodies against three long synthetic peptides (LSPs) derived from the glutamate-rich protein (GLURP) of Plasmodium falciparum were analyzed in three cohorts from Liberia, Ghana, and Senegal. Two overlapping LSPs, LR67 and LR68, are derived from the relatively conserved N-terminal nonrepeat region (R0), and the third, LR70, is derived from the R2 repeat region. A high prevalence of antibody responses to each LSP was observed in all three areas of endemic infection. Levels of cytophilic immu...

  16. Chronic osteomyelitis mimicking sarcoma

    OpenAIRE

    Gulmann, C; Young, O.; Tolan, M.; O’Riordan, D.; Leader, M

    2003-01-01

    This report describes a rare case of chronic osteomyelitis in a 60 year old man mimicking a soft tissue sarcoma. Chronic osteomyelitis is an infrequent cause of a soft tissue mass and is usually diagnosed clinically by a combination of radiology and microbiology. Rarely, COM can mimic a primary bony neoplasm, but this is the first reported case where it mimicked a soft tissue sarcoma. The clinical, radiological, and histological appearances of this case will be discussed.

  17. Long-Term Follow-Up of HLA-A2+ Patients with High-Risk, Hormone-Sensitive Prostate Cancer Vaccinated with the Prostate Specific Antigen Peptide Homologue (PSA146-154)

    OpenAIRE

    Perambakam, Supriya; Xie, Hui; Edassery, Seby; Peace, David J.

    2011-01-01

    Twenty-eight HLA-A2+ patients with high-risk, locally advanced or metastatic, hormone-sensitive prostate cancer were immunized with a peptide homologue of prostate-specific antigen, PSA146-154, between July 2002 and September 2004 and monitored for clinical and immune responses. Fifty percent of the patients developed strong PSA146-154-peptide-specific delayed-type hypersensitivity skin responses, tetramer and/or IFN-γ responses within one year. Thirteen patients had stable or declining serum...

  18. Long-Term Follow-Up of HLA-A2+ Patients with High-Risk, Hormone-Sensitive Prostate Cancer Vaccinated with the Prostate Specific Antigen Peptide Homologue (PSA146-154)

    OpenAIRE

    Perambakam, Supriya; Xie, Hui; Edassery, Seby; Peace, David J.

    2010-01-01

    Twenty-eight HLA-A2+ patients with high-risk, locally advanced or metastatic, hormone-sensitive prostate cancer were immunized with a peptide homologue of prostate-specific antigen, PSA146-154, between July 2002 and September 2004 and monitored for clinical and immune responses. Fifty percent of the patients developed strong PSA146-154-peptide-specific delayed-type hypersensitivity skin responses, tetramer and/or IFN-γ responses within one year. Thirteen patients had stable or declining serum...

  19. Carcinoembryonic antigen continuous epitopes determined by the spot method.

    Science.gov (United States)

    Solassol, I; Granier, C; Pèlegrin, A

    2001-01-01

    Carcinoembryonic antigen (CEA) is a heavily glycosylated tumor-associated protein with an N-A1-B1-A2-B2-A3-B3 domain structure. Circulating CEA immunoassays are used for monitoring digestive cancer patients, and radiolabeled anti-CEA monoclonal antibodies (MAb) are used for the diagnosis and therapy of CEA-positive tumors. The five major nonoverlapping epitopes (Gold 1-5) have been broadly correlated with the domain organization, but there is no precise localization of the epitopes at the sequence level. In an attempt to identify the peptide sequences corresponding to the five Gold epitopes on the CEA molecule, we prepared a set of 227 overlapping fifteen-mer peptides corresponding to the complete CEA sequence with the SPOT method. Using five high affinity MAbs directed against the five CEA Gold epitopes, we demonstrated that none of these epitopes could be mimicked by a fifteen-mer peptide sequence. However, using rabbit and goat anti-CEA sera, we identified six major continuous antigenic regions. All are included in the Ig-like domains of the CEA: two in the A1 domain (residues 120-134 and 153-164), one each in the A2 (329-337) and A3 domains (508-513), one at the junction between the A3 and B3 domains (553-561) and one in the B3 domain (565-573). A very homologous sequence (common residues VSPRL) was mapped in each of the three A domains. Thus, in terms of occurrence of continuous epitopes, the Ig-like domains A1, A2, A3 and B3 seem to be the most antigenic parts of CEA. These peptide sequences should be good candidates for the future development of site-specific anti-CEA MAbs. PMID:11275797

  20. Detection and therapy of occult and metastatic medullary thyroid cancer with radiolabeled anti-carcino-embryonic-antigen antibodies and peptides

    International Nuclear Information System (INIS)

    -CEA MAbs are encouraging. Its combination with stem cell support may further improve their therapeutic efficacy. Further experimental as well as clinical studies on the therapeutic application of radiolabeled antibodies and peptides are ongoing. (author)

  1. The production and crystallization of the human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 complexed with deamidated gliadin peptides implicated in coeliac disease

    International Nuclear Information System (INIS)

    The production and crystallization of human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 in complex with deamidated gliadin peptides is reported. Crystals of HLA-DQ2PQPELPYPQ diffracted to 3.9 Å, while the HLA-DQ8EGSFQPSQE crystals diffracted to 2.1 Å, allowing structure determination by molecular replacement. The major histocompatibility complex (MHC) class II molecules HLA-DQ2 and HLA-DQ8 are key risk factors in coeliac disease, as they bind deamidated gluten peptides that are subsequently recognized by CD4+ T cells. Here, the production and crystallization of both HLA-DQ2 and HLA-DQ8 in complex with the deamidated gliadin peptides DQ2 α-I (PQPELPYPQ) and DQ8 α-I (EGSFQPSQE), respectively, are reported

  2. The production and crystallization of the human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 complexed with deamidated gliadin peptides implicated in coeliac disease

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Kate N.; Reid, Hugh H.; Borg, Natalie A.; Broughton, Sophie E.; Huyton, Trevor [The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia); Anderson, Robert P. [Autoimmunity and Transplantation Division, Walter and Eliza Hall Institute, 1G Royal Parade, Parkville, Victoria 3050 (Australia); Department of Gastroenterology, The Royal Melbourne Hospital, Grattan Street, Parkville, Victoria 3050 (Australia); McCluskey, James [Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3010 (Australia); Rossjohn, Jamie, E-mail: jamie.rossjohn@med.monash.edu.au [The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia)

    2007-12-01

    The production and crystallization of human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 in complex with deamidated gliadin peptides is reported. Crystals of HLA-DQ2{sup PQPELPYPQ} diffracted to 3.9 Å, while the HLA-DQ8{sup EGSFQPSQE} crystals diffracted to 2.1 Å, allowing structure determination by molecular replacement. The major histocompatibility complex (MHC) class II molecules HLA-DQ2 and HLA-DQ8 are key risk factors in coeliac disease, as they bind deamidated gluten peptides that are subsequently recognized by CD4{sup +} T cells. Here, the production and crystallization of both HLA-DQ2 and HLA-DQ8 in complex with the deamidated gliadin peptides DQ2 α-I (PQPELPYPQ) and DQ8 α-I (EGSFQPSQE), respectively, are reported.

  3. ZP-binding peptides identified via phage display stimulate production of sperm antibodies in dogs.

    Science.gov (United States)

    Samoylova, Tatiana I; Cox, Nancy R; Cochran, Anna M; Samoylov, Alexandre M; Griffin, Brenda; Baker, Henry J

    2010-07-01

    Zona pellucida (ZP) glycoproteins play a central role in sperm-oocyte binding and fertilization. Sperm protein sequences that are involved in sperm-ZP recognition and have an important role in fertilization represent attractive targets for development of contraceptive vaccines, yet are currently unknown. To identify peptide sequences that recognize and bind to ZP proteins, we developed a novel selection procedure from phage display libraries that utilizes intact oocytes surrounded by ZP proteins. The major advantage of this procedure is that ZP proteins remain in their native conformation unlike a selection protocol previously published that utilized solubilized ZP on artificial solid support. Several peptides of 7 and 12 amino acids with binding specificity to canine ZP proteins were identified. Four of them (LNSFLRS, SSWYRGA, YLPIYTIPSMVY, and NNQSPILKLSIH) plus a control ZP-binding peptide (YLPVGGLRRIGG) from the literature were synthesized and tested for antigenic properties in dogs. NNQSPILKLSIH peptide stimulated production of anti-peptide antibodies. These antibodies bind to the acrosomal region of the canine sperm cell, demonstrating ability to act as sperm antibodies. The identified ZP-binding peptides (mimicking sperm cell surface antigens) may be useful in the design of immunocontraceptive agents for dogs. PMID:20434854

  4. Lemierre's Syndrome Mimicking Leptospirosis

    OpenAIRE

    Lin, Dagmar; Suwantarat, Nuntra; Young, Royden S.

    2010-01-01

    Lemierre's syndrome is a suppurative thrombophlebitis involving the internal jugular vein, most commonly associated with Fusobacterium necrophorum, usually a complication of oropharyngeal infections. This syndrome is rare and is often overlooked. We present a case of sepsis mimicking initially severe leptospirosis (Weil's disease) due to acute febrile illness with multiorgan failure and hyperbilirubinemia. Finally, blood cultures revealed Fusobacterium necrophorum and computed tomography (CT)...

  5. Detection of PMTV Using Polyclonal Antibodies Raised Against a Capsid-Specific Peptide Antigen / Detección de PMTV Utilizando Anticuerpos Policlonales Contra un Péptido Antigénico Derivado de la Cápside Viral

    Directory of Open Access Journals (Sweden)

    Yuliana Gallo García

    2013-12-01

    Full Text Available Potato mop-top virus (PMTV; genus Pomovirus;family Virgaviridae is the causing agent of the spraing disease in potato (Solanum tuberosum. PMTV is transmitted by Spongospora subterranea f. sp. subterranea (Sss. This disease has a widespread distribution in potato growing regions around the world. The possibility of obtaining strain specific antibodies at low cost can greatly increase the sensitivity and use of serological tests in seed certification programs, plant breeding and quarantine regulations to avoid dissemination of this injurious virus. This work presents an alternative procedure for the production of PMTV specific antibodies useful in serological test such as ELISAand lateral flow. In contrast to standard methods requiring theisolation of viral particles or expression of recombinant capsid, this method uses peptides mimicking the N-terminal region of PMTV capsid protein as antigen for the production of specific polyclonal antibodies. The antibodies were tested against bait plants grown in soil infested with viruliferous Sss, as well as potato plants obtained from naturally Sss infested fields in Colombia. PMTV was detected in 9/14 and 24/28 foliage samples of N. benthamiana and S. phureja, respectively. In the case of field plants, the virus wasdetected in eight out of 12 root tissues evaluated. The minimumpeptide concentration detected by ELISA was of the order of 0.1 nM. / Potato mop-top virus (PMTV; género Pomovirus; familia Virgaviridae es transmitido por Spongospora subterranea f. sp. subterranea (Sss, agente causal de la sarna polvosa de la papa. Esta enfermedad tiene una amplia distribución en las regiones cultivadoras de papa alrededor del mundo. La posibilidad de obtener anticuerpos específicos contra cepas de este virus, puede incrementar la sensibilidad y la utilización de pruebas serológicas en programas de certificación de semilla, mejoramiento genético y regulaciones cuarentenarias que eviten su diseminaci

  6. Urticaria mimickers in children.

    Science.gov (United States)

    Mathur, Anubhav N; Mathes, Erin F

    2013-01-01

    Acute urticaria is a self-limited cutaneous condition marked by transient, erythematous, and pruritic wheals. It is a hypersensitivity response that is often secondary to infection, medications, or food allergies in children. In contrast, the urticarial "mimickers" described in this review article are often seen in the context of fever and extracutaneous manifestations in pediatric patients. The differential diagnosis ranges from benign and self-limited hypersensitivity responses to multisystem inflammatory diseases. Establishing the correct diagnosis of an urticarial rash in a pediatric patient is necessary to both prevent an unnecessary work up for self-limited conditions and to appropriately recognize and evaluate multisystem inflammatory disorders. Herein, we describe two cases to illustrate the clinical manifestations, laboratory findings, histopathology and differential diagnoses for several mimickers of acute urticaria including: urticaria multiforme, serum sickness like reaction, Henoch-Schönlein purpura, acute hemorrhagic edema of infancy, systemic onset juvenile idiopathic arthritis, cryopyrin associated periodic syndromes, and urticarial vasculitis. PMID:24552410

  7. Alternative Ii-independent antigen-processing pathway in leukemic blasts involves TAP-dependent peptide loading of HLA class II complexes

    NARCIS (Netherlands)

    M.M. van Luijn; M.E.D. Chamuleau; M.E. Ressing; E.J. Wiertz; S. Ostrand-Rosenberg; Y. Souwer; A. Zevenbergen; G.J. Ossenkoppele; A.A. van de Loosdrecht; S.M. Ham

    2010-01-01

    During HLA class II synthesis in antigen-presenting cells, the invariant chain (Ii) not only stabilizes HLA class II complexes in the endoplasmic reticulum, but also mediates their transport to specialized lysosomal antigen-loading compartments termed MIICs. This study explores an alternative HLA cl

  8. Towards High-throughput Immunomics for Infectious Diseases: Use of Next-generation Peptide Microarrays for Rapid Discovery and Mapping of Antigenic Determinants

    DEFF Research Database (Denmark)

    J. Carmona, Santiago; Nielsen, Morten; Schafer-Nielsen, Claus;

    2015-01-01

    , we developed a highly-multiplexed platform based on next-generation high-density peptide microarrays to map these specificities in Chagas Disease, an exemplar of a human infectious disease caused by the protozoan Trypanosoma cruzi. We designed a high-density peptide microarray containing more than...

  9. High-affinity human leucocyte antigen class I binding variola-derived peptides induce CD4(+) T cell responses more than 30 years post-vaccinia virus vaccination

    DEFF Research Database (Denmark)

    Wang, M.; Tang, Sheila Tuyet; Lund, Ole; Dziegiel, M. H.; Buus, S.; Claesson, M. H.

    2009-01-01

    Interferon-gamma secreting T lymphocytes against pox virus-derived synthetic 9-mer peptides were tested by enzyme-linked immunospot in peripheral blood of individuals vaccinated with vaccinia virus more than 30 years ago. The peptides were characterized biochemically as high-affinity human leucoc...

  10. The central repeat domain 1 of Kaposi's sarcoma-associated herpesvirus (KSHV) latency associated-nuclear antigen 1 (LANA1) prevents cis MHC class I peptide presentation

    International Nuclear Information System (INIS)

    KSHV LANA1, a latent protein expressed during chronic infection to maintain a viral genome, inhibits major histocompatibility complex class I (MHC I) peptide presentation in cis as a means of immune evasion. Through deletional cloning, we localized this function to the LANA1 central repeat 1 (CR1) subregion. Other CR subregions retard LANA1 translation and proteasomal processing but do not markedly inhibit LANA1 peptide processing by MHC I. Inhibition of proteasomal processing ablates LANA1 peptide presentation. Direct expression of LANA1 within the endoplasmic reticulum (ER) overcomes CR1 inhibition suggesting that CR1 acts prior to translocation of cytoplasmic peptides into the ER. By physically separating CR1 from other subdomains, we show that LANA1 evades MHC I peptide processing by a mechanism distinct from other herpesviruses including Epstein-Barr virus (EBV). Although LANA1 and EBV EBNA1 are functionally similar, they appear to use different mechanisms to evade host cytotoxic T lymphocyte surveillance.

  11. A comparison of antigenic peptides in muscle larvae of several Trichinella species by two-dimensional western-blot analysis with monoclonal antibodies

    Directory of Open Access Journals (Sweden)

    Dea-Ayuela M.A.

    2001-06-01

    Full Text Available The antigens recognised by mAb US5 specific to 53 kDa glycoprotein (gp 53 in T. spiralis L-1 muscle larvae (TSL1 antigens, mAb US9 specific to gp 53 in TSL1 from all encapsulated species and mAb US4 specific to a tyvelose containing tetrasaccharide present in TSL1, were investigated in crude extracts from muscle larvae of T. spiralis, T. nativa and T. britovi by 2D-electrophoresis and western-blot. At least four proteins of different pI were recognised by mAb US5 on T. spiralis antigens. Recognition profile of mAb US9 on T. spiralis antigens exhibited some variation with regard to that of the US5. Polymorphism was apparent in gp 53. High reactivity was shown by the mAb US4 with the three species.

  12. Long-Term Follow-Up of HLA-A2+ Patients with High-Risk, Hormone-Sensitive Prostate Cancer Vaccinated with the Prostate Specific Antigen Peptide Homologue (PSA146-154

    Directory of Open Access Journals (Sweden)

    Supriya Perambakam

    2010-01-01

    Full Text Available Twenty-eight HLA-A2+ patients with high-risk, locally advanced or metastatic, hormone-sensitive prostate cancer were immunized with a peptide homologue of prostate-specific antigen, PSA146-154, between July 2002 and September 2004 and monitored for clinical and immune responses. Fifty percent of the patients developed strong PSA146-154-peptide-specific delayed-type hypersensitivity skin responses, tetramer and/or IFN-γ responses within one year. Thirteen patients had stable or declining serum levels of PSA one year post-vaccination. A decreased risk of biochemical progression was observed in patients who developed augmented tetramer responses at six months compared to pre-vaccination levels (P=.02. Thirteen patients have died while 15 patients remain alive with a mean overall survival of 60 months (95% CI, 51 to 68 months per Kaplan-Meier analysis. A trend towards greater overall survival was detected in men with high-risk, hormone-sensitive CaP who developed specific T-cell immunity following vaccination with PSA146-154 peptide.

  13. Cloning,expression and purification of B cell epitope antigen peptide of EGFR dimerization%EGFR二聚化B细胞表位抗原肤基因克隆、表达与纯化

    Institute of Scientific and Technical Information of China (English)

    朱磊; 吴梅芝; 赵林; 黄绮玲; 梁梅; 李黄金

    2011-01-01

    目的 利用基因工程手段建立表皮生长因子受体(EGFR)二聚化B细胞表位抗原肽MVF-ER的高效制备方法.方法 采用重叠延伸PCR扩增MVF-ER后克隆于表达载体pET32a,于大肠杆菌BL21(DE3)进行表达,产物采用肠激酶酶切和镍离子鳌合亲和层析法纯化.结果 通过10对引物5步重叠延伸得到273bp的扩增产物,目的基因与硫氧环蛋白(Trx)融合后可高效表达,经酶切和层析后得到纯度为95%的抗原肤.结论 成功建立抗原肽"MVF-ER"的高效制备方法,为进一步研究EGFR过表达恶性肿瘤的治疗性疫苗打下了坚实基础.%We aim to establish a high performance preparation system for B cell epitope antigen peptide of EGFR dimerization for further research on therapeutic vaccine of EGFR over-expression tumors. The MVF-ER gene of 273 bp was amplified by splicing overlap extension PCR (SOE-PCR), then cloned into the vector of pET32a, and expressed in E.coli BL21 (DE3) in the form of fusion with Trx. The expression product was purified by Ni+ affinity chromatography. The antigen peptide was recovered from the fusion protein by enterokinase and purified to a purity of 95% confirmed by SDS-PAGE. The results above showed that the preparation method of MVF-ER antigen peptide was successfully established, which will facilitate further study of the therapeutic cancer vaccine.

  14. A modern approach for epitope prediction: identification of foot-and-mouth disease virus peptides binding bovine leukocyte antigen (BoLA) class I molecules

    DEFF Research Database (Denmark)

    Pandya, Mital; Rasmussen, Michael; Hansen, Andreas;

    2015-01-01

    pathogens, such as foot-and-mouth disease virus (FMDV). Six synthetic BoLA class I (BoLA-I) molecules were produced, and the peptide binding motif was generated for five of the six molecules using a combined approach of positional scanning combinatorial peptide libraries (PSCPLs) and neural network......-based predictions (NetMHCpan). The updated NetMHCpan server was used to predict BoLA-I binding peptides within the P1 structural polyprotein sequence of FMDV (strain A24 Cruzeiro) for BoLA-1*01901, BoLA-2*00801, BoLA-2*01201, and BoLA-4*02401. Peptide binding affinity and stability were determined for these Bo....... The results of these analyses showed that BoLA alleles cluster into three distinct groups with the potential to define “BoLA supertypes.” This streamlined approach identifies potential T cell epitopes from pathogens, such as FMDV, and provides insight into T cell immunity following infection or vaccination....

  15. Antigen-Specific CD4+ T Cells Recognize Epitopes of Protective Antigen following Vaccination with an Anthrax Vaccine

    OpenAIRE

    Laughlin, Elsa M.; Miller, Joseph D.; James, Eddie; Fillos, Dimitri; Ibegbu, Chris C.; Mittler, Robert S.; Akondy, Rama; Kwok, William; Ahmed, Rafi; Nepom, Gerald,

    2007-01-01

    Detection of antigen-specific CD4+ T cells is facilitated by the use of fluorescently labeled soluble peptide-major histocompatibility complex (MHC) multimers which mirror the antigen specificity of T-cell receptor recognition. We have used soluble peptide-MHC class II tetramers containing peptides from the protective antigen (PA) of Bacillus anthracis to detect circulating T cells in peripheral blood of subjects vaccinated with an anthrax vaccine. PA-specific HLA class II-restricted T lympho...

  16. 68Ga-Labeled Anti-Prostate-Specific Membrane Antigen Peptide as Marker for Androgen Deprivation Therapy Response in Prostate Cancer.

    Science.gov (United States)

    Schlenkhoff, Carl Diedrich; Gaertner, Florian; Essler, Markus; Hauser, Stefan; Ahmadzadehfar, Hojjat

    2016-05-01

    Prostate cancer was diagnosed in a 71-year-old man with an elevated prostate-specific antigen. The CT of the abdomen showed multiple para-aortal lymph nodes, and thus, a Ga anti-prostate-specific membrane antigen (PSMA-11) PET/CT was initiated, which showed, aside from the prostate cancer and multiple iliacal and para-aortal lymph node metastases, an increased tracer uptake in a lymph node left cervical. According to this advanced disease, a palliative therapy with GnRH agonist was initiated. A second PSMA-11 PET/CT was performed 4 months later, which showed a very good response; thus, additional radiation of the pelvis and the draining lymphatic system was performed. PMID:26859213

  17. Selection of Genetic engineering peptide ligands for TNF receptor imaging

    International Nuclear Information System (INIS)

    Objective: To screen the peptide ligands of TNF receptor from phage 6-mer peptide library with the purpose of developing new peptides radiopharmaceuticals for TNF receptor imaging. Methods: The soluble protein of TNF receptor I (sTNFR I) was used to screen the TNF-specific epitopes from phage 6-mer peptide library. After four rounds of affinity screening, the peptides displayed on the selected phage were directly subjected to ELISA to determine their immunological activity to sTNFR. The amino acid sequences of the peptides with highest immunological activity were deduced through DNA sequencing. And their conserved sequences were further determined. Results: Peptides sequences mimicking TNF-specific epitopes were obtained. Conclusion: The short peptides sequences mimicking TNF -specific epitopes were successfully acquired. The method which was established in the present study may provide a feasible way in peptides radiopharmaceuticals development for TNF receptor imaging. (authors)

  18. Parasite Manipulation of the Invariant Chain and the Peptide Editor H2-DM Affects Major Histocompatibility Complex Class II Antigen Presentation during Toxoplasma gondii Infection

    OpenAIRE

    Leroux, Louis-Philippe; Nishi, Manami; El-Hage, Sandy; Fox, Barbara A.; Bzik, David J.; Dzierszinski, Florence S.

    2015-01-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite. This apicomplexan is the causative agent of toxoplasmosis, a leading cause of central nervous system disease in AIDS. It has long been known that T. gondii interferes with major histocompatibility complex class II (MHC-II) antigen presentation to attenuate CD4+ T cell responses and establish persisting infections. Transcriptional downregulation of MHC-II genes by T. gondii was previously established, but the precise mechanisms...

  19. A phase II trial of personalized peptide vaccination in castration-resistant prostate cancer patients: prolongation of prostate-specific antigen doubling time

    OpenAIRE

    Noguchi, Masanori; MORIYA, FUKUKO; SUEKANE, SHIGETAKA; Ohnishi, Rei; Matsueda, Satoko; Sasada, Tetsuro; Yamada, Akira; Itoh, Kyogo

    2013-01-01

    Background Cancer vaccine is one of the attractive treatment modalities for patients with castration-resistant prostate cancer (CRPC). However, because of delayed immune responses, its clinical benefits, besides for overall survival (OS), are not well captured by the World Health Organization (WHO) and Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Several surrogate markers for evaluation of cancer vaccine, including prostate-specific antigen doubling time (PSADT), are curren...

  20. Synthesis and characterization of antigenic influenza A M2e protein peptide-poly(acrylic) acid bioconjugate and determination of toxicity in vitro.

    Science.gov (United States)

    Kilinc, Yasemin Budama; Akdeste, Zeynep Mustafaeva; Koc, Rabia Cakir; Bagirova, Melahat; Allahverdiyev, Adil

    2014-01-01

    The influenza A virus is a critical public health problem that causes epidemics and pandemics, and occurs widely all over the world. Various vaccines against the virus have not provided a solution to the problem. Different approaches, particularly M2e peptide-based vaccines, are available for developing universal vaccines against influenza A. However, it is important to select a suitable carrier to obtain an effective vaccine. Accordingly, studies on the usage of various carriers are ongoing. Particularly, polymer-based carriers have gained importance due to both drug delivery and adjuvant effects. Therefore, bioconjugate of the M2e protein peptide from the influenza A virus covalent bonded with poly(acrylic) acid was synthesized in our study for the first time. The characterization was performed using size-exclusion chromatography and fluorescence spectroscopy; subsequently, it was found that the bioconjugate of the examined lower doses (0.05 and 0.5 mg/ml) have no toxic effects on human cell lines. These results suggest that, in the future, the poly(acrylic) acid bioconjugate of the M2e peptide should be studied in vivo for universal vaccine development against the influenza A virus. PMID:25482080

  1. Multimerized HIV-gp41-derived peptides as fusion inhibitors and vaccines.

    Science.gov (United States)

    Nomura, Wataru; Mizuguchi, Takaaki; Tamamura, Hirokazu

    2016-11-01

    To date, several antigens based on the amino-terminal leucine/isoleucine heptad repeat (NHR) region of an HIV-1 envelope protein gp41 and fusion inhibitors based on the carboxy-terminal leucine/isoleucine heptad repeat (CHR) region of gp41 have been reported. We have developed a synthetic antigen targeting the membrane-fusion mechanism of HIV-1. This uses a template designed with C3-symmetric linkers and mimics the trimeric form of the NHR-derived peptide N36. The antiserum obtained by immunization of the N36 trimeric antigen binds preferentially to the N36 trimer and blocks HIV-1 infection effectively, compared with the antiserum obtained by immunization of the N36 monomer. Using another template designed with different C3-symmetric linkers, we have also developed a synthetic peptide mimicking the trimeric form of the CHR-derived peptide C34, with ∼100 times the inhibitory activity against the HIV-1 fusion mechanism than that of the monomer C34 peptide. A dimeric derivative of C34 has potent inhibitory activity at almost the same levels as this C34 trimer mimic, suggesting that presence of a dimeric form of C34 is structurally critical for fusion inhibitors. As examples of rising mid-size drugs, this review describes an effective strategy for the design of HIV vaccines and fusion inhibitors based on a relationship with the native structure of proteins involved in HIV fusion mechanisms. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 622-628, 2016. PMID:26583370

  2. Kawasaki Disease Mimicking Retropharyngeal Abscess

    Science.gov (United States)

    Srividhya, Vazhkudai Sridharan; Vasanthi, Thiruvengadam; Shivbalan, Somu

    2010-01-01

    Kawasaki disease is an acute, self-limiting febrile mucocutaneous vasculitis of infants and young children. Retropharyngeal lymphadenopathy is a rare presentation of Kawasaki disease. We present a case of Kawasaki disease mimicking a retropharyngeal abscess, with upper airway obstruction resulting in delayed diagnosis. PMID:20635457

  3. A new approach for the molecular epitope identification in protein antigens by combination of partial proteolytic digestion of an immobilized immune complex with mass spectrometric peptide mapping

    International Nuclear Information System (INIS)

    The most widely used routine test for the detection of antibodies against the acetylcholine receptor (AChR) in sera from patients with myasthenia gravis (MG) employs human amputates as antigen source (AChRAMP). From the results of the study we conclude that the TE671 assay is a useful alternative to the conventional assay using AChR from amputated muscle, as AChRTE671 is more homogeneous, more readily available, and safer than AChRAMP prepared from potentially infection material. However, there are important differences between the two assays, namely a higher cut off point for AChRTE671 and by one third lower AChRTE671 titers in patients with generalized myasthenia. (orig.)

  4. A new approach for the molecular epitope identification in protein antigens by combination of partial proteolytic digestion of an immobilized immune complex with mass spectrometric peptide mapping

    Energy Technology Data Exchange (ETDEWEB)

    Fiedler, W.; Etspueler, H.; Suckau, D.; Przybylski, M. (Konstanz Univ. (Germany). Fakultaet fuer Chemie)

    1992-05-01

    The most widely used routine test for the detection of antibodies against the acetylcholine receptor (AChR) in sera from patients with myasthenia gravis (MG) employs human amputates as antigen source (AChR{sub AMP}). From the results of the study we conclude that the TE671 assay is a useful alternative to the conventional assay using AChR from amputated muscle, as AChR{sub TE671} is more homogeneous, more readily available, and safer than AChR{sub AMP} prepared from potentially infection material. However, there are important differences between the two assays, namely a higher cut off point for AChR{sub TE671} and by one third lower AChR{sub TE671} titers in patients with generalized myasthenia. (orig.).

  5. Cancer vaccine--Antigenics.

    Science.gov (United States)

    2002-01-01

    purified complexes of tumour-derived HSPs linked to tumour antigen peptides. When these HSPPC are readministered to a patient following surgery or biopsy of the tumour, the antigenic tumour peptides are expressed on the surface of potent antigen-presenting cells of the immune system, such as macrophages and dendritic cells. This stimulates a much more powerful anti-tumour immune response than that generated by expression of the same antigens by the tumour cell. Thus, Antigenics autologous HSP technology is attractive because it is highly specific for individual patients and circumvents the need for identification of specific antigens for individual cancers (i.e. it does not require definition of the antigenic epitopes on cancer cells) and it overcomes the immune tolerance associated with various tumours. Oncophage is manufactured in a 10-hour process from surgically resected autologous tumour. A minimum of 1-3g of tumour tissue is required to produce enough Oncophage for a course of treatment. The major limiting factor for producing Oncophage from a particular cancer is the ability to purify HSP from that cancer. From clinical studies to date, Antigenics has been able to produce HSP from 100, 98, 90, 71 and 30% of colorectal carcinoma, renal cell carcinoma, melanoma, gastric cancer and pancreatic cancer tumours, respectively. The low success rate with pancreatic cancers is because of the high concentration of proteases in that tissue type. HSPs are a family of highly conserved proteins present in the cells of all organisms. They function as molecular chaperones, assisting the correct folding of polypeptides and aiding intracellular protein transport. In addition, HSPs associate with a broad range of peptides derived from intracellular protein degradation, including antigenic peptides produced in tumour cells. Antigenics has exclusively licensed worldwide rights to its HSP immunotherapeutic complexes from Mount Sinai School of Medicine and Fordham University in the USA. On

  6. Multicystic Hepatocarcinoma Mimicking Liver Abscess

    Directory of Open Access Journals (Sweden)

    Evangelos Falidas

    2013-01-01

    Full Text Available The diagnosis of hepatocellular carcinoma (HCC became easier in relation to the improved radiological examinations; however, the neoplasm may occur under atypical presentations mimicking other benign or malignant processes. Multicystic HCC mimicking a liver abscess associated with septic-type fever and leukocytosis is rare, has a poor prognosis, and poses diagnostic and therapeutic dilemmas. We present the case of an 80-year-old patient, who presented with fever, leukocytosis, and large cystic masses involving right and left lobes of the liver initially considered abscesses and finally diagnosed as HCC after open drainage and liver biopsy. Although the patient died on the tenth postoperative day due to pulmonary oedema, the authors emphasize the high index of suspicion needed in the diagnosis of this unusual presentation of HCC.

  7. Calcitonin Gene-Related Peptide-Exposed Endothelial Cells Bias Antigen Presentation to CD4+ T Cells toward a Th17 Response.

    Science.gov (United States)

    Ding, Wanhong; Stohl, Lori L; Xu, Linghui; Zhou, Xi K; Manni, Michela; Wagner, John A; Granstein, Richard D

    2016-03-01

    Calcitonin gene-related peptide (CGRP) is a neuropeptide with well-established immunomodulatory functions. CGRP-containing nerves innervate dermal blood vessels and lymph nodes. We examined whether CGRP regulates the outcome of Ag presentation by Langerhans cells (LCs) to T cells through actions on microvascular endothelial cells (ECs). Exposure of primary murine dermal microvascular ECs (pDMECs) to CGRP followed by coculture with LCs, responsive CD4(+) T cells and Ag resulted in increased production of IL-6 and IL-17A accompanied by inhibition of IFN-γ, IL-4, and IL-22 compared with wells containing pDMECs treated with medium alone. Physical contact between ECs and LCs or T cells was not required for this effect and, except for IL-4, we demonstrated that IL-6 production by CGRP-treated pDMECs was involved in these effects. CD4(+) cells expressing cytoplasmic IL-17A were increased, whereas cells expressing cytoplasmic IFN-γ or IL-4 were decreased by the presence of CGRP-treated pDMECs. In addition, the level of retinoic acid receptor-related orphan receptor γt mRNA was significantly increased, whereas T-bet and GATA3 expression was inhibited. Immunization at the site of intradermally administered CGRP led to a similar bias in CD4(+) T cells from draining lymph node cells toward IL-17A and away from IFN-γ. Actions of nerve-derived CGRP on ECs may have important regulatory effects on the outcome of Ag presentation with consequences for the expression of inflammatory skin disorders involving Th17 cells. PMID:26829986

  8. Multiple antigen glycopeptides (MAGs) with Tn tumour antigens and incorporated adjuvant: synthesis and immunobiological activities

    Czech Academy of Sciences Publication Activity Database

    Ježek, Jan; Kelkar, Shripad; Vepřek, Pavel; Hajdůch, M.; Sejbal, J.; Trnka, T.

    Napoli : Edizioni Ziino, 2002 - (Benedetti, E.; Pedone, C.), s. 524-525 ISBN 88-900948-1-8. [Peptides 2002. European Peptide Symposium /27./. Sorrento (IT), 31.08.2002-06.09.2002] R&D Projects: GA ČR GA303/01/0690 Institutional research plan: CEZ:AV0Z4055905 Keywords : Tn antigen * multiple antigen glycopeptide * synthetic vaccine Subject RIV: CE - Biochemistry

  9. Production of peptide antisera specific for mouse and rat proinsulin C-peptide 2

    DEFF Research Database (Denmark)

    Blume, N; Madsen, O D; Kofod, Hans;

    1990-01-01

    Mice and rats have two functional non-allelic insulin genes. By using a synthetic peptide representing a common sequence in mouse and rat C-peptide 2 as antigen, we have produced rabbit antisera specific for an epitope which is not present in mouse or rat C-peptide 1. Long-term immunization did n...

  10. Targeting and mimicking collagens via triple helical peptide assembly

    OpenAIRE

    Li, Yang; Yu, S. Michael

    2013-01-01

    As the major structural component of the extracellular matrix, collagen plays a crucial role in tissue development and regeneration. Since structural and metabolic abnormalities of collagen are associated with numerous debilitating diseases and pathologic conditions, the ability to target collagens of diseased tissues could lead to new diagnostics and therapeutics. Collagen is also a natural biomaterial widely used in drug delivery and tissue engineering, and construction of synthetic collage...

  11. Classification of human leukocyte antigen (HLA) supertypes

    DEFF Research Database (Denmark)

    Wang, Mingjun; Claesson, Mogens H

    2014-01-01

    Identification of new antigenic peptides, derived from infectious agents or cancer cells, which bind to human leukocyte antigen (HLA) class I and II molecules, is of importance for the development of new effective vaccines capable of activating the cellular arm of the immune response. However, the...... barrier to the development of peptide-based vaccines with maximum population coverage is that the restricting HLA genes are extremely polymorphic resulting in a vast diversity of peptide-binding HLA specificities and a low population coverage for any given peptide-HLA specificity. One way to reduce this...... complexity is to group thousands of different HLA molecules into several so-called HLA supertypes: a classification that refers to a group of HLA alleles with largely overlapping peptide binding specificities. In this chapter, we focus on the state-of-the-art classification of HLA supertypes including HLA...

  12. OVARIAN CALCIFICATION MIMICKING VESICLE CALCULUS

    Directory of Open Access Journals (Sweden)

    Pallavi

    2013-04-01

    Full Text Available INTRODUCTION: Calcification in ovary is usually dystrophic in natu re, forming secondary to degeneration of the epithelium or in association wit h areas of necrosis. It may occur in cases of endometriosis [1] or in some ovarian tumor eg. Fibro thecoma [2] , Brenner’s tumor [3] , cavernous hemangioma [4] etc. Benign unilateral densely calcified ovary wit hout any association with tumor or endometriosis has not been reported previously. We report a case of heavily calcified left ovary which mimicked as vesicle calculus on X- ray leading to confusion in diagnosis.

  13. Black hole mimickers: Regular versus singular behavior

    International Nuclear Information System (INIS)

    Black hole mimickers are possible alternatives to black holes; they would look observationally almost like black holes but would have no horizon. The properties in the near-horizon region where gravity is strong can be quite different for both types of objects, but at infinity it could be difficult to discern black holes from their mimickers. To disentangle this possible confusion, we examine the near-horizon properties, and their connection with far away asymptotic properties, of some candidates to black mimickers. We study spherically symmetric uncharged or charged but nonextremal objects, as well as spherically symmetric charged extremal objects. Within the uncharged or charged but nonextremal black hole mimickers, we study nonextremal ε-wormholes on the threshold of the formation of an event horizon, of which a subclass are called black foils, and gravastars. Within the charged extremal black hole mimickers we study extremal ε-wormholes on the threshold of the formation of an event horizon, quasi-black holes, and wormholes on the basis of quasi-black holes from Bonnor stars. We elucidate whether or not the objects belonging to these two classes remain regular in the near-horizon limit. The requirement of full regularity, i.e., finite curvature and absence of naked behavior, up to an arbitrary neighborhood of the gravitational radius of the object enables one to rule out potential mimickers in most of the cases. A list ranking the best black hole mimickers up to the worst, both nonextremal and extremal, is as follows: wormholes on the basis of extremal black holes or on the basis of quasi-black holes, quasi-black holes, wormholes on the basis of nonextremal black holes (black foils), and gravastars. Since in observational astrophysics it is difficult to find extremal configurations (the best mimickers in the ranking), whereas nonextremal configurations are really bad mimickers, the task of distinguishing black holes from their mimickers seems to be less

  14. Deletion of naïve T cells recognizing the minor histocompatibility antigen HY with toxin-coupled peptide-MHC class I tetramers inhibits cognate CTL responses and alters immunodominance

    OpenAIRE

    Hess, Sabrina M.; Young, Ellen F.; Miller, Keith R.; Vincent, Benjamin G.; Buntzman, Adam S.; Collins, Edward J.; Frelinger, Jeffrey A.; Hess, Paul R.

    2013-01-01

    Alloreactive T-cell responses directed against minor histocompatibility (H) antigens, which arise from diverse genetic disparities between donor and recipient outside the MHC, are an important cause of rejection of MHC-matched grafts. Because clinically significant responses appear to be directed at only a few antigens, the selective deletion of naïve T cells recognizing donor-specific, immunodominant minor H antigens in recipients before transplantation may be a useful tolerogenic strategy. ...

  15. Production of Functionally Active and Immunogenic Non-Glycosylated Protective Antigen from Bacillus anthracis in Nicotiana benthamiana by Co-Expression with Peptide-N-Glycosidase F (PNGase F) of Flavobacterium meningosepticum.

    Science.gov (United States)

    Mamedov, Tarlan; Chichester, Jessica A; Jones, R Mark; Ghosh, Ananya; Coffin, Megan V; Herschbach, Kristina; Prokhnevsky, Alexey I; Streatfield, Stephen J; Yusibov, Vidadi

    2016-01-01

    Bacillus anthracis has long been considered a potential biological warfare agent, and therefore, there is a need for a safe, low-cost and highly efficient anthrax vaccine with demonstrated long-term stability for mass vaccination in case of an emergency. Many efforts have been made towards developing an anthrax vaccine based on recombinant protective antigen (rPA) of B. anthracis, a key component of the anthrax toxin, produced using different expression systems. Plants represent a promising recombinant protein production platform due to their relatively low cost, rapid scalability and favorable safety profile. Previous studies have shown that full-length rPA produced in Nicotiana benthamiana (pp-PA83) is immunogenic and can provide full protection against lethal spore challenge; however, further improvement in the potency and stability of the vaccine candidate is necessary. PA of B. anthracis is not a glycoprotein in its native host; however, this protein contains potential N-linked glycosylation sites, which can be aberrantly glycosylated during expression in eukaryotic systems including plants. This glycosylation could affect the availability of certain key epitopes either due to masking or misfolding of the protein. Therefore, a non-glycosylated form of pp-PA83 was engineered and produced in N. benthamiana using an in vivo deglycosylation approach based on co-expression of peptide-N-glycosidase F (PNGase F) from Flavobacterium meningosepticum. For comparison, versions of pp-PA83 containing point mutations in six potential N-glycosylation sites were also engineered and expressed in N. benthamiana. The in vivo deglycosylated pp-PA83 (pp-dPA83) was shown to have in vitro activity, in contrast to glycosylated pp-PA83, and to induce significantly higher levels of toxin-neutralizing antibody responses in mice compared with glycosylated pp-PA83, in vitro deglycosylated pp-PA83 or the mutated versions of pp-PA83. These results suggest that pp-dPA83 may offer advantages

  16. Human Leukocyte Antigen (HLA) B27 Allotype-Specific Binding and Candidate Arthritogenic Peptides Revealed through Heuristic Clustering of Data-independent Acquisition Mass Spectrometry (DIA-MS) Data.

    Science.gov (United States)

    Schittenhelm, Ralf B; Sivaneswaran, Saranjah; Lim Kam Sian, Terry C C; Croft, Nathan P; Purcell, Anthony W

    2016-06-01

    Expression of HLA-B27 is strongly associated with ankylosing spondylitis (AS) and other spondyloarthropathies. While this is true for the majority of HLA-B27 allotypes, HLA-B*27:06 and HLA-B*27:09 are not associated with AS. These two subtypes contain polymorphisms that are ideally positioned to influence the bound peptide repertoire. The existence of disease-inducing peptides (so-called arthritogenic peptides) has therefore been proposed that are exclusively presented by disease-associated HLA-B27 allotypes. However, we have recently demonstrated that this segregation of allotype-bound peptides is not the case and that many peptides that display sequence features predicted to favor binding to disease-associated subtypes are also capable of being presented naturally by protective alleles. To further probe more subtle quantitative changes in peptide presentation, we have used a combination of data-independent acquisition (DIA) and multiple reaction monitoring (MRM) mass spectrometry to quantify the abundance of 1646 HLA-B27 restricted peptides across the eight most frequent HLA-B27 allotypes (HLA-B*27:02-HLA-B*27:09). We utilized K means cluster analysis to group peptides with similar allelic binding preferences across the eight HLA-B27 allotypes, which enabled us to identify the most-stringent binding characteristics for each HLA-B27 allotype and further refined their existing consensus-binding motifs. Moreover, a thorough analysis of this quantitative dataset led to the identification of 26 peptides, which are presented in lower abundance by HLA-B*27:06 and HLA-B*27:09 compared with disease-associated HLA-B27 subtypes. Although these differences were observed to be very subtle, these 26 peptides might encompass the sought-after arthritogenic peptide(s). PMID:26929215

  17. Acquired vulval lymphangiectases mimicking genital warts

    OpenAIRE

    Sharma Rajeev; Tomar Sudarshan; Chandra Mithilesh

    2002-01-01

    Acquired lymphangiectasia can sometimes occur on the vulva and cause diagnostic difficulties especially if they have a warty appearance. We report a case of acquired vulva I lymphangiectasia which mimicked genital warts.

  18. Acquired vulval lymphangiectases mimicking genital warts

    Directory of Open Access Journals (Sweden)

    Sharma Rajeev

    2002-01-01

    Full Text Available Acquired lymphangiectasia can sometimes occur on the vulva and cause diagnostic difficulties especially if they have a warty appearance. We report a case of acquired vulva I lymphangiectasia which mimicked genital warts.

  19. Cerebellopontine angle pilocytic astrocytoma mimicking acoustic schwannoma

    Energy Technology Data Exchange (ETDEWEB)

    Takada, Y.; Ohno, K.; Tamaki, M.; Hirakawa, K. [Dept. of Neurosurgery, Tokyo Medical and Dental Univ. (Japan)

    1999-12-01

    We describe a case of pilocytic astrocytoma of the cerebellum mimicking an acoustic schwannoma. The tumour protruded into the porus acusticus and enlarged the internal auditory meatus, which is a quite unusual characteristic of glial tumours. (orig.)

  20. Cerebellopontine angle pilocytic astrocytoma mimicking acoustic schwannoma

    International Nuclear Information System (INIS)

    We describe a case of pilocytic astrocytoma of the cerebellum mimicking an acoustic schwannoma. The tumour protruded into the porus acusticus and enlarged the internal auditory meatus, which is a quite unusual characteristic of glial tumours. (orig.)

  1. Mimicking Portfolios and Exact Arbitrage Pricing.

    OpenAIRE

    Huberman, Gur; Kandel, Shmuel; Robert F. Stambaugh

    1987-01-01

    The authors characterize the sets of mimicking positions whose returns can serve in place of factors in an exact K-factor arbitrage pricing relation for a set of N assets. All of the sets are K-dimensional nonsingular linear transformations of each other. The authors interpret three examples of such transformations and discuss empirical considerations. They also provide conditions under which the mimicking positions can be expressed as portfolios and characterize the relation between mimickin...

  2. Nanofiltration of hormone mimicking trace organic contaminants

    OpenAIRE

    Nghiem, D.L.; Schaefer, Andrea; Elimelech, M.

    2005-01-01

    The removal mechanisms of three hormone mimicking organic compounds by nanofiltration (NF) membranes have been examined. Two NF membranes having different pore size were used in laboratory-scale nanofiltration experiments with feed solutions spiked with a hormone mimicking compound ¾ nonylphenol, tert-butyl phenol, or bisphenol A. Retention of the compounds was determined at various solution chemistries, namely aqueous solution pH, ionic strength, and presence of natural organi...

  3. Tissue mimicking materials for dental ultrasound

    OpenAIRE

    Singh, Rahul S.; Culjat, Martin O.; Grundfest, Warren S.; Brown, Elliott R.; White, Shane N

    2008-01-01

    While acoustic tissue mimicking materials have been explored for a variety of soft and hard biological tissues, no dental hard tissue mimicking materials have been characterized. Tooth phantoms are necessary to better understand acoustic phenomenology within the tooth environment and to accelerate the advancement of dental ultrasound imaging systems. In this study, soda lime glass and dental composite were explored as surrogates for human enamel and dentin, respectively, in terms of compressi...

  4. MHC Class Ⅰ Antigen Presentation- Recently Trimmed and Well Presented

    Institute of Scientific and Technical Information of China (English)

    Barry Flutter; Bin Gao

    2004-01-01

    Presentation of antigenic peptide to T cells by major histocompatibility complex (MHC) class Ⅰ molecules is the key to the cellular immune response. Non-self intracellular proteins are processed into short peptides and transported into endoplasmic reticulum (ER) where they are assembled with class Ⅰ molecules assisted by several chaperone proteins to form trimeric complex. MHC class Ⅰ complex loaded with optimised peptides travels to the cell surface of antigen presentation cells to be recognised by T cells. The cells presenting non-self peptides are cleared by CD8 positive T cells. In order to ensure that T cells detect an infection or mutation within the target cells the process of peptide loading and class Ⅰ expression must be carefully regulated. Many of the cellular components involved in antigen processing and class Ⅰ presentation are known and their various functions are now becoming clearer. Cellular & Molecular Immunology. 2004;1(1):22-30.

  5. MHC Class I Antigen Presentation- Recently Trimmed and Well Presented

    Institute of Scientific and Technical Information of China (English)

    BarryFlutter; BinGao

    2004-01-01

    Presentation of antigenic peptide to T cells by major histocompatibility complex (MHC) class I molecules is the key to the cellular immune response. Non-self intracellular proteins are processed into short peptides and transported into endoplasmic reticulum (ER) where they are assembled with class I molecules assisted by several chaperone proteins to form trimeric complex. MHC class I complex loaded with optimised peptides travels to the cell surface of antigen presentation cells to be recognised by T cells. The cells presenting non-self peptides are cleared by CD8 positive T cells. In order to ensure that T cells detect an infection or mutation within the target cells the process of peptide loading and class I expression must be carefully regulated. Many of the cellular components involved in antigen processing and class I presentation are known and their various functions are now becoming clearer. Cellular & Molecular Immunology. 2004;1(1):22-30.

  6. How to Make a Non-Antigenic Protein (Auto) Antigenic: Molecular Complementarity Alters Antigen Processing and Activates Adaptive-Innate Immunity Synergy.

    Science.gov (United States)

    Root-Bernstein, Robert

    2015-01-01

    Evidence is reviewed that complementary proteins and peptides form complexes with increased antigenicity and/or autoimmunogenicity. Five case studies are highlighted: 1) diphtheria toxin-antitoxin (antibody), which induces immunity to the normally non-antigenic toxin, and autoimmune neuritis; 2) tryptophan peptide of myelin basic protein and muramyl dipeptide ("adjuvant peptide"), which form a complex that induces experimental allergic encephalomyelitis; 3) an insulin and glucagon complex that is far more antigenic than either component individually; 4) various causes of experimental autoimmune myocarditis such as C protein in combination with its antibody, or coxsackie B virus in combination with the coxsackie and adenovirus receptor; 5) influenza A virus haemagglutinin with the outer membrane protein of the Haemophilus influenzae, which increases antigenicity. Several mechanisms cooperate to alter immunogenicity. Complexation alters antigen processing, protecting the components against proteolysis, altering fragmentation and presenting novel antigens to the immune system. Complementary antigens induce complementary adaptive immune responses (complementary antibodies and/or T cell receptors) that produce circulating immune complexes (CIC). CIC stimulate innate immunity. Concurrently, complementary antigens stimulate multiple Toll-like receptors that synergize to over-produce cytokines, which further stimulate adaptive immunity. Thus innate and adaptive immunity form a positive feedback loop. If components of the complex mimic a host protein, then autoimmunity may result. Enhanced antigenicity for production of improved vaccines and/or therapeutic autoimmunity (e.g., against cancer cells) might be achieved by using information from antibody or TCR recognition sites to complement an antigen; by panning for complements in randomized peptide libraries; or using antisense peptide strategies to design complements. PMID:26179268

  7. Giant hydronephrosis mimicking progressive malignancy

    Directory of Open Access Journals (Sweden)

    Heidenreich Axel

    2003-10-01

    Full Text Available Abstract Background Cases of giant hydronephroses are rare and usually contain no more than 1–2 litres of fluid in the collecting system. We report a remarkable case of giant hydronephrosis mimicking a progressive malignant abdominal tumour. Case presentation A 78-year-old cachectic woman presented with an enormous abdominal tumour, which, according to the patient, had slowly increased in diameter. Medical history was unremarkable except for a hysterectomy >30 years before. A CT scan revealed a giant cystic tumour filling almost the entire abdominal cavity. It was analysed by two independent radiologists who suspected a tumour originating from the right kidney and additionally a cystic ovarian neoplasm. Subsequently, a diagnostic and therapeutic laparotomy was performed: the tumour presented as a cystic, 35 × 30 × 25 cm expansive structure adhesive to adjacent organs without definite signs of invasive growth. The right renal hilar vessels could finally be identified at its basis. After extirpation another tumourous structure emerged in the pelvis originating from the genital organs and was also resected. The histopathological examination revealed a >15 kg hydronephrotic right kidney, lacking hardly any residual renal cortex parenchyma. The second specimen was identified as an ovary with regressive changes and a large partially calcified cyst. There was no evidence of malignant growth. Conclusion Although both clinical symptoms and the enormous size of the tumour indicated malignant growth, it turned out to be a giant hydronephrosis. Presumably, a chronic obstruction of the distal ureter had caused this extraordinary hydronephrosis. As demonstrated in our case, an accurate diagnosis of giant hydronephrosis remains challenging due to the atrophy of the renal parenchyma associated with chronic obstruction. Therefore, any abdominal cystic mass even in the absence of other evident pathologies should include the differential diagnosis of a

  8. 猪带绦虫六钩蚴TSO45-4B抗原FnⅢ结构域相应的线性B细胞表位肽免疫原性研究%Research on immunity response about Taenia solium oncosphere TSO45-4B antigens FnⅢ structure domain linear B cells epitope peptides

    Institute of Scientific and Technical Information of China (English)

    王媛媛; 陶志勇; 杨小迪; 王小莉; 常雪莲; 陈勇; 孙新; 夏惠; 方强

    2013-01-01

    Objective: To observe the humoral immune response induced by Taenia solium oncosphere TSO45-4B antigens Fn Ⅲ structure domain linear B cells epitope peptides in mice. Methods: The two predicted B cell epitope peptides of TSO45-4B Fn Ⅲ structure domain conjugated with carrier protein of keyhole limpet hemocyanin were synthesized and used to immunize mice. The mice specific serum antibody titer to the epitope peptides synthesized was tested by ELISA. Results: The specific antibody to one of the predicted epitope peptides synthesized was found in mice serum,and the titer was 1: 1 280. Conclusions: One of the two predicted linear B cell epitope peptides of TSO45-4B FnⅢ structure domain can induce the humoral immune response in mice.%目的:观察载体蛋白偶联的TSO45-4B抗原FnⅢ结构域相应的线性B细胞表位肽诱导的体液免疫反应.方法:人工合成TSO45-4B抗原FnⅢ结构域2条预测表位肽,偶联钥孔血蓝蛋白免疫小鼠,采用ELISA法检测小鼠血清中预测表位肽特异性抗体滴度.结果:免疫小鼠血清中检测到1条预测表位肽特异性抗体,其效价达到1:1 280.结论:设计的1条TSO45-4B抗原FnⅢ结构域线性B细胞表位肽可诱导小鼠产生体液免疫反应.

  9. Identification of peptides from foot‐and‐mouth disease virus structural proteins bound by class I swine leukocyte antigen (SLA) alleles, SLA‐1*0401 and SLA‐2*0401

    DEFF Research Database (Denmark)

    Pedersen, Lasse Eggers; Harndahl, M.; Nielsen, Morten;

    2013-01-01

    within the structural proteins of foot‐and‐mouth disease virus (FMDV), strain A24 were analyzed as candidate T‐cell epitopes. Peptides predicted by the NetMHCpan were tested in ELISA for binding to the SLA‐1*0401 and SLA‐2*0401 major histocompatibility complex class I proteins. Four of the 10 predicted...... FMDV peptides bound to SLA‐2*0401, whereas five of the nine predicted FMDV peptides bound to SLA‐1*0401. These methods provide the characterization of T‐cell epitopes in response to pathogens in more detail. The development of such approaches to analyze vaccine performance will contribute to a more...

  10. Diagnostic and immunoprophylactic applications of synthetic peptides in veterinary microbiology

    Directory of Open Access Journals (Sweden)

    Saravanan Paramasivam

    2009-10-01

    Full Text Available Chemically synthesized peptides are considered as potential reagents for various applications in biological sciences. They mimic naturally occurring peptides or segments of proteins and have emerged as diagnostic reagents and safe immunogens in animal science. Carefully selected peptides resembling authentic epitopes serve as synthetic antigens in diagnostic tests. Synthetic peptide-based vaccines can elicit antibodies against animal pathogens. The early use of synthetic peptides as a vaccine for foot-and-mouth disease stimulated interest in the development of peptide-based diagnostics and immunoprophylactics. The development of a peptide vaccine for canine parvovirus confirmed the usefulness of peptides as immunoprophylactics. Recently, the advent of the technology for the development of multiple antigenic peptides (MAPs has provided a well-defined method for the production of highly immunogenic peptides and anti-peptide antibodies. Antibodies raised against major epitopes can be used in the detection of the native antigen (virus in the enzyme-linked immunosorbent assay (ELISA and other tests, vindicating the usefulness of peptides for safe, chemically defined, non-infectious diagnostics and immunoprophylactics. This article focuses on the methods for selecting and preparing peptides for the predicted epitopes, their characterization and use, and the application of MAPs.

  11. Peptides interfering 3A protein dimerization decrease FMDV multiplication

    OpenAIRE

    Mónica González-Magaldi; Ángela Vázquez-Calvo; de la Torre, Beatriz G; Javier Valle; David Andreu; Francisco Sobrino

    2015-01-01

    Nonstructural protein 3A is involved in relevant functions in foot-and-mouth disease virus (FMDV) replication. FMDV 3A can form homodimers and preservation of the two hydrophobic ??-helices (??1 and ??2) that stabilize the dimer interface is essential for virus replication. In this work, small peptides mimicking residues involved in the dimer interface were used to interfere with dimerization and thus gain insight on its biological function. The dimer interface peptides ??1, ??2 and that span...

  12. Molecular mimics of the tumour antigen MUC1.

    Directory of Open Access Journals (Sweden)

    Tharappel C James

    Full Text Available A key requirement for the development of cancer immunotherapy is the identification of tumour-associated antigens that are differentially or exclusively expressed on the tumour and recognized by the host immune system. However, immune responses to such antigens are often muted or lacking due to the antigens being recognized as "self", and further complicated by the tumour environment and regulation of immune cells within. In an effort to circumvent the lack of immune responses to tumour antigens, we have devised a strategy to develop potential synthetic immunogens. The strategy, termed mirror image phage display, is based on the concept of molecular mimicry as demonstrated by the idiotype/anti-idiotype paradigm in the immune system. Here as 'proof of principle' we have selected molecular mimics of the well-characterised tumour associated antigen, the human mucin1 protein (MUC1 from two different peptide phage display libraries. The putative mimics were compared in structure and function to that of the native antigen. Our results demonstrate that several of the mimic peptides display T-cell stimulation activity in vitro when presented by matured dendritic cells. The mimic peptides and the native MUC1 antigenic epitopes can cross-stimulate T-cells. The data also indicate that sequence homology and/or chemical properties to the original epitope are not the sole determining factors for the observed immunostimulatory activity of the mimic peptides.

  13. Mimicking the germinal center reaction in hybridoma cells to isolate temperature-selective anti-PEG antibodies

    OpenAIRE

    Su, Yu-Cheng; Al-Qaisi, Talal S; Tung, Hsin-Yi; Cheng, Tian-Lu; Chuang, Kuo-Hsiang; Chen, Bing-Mae; Roffler, Steve R.

    2014-01-01

    Modification of antibody class and binding properties typically requires cloning of antibody genes, antibody library construction, phage or yeast display and recombinant antibody expression. Here, we describe an alternative “cloning-free” approach to generate antibodies with altered antigen-binding and heavy chain isotype by mimicking the germinal center reaction in antibody-secreting hybridoma cells. This was accomplished by lentiviral transduction and controllable expression of activation-i...

  14. A case of prostate cancer in 34 year old man presenting with generalized lymphadenopathy mimicking malignant lymphoma.

    OpenAIRE

    Ahn, M. J.; Oh, S. J.; Lee, Y. Y.; Jung, T. J.; Kim, I. S.; Choi, I. Y.; Jang, S. J.; Park, Y. W.; Shin, K. Y.; Kim, Y. S.

    1997-01-01

    We report a case of prostate cancer in 34 year old man presenting with generalized lymphadenopathy mimicking malignant lymphoma without any urinary symptoms. Lymph node biopsy revealed metastatic adenocarcinoma and immunohistochemical stain was strongly positive to prostate antigen (PSA). Serum PSA level was also markedly elevated. Transrectal ultrasonogram showed mild enlargement in right lobe of prostate. Needle biopsy finding of prostate also was consistent with adenocarcinoma. Bone scan r...

  15. Carbohydrate-functionalized nanovaccines preserve HIV-1 antigen stability and activate antigen presenting cells.

    Science.gov (United States)

    Vela Ramirez, J E; Roychoudhury, R; Habte, H H; Cho, M W; Pohl, N L B; Narasimhan, B

    2014-01-01

    The functionalization of polymeric nanoparticles with ligands that target specific receptors on immune cells offers the opportunity to tailor adjuvant properties by conferring pathogen mimicking attributes to the particles. Polyanhydride nanoparticles are promising vaccine adjuvants with desirable characteristics such as immunomodulation, sustained antigen release, activation of antigen presenting cells (APCs), and stabilization of protein antigens. These capabilities can be exploited to design nanovaccines against viral pathogens, such as HIV-1, due to the important role of dendritic cells (DCs) and macrophages in viral spread. In this work, an optimized process was developed for carbohydrate functionalization of HIV-1 antigen-loaded polyanhydride nanoparticles. The carbohydrate-functionalized nanoparticles preserved antigenic properties upon release and also enabled sustained antigen release kinetics. Particle internalization was observed to be chemistry-dependent with positively charged nanoparticles being taken up more efficiently by DCs. Up-regulation of the activation makers CD40 and CD206 was demonstrated with carboxymethyl-α-d-mannopyranosyl-(1,2)-d-mannopyranoside functionalized nanoparticles. The secretion of the cytokines IL-6 and TNF-α was shown to be chemistry-dependent upon stimulation with carbohydrate-functionalized nanoparticles. These results offer important new insights upon the interactions between carbohydrate-functionalized nanoparticles and APCs and provide foundational information for the rational design of targeted nanovaccines against HIV-1. PMID:25068589

  16. Carcinoma-associated antigens

    International Nuclear Information System (INIS)

    This invention relates to novel antigens associated with breast carcinoma, anti-sera specific to said antigens, 125I-labeled forms of said antigens and methods of detecting said antigens in serum or plasma. The invention also relates to a diagnostic kit containing standardised antigens or antisera or marked forms thereof for the detection of said antigens in human blood, serum or plasma. (author)

  17. Peripancreatic fat necrosis mimicking pancreatic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Thurnher, M.M.; Schima, W.; Turetschek, K.; Thurnher, S.A. [Vienna Univ. (Austria). Inst. fuer Radiologie; Fuegger, R. [Dept. of Surgery, University of Vienna (Austria); Oberhuber, G. [Dept. of Pathology, University of Vienna (Austria)

    2001-06-01

    A case of peripancreatic fat necrosis, after an episode of acute pancreatitis, which mimicked pancreatic cancer with lymph node metastases, is presented. We describe the imaging findings with helical CT scanning and with unenhanced and mangafodipir-enhanced MR imaging, with special emphasis on the differential diagnoses. (orig.)

  18. Diffuse anaplastic leptomeningeal oligodendrogliomatosis mimicking neurosarcoidosis

    OpenAIRE

    Leep Hunderfund, Andrea N.; Zabad, Rana K.; Aksamit, Allen J.; Morris, Jonathan M; Meyer, Fredric B.; Thorell, William E.; Parisi, Joseph E.; Giannini, Caterina

    2013-01-01

    Diffuse leptomeningeal oligodendrogliomatosis is a rare, frequently fatal CNS malignancy that most often affects children.1 Although potentially treatable with chemotherapy and radiation, the radiologic findings are nonspecific and pathologic confirmation of the diagnosis is difficult. We describe an adult patient whose initial presentation mimicked neurosarcoidosis. Despite extensive imaging abnormalities, 3 biopsies were required before the diagnosis of diffuse leptomeningeal oligodendrogli...

  19. Peripancreatic fat necrosis mimicking pancreatic cancer

    International Nuclear Information System (INIS)

    A case of peripancreatic fat necrosis, after an episode of acute pancreatitis, which mimicked pancreatic cancer with lymph node metastases, is presented. We describe the imaging findings with helical CT scanning and with unenhanced and mangafodipir-enhanced MR imaging, with special emphasis on the differential diagnoses. (orig.)

  20. Microfilariasis of the breast mimicking malignancy

    OpenAIRE

    Tamojit Chaudhuri; Kamlesh Yadava; Pabitra Ray

    2013-01-01

    We report a 65-year-old female who presented with a 3.5x3 cm retro-areolar lump of the right breast with associated right axillary lymphadenopathy, mimicking breast cancer. Mammography showed a well-defined mass in the central quadrant of the right breast. Fine needle aspiration cytology from the breast lump demonstrated many microfilariae of Wuchereria bancrofti.

  1. Microfilariasis of the breast mimicking malignancy

    OpenAIRE

    Chaudhuri, Tamojit; Yadava, Kamlesh; Ray, Pabitra

    2013-01-01

    We report a 65-year-old female who presented with a 3.5×3 cm retro-areolar lump of the right breast with associated right axillary lymphadenopathy, mimicking breast cancer. Mammography showed a well-defined mass in the central quadrant of the right breast. Fine needle aspiration cytology from the breast lump demonstrated many microfilariae of Wuchereria bancrofti.

  2. Giant Hidroacanthoma Simplex Mimicking Bowen's Disease

    OpenAIRE

    Niiyama, Shiro; Oharaseki, Toshiaki; Mukai, Hideki

    2015-01-01

    Hidroacanthoma simplex is a benign tumor of the skin, macroscopically resembling seborrheic keratosis or Bowen's disease and histologically mimicking clonal-type seborrheic keratosis. We observed a plaque of 70 × 50 mm on the right flank part. From clinical appearance, we suspected Bowen's disease; however, based on immunohistochemical findings, we made a diagnosis of hidroacanthoma simplex.

  3. An adult intussusception mimicking early appendicitis

    Institute of Scientific and Technical Information of China (English)

    Wei-Chun Tseng; Cheng-Ting Hsiao; Yu-Cheng Hung

    2012-01-01

    Adult intussusception is rare with variable clinical presentation. We reported a case of adult intussusception presenting with symptoms mimicking acute appendicitis. The patient presented as an abdominal pain from epigastric area with shifting gradually to RLQ. The atypical presentation of adult intussusception remains a diagnostic challenge to the emergency physician.

  4. Preparation of particulate cyclic citrullinated peptide antigens and optimization of experimental conditions%颗粒型环瓜氨酸肽抗原的制备及条件优化

    Institute of Scientific and Technical Information of China (English)

    付琳; 裘宇容; 姜云飞; 夏佳音; 王海芳

    2013-01-01

    目的 探讨颗粒型环瓜氨酸肽抗原的制备方法,并对实验条件进行优化.方法 通过碳二亚胺交联法将人工合成的CCP与BSA共价偶联,使偶联产物蛋白大小在70-170 KD之间,经紫外吸收光谱鉴定偶联成功.采用碳二亚胺两步法将偶联成功的CCP与BSA复合物又与聚苯乙烯微球偶联,优化偶联条件,根据蛋白偶联量和偶联效率判断偶联效果.结果 (1)BSA与CCP偶联质量比为1∶1,EDC与NHS用量比为2∶3,偶联pH为6.0,BSA与CCP偶联可以达到较好的效果.BSA与CCP偶联产物在70 KD-170 KD之间,紫外吸收峰有明显左移.(2)微球与偶联蛋白的吸附效率随着EDC用量的增大而增大,当EDC用量达到7.5 mg/ml时,偶联蛋白最大效率达到63.66%.(3)随着偶联时间的延长,蛋白偶联微球的效率不断增加,在偶联时间为0.5-2 h内,偶联效率增加最快,当反应时间2 h后,反应趋于平衡.(4)对不同偶联反应pH值条件进行筛选,pH为7.5时偶联效果最好,pH7.0-8.0为适宜偶联的pH范围.结论 CCP-BSA偶联产物蛋白与胶乳颗粒偶联,当EDC浓度为7.5 mg/ml,偶联时间为2 h,反应PH值为7.5,蛋白偶联效率可达到63.66%.%Objective To investigate the preparation method of particulate cyclic citrullinated peptide antigens,and optimize the experimental conditions. Methods The artificially synthesized CCP was covalent coupled with BSA by the method of carbodiimide cross linking,and the protein sizes of1 the coupled products were between 70 to 170 KD. The covalent coupling was tested by ultraviolet absorption spectrum. Then the successful coupling complex of BSA and CCP were covalently coupled to the microspheres,and the coupling conditions were optimized. The covalent coupling effect was determined according to the protein coupling quantity and the coupling efficiency. Results (1) When the mass ra tio of BSA and CCP was 1 : 1,the ratio of EDC and NHS was 2 : 3,and the pH of coupling was 6.0,the coupling result of BSA

  5. Identification of peptides from foot‐and‐mouth disease virus structural proteins bound by class I swine leukocyte antigen (SLA) alleles, SLA‐1*0401 and SLA‐2*0401

    DEFF Research Database (Denmark)

    Pedersen, Lasse Eggers; Harndahl, M.; Nielsen, Morten; Patch, J. R.; Jungersen, Gregers; Buus, S.; Golde, W. T.

    2013-01-01

    within the structural proteins of foot‐and‐mouth disease virus (FMDV), strain A24 were analyzed as candidate T‐cell epitopes. Peptides predicted by the NetMHCpan were tested in ELISA for binding to the SLA‐1*0401 and SLA‐2*0401 major histocompatibility complex class I proteins. Four of the 10 predicted...

  6. Hybrid biomimetic scaffold composed of electrospun polycaprolactone nanofibers and self-assembled peptide amphiphile nanofibers

    OpenAIRE

    Tambralli, Ajay; Blakeney, Bryan; Anderson, Joel; Kushwaha, Meenakshi; Andukuri, Adinarayana; Dean, Derrick; Jun, Ho-Wook

    2009-01-01

    Nanofibrous electrospun poly (ε-caprolactone) (ePCL) scaffolds have inherent structural advantages, but lack of bioactivity has limited their usefulness in biomedical applications. Thus, here we report the development of a hybrid, nanostructured, extracellular matrix (ECM) mimicking scaffold by a combination of ePCL nanofibers and self-assembled peptide amphiphile (PA) nanofibers. The PAs have ECM mimicking characteristics including a cell adhesive ligand (RGDS) and matrix metalloproteinase-2...

  7. Development of a candidate influenza vaccine based on virus-like particles displaying influenza M2e peptide into the immunodominant loop region of hepatitis B core antigen: Insertion of multiple copies of M2e increases immunogenicity and protective efficiency.

    Science.gov (United States)

    Ravin, Nikolai V; Blokhina, Elena A; Kuprianov, Victor V; Stepanova, Liudmila A; Shaldjan, Aram A; Kovaleva, Anna A; Tsybalova, Liudmila M; Skryabin, Konstantin G

    2015-06-26

    The extracellular domain of the transmembrane protein M2 (M2e) of influenza A virus is a promising target for the development of "universal" vaccines against influenza. M2e is a poor immunogen by itself; however, when M2e is linked to an appropriate carrier, such as hepatitis B virus core (HBc) particles, it becomes highly immunogenic. Insertions of target peptides into the surface-exposed major immunodominant loop region (MIR) of the HBc antigen are especially immunogenic, but such insertions often affect the protein folding and formation of recombinant virus-like particles. To facilitate an appropriate conformation of the M2e insert, we introduced flexible linkers at the junction points between the insert and flanking HBc sequences. This approach allowed the construction of recombinant HBc particles carrying 1, 2 and 4 copies of M2e in the MIR region. These particles were produced in Escherichia coli and purified to homogeneity. The immune response and protective activity of hybrid HBc particles in mice correlated with the number of inserted M2e peptides: the highest immunogenicity and complete protection of mice against the lethal challenge by influenza virus was observed with particles carrying four copies of M2e. The possibility of the simultaneous presentation of M2e peptides from several important influenza strains on a single HBc particle could also facilitate the development of a broad-specificity vaccine efficient not only against influenza A strains of human origin but also for newly emerging strains of animal origin, such as the avian influenza. PMID:25937448

  8. The Internal Sequence of the Peptide-Substrate Determines Its N-Terminus Trimming by ERAP1

    OpenAIRE

    Evnouchidou, Irini; Momburg, Frank; Papakyriakou, Athanasios; Chroni, Angeliki; Leondiadis, Leondios; Chang, Shih-Chung; Stratikos, Efstratios; Goldberg, Alfred L.

    2008-01-01

    Background: Endoplasmic reticulum aminopeptidase 1 (ERAP1) trims N-terminally extended antigenic peptide precursors down to mature antigenic peptides for presentation by major histocompatibility complex (MHC) class I molecules. ERAP1 has unique properties for an aminopeptidase being able to trim peptides in vitro based on their length and the nature of their C-termini. Methodology/Principal Findings: In an effort to better understand the molecular mechanism that ERAP1 uses to trim peptides, w...

  9. Efficient generation of monoclonal antibodies against peptide in the context of MHCII using magnetic enrichment.

    Science.gov (United States)

    Spanier, Justin A; Frederick, Daniel R; Taylor, Justin J; Heffernan, James R; Kotov, Dmitri I; Martinov, Tijana; Osum, Kevin C; Ruggiero, Jenna L; Rust, Blake J; Landry, Samuel J; Jenkins, Marc K; McLachlan, James B; Fife, Brian T

    2016-01-01

    Monoclonal antibodies specific for foreign antigens, auto-antigens, allogeneic antigens and tumour neo-antigens in the context of major histocompatibility complex II (MHCII) are highly desirable as novel immunotherapeutics. However, there is no standard protocol for the efficient generation of monoclonal antibodies that recognize peptide in the context of MHCII, and only a limited number of such reagents exist. In this report, we describe an approach for the generation and screening of monoclonal antibodies specific for peptide bound to MHCII. This approach exploits the use of recombinant peptide:MHC monomers as immunogens, and subsequently relies on multimers to pre-screen and magnetically enrich the responding antigen-specific B cells before fusion and validation, thus saving significant time and reagents. Using this method, we have generated two antibodies enabling us to interrogate antigen presentation and T-cell activation. This methodology sets the standard to generate monoclonal antibodies against the peptide-MHCII complexes. PMID:27292946

  10. Oasissofas: Growing food while mimicking the forests

    OpenAIRE

    Edralin, Don Immanuel; Manuel R. Reyes; Le, K.N.; Izhar, L.; Creason, S.

    2013-01-01

    Water quality in urban areas can be enhanced by biomimicry. In this study, we mimicked the forest by growing vegetables in 6’ x 3’ beds called oasissofas copying a ‘forest ecosystem’ of: continues mulch; minimum soil disturbance – no tillage; and spatial and rotational species diversification. A highly fertilized, compacted and herbicide applied monoculture lawn at the North Carolina Agricultural and Technical State University campus was converted into an experimental site to test if an oasis...

  11. Retroperitoneal Leiomyosarcoma Mimicking Acute Appendicitis: Laparoscopic Management

    OpenAIRE

    Agresta, Ferdinando; De Simone, Paolo; Michelet, Ivan; Bedin, Natalino

    2003-01-01

    Background: Retroperitoneal leiomyosarcomas (RLMS) are a challenging clinical entity. The vast majority of patients are operated on when tumors are advanced. We report herein a case of RLMS, mimicking acute appendiceal disease and treated successfully via laparoscopy. Methods: A 37-year-old woman, para 1, was admitted to our department for right lower quadrant abdominal pain, fever, and leukocytosis. She had no changes in gastrointestinal and urologic function. A physical examination revealed...

  12. Wells Syndrome Mimicking Erythema Elevatum Diutinum

    OpenAIRE

    Rai Ranju; Sharma Vinod Kumar; Kaur Inderjeet; Kumar Bhushan

    2001-01-01

    Wells syndrome is a rare inflammatory dermatosis clinically characterised by recurrent itchy erythematous oedematous plaques with features resembling both urticaria and cellulites and histologically characterised by tissue eosinophilia, oedema and flame figures. Erythema elevatum diutinum(EED) is a chronic localized form of cutaneous vasculitis clinically consisting of symmetrical papules and nodules most often of the back of the hands. We present a case of wells syndrome mimicking EED clini...

  13. Wells Syndrome Mimicking Erythema Elevatum Diutinum

    Directory of Open Access Journals (Sweden)

    Rai Ranju

    2001-01-01

    Full Text Available Wells syndrome is a rare inflammatory dermatosis clinically characterised by recurrent itchy erythematous oedematous plaques with features resembling both urticaria and cellulites and histologically characterised by tissue eosinophilia, oedema and flame figures. Erythema elevatum diutinum(EED is a chronic localized form of cutaneous vasculitis clinically consisting of symmetrical papules and nodules most often of the back of the hands. We present a case of wells syndrome mimicking EED clinically.

  14. Acute Myopericarditis Mimicking Acute Myocardial Infarction

    OpenAIRE

    Seval İzdeş; Neriman Defne Altıntaş; Gülin Karaaslan; Recep Uygun; Abdulkadir But

    2011-01-01

    Acute coronary syndromes among young adults are relatively low when compared with older population in the intensive care unit. Electrocardiographic abnormalities mimicking acute coronary syndromes may be caused by non-coronary syndromes and the differential diagnosis requires a detailed evaluation. We are reporting a case of myopericarditis presenting with acute ST elevation and elevated cardiac enzymes simulating acute coronary syndrome. In this case report, the literature is reviewed to dis...

  15. High-altitude cerebral oedema mimicking stroke

    OpenAIRE

    Yanamandra, Uday; Gupta, Amul; Patyal, Sagarika; Varma, Prem Prakash

    2014-01-01

    High-altitude cerebral oedema (HACO) is the most fatal high-altitude illness seen by rural physicians practising in high-altitude areas. HACO presents clinically with cerebellar ataxia, features of raised intracranial pressure (ICP) and coma. Early identification is important as delay in diagnosis can be fatal. We present two cases of HACO presenting with focal deficits mimicking stroke. The first patient presented with left-sided hemiplegia associated with the rapid deterioration in the sens...

  16. A Pilocytic Astrocytoma Mimicking a Clinoidal Meningioma

    OpenAIRE

    Hong, Christopher S.; Lehman, Norman L.; Eric Sauvageau

    2014-01-01

    Pilocytic astrocytomas and meningiomas are benign, primary brain tumors that may involve the optic tract. Classically, the presence of a dural “tail” sign may differentiate a meningioma from other intracranial lesions. In this report, we describe a mass with the typical appearance of a clinoidal meningioma on magnetic resonance imaging (MRI) but postoperatively diagnosed as a pilocytic astrocytoma. This case illustrates the rare occurrence of a pilocytic astrocytoma mimicking a meningioma on ...

  17. Distinct uptake mechanisms but similar intracellular processing of two different toll-like receptor ligand-peptide conjugates in dendritic cells.

    NARCIS (Netherlands)

    Khan, S.; Bijker, M.S.; Weterings, J.J.; Tanke, H.J.; Adema, G.J.; Hall, T. van; Drijfhout, J.W.; Melief, C.J.; Overkleeft, H.S.; Marel, G.A. van der; Filippov, D.V.; Burg, S.H. van der; Ossendorp, F.

    2007-01-01

    Covalent conjugation of Toll-like receptor ligands (TLR-L) to synthetic antigenic peptides strongly improves antigen presentation in vitro and T lymphocyte priming in vivo. These molecularly well defined TLR-L-peptide conjugates, constitute an attractive vaccination modality, sharing the peptide ant

  18. Heat shock protein-peptide complex-96 (Vitespen for the treatment of cancer

    Directory of Open Access Journals (Sweden)

    Robert J. Amato

    2011-12-01

    Full Text Available Heat shock proteins (HSPs are the most abundant and ubiquitous soluble intracellular proteins. Members of the HSP family bind peptides, they include antigenic peptides generated within cells. HSPs also interact with antigen-presenting cells (APCs through CD91 and other receptors, eliciting a cascade of events that includes re-presentation of HSP-chaperoned peptides by major histocompatability complex (MHC, translocation of nuclear factorkappaB (NFkB into the nuclei, and maturation of dendritic cells (DCs. These consequences point to a key role of heat shock proteins in fundamental immunological phenomena such as activation of APCs, indirect presentation (or crosspriming of antigenic peptides, and chaperoning of peptides during antigen presentation. The properties of HSPs also allow them to be used for immunotherapy of cancers and infections in novel ways. This paper reviews the development and clinical trial progress of vitespen, an HSP peptide complex vaccine based on tumor-derived glycoprotein 96.

  19. Peptides Interfering 3A Protein Dimerization Decrease FMDV Multiplication.

    Directory of Open Access Journals (Sweden)

    Mónica González-Magaldi

    Full Text Available Nonstructural protein 3A is involved in relevant functions in foot-and-mouth disease virus (FMDV replication. FMDV 3A can form homodimers and preservation of the two hydrophobic α-helices (α1 and α2 that stabilize the dimer interface is essential for virus replication. In this work, small peptides mimicking residues involved in the dimer interface were used to interfere with dimerization and thus gain insight on its biological function. The dimer interface peptides α1, α2 and that spanning the two hydrophobic α-helices, α12, impaired in vitro dimer formation of a peptide containing the two α-helices, this effect being higher with peptide α12. To assess the effect of dimer inhibition in cultured cells, the interfering peptides were N-terminally fused to a heptaarginine (R7 sequence to favor their intracellular translocation. Thus, when fused to R7, interference peptides (100 μM were able to inhibit dimerization of transiently expressed 3A, the higher inhibitions being found with peptides α1 and α12. The 3A dimerization impairment exerted by the peptides correlated with significant, specific reductions in the viral yield recovered from peptide-treated FMDV infected cells. In this case, α2 was the only peptide producing significant reductions at concentrations lower than 100 μM. Thus, dimer interface peptides constitute a tool to understand the structure-function relationship of this viral protein and point to 3A dimerization as a potential antiviral target.

  20. Phosphorylation of threonine in the proline-rich carboxy-terminal region of simian virus 40 large T antigen.

    OpenAIRE

    Scheidtmann, K H; Kaiser, A.; Carbone, A.; Walter, G.

    1981-01-01

    The position of phosphothreonine in the predicted primary structure of simian virus 40 large T antigen was determined by different methods. After digestion of large T antigen with trypsin and subsequent two-dimensional peptide mapping, a single peptide containing phosphothreonine could be separated from the bulk of phosphoserine-containing peptides. Its amino acid composition was determined by differential labeling with various amino acids in vivo. The high yield of proline (4.5 mol) within t...

  1. Mapping of phosphorylation sites in polyomavirus large T antigen

    International Nuclear Information System (INIS)

    The phosphorylation sites of polyomavirus large T antigen from infected or transformed cells were investigated. Tryptic digestion of large T antigen from infected, 32P/sub i/-labeled cells revealed seven major phosphopeptides. Five of these were phosphorylated only at serine residues, and two were phosphorylated at serine and threonine residues. The overall ratio of phosphoserine to phosphothreonine was 6:1. The transformed cell line B4 expressed two polyomavirus-specific phosphoproteins: large T antigen, which was only weakly phosphorylated, and a truncated form of large T antigen of 34,000 molecular weight which was heavily phosphorylated. Both showed phosphorylation patterns similar to that of large T antigen from infected cells. Peptide analyses of large T antigens encoded by the deletion mutants dl8 and dl23 or of specific fragments of wild-type large T antigen indicated that the phosphorylation sites are located in an amino-terminal region upstream of residue 194. The amino acid composition of the phosphopeptides as revealed by differential labeling with various amino acids indicated that several phosphopeptides contain overlapping sequences and that all phosphorylation sites are located in four tryptic peptides derived from a region between Met71 and Arg191. Two of the potential phosphorylation sites were identified as Ser81 and Thr187. The possible role of this modification of large T antigen is discussed

  2. Mapping of phosphorylation sites in polyomavirus large T antigen

    Energy Technology Data Exchange (ETDEWEB)

    Hassauer, M.; Scheidtmann, K.H.; Walter, G.

    1986-06-01

    The phosphorylation sites of polyomavirus large T antigen from infected or transformed cells were investigated. Tryptic digestion of large T antigen from infected, /sup 32/P/sub i/-labeled cells revealed seven major phosphopeptides. Five of these were phosphorylated only at serine residues, and two were phosphorylated at serine and threonine residues. The overall ratio of phosphoserine to phosphothreonine was 6:1. The transformed cell line B4 expressed two polyomavirus-specific phosphoproteins: large T antigen, which was only weakly phosphorylated, and a truncated form of large T antigen of 34,000 molecular weight which was heavily phosphorylated. Both showed phosphorylation patterns similar to that of large T antigen from infected cells. Peptide analyses of large T antigens encoded by the deletion mutants dl8 and dl23 or of specific fragments of wild-type large T antigen indicated that the phosphorylation sites are located in an amino-terminal region upstream of residue 194. The amino acid composition of the phosphopeptides as revealed by differential labeling with various amino acids indicated that several phosphopeptides contain overlapping sequences and that all phosphorylation sites are located in four tryptic peptides derived from a region between Met71 and Arg191. Two of the potential phosphorylation sites were identified as Ser81 and Thr187. The possible role of this modification of large T antigen is discussed.

  3. Injectable polymer microspheres enhance immunogenicity of a contraceptive peptide vaccine

    OpenAIRE

    Cui, Chengji; Stevens, Vernon C.; Schwendeman, Steven P.

    2006-01-01

    Advanced contraceptive peptide vaccines suffer from the unavailability of adjuvants capable of enhancing the antibody response with acceptable safety. We sought to overcome this limitation by employing two novel poly(lactic-co-glycolic acid) (PLGA) microsphere formulations to deliver a synthetic human chorionic gonadotropin (hCG) peptide antigen co-synthesized with a T-cell epitope from tetanus toxoid, C-TT2-CTP35: surface-conjugated immunogen to induce phagocytosis; and encapsulated peptide ...

  4. Pathogen-Mimicking Polymeric Nanoparticles based on Dopamine Polymerization as Vaccines Adjuvants Induce Robust Humoral and Cellular Immune Responses.

    Science.gov (United States)

    Liu, Qi; Jia, Jilei; Yang, Tingyuan; Fan, Qingze; Wang, Lianyan; Ma, Guanghui

    2016-04-01

    Aiming to enhance the immunogenicity of subunit vaccines, a novel antigen delivery and adjuvant system based on dopamine polymerization on the surface of poly(D,L-lactic-glycolic-acid) nanoparticles (NPs) with multiple mechanisms of immunity enhancement is developed. The mussel-inspired biomimetic polydopamine (pD) not only serves as a coating to NPs but also functionalizes NP surfaces. The method is facile and mild including simple incubation of the preformed NPs in the weak alkaline dopamine solution, and incorporation of hepatitis B surface antigen and TLR9 agonist unmethylated cytosine-guanine (CpG) motif with the pD surface. The as-constructed NPs possess pathogen-mimicking manners owing to their size, shape, and surface molecular immune-activating properties given by CpG. The biocompatibility and biosafety of these pathogen-mimicking NPs are confirmed using bone marrow-derived dendritic cells. Pathogen-mimicking NPs hold great potential as vaccine delivery and adjuvant system due to their ability to: 1) enhance cytokine secretion and immune cell recruitment at the injection site; 2) significantly activate and maturate dendritic cells; 3) induce stronger humoral and cellular immune responses in vivo. Furthermore, this simple and versatile dopamine polymerization method can be applicable to endow NPs with characteristics to mimic pathogen structure and function, and manipulate NPs for the generation of efficacious vaccine adjuvants. PMID:26849717

  5. Regulation of antigen presentation by acidic pH

    OpenAIRE

    1990-01-01

    The effect of pH on functional association of peptide antigens with APC membranes was investigated by using aldehyde-fixed B cells and class II- restricted T cell hybridomas to assess antigen/MHC complex formation. The results indicated that the rate and extent of functional peptide binding was markedly increased at pH 5.0 as compared with pH 7.3. The pH dependence of binding was preserved after pretreatment of fixed APC with pH 5.0 buffer, suggesting that pH had a direct effect on the intera...

  6. Histocompatibility antigen test

    Science.gov (United States)

    ... more common in certain autoimmune diseases . For example, HLA-B27 antigen is found in many people (but not ... More Ankylosing spondylitis Autoimmune disorders Bone marrow transplant HLA-B27 antigen Kidney transplant Reactive arthritis Update Date 2/ ...

  7. Immunodiagnosis of parasitic diseases with synthetic peptides.

    Science.gov (United States)

    Noya, O; Patarroyo, M E; Guzmán, F; Alarcón de Noya, B

    2003-08-01

    Parasitic diseases remain as a major public health problem worldwide, not only based on their historically high morbidity and mortality rates, but also because risk factors associated with their transmission are increasing. Laboratory diagnosis and particularly immunodiagnosis is a basic tool for the demonstration, clinical management and control of these infections. Classically, the serological tests for the detection of antibodies or antigens are based on the use of crude and purified antigens. Synthetic peptides have opened a new field and perspectives, as the source of pure epitopes and molecules for diagnosis of malaria, Chagas' disease, leishmaniasis, schistosomiasis, hidatidosis, cysticercosis and fasciolosis based on the detection of antibodies and circulating antigens. Herein, are critically reviewed the relevant advances and applications of the synthetic peptides on immunodiagnosis of parasitic diseases. A variety of sequences, constructs (monomers, polymers, MAPs), immunological methods and samples have been used, demonstrating their diagnostic potential. However, in most parasitic infections it is necessary to use more than a single peptide in order to avoid the genetic restriction against certain epitopes, as well as to test them in well characteized groups of patients, in order to confirm their sensitivity and specificity. The concept of multidiagnosis with synthetic peptides, using a novel multi-dot blot assay is introduced. Finally, the chemical imitation of antigens, offers a tremendous posibilities in the diagnosis of parasitic infections in developing countries since this strategy is cheaper, simpler, reproducible, useful for large scale testing and in most cases, specific and sensitive. PMID:14529537

  8. Neutrophil elastase enhances antigen presentation by upregulating human leukocyte antigen class I expression on tumor cells.

    Science.gov (United States)

    Chawla, Akhil; Alatrash, Gheath; Philips, Anne V; Qiao, Na; Sukhumalchandra, Pariya; Kerros, Celine; Diaconu, Iulia; Gall, Victor; Neal, Samantha; Peters, Haley L; Clise-Dwyer, Karen; Molldrem, Jeffrey J; Mittendorf, Elizabeth A

    2016-06-01

    Neutrophil elastase (NE) is an innate immune cell-derived inflammatory mediator that we have shown increases the presentation of tumor-associated peptide antigens in breast cancer. In this study, we extend these observations to show that NE uptake has a broad effect on enhancing antigen presentation by breast cancer cells. We show that NE increases human leukocyte antigen (HLA) class I expression on the surface of breast cancer cells in a concentration and time-dependent manner. HLA class I upregulation requires internalization of enzymatically active NE. Western blots of NE-treated breast cancer cells confirm that the expression of total HLA class I as well as the antigen-processing machinery proteins TAP1, LMP2, and calnexin does not change following NE treatment. This suggests that NE does not increase the efficiency of antigen processing; rather, it mediates the upregulation of HLA class I by stabilizing and reducing membrane recycling of HLA class I molecules. Furthermore, the effects of NE extend beyond breast cancer since the uptake of NE by EBV-LCL increases the presentation of HLA class I-restricted viral peptides, as shown by their increased sensitivity to lysis by EBV-specific CD8+ T cells. Together, our results show that NE uptake increases the responsiveness of breast cancer cells to adaptive immunity by broad upregulation of membrane HLA class I and support the conclusion that the innate inflammatory mediator NE enhances tumor cell recognition and increases tumor sensitivity to the host adaptive immune response. PMID:27129972

  9. Prognostic value of increased carbohydrate antigen in patients with heart failure

    OpenAIRE

    Méndez, Ana B; Ordoñez-Llanos, Jordi; Ferrero, Andreu; Noguero, Mariana; Mir, Teresa; Mora, Josefina; Bayes-Genis, Antoni; Mirabet, Sònia; Cinca, Juan; Roig, Eulàlia

    2014-01-01

    AIM: To study the prognostic value of carbohydrate antigen 125 (CA125) and whether it adds prognostic information to N-terminal pro-brain natriuretic peptide (NT-proBNP) in stable heart failure (HF) patients.

  10. Hypertrophic Nonunion Humerus Mimicking an Enchondroma

    Directory of Open Access Journals (Sweden)

    N. K. Magu

    2014-01-01

    Full Text Available Introduction. Although fractures of humeral shaft show excellent results with conservative management, nonunion does occur. Case Report. We bring forth the case of a young male with a 1.5-year-old hypertrophic nonunion of the humerus mimicking an enchondroma. The initial X-ray images of the patient appeared to be an enchondroma, which only on further evaluation and histopathological analysis was diagnosed conclusively to be a hypertrophic nonunion. Discussion. Enchondromas are often incidentally diagnosed benign tumours. It is however not common to misdiagnose a hypertrophic nonunion to be an enchondroma. We present this case to highlight the unique diagnostic dilemma the treating team had to face.

  11. Benzalkonium Chloride Intoxication Mimicking Herpes Zoster Encephalitis

    Directory of Open Access Journals (Sweden)

    Ekrem Güler

    2011-06-01

    Full Text Available Benzalkonium chloride (BAC is a frequently used disinfectant and its most well-known side effect is contact dermatitis. In this report, two children who had vesicular dermatitis, headache, lethargy, fever and encephalopathy mimicking Herpes zoster encephalitis were presented. Their consciousness level improved on the second day. From the medical history it was understood that the mother had applied 20% BAC solution to the scalps of two children. The aim of the presentation of this report is to draw attention to the fact that BAC application to the scalp for treating pediculosis capitis may resemble the herpes encephalitis clinical picture.

  12. Actinomycosis mimicking recurrent carcinoma after Whipple's operation

    Institute of Scientific and Technical Information of China (English)

    Jun-Te Hsu; Hung-Chieh Lo; Yi-Yin Jan; Han-Ming Chen

    2005-01-01

    Actinomycosis is a rare, chronic, spreading, suppurative,granulomatous and fibrosing infection. Actinomyces are normal inhabitants of the oral cavity and gastrointestinal tract. They rarely cause disease and are seldom reported as pathogens. Herein, we reported on a 69-year-old male patient who had undergone Whipple's operation due to ampulla Vater carcinoma, and became infected with actinomycosis at the pancreaticojejunostomy, which mimicked a recurrent malignancy. He was treated with radical resection of the mass at the pancreaticojejunostomy and had an uneventful postoperative course.

  13. Pulmonary lesions mimicking pericardial effusion on ultrasonography

    International Nuclear Information System (INIS)

    Two children with right middle lobe lesions mimicking pericardial effusion on ultrasonography are presented. They were admitted with fever and chest radiographs showed atelectasis or consolidation of the middle lobe of the right lung along the right heart border. A low-echogenic layer suggesting pericardial fluid was seen on ultrasonography, but with a spatial distribution closely corresponding to the lesions seen on the chest radiographs. If the possibility that a lung lesion adjacent to the heart can simulate pericardial fluid on ultrasonography is kept in mind, the correct diagnosis should not be difficult to make. (orig.)

  14. APL1, an altered peptide ligand derived from human heat-shock protein 60, increases the frequency of Tregs and its suppressive capacity against antigen responding effector CD4 + T cells from rheumatoid arthritis patients.

    Science.gov (United States)

    Barberá, Ariana; Lorenzo, Noraylis; van Kooten, Peter; van Roon, Joel; de Jager, Wilco; Prada, Dinorah; Gómez, Jorge; Padrón, Gabriel; van Eden, Willem; Broere, Femke; Del Carmen Domínguez, María

    2016-07-01

    Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by a chronic relapsing-remitting joint inflammation. Perturbations in the balance between CD4 + T cells producing IL-17 and CD4 + CD25(high)FoxP3 + Tregs correlate with irreversible bone and cartilage destruction in RA. APL1 is an altered peptide ligand derived from a CD4+ T-cell epitope of human HSP60, an autoantigen expressed in the inflamed synovium, which increases the frequency of CD4 + CD25(high)FoxP3+ Tregs in peripheral blood mononuclear cells from RA patients. The aim of this study was to evaluate the suppressive capacity of Tregs induced by APL1 on proliferation of effector CD4+ T cells using co-culture experiments. Enhanced Treg-mediated suppression was observed in APL1-treated cultures compared with cells cultured only with media. Subsequent analyses using autologous cross-over experiments showed that the enhanced Treg suppression in APL1-treated cultures could reflect increased suppressive function of Tregs against APL1-responsive T cells. On the other hand, APL1-treatment had a significant effect reducing IL-17 levels produced by effector CD4+ T cells. Hence, this peptide has the ability to increase the frequency of Tregs and their suppressive properties whereas effector T cells produce less IL-17. Thus, we propose that APL1 therapy could help to ameliorate the pathogenic Th17/Treg balance in RA patients. PMID:27241313

  15. PREDICTION OF ANTIGENIC AND BINDING SITES OF NEUROTOXIN 23 OF SCORPION (LYCHASMUCRONACTUS SP.)

    OpenAIRE

    Bharati K Thosare; Ingale, Arun G

    2015-01-01

    Identification of antigenic and binding site of protein is highly desirable for the design of vaccines and immunodiagnostics. The present exercise deals with a prediction of antigenic as well as binding sites of neurotoxin 23 of Lychasmucronactus. This species of scorpion having diverse molecules of toxic peptide, the peptide neurotoxin 23 is 96 amino acids long of which 23 to 96 specifically code for neurotoxin. The total of 27 such different ligand binding residue were identifie...

  16. Mimicked Web Page Detection over Internet

    Directory of Open Access Journals (Sweden)

    Y. Narasimha Rao

    2014-01-01

    Full Text Available Phishing is process of steeling valuable information such as ATM pins, Credit card details over internet. Where the attacker creates mimicked web pages from the legitimate web pages to fool users. In this paper, we propose an effective anti-phishing solution, by combining image based visual similarity based approach to detect plagiarized web pages. We used effective algorithms for our detection mechanism, speeded up Robust Features (SURF algorithm in order to generate signature based on extracting stable key points from the screen shot of the web page. When a legitimate web page is registered with our system, this algorithm applied on that web page in order to generate signatures, and these signatures are stored in the database for our trained system. When there is a suspected web page, this algorithm is applied to generate both the signatures of the suspected page and is verified against our database of corresponding legitimate web pages. Our results verified that our proposed system is very effective to detect the mimicked web pages with minimal false positives

  17. Inflammatory Myofibroblastic Tumor Mimicking Apical Periodontitis.

    Science.gov (United States)

    Adachi, Makoto; Kiho, Kazuki; Sekine, Genta; Ohta, Takahisa; Matsubara, Makoto; Yoshida, Takakazu; Katsumata, Akitoshi; Tanuma, Jun-ichi; Sumitomo, Shinichiro

    2015-12-01

    Inflammatory myofibroblastic tumors (IMTs) are rare. IMTs of the head and neck occur in all age groups, from neonates to old age, with the highest incidence occurring in childhood and early adulthood. An IMT has been defined as a histologically distinctive lesion of uncertain behavior. This article describes an unusual case of IMT mimicking apical periodontitis in the mandible of a 42-year-old man. At first presentation, the patient showed spontaneous pain and percussion pain at teeth #28 to 30, which continued after initial endodontic treatment. Panoramic radiography revealed a radiolucent lesion at the site. Cone-beam computed tomographic imaging showed osteolytic lesions, suggesting an aggressive neoplasm requiring incisional biopsy. Histopathological examination indicated an IMT. The lesion was removed en bloc under general anesthesia, and the patient manifested no clinical evidence of recurrence for 24 months. Lesions of nonendodontic origin should be included in the differential diagnosis of apical periodontitis. Every available diagnostic tool should be used to confirm the diagnosis. Cone-beam computed tomographic imaging is very helpful for differential diagnosis in IMTs mimicking apical periodontitis. PMID:26602450

  18. A novel affinity purification method to isolate peptide specific antibodies

    DEFF Research Database (Denmark)

    Karlsen, Alan E; Lernmark, A; Kofod, Hans; Dyrberg, T

    1990-01-01

    affinity-purify anti-peptide antibodies. To test our system, rabbits were immunized with model peptides representing sequences of the putative rabbit growth hormone receptor and several HLA-DQ beta-chain molecules. Polystyrene plastic beads were coated with peptides. Immune serum was incubated with the...... beads and after a wash step the bound antibodies were eluted in 1 M acetic acid. The eluted material was composed predominantly of intact immunoglobulin as evidenced by the presence of heavy and light chain bands in SDS-PAGE. The eluted antibodies were peptide specific in ELISA and bound only to intact......, antigenic protein in immunoblot analyses. The sequence-specific nature of the eluted antibodies was confirmed since binding to the antigenic proteins could be displaced by the immunizing but not by unrelated peptides....

  19. Studies on human proinsulin.C-peptide radioimmunoassay method

    International Nuclear Information System (INIS)

    125I-labelled human.C-peptide was prepared by the chloramin T method, the enzymic method and the active ester method, respectively. Using respective 125I-labelled human.C-peptides in human proinsulin.C-peptide RIA, we compared the binding (B0/T %) to antibody, displacement by standard human.C-peptide, recovery, and stability. The usable 125I-labelled antigen for human proinsulin.C-peptide RIA could be prepared by the chloramin T method and the enzymic method which labelled 125I to tyrosyl human proinsulin connecting peptide, and by an active ester method which conjugates 125I-labelled active ester to human proinsulin connecting peptide. No differences among those 125I-labelled antigens were observed in displacement (B/B0 %) by standard human.C-peptide or the recovery test. In the case of constant preparation of 125I-labelled antigen for RIA, the enzymic method was the best from the viewpoint that reaction ratio is stable and the stability of B0/T % was good. (auth.)

  20. Selective transport of internalized antigens to the cytosol for MHC class I presentation in dendritic cells

    NARCIS (Netherlands)

    Rodriguez, A; Regnault, A; Kleijmeer, M; Ricciardi-Castagnoli, P; Amigorena, S

    1999-01-01

    In order for cytotoxic T cells to initiate immune responses, peptides derived from internalized antigens must be presented to the cytotoxic T cells on major histocompatibility complex (MHC) class I molecules. Here we show that dendritic cells, the only antigen-presenting cells that initiate immune r

  1. No Major Role for Insulin-Degrading Enzyme in Antigen Presentation by MHC Molecules

    OpenAIRE

    Culina, Slobodan; Mauvais, François-Xavier; Hsu, Hsiang-Ting; Burgevin, Anne; Guénette, Suzanne; Moser, Anna; van Endert, Peter

    2014-01-01

    Antigen presentation by MHC class I molecules requires degradation of epitope source proteins in the cytosol. Although the preeminent role of the proteasome is clearly established, evidence suggesting a significant role for proteasome-independent generation of class I ligands has been reported repeatedly. However, an enzyme responsible for such a role has not been identified. Recently insulin-degrading enzyme (IDE) was shown to produce an antigenic peptide derived from the tumor antigen MAGE-...

  2. Isolation and characterization of antigen-Ia complexes involved in T cell recognition

    DEFF Research Database (Denmark)

    Buus, S; Sette, A; Colon, S M;

    1986-01-01

    Using equilibrium dialysis, it has been previously demonstrated that immunogenic peptides bind specifically to the Ia molecules serving as restriction elements in the immune response to these antigens. Using gel filtration to study the formation of ovalbumin (OVA) peptide-I-Ad complexes, it is...

  3. Chitosan-based delivery systems for protein therapeutics and antigens

    NARCIS (Netherlands)

    Amidi, M.; Mastrobattista, E.; Jiskoot, W.; Hennink, W.E.

    2010-01-01

    Therapeutic peptides/proteins and protein-based antigens are chemically and structurally labile compounds, which are almost exclusively administered by parenteral injections. Recently, non-invasive mucosal routes have attracted interest for administration of these biotherapeutics. Chitosan-based del

  4. The antigen specific composition of melanoma tumor infiltrating lymphocytes?

    DEFF Research Database (Denmark)

    Hadrup, Sine Reker

    2012-01-01

    Large numbers of tumor associated antigens has been characterized, but only a minor fraction of these are recognized by tumor infiltrating lymphocytes of melanoma, although these have shown the ability to recognize tumor and provide tumor regression upon adoptive transfer. Thus the peptide...... recognition of the majority of the CD8 tumor infiltrating lymphocytes remains to be identified....

  5. Mimicking Seawater For Culturing Marine Bacteria

    DEFF Research Database (Denmark)

    Rygaard, Anita Mac; Sonnenschein, Eva; Gram, Lone;

    2015-01-01

    Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum as...... solidifying agents, and enumerated bacteria from seawater and algal exudates. We tested if culturability could be influenced by addition of quorum sensing signals (AHLs). All plates were incubated at 15°C. Bacterial counts (CFU/g) from algal exudates from brown algae were highest on media containing algal...... polymers. In general, bacteria isolated from algal exudates preferred more rich media than bacteria isolated from seawater. Overall, culturability ranged from 0.01 to 0.8% as compared to total cell count. Substitution of agar with gellan gum increased the culturability of seawater bacteria approximately...

  6. Pelvic-peritoneal tuberculosis mimicking ovarian cancer

    International Nuclear Information System (INIS)

    Pelvic-peritoneal tuberculosis is a common extrapulmonary site in young females mimicking an advanced ovarian malignancy. We present 2 cases with the classical triad of advanced-stage ovarian carcinoma-ascites, abdominopelvic masses and elevated serum CA-125 levels. Laparoscopic examination revealed peritoneal nodules which on biopsy showed granulomatous inflammation and no malignant cells. Patients were started on anti-tuberculous therapy and on follow-up their symptoms as well as CA-125 levels normalized. Medical awareness of peritoneal tuberculosis is lacking and many young women with this disease undergo unnecessary extended surgery. Diagnostic laparoscopy combined with peritoneal biopsy seems to be a sufficient and safe method to provide a definitive diagnosis for this curable infection. If left untreated, the disease may disseminate and result in significant organ dysfunctions particularly infertility. (author)

  7. High-altitude cerebral oedema mimicking stroke.

    Science.gov (United States)

    Yanamandra, Uday; Gupta, Amul; Patyal, Sagarika; Varma, Prem Prakash

    2014-01-01

    High-altitude cerebral oedema (HACO) is the most fatal high-altitude illness seen by rural physicians practising in high-altitude areas. HACO presents clinically with cerebellar ataxia, features of raised intracranial pressure (ICP) and coma. Early identification is important as delay in diagnosis can be fatal. We present two cases of HACO presenting with focal deficits mimicking stroke. The first patient presented with left-sided hemiplegia associated with the rapid deterioration in the sensorium. Neuroimaging revealed features suggestive of vasogenic oedema. The second patient presented with monoplegia of the lower limb. Neuroimaging revealed perfusion deficit in anterior cerebral artery territory. Both patients were managed with dexamethasone and they improved dramatically. Clinical picture and neuroimaging closely resembled acute ischaemic stroke in both cases. Thrombolysis in these patients would have been disastrous. Recent travel to high altitude, young age, absence of atherosclerotic risk factors and features of raised ICP concomitantly directed the diagnosis to HACO. PMID:24671373

  8. Contiguous spinal metastasis mimicking infectious spondylodiscitis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chul Min; Lee, Seung Hun [Dept. of Radiology, Hanyang University Hospital, Seoul (Korea, Republic of); Bae, Ji Yoon [Dept. of Pathology, National Police Hospital, Seoul (Korea, Republic of)

    2015-12-15

    Differential diagnosis between spinal metastasis and infectious spondylodiscitis is one of the occasional challenges in daily clinical practice. We encountered an unusual case of spinal metastasis in a 75-year-old female breast cancer patient that mimicked infectious spondylodiscitis. Magnetic resonance imaging (MRI) showed diffuse bone marrow infiltrations with paraspinal soft tissue infiltrative changes in 5 contiguous cervical vertebrae without significant compression fracture or cortical destruction. These MRI findings made it difficult to differentiate between spinal metastasis and infectious spondylodiscitis. Infectious spondylodiscitis such as tuberculous spondylodiscitis was regarded as the more appropriate diagnosis due to the continuous involvement of > 5 cervical vertebrae. The patient's clinical presentation also supported the presumptive diagnosis of infectious spondylodiscitis rather than spinal metastasis. Intravenous antibiotics were administered, but clinical symptoms worsened despite treatment. After pathologic confirmation by computed tomography-guided biopsy, we were able to confirm a final diagnosis of spinal metastasis.

  9. EVENTRATION OF LEFT HEMIDIAPHRAGM MIMICKING AS CAVITY

    Directory of Open Access Journals (Sweden)

    Kansal

    2015-10-01

    Full Text Available Eventration of diaphragm is a condition in which there is abnormal elevation of the diaphragm as a result of thinning of muscular layer. It can be congenital as well as acquired. It is more common left sided. Herniation of the abdominal contents can be there. Clinical manifestations range from asymptomatic to life threatening respiratory distress requiring mechanical ventilator support. Ultrasound provides valuable information regarding the integrity of the diaphragm. Other imaging modalities include fluoroscopy, CT and MRI that provide valuable information when diagnosis is in doubt. We are presenting a case report of 25-year-old male with eventration of left hemidiaphragm mimicking as cavity. After taking detail history, examination and proper investigations we finally reached to this diagnosis.

  10. Structural characteristics of an antigen required for its interaction with Ia and recognition by T cells

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Colon, S;

    1987-01-01

    A detailed analysis of the residues within an immunogenic peptide that endow it with the capacity to interact with Ia and to be recognized by T cells is presented. Ia interacts with only a few of the peptide residues and overall exhibits a very broad specificity. Some residues appear to interact...... both with Ia and with T cells, leading to a model in which a peptide antigen is 'sandwiched' between Ia and the T-cell receptor....

  11. Development of a candidate influenza vaccine based on virus-like particles displaying influenza M2e peptide into the immunodominant region of hepatitis B core antigen: Broad protective efficacy of particles carrying four copies of M2e.

    Science.gov (United States)

    Tsybalova, Liudmila M; Stepanova, Liudmila A; Kuprianov, Victor V; Blokhina, Elena A; Potapchuk, Marina V; Korotkov, Alexander V; Gorshkov, Andrey N; Kasyanenko, Marina A; Ravin, Nikolai V; Kiselev, Oleg I

    2015-06-26

    A long-term objective when designing influenza vaccines is to create one with broad cross-reactivity that will provide effective control over influenza, no matter which strain has caused the disease. Here we summarize the results from an investigation into the immunogenic and protective capacities inherent in variations of a recombinant protein, HBc/4M2e. This protein contains four copies of the ectodomain from the influenza virus protein M2 (M2e) fused within the immunodominant loop of the hepatitis B virus core antigen (HBc). Variations of this basic design include preparations containing M2e from the consensus human influenza virus; the M2e from the highly pathogenic avian A/H5N1 virus and a combination of two copies from human and two copies from avian influenza viruses. Intramuscular delivery in mice with preparations containing four identical copies of M2e induced high IgG titers in blood sera and bronchoalveolar lavages. It also provoked the formation of memory T-cells and antibodies were retained in the blood sera for a significant period of time post immunization. Furthermore, these preparations prevented the death of 75-100% of animals, which were challenged with lethal doses of virus. This resulted in a 1.2-3.5 log10 decrease in viral replication within the lungs. Moreover, HBc particles carrying only "human" or "avian" M2e displayed cross-reactivity in relation to human (A/H1N1, A/H2N2 and A/H3N2) or A/H5N1 and A(H1N1)pdm09 viruses, respectively; however, with the particles carrying both "human" and "avian" M2e this effect was much weaker, especially in relation to influenza virus A/H5N1. It is apparent from this work that to quickly produce vaccine for a pandemic it would be necessary to have several variations of a recombinant protein, containing four copies of M2e (each one against a group of likely influenza virus strains) with these relevant constructs housed within a comprehensive collection Escherichia coli-producers and maintained ready for use

  12. Click Chemistry in Peptide-Based Drug Design

    Directory of Open Access Journals (Sweden)

    Irwin Chaiken

    2013-08-01

    Full Text Available Click chemistry is an efficient and chemoselective synthetic method for coupling molecular fragments under mild reaction conditions. Since the advent in 2001 of methods to improve stereochemical conservation, the click chemistry approach has been broadly used to construct diverse chemotypes in both chemical and biological fields. In this review, we discuss the application of click chemistry in peptide-based drug design. We highlight how triazoles formed by click reactions have been used for mimicking peptide and disulfide bonds, building secondary structural components of peptides, linking functional groups together, and bioconjugation. The progress made in this field opens the way for synthetic approaches to convert peptides with promising functional leads into structure-minimized and more stable forms.

  13. Selection of trkB-binding peptides from a phage-displayed random peptide library

    Institute of Scientific and Technical Information of China (English)

    马仲才; 吴晓兰; 曹明媚; 潘卫; 朱分禄; 陈景山; 戚中田

    2003-01-01

    Brain-derived neurotrophic factor (BDNF) shows potential in the treatment of neurodegenerative diseases, but the therapeutic application of BDNF has been greatly limited because it is too large in molecular size to permeate blood-brain barrier. To develop low-molecular-weight BDNF-like peptides, we selected a phage-displayed random peptide library using trkB expressed on NIH 3T3 cells as target in the study. With the strategy of peptide library incubation with NIH 3T3 cells and competitive elution with 1 υg/mL of BDNF in the last round of selection, the specific phages able to bind to the natural conformation of trkB and antagonize BDNF binding to trkB were enriched effectively. Five trkB-binding peptides were obtained, in which a core sequence of CRA/TXφXXφXXC (X represents the random amino acids, φ represents T, L or I) was identified. The BDNF-like activity of these five peptides displayed on phages was not observed, though all of them antagonized the activity of BDNF in a dose-dependent manner. Similar results were obtained with the synthetic peptide of C1 clone, indicating that the 5 phage-derived peptides were trkB antagonists. These low-molecular-weight antagonists of trkB may be of potential application in the treatment of neuroblastoma and chronic pain. Meanwhile, the obtained core sequence also could be used as the base to construct the secondary phage-displayed peptide library for further development of small peptides mimicking BDNF activity.

  14. Diet mimicking fasting promotes regeneration and reduces autoimmunity and multiple sclerosis symptoms

    Science.gov (United States)

    Choi, In Young; Piccio, Laura; Childress, Patra; Bollman, Bryan; Ghosh, Arko; Brandhorst, Sebastian; Suarez, Jorge; Michalsen, Andreas; Cross, Anne H.; Morgan, Todd E.; Wei, Min; Paul, Friedemann; Bock, Markus; Longo, Valter D.

    2016-01-01

    Summary Dietary interventions have not been effective in the treatment of multiple sclerosis (MS). Here we show that periodic 3 day cycles of a fasting mimicking diet (FMD) are effective in ameliorating demyelination and symptoms in a murine experimental autoimmune encephalomyelitis (EAE) model. The FMD reduced clinical severity in all mice, and completely reversed symptoms in 20% of the animals. These improvements were associated with increased corticosterone levels and Treg cell number, reduced levels of pro-inflammatory cytokines, TH1 and TH17 cells, and antigen presenting cells (APCs). Moreover, the FMD promoted oligodendrocyte precursor cell regeneration and remyelination in axons in response to both EAE and cuprizone MS models, supporting its effects on both suppression of autoimmunity and remyelination. We also report preliminary data suggesting that a FMD or a chronic ketogenic diet are safe, feasible and potentially effective in the treatment of relapsing remitting multiple sclerosis (RRMS) patients (NCT01538355). PMID:27239035

  15. Zooming into the binding groove of HLA molecules : which positions and which substitutions change peptide binding most?

    NARCIS (Netherlands)

    van Deutekom, Hanneke W M; Kesmir, C.

    2015-01-01

    Human leukocyte antigen (HLA) genes are the most polymorphic genes in the human genome. Almost all polymorphic residues are located in the peptide-binding groove, resulting in different peptide-binding preferences. Whether a single amino acid change can alter the peptide-binding repertoire of an HLA

  16. Controlled Deposition of HAp Mimicking Tooth Enamel

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Chemical compositions and microsturcture of mature human tooth enamel were investigated by XRD , FTIR and SEM to further understand the characteristics of tooth enamel. In order to obtain apatite crystals chemically and structurally similar to those in tooth enamel, biomimetic way was employed. Selfassembled monolyers terminated with-SO3 H groups were used as deposition substrates and 1.5 SBF ( the concentrations of Ca2+ and PO43- ions 1.5 times than those in simulated body fluid ) with and without 5 ppm F- were used as soaking medium. The XRD and FTIR results showed that both the deposited fluoride-substituted hydroxyapatite( F-HAp ) crystals in 1.5 SBF with F- and hydroxyapatite ( HAp ) crystals in 1.5 SBF were carbonate-containing, mimicking human tooth enamel in chemical compositions. The SEM photos showed that needle-like F-HAp crystals bad large aspect ratios and grew in bundles, which were similar to the crystals in human tooth enamel.The results provide available information on dental restoration.

  17. Hyperdense dots mimicking microcalcifications : Mammographic findings

    International Nuclear Information System (INIS)

    To differentiate fine hyperdense dots mimicking microcalcifications from true microcalcifications on mammography. Mammograms showing hyperdense dots in ten patients (mean age, 59 years) were evaluated. Two radiologists were asked to differentiate with the naked eye the hyperdense dots seen on ten mammograms and proven microcalcifications seen on ten mammograms. Densitometry was also performed for all lesions and the contrast index was calculated. The shape and distribution of the hyperdense dots were evaluated and enquires were made regarding any history of breast disease and corresponding treatment. Biopsies were performed for two patients with hyperdense dots. Two radiologists made correct diagnoses in 19/20 cases(95%). The contrast index was 0.10-0.88 (mean 0.58) for hyperdense dots and 0.02-0.45 (mean 0.17) for true microcalcifications. The hyperdense dots were finer and homogeneously rounder than the microcalcifications. Distribution of the hyperdense dots was more superficial in subcutaneous fat (seven cases) and subareolar area (six cases). All ten patients with hyperdense dots had history of mastitis and abscesses and had been treated by open drainage (six cases) and/or folk remedy (four cases). In eight patients, herb patches had been attached. Biopsies of hyperdense dots did not show any microcalcification or evidence of malignancy. These hyperdense dots were seen mainly in older patients. Their characteristic density, shape, distribution and clinical history makes differential diagnosis from true microcalcifications easy and could reduce unnecessary diagnostic procedures such as surgical biopsy

  18. Hyperdense dots mimicking microcalcifications : Mammographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nam Hyeon; Park, Jeong Mi; Goo, Hyun Woo; Bang, Sun Woo [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    1996-12-01

    To differentiate fine hyperdense dots mimicking microcalcifications from true microcalcifications on mammography. Mammograms showing hyperdense dots in ten patients (mean age, 59 years) were evaluated. Two radiologists were asked to differentiate with the naked eye the hyperdense dots seen on ten mammograms and proven microcalcifications seen on ten mammograms. Densitometry was also performed for all lesions and the contrast index was calculated. The shape and distribution of the hyperdense dots were evaluated and enquires were made regarding any history of breast disease and corresponding treatment. Biopsies were performed for two patients with hyperdense dots. Two radiologists made correct diagnoses in 19/20 cases(95%). The contrast index was 0.10-0.88 (mean 0.58) for hyperdense dots and 0.02-0.45 (mean 0.17) for true microcalcifications. The hyperdense dots were finer and homogeneously rounder than the microcalcifications. Distribution of the hyperdense dots was more superficial in subcutaneous fat (seven cases) and subareolar area (six cases). All ten patients with hyperdense dots had history of mastitis and abscesses and had been treated by open drainage (six cases) and/or folk remedy (four cases). In eight patients, herb patches had been attached. Biopsies of hyperdense dots did not show any microcalcification or evidence of malignancy. These hyperdense dots were seen mainly in older patients. Their characteristic density, shape, distribution and clinical history makes differential diagnosis from true microcalcifications easy and could reduce unnecessary diagnostic procedures such as surgical biopsy.

  19. Non-harmful insertion of data mimicking computer network attacks

    Science.gov (United States)

    Neil, Joshua Charles; Kent, Alexander; Hash, Jr, Curtis Lee

    2016-06-21

    Non-harmful data mimicking computer network attacks may be inserted in a computer network. Anomalous real network connections may be generated between a plurality of computing systems in the network. Data mimicking an attack may also be generated. The generated data may be transmitted between the plurality of computing systems using the real network connections and measured to determine whether an attack is detected.

  20. Mimicking Stem Cell Niches to Increase Stem Cell Expansion

    OpenAIRE

    Dellatore, Shara M.; Garcia, A. Sofia; Miller, William M.

    2008-01-01

    Niches regulate lineage-specific stem cell self-renewal vs. differentiation in vivo and are comprised of supportive cells and extracellular matrix components arranged in a 3-dimensional topography of controlled stiffness in the presence of oxygen and growth factor gradients. Mimicking stem cell niches in a defined manner will facilitate production of the large numbers of stem cells needed to realize the promise of regenerative medicine and gene therapy. Progress has been made in mimicking com...

  1. Gallbladder metastasis from renal cell carcinoma mimicking acute cholecystitis

    Directory of Open Access Journals (Sweden)

    Sand M

    2009-02-01

    Full Text Available Abstract Renal cell carcinoma constitutes about 3% of adult malignancies. It has a high metastatic potential associated with synchronous or metachronous metastatic disease. Further, it is known to metastasize mainly to the lung, bone, brain, liver, or adrenal glands. In very rare cases it can metastasize to the gallbladder mimicking acute cholecystitis on clinical exam. In this case we present a patient who developed a gallbladder metastasis five years after a renal cell carcinoma mimicking acute cholecystitis.

  2. Immunodiagnosis of Canine Visceral Leishmaniasis Using Mimotope Peptides Selected from Phage Displayed Combinatorial Libraries

    Science.gov (United States)

    Toledo-Machado, Christina Monerat; Machado de Avila, Ricardo Andrez; NGuyen, Christophe; Granier, Claude; Bueno, Lilian Lacerda; Carneiro, Claudia Martins; Menezes-Souza, Daniel; Carneiro, Rubens Antonio; Chávez-Olórtegui, Carlos; Fujiwara, Ricardo Toshio

    2015-01-01

    ELISA and RIFI are currently used for serodiagnosis of canine visceral leishmaniasis (CVL). The accuracy of these tests is controversial in endemic areas where canine infections by Trypanosoma cruzi may occur. We evaluated the usefulness of synthetic peptides that were selected through phage display technique in the serodiagnosis of CVL. Peptides were chosen based on their ability to bind to IgGs purified from infected dogs pooled sera. We selected three phage clones that reacted only with those IgGs. Peptides were synthesized, polymerized with glutaraldehyde, and used as antigens in ELISA assays. Each individual peptide or a mix of them was reactive with infected dogs serum. The assay was highly sensitive and specific when compared to soluble Leishmania antigen that showed cross-reactivity with anti-T. cruzi IgGs. Our results demonstrate that phage display technique is useful for selection of peptides that may represent valuable synthetic antigens for an improved serodiagnosis of CVL. PMID:25710003

  3. Low dose antigen promotes induction of FOXP3 in human CD4+ T cells

    OpenAIRE

    Long, S. Alice; Rieck, Mary; Tatum, Megan; Bollyky, Paul L.; Wu, Rebecca P.; Muller, Isabelle; Ho, Jhon-Chun; Shilling, Heather G.; Buckner, Jane H.

    2011-01-01

    Low antigen dose promotes induction and persistence of Treg in mice, yet few studies have addressed the role of antigen dose in the induction of adaptive CD4+FOXP3+ Treg in humans. To this end, we examined the level of FOXP3 expression in human CD4+CD25− T cells upon activation with autologous antigen presenting cells and varying doses of peptide. Antigen specific T cells expressing FOXP3 were identified by flow cytometry using MHC Class II tetramer (Tmr). We found an inverse relationship bet...

  4. Prediction of MHC binding peptides and epitopes from alfalfa mosaic virus.

    Science.gov (United States)

    Gomase, Virendra S; Kale, Karbhari V; Chikhale, Nandkishor J; Changbhale, Smruti S

    2007-08-01

    Peptide fragments from alfalfa mosaic virus involved multiple antigenic components directing and empowering the immune system to protect the host from infection. MHC molecules are cell surface proteins, which take active part in host immune reactions and involvement of MHC class-I & II in response to almost all antigens. Coat protein of alfalfa mosaic virus contains 221 aa residues. Analysis found five MHC ligands in coat protein as 64-LSSFNGLGV-72; 86- RILEEDLIY-94; 96-MVFSITPSY-104; 100- ITPSYAGTF-108; 110- LTDDVTTED-118; having rescaled binding affinity and c-terminal cleavage affinity more than 0.5. The predicted binding affinity is normalized by the 1% fractil. The MHC peptide binding is predicted using neural networks trained on c-terminals of known epitopes. In analysis predicted MHC/peptide binding is a log transformed value related to the IC50 values in nM units. Total numbers of peptides found are 213. Predicted MHC binding regions act like red flags for antigen specific and generate immune response against the parent antigen. So a small fragment of antigen can induce immune response against whole antigen. This theme is implemented in designing subunit and synthetic peptide vaccines. The sequence analysis method allows potential drug targets to identify active sites against plant diseases. The method integrates prediction of peptide MHC class I binding; proteosomal c-terminal cleavage and TAP transport efficiency. PMID:17691913

  5. Peptide specific expansion of CD8(+) T cells by recombinant plate bound MHC/peptide complexes

    DEFF Research Database (Denmark)

    Schmidt, Esben G W; Buus, Soren; Thorn, Mette;

    2009-01-01

    in vitro T cell stimulation was investigated. By use of an antigenic peptide derived from the cytomegalovirus (CMVp) we tested the stimulatory efficacy of recombinant plate bound MHC molecules (PB-MHC), being immobilized in culture plates. A single stimulation of non-adherent peripheral blood...... effect of new stimulatory cocktails, e.g. cytokines and co-stimulatory molecules, by use of the present rapid and easy-to-use method of expanding peptide specific T cells.......Development of methods for efficient in vitro stimulation and expansion of peptide specific CD8(+) T cells is compelling not only with respect to adoptive T cell therapy but also regarding analysis of T cell responses and search for new immunogenic peptides. In the present study, a new approach to...

  6. Programmed Nanomaterial Assemblies in Large Scales: Applications of Synthetic and Genetically- Engineered Peptides to Bridge Nano-Assemblies and Macro-Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Hiroshi

    2014-09-09

    Work is reported in these areas: Large-scale & reconfigurable 3D structures of precise nanoparticle assemblies in self-assembled collagen peptide grids; Binary QD-Au NP 3D superlattices assembled with collagen-like peptides and energy transfer between QD and Au NP in 3D peptide frameworks; Catalytic peptides discovered by new hydrogel-based combinatorial phage display approach and their enzyme-mimicking 2D assembly; New autonomous motors of metal-organic frameworks (MOFs) powered by reorganization of self-assembled peptides at interfaces; Biomimetic assembly of proteins into microcapsules on oil-in-water droplets with structural reinforcement via biomolecular recognition-based cross-linking of surface peptides; and Biomimetic fabrication of strong freestanding genetically-engineered collagen peptide films reinforced by quantum dot joints. We gained the broad knowledge about biomimetic material assembly from nanoscale to microscale ranges by coassembling peptides and NPs via biomolecular recognition. We discovered: Genetically-engineered collagen-like peptides can be self-assembled with Au NPs to generate 3D superlattices in large volumes (> μm{sup 3}); The assembly of the 3D peptide-Au NP superstructures is dynamic and the interparticle distance changes with assembly time as the reconfiguration of structure is triggered by pH change; QDs/NPs can be assembled with the peptide frameworks to generate 3D superlattices and these QDs/NPs can be electronically coupled for the efficient energy transfer; The controlled assembly of catalytic peptides mimicking the catalytic pocket of enzymes can catalyze chemical reactions with high selectivity; and, For the bacteria-mimicking swimmer fabrication, peptide-MOF superlattices can power translational and propellant motions by the reconfiguration of peptide assembly at the MOF-liquid interface.

  7. A Novel Colorimetric Immunoassay Utilizing the Peroxidase Mimicking Activity of Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hyun Gyu Park

    2013-05-01

    Full Text Available A simple colorimetric immunoassay system, based on the peroxidase mimicking activity of Fe3O4 magnetic nanoparticles (MNPs, has been developed to detect clinically important antigenic molecules. MNPs with ca. 10 nm in diameter were synthesized and conjugated with specific antibodies against target molecules, such as rotaviruses and breast cancer cells. Conjugation of the MNPs with antibodies (MNP-Abs enabled specific recognition of the corresponding target antigenic molecules through the generation of color signals arising from the colorimetric reaction between the selected peroxidase substrate, 3,3',5,5'-tetramethylbenzidine (TMB and H2O2. Based on the MNP-promoted colorimetric reaction, the target molecules were detected and quantified by measuring absorbance intensities corresponding to the oxidized form of TMB. Owing to the higher stabilities and economic feasibilities of MNPs as compared to horseradish peroxidase (HRP, the new colorimetric system employing MNP-Abs has the potential of serving as a potent immunoassay that should substitute for conventional HRP-based immunoassays. The strategy employed to develop the new methodology has the potential of being extended to the construction of simple diagnostic systems for a variety of biomolecules related to human cancers and infectious diseases, particularly in the realm of point-of-care applications.

  8. The case of malignancy mimicking legionella pneumonia

    Directory of Open Access Journals (Sweden)

    Ali Karakuş

    2013-09-01

    Full Text Available Legionella pneumophila is a bacterium, which can grow inwater pipe networks and climate systems. Contaminationoccurs by aspiration of infected water or aerosol inhalation.It is usually presented with fever, bradycardia, andchange in mental status, hyponatremia, elevation of liverenzymes and deterioration of renal function. The definitediagnosis is established by detection of the antigens andcultivating in the culture medium. Also, malign lung tumorscan encounter with the same clinical findings, so lungcancer should be remembered in differential diagnosis.The patient hospitalized for the Legionella pneumophiladue to the physical examination and laboratory findingsduring the first evaluation in the emergency department.However, further examinations pointed to the cancer. Weaimed to emphasize the probability of malignant tumorsin terms of hyponatremia, increase in the liver enzymes,and failure in the renal functions, which were usually experiencedin emergency unit. J Clin Exp Invest 2013; 4(3: 390-392Key words: Legionella pneumophila, pneumonia, lung malignancy

  9. A Study of Molecular Mimicry and Immunological Cross-reactivity between Hepatitis B Surface Antigen and Myelin Mimics

    Directory of Open Access Journals (Sweden)

    Diego Vergani

    2005-01-01

    Full Text Available On the basis of the reported association between hepatitis B vaccination (HBvacc and autoimmune demyelinating complications such as multiple sclerosis (MS, we have looked for aminoacid similarities between the small hepatitis B virus surface antigen (SHBsAg, and the MS-autoantigens myelin basic protein (MBP and myelin oligodendrocyte glycoprotein (MOG that could serve as targets of immunological cross-reactivity. Twenty-mer peptides spanning 4 SHBsAg/MOG and 1 SHBsAg/MBP mimicking pairs, were constructed and tested by ELISA as targets of cross-reactive responses. A total of 147 samples from 58 adults were collected before HBvacc (58/58, and post-HBvacc (48/58 before the second and 41/58 before the third boost. Eighty-seven sera from anti-SHBsAg antibody negative patients with various diseases were tested as pathological controls. Reactivity to at least one of the SHBsAg peptides was found in 8 (14% pre-HBvacc subjects; amongst the remaining 50, reactivity to at least one of the SHBsAg peptides appeared in 47 (94% post-HBvacc. Reactivity to at least one of the MOG mimics was present in 4 (8% pre-HBvacc and in 30 (60% post-HBvacc (p < 0.001. Overall 30/50 (60% vaccinees had SHBsAg/MOG double reactivity on at least one occasion compared to none before-vaccination and in 2 (2% of the pathological controls (p < 0.001 for both. SHBsAg/MOG double reactivity was cross-reactive as confirmed by inhibition studies. At 6 months post-vaccination, 3 of the 4 anti-MOG reactive cases before vaccination and 7 of the 24 (29% of the anti-MOG reactive cases at 3 months post-vaccination had lost their reactivity to MOG5-24. There was no reactivity to the SHBsAg/MBP mimics. None of the vaccinees reported symptoms of demyelinating disorders. In view of the observed SHBsAg/MOG cross-reactivity, the vaccine's possible role as an immunomodulator of viral/self cross-reactivity must be further investigated.

  10. Evaluation of the effect of expansion and shear stress on a self-assembled endothelium mimicking nanomatrix coating for drug eluting stents in vitro and in vivo

    International Nuclear Information System (INIS)

    Coating stability is increasingly recognized as a concern impacting the long-term effectiveness of drug eluting stents (DES). In particular, unstable coatings have been brought into focus by a recently published report (Denardo et al 2012 J. Am. Med. Assoc. 307 2148–50). Towards the goal of overcoming current challenges of DES performance, we have developed an endothelium mimicking nanomatrix coating composed of peptide amphiphiles that promote endothelialization, but limit smooth muscle cell proliferation and platelet adhesion. Here, we report a novel water evaporation based method to uniformly coat the endothelium mimicking nanomatrix onto stents using a rotational coating technique, thereby eliminating residual chemicals and organic solvents, and allowing easy application to even bioabsorbable stents. Furthermore, the stability of the endothelium mimicking nanomatrix was analyzed after force experienced during expansion and shear stress under simulated physiological conditions. Results demonstrate uniformity and structural integrity of the nanomatrix coating. Preliminary animal studies in a rabbit model showed no flaking or peeling, and limited neointimal formation or restenosis. Therefore, it has the potential to improve the clinical performance of DES by providing multifunctional endothelium mimicking characteristics with structural integrity on stent surfaces. (paper)

  11. Immunogenicity of the hTERT540-548 peptide in cancer

    DEFF Research Database (Denmark)

    Wenandy, L.; Sorensen, R.B.; Sengelov, L.;

    2008-01-01

    Human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase, is an attractive target antigen for cancer immunotherapy due to its expression in the vast majority of human tumors. The first immunogenic peptide described from hTERT was the HLA-A2-restricted peptide hTERT540...

  12. Design and Characterization of a Peptide Mimotope of the HIV-1 gp120 Bridging Sheet

    Science.gov (United States)

    Schiavone, Marco; Fiume, Giuseppe; Caivano, Antonella; de Laurentiis, Annamaria; Falcone, Cristina; Masci, Francesca Fasanella; Iaccino, Enrico; Mimmi, Selena; Palmieri, Camillo; Pisano, Antonio; Pontoriero, Marilena; Rossi, Annalisa; Scialdone, Annarita; Vecchio, Eleonora; Andreozzi, Concetta; Trovato, Maria; Rafay, Jan; Ferko, Boris; Montefiori, David; Lombardi, Angela; Morsica, Giulia; Poli, Guido; Quinto, Ileana; Pavone, Vincenzo; de Berardinis, Piergiuseppe; Scala, Giuseppe

    2012-01-01

    The Bridging Sheet domain of HIV-1 gp120 is highly conserved among the HIV-1 strains and allows HIV-1 binding to host cells via the HIV-1 coreceptors. Further, the bridging sheet domain is a major target to neutralize HIV-1 infection. We rationally designed four linear peptide epitopes that mimic the three-dimensional structure of bridging sheet by using molecular modeling. Chemically synthesized peptides BS3 and BS4 showed a fair degree of antigenicity when tested in ELISA with IgG purified from HIV+ broadly neutralizing sera while the production of synthetic peptides BS1 and BS2 failed due to their high degree of hydrophobicity. To overcome this limitation, we linked all four BS peptides to the COOH-terminus of GST protein to test both their antigenicity and immunogenicity. Only the BS1 peptide showed good antigenicity; however, no envelope specific antibodies were elicited upon mice immunization. Therefore we performed further analyses by linking BS1 peptide to the NH2-terminus of the E2 scaffold from the Geobacillus Stearothermophylus PDH complex. The E2-BS1 fusion peptide showed good antigenic results, however only one immunized rabbit elicited good antibody titers towards both the monomeric and oligomeric viral envelope glycoprotein (Env). In addition, moderate neutralizing antibodies response was elicited against two HIV-1 clade B and one clade C primary isolates. These preliminary data validate the peptide mimotope approach as a promising tool to obtain an effective HIV-1 vaccine. PMID:22754323

  13. Construction and Functional Test of HLA-A*2402-Peptide Tetramer

    Institute of Scientific and Technical Information of China (English)

    XiaolingLu; XiongwenWu; ZhihuiLiang; XiufangWeng; QingLi; FeiliGong

    2005-01-01

    HLA-A*2402 is one of the most frequent HLA-A allele in Asian population. To construct HLA-A*2402-peptide tetramers, the transmembrane and intracellular segments of HLA-A*2402 cDNA were replaced with BSP sequence to form a fusion gene of sHLA-A*2402-BSP. The sHLA-A*2402-BSP fusion protein and β2m were high-level expressed as insoluble aggregates in E.coli, and refolded to form an HLA-A*2402-peptide monomeric complex by dilution method in the presence of an antigenic peptide. The HLA-A*2402-peptide monomeric complex was biotinated and tetramized to prepare HLA-A*2402-peptide tetramer. Then using the HLA-A*2402-peptide tetramers to detect antigen-specific cytotoxic T lymphocyte (CTL) induced by artificial antigen presenting cell (aAPC) in vitro. The results showed that HLA-A*2402-peptide tetramer was prepared correctly, and functional in detecting antigen-specific CTL in vitro, HLA-A*2402-peptide monomeric and its multimeric complexes are expected to provide a powerful tool for studying mechanisms of immune-related diseases in Asian populations .Cellular & Molecular Immunology. 2005;2(2): 145-149.

  14. Targeted Protein Degradation by Salmonella under Phagosome-Mimicking Culture Conditions Investigated Using Comparative Peptidomics

    Energy Technology Data Exchange (ETDEWEB)

    Manes, Nathan P.; Gustin, Jean K.; Rue, Joanne; Mottaz, Heather M.; Purvine, Samuel O.; Norbeck, Angela D.; Monroe, Matthew E.; Zimmer, Jennifer S.; Metz, Thomas O.; Adkins, Joshua N.; Smith, Richard D.; Heffron, Fred

    2007-04-01

    The pathogen Salmonella enterica is known to cause both food poisoning and typhoid fever. Due to the emergence of antibiotic-resistant isolates and the threat of bioterrorism (e.g., contamination of the food supply), there is a growing need to study this bacterium. In this investigation, comparative peptidomics was used to study Salmonella enterica serovar Typhimurium cultured in either a rich medium or in an acidic, low magnesium, and minimal nutrient medium designed to roughly mimic the macrophage phagosomal compartment (within which Salmonella are known to survive). Native peptides from cleared cell lysates were enriched by using isopropanol extraction and analyzed by using both LC-MS/MS and LC-FTICR-MS. We identified 5,163 distinct peptides originating from 682 proteins and the data clearly indicated that compared to cells cultured in the rich medium, Salmonella cultured in the phagosome-mimicking medium had dramatically higher abundances of a wide variety of protein degradation products, especially from ribosomal proteins. Salmonella from the same cultures were also analyzed by using bottom-up proteomics, and when the peptidomic and proteomic data were analyzed together, two clusters of proteins targeted for proteolysis were tentatively identified. Possible roles of targeted proteolysis by phagocytosed Salmonella are discussed.

  15. Solid-phase peptide quantitation assay using labeled monoclonal antibody and glutaraldehyde fixation

    International Nuclear Information System (INIS)

    A solid-phase radioimmunoassay utilizing iodinated peptide-specific monoclonal antibody as a detection system instead of labeled peptide has been developed. Regional specific monoclonal antibodies to either gastrin-releasing peptide or gastrin were used as models to validate the general application of our modified assay. Conditions for radioactive labeling of the monoclonal antibody were determined to minimize oxidant damage, which compromises the sensitivity of other reported peptide quantitation assays. Pretreatment of 96-well polyvinyl chloride test plates with a 5% glutaraldehyde solution resulted in consistent retention of sufficient target peptide on the solid-phase matrix to allow precise quantitation. This quantitative method is completed within 1 h of peptide solid phasing. Pretreatment of assay plates with glutaraldehyde increased binding of target peptide and maximized antibody binding by optimizing antigen presentation. The hypothesis that glutaraldehyde affects both peptide binding to the plate and orientation of the peptide was confirmed by analysis of several peptide analogs. These studies indicate that peptide binding was mediated through a free amino group leaving the carboxy-terminal portion of the target peptide accessible for antibody binding. It was observed that the length of the peptide also affects the amount of monoclonal antibody that will bind. Under the optimal conditions, results from quantitation of gastrin-releasing peptide in relevant samples agree well with those from previously reported techniques. Thus, we report here a modified microplate assay which may be generally applied for the rapid and sensitive quantitation of peptide hormones

  16. Immunogenicity of a synthetic HBsAg peptide: enhancement by conjugation to a fatty acid carrier.

    Science.gov (United States)

    Hopp, T P

    1984-01-01

    Effective immunization with short polypeptide antigens has typically only been possible when the peptide is conjugated to a large carrier substance, usually a protein. Such immunizations suffer from difficulties in producing conjugates of reliable composition, and from unwanted anti-carrier immune responses. When a chemically synthesized peptide, bearing hepatitis B virus a-determinant specificity, was conjugated to a dipalmityl-lysine moiety, a significant improvement in anti-hepatitis B surface antigen response was obtained, in comparison to the corresponding peptide-keyhole limpet hemocyanin conjugate. Dipalmityl lysyl peptide conjugates are readily made by standard Merrifield synthesis procedures, and are relatively free of byproducts that might cause unwanted immune responses. Gel filtration experiments suggest that the conjugates form large aggregates, possibly micelles, which may play a significant role in the enhancement of the anti-peptide response. These properties suggest that fatty acid conjugation may be a useful procedure for producing chemically synthesized peptide vaccines. PMID:6423970

  17. Human peptide transporters

    DEFF Research Database (Denmark)

    Nielsen, Carsten Uhd; Brodin, Birger; Jørgensen, Flemming Steen;

    2002-01-01

    Peptide transporters are epithelial solute carriers. Their functional role has been characterised in the small intestine and proximal tubules, where they are involved in absorption of dietary peptides and peptide reabsorption, respectively. Currently, two peptide transporters, PepT1 and PepT2, wh...

  18. Endoplasmic reticulum aminopeptidase 1 (ERAP1) trims MHC class I-presented peptides in vivo and plays an important role in immunodominance

    OpenAIRE

    Ian A York; Brehm, Michael A.; Zendzian, Sophia; Towne, Charles F.; Rock, Kenneth L.

    2006-01-01

    CD8+ T cells respond to short peptides bound to MHC class I molecules. Although most antigenic proteins contain many sequences that could bind to MHC class I, few of these peptides actually stimulate CD8+ T cell responses. Moreover, the T cell responses that are generated often follow a very reproducible hierarchy to different peptides for reasons that are poorly understood. We find that the loss of a single enzyme, endoplasmic reticulum aminopeptidase 1 (ERAP1), in the antigen-processing pat...

  19. The Specificity of Trimming of MHC Class I-Presented Peptides in the Endoplasmic Reticulum1

    OpenAIRE

    Hearn, Arron; Ian A York; Rock, Kenneth L.

    2009-01-01

    Aminopeptidases in the endoplasmic reticulum (ER) can cleave antigenic peptides and in so doing either create or destroy MHC class I-presented epitopes. However the specificity of this trimming process overall and of the major ER aminopeptidase ERAP1 in particular is not well understood. This issue is important because peptide trimming influences the magnitude and specificity of CD8 T cell responses. By systematically varying the N-terminal flanking sequences of peptides in a cell free bioche...

  20. Injectable polymer microspheres enhance immunogenicity of a contraceptive peptide vaccine.

    Science.gov (United States)

    Cui, Chengji; Stevens, Vernon C; Schwendeman, Steven P

    2007-01-01

    Advanced contraceptive peptide vaccines suffer from the unavailability of adjuvants capable of enhancing the antibody response with acceptable safety. We sought to overcome this limitation by employing two novel poly(lactic-co-glycolic acid) (PLGA) microsphere formulations to deliver a synthetic human chorionic gonadotropin (hCG) peptide antigen co-synthesized with a T-cell epitope from tetanus toxoid (TT), C-TT2-CTP35: surface-conjugated immunogen to induce phagocytosis; and encapsulated peptide to provide a depot effect, with MgCO(3) co-encapsulated in the polymer to neutralize acidity from the biodegrading PLGA polyester. A single immunization of encapsulated peptide in rabbits elicited a stronger antibody response with equivalent duration relative to a positive control--three injections of the peptide administered in a squalene-based water-in-oil emulsion. Surface-conjugated peptide was less effective but enhanced antibody levels at 1/5 the dose, relative to soluble antigen. Most remarkable and unexpected was the finding that co-encapsulation of base was essential to attain the powerful adjuvant effect of the PLGA-MgCO(3) system, as the MgCO(3)-free microspheres were completely ineffective. A promising contraceptive hCG peptide vaccine with acceptable side effects (i.e., local tissue reactions) was achieved by minimizing PLGA and MgCO(3) doses, without significantly affecting antibody response. PMID:16996662

  1. Describing the Peptide Binding Specificity of HLA-C

    DEFF Research Database (Denmark)

    Rasmussen, Michael; Harndahl, Mikkel Nors; Nielsen, Morten;

    for 5 HLA-C molecules and for all, but one, molecule we find a high frequency of binders, >70%, among these peptides. To extend the examined peptide space, we use bioinformatic prediction tools to search for additional binders. Finally, we update our prediction tool, NetMHCpan, with the HLA-C affinity......Human leukocyte antigen (HLA) presents peptides to T-cells for immune scrutiny. Whereas HLA-A and -B have been described in great detail, HLA-C has received much less attention. Here, to increase the coverage of HLA-C and the accuracy of the corresponding tools, we have generated HLA-C molecules......; peptide-binding assays, data and predictors; and tetramers; representing the most prevalent HLA-C molecules. We have combined positional scanning combinatorial peptide library (PSCPL) with a homogenous high-throughput dissociation assay and generated specificity matrices for 11 different HLA-C molecules...

  2. Antigen-activated dendritic cells ameliorate influenza A infections

    OpenAIRE

    Boonnak, Kobporn; Vogel, Leatrice; Orandle, Marlene; Zimmerman, Daniel; Talor, Eyal; Subbarao, Kanta

    2013-01-01

    Influenza A viruses cause significant morbidity and mortality worldwide. There is a need for alternative or adjunct therapies, as resistance to currently used antiviral drugs is emerging rapidly. We tested ligand epitope antigen presentation system (LEAPS) technology as a new immune-based treatment for influenza virus infection in a mouse model. Influenza-J-LEAPS peptides were synthesized by conjugating the binding ligand derived from the β2-microglobulin chain of the human MHC class I molecu...

  3. Munchausen syndrome mimicking psychiatric disease with concomitant genuine physical illness

    Science.gov (United States)

    Almeida, Jaime; da Silva, Joaquim Alves; Xavier, Miguel; Gusmão, Ricardo

    2010-01-01

    Munchausen syndrome is a disorder in which patients intentionally produce symptoms mimicking physical or psychiatric illnesses with the aim to assume the sick role and to gain medical attention. Once a patient receives a Munchausen syndrome diagnosis every complaint made thence tends to be regarded with scepticism by clinical staff. However, it is possible that a bona fide illness, which might be disregarded, may coexist in these patients. We report a case of MS mimicking psychiatric disease with concomitant genuine acute physical illness. Despite the initial doubts about the veracity of the latter, due to its prompt recognition, treatment was successful. PMID:22798096

  4. Chitosan-Poly (I:C-PADRE Based Nanoparticles as Delivery Vehicles for Synthetic Peptide Vaccines

    Directory of Open Access Journals (Sweden)

    Jorge F. Correia-Pinto

    2015-09-01

    Full Text Available The safety and precision of peptide antigens has prompted the search for adjuvants capable of increasing the immune response against these intrinsically poorly immunogenic antigens. The integration of both immunostimulants and peptide antigens within nanometric delivery systems for their co-delivery to immune cells is a promising vaccination strategy. With this in mind, the potential synergistic effect of the immunostimulant poly (I:C (pIC and a T-Helper peptide (PADRE, integrated into a chitosan (CS based nanostructure, was explored. The value of this nanostructured combination of materials was assessed for a peptide antigen (1338aa derived from the HPV-16 L2 protein. These nanoparticles, produced by ionic gelation technique, exhibited a nanometric size (<300 nm, a high positive surface charge (>40 mV and high pIC association efficiency (>96%. They also showed capacity for the association of both the 1338aa and PADRE peptides. The influence of the presence of pIC and PADRE in the nanocomposition, as well as that of the peptide presentation form (encapsulated versus surface adsorbed on the antibody induction was evaluated in a preliminary in vivo study. The data obtained highlights the possibility to engineer nanoparticles through the rational combination of a number of adjuvant molecules together with the antigen.

  5. Design, automated synthesis and immunological evaluation of NOD2-ligand–antigen conjugates

    Directory of Open Access Journals (Sweden)

    Marian M. J. H. P. Willems

    2014-06-01

    Full Text Available The covalent attachment of an innate immune system stimulating agent to an antigen can provide active vaccine modalities capable of eliciting a potent immune response against the incorporated antigen. Here we describe the design, automated synthesis and immunological evaluation of a set of four muramyl dipeptide–peptide antigen conjugates. Muramyl dipeptide (MDP represents a well-known ligand for the intracellular NOD2 receptor and our study shows that covalently linking an MDP-moiety to an antigenic peptide can lead to a construct that is capable of stimulating the NOD2 receptor if the ligand is attached at the anomeric center of the muramic acid. The constructs can be processed by dendritic cells (DCs and the conjugation does not adversely affect the presentation of the incorporated SIINFEKL epitope on MHC-I molecules. However, stimulation of the NOD2 receptor in DCs was not sufficient to provide a strong immunostimulatory signal.

  6. TUMOR SELECTIVE DRUG DELIVERY BY NEUROTENSIN BRANCHED PEPTIDES

    Directory of Open Access Journals (Sweden)

    L. Depau

    2012-05-01

    Full Text Available Detection of new tumor-selective targets, which allow either cancer cell tracing or therapy, is a crucial issue in cancer research. Membrane receptors for endogenous peptides such as Neurotensin are over-expressed in many human cancers and could therefore be used as tumor-specific antigen, while peptide ligands might act as targeting agents. The development of peptides as drug has always been limited by their short half-life, due to degradation by peptidases and proteases. Chemical modification, which can stabilize the molecules, may modify peptide affinity or specificity. More- over, coupling of peptides to effector units for imaging or therapy, may interfere with biological activity. We demonstrated that peptide sequences, when synthesized in an oligo-branched form, be- come resistant to proteolysis and thank to their multimericity are more efficient than correspon- ding monomers in binding cellular antigens1. Moreover, the branched core allow coupling of effector units without affecting peptide activity. Drug-armed tetra-branched neurotensin peptides (NT4 were synthesized with different conjugation methods, resulting either in uncleavable adducts or drug-releasing molecules2-4. Recently we de- veloped DOPC liposomes filled with the cytotoxic drug Doxorubicin (Doxo and functionalized with NT4. Armed DOPC liposomes showed a clear advantage with respect to nude liposomes in drug internalization and their cytotoxicity is fourfold increased with respect to the same nude lipo- somes. Conjugation to NT4 switches drug internalization to a peptide-receptor mediated mechanism, which greatly increases drug selectivity and also might allow by-passing drug cell resistance. In vitro and in vivo results indicated that branched NT peptides are valuable tools for tumor selective targeting.

  7. Development of recombinant antigen array for simultaneous detection of viral antibodies.

    Directory of Open Access Journals (Sweden)

    Yi Liu

    Full Text Available Protein microarrays have been developed to study antibody reactivity against a large number of antigens, demonstrating extensive perspective for clinical application. We developed a viral antigen array by spotting four recombinant antigens and synthetic peptide, including glycoprotein G of herpes simplex virus (HSV type 1 and 2, phosphoprotein 150 of cytomegalovirus (CMV, Rubella virus (RV core plus glycoprotein E1 and E2 as well as a E1 peptide with the optimal concentrations on activated glass slides to simultaneously detect IgG and IgM against HSV1, HSV2, CMV and RV in clinical specimens of sera and cerebrospinal fluids (CSFs. The positive reference sera were initially used to measure the sensitivity and specificity of the array with the optimal conditions. Then clinical specimens of 144 sera and 93 CSFs were tested for IgG and IgM antibodies directed against HSV1, HSV2, CMV and RV by the antigen array. Specificity of the antigen array for viral antibodies detection was satisfying compared to commercial ELISA kits but sensitivity of the array varied relying on quality and antigenic epitopes of the spotting antigens. In short, the recombinant antigen array has potential to simultaneous detect multiple viral antibodies using minute amount (3 µl of samples, which holds the particularly advantage to detect viral antibodies in clinical CSFs being suspicious of neonatal meningitis and encephalitis.

  8. 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, Morten Hanefeld; Borre, M; Björkman, A; Marbiah, N T; Dolopaye, E; Hanson, A P; Jepsen, S

    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...

  9. Yeast retrotransposon particles as antigen delivery systems.

    Science.gov (United States)

    Kingsman, A J; Burns, N R; Layton, G T; Adams, S E

    1995-05-31

    The development of technologies to produce recombinant proteins for use in the pharmaceutical industry has made substantial advances, in particular in the area of generating antigens containing multiple copies of important immunological regions. One such antigen-carrier system is based on the ability of a protein encoded by the yeast retrotransposon, Ty, to self-assemble into virus-like particles. Ty-fusion proteins retain this ability to form particles, and a range of hybrid VLPs carrying a variety of heterologous antigens have been produced and shown to induce potent immune responses. In particular, hybrid VLPs carrying the core protein p24 of HIV (p24-VLPs) have been shown to induce antibody and T-cell proliferative responses in both experimental animals and human volunteers, and immunization of rabbits with VLPs carrying the principal neutralizing determinant of HIV (V3-VLPs) resulted in the induction of neutralizing antibody responses and T-cell proliferation. Further studies with V3-VLPs have shown that this particulate antigen stimulates enhanced V3-specific lymphoproliferative responses as compared to whole recombinant gp120 or to V3 peptide conjugated to albumin. The V3-VLPs also induce potent CTL responses following immunization of mice in the absence of adjuvant. These responses are MHC class I restricted and are mediated by CD8-positive cells. These observations therefore demonstrate that hybrid Ty-VLPs induce both humoral and cellular immune responses against HIV and suggest that these immunogens may be important in combatting AIDS and other infections. PMID:7625653

  10. Multiple peptide resistance factor (MprF)-mediated Resistance of Staphylococcus aureus against antimicrobial peptides coincides with a modulated peptide interaction with artificial membranes comprising lysyl-phosphatidylglycerol.

    Science.gov (United States)

    Andrä, Jörg; Goldmann, Torsten; Ernst, Christoph M; Peschel, Andreas; Gutsmann, Thomas

    2011-05-27

    Modification of the membrane lipid phosphatidylglycerol (PG) of Staphylococcus aureus by enzymatic transfer of a l-lysine residue leading to lysyl-PG converts the net charge of PG from -1 to +1 and is thought to confer resistance to cationic antimicrobial peptides (AMPs). Lysyl-PG synthesis and translocation to the outer leaflet of the bacterial membrane are achieved by the membrane protein MprF. Consequently, mutants lacking a functional mprF gene are in particular vulnerable to the action of AMPs. Hence, we aim at elucidating whether and to which extent lysyl-PG modulates membrane binding, insertion, and permeabilization by various AMPs. Lysyl-PG was incorporated into artificial lipid bilayers, mimicking the cytoplasmic membrane of S. aureus. Moreover, we determined the activity of the peptides against a clinical isolate of S. aureus strain SA113 and two mutants lacking a functional mprF gene and visualized peptide-induced ultrastructural changes of bacteria by transmission electron microscopy. The studied peptides were: (i) NK-2, an α-helical fragment of mammalian NK-lysin, (ii) arenicin-1, a lugworm β-sheet peptide, and (iii) bee venom melittin. Biophysical data obtained by FRET spectroscopy, Fourier transform infrared spectroscopy, and electrical measurements with planar lipid bilayers were correlated with the biological activities of the peptides. They strongly support the hypothesis that peptide-membrane interactions are a prerequisite for eradication of S. aureus. However, degree and mode of modulation of membrane properties such as fluidity, capacitance, and conductivity were unique for each of the peptides. Altogether, our data support and underline the significance of lysyl-PG for S. aureus resistance to AMPs. PMID:21474443

  11. Antigen smuggling in tuberculosis.

    Science.gov (United States)

    Hudrisier, Denis; Neyrolles, Olivier

    2014-06-11

    The importance of CD4 T lymphocytes in immunity to M. tuberculosis is well established; however, how dendritic cells activate T cells in vivo remains obscure. In this issue of Cell Host & Microbe, Srivastava and Ernst (2014) report a mechanism of antigen transfer for efficient activation of antimycobacterial T cells. PMID:24922567

  12. Antigen detection systems

    Science.gov (United States)

    Infectious agents or their constituent parts (antigens or nucleic acids) can be detected in fresh, frozen, or fixed tissues or other specimens, using a variety of direct or indirect assays. The assays can be modified to yield the greatest sensitivity and specificity but in most cases a particular m...

  13. Scaffolded Antigens in Yeast Cell Particle Vaccines Provide Protection against Systemic Polyoma Virus Infection

    OpenAIRE

    Tipper, Donald J.; Szomolanyi-Tsuda, Eva

    2016-01-01

    Background. U65, a self-aggregating peptide scaffold, traps fused protein antigens in yeast cells. Conversion to Yeast Cell Particle (YCP) vaccines by partial removal of surface mannoproteins exposes β-glucan, mediating efficient uptake by antigen-presenting cells (APCs). YCP vaccines are inexpensive, capable of rapid large-scale production and have potential for both parenteral and oral use. Results. YCP processing by alkaline hydrolysis exposes up to 20% of the glucan but converts scaffolde...

  14. Antigen-Based Immune Therapeutics for Type 1 Diabetes: Magic Bullets or Ordinary Blanks?

    OpenAIRE

    Slobodan Culina; Roberto Mallone; Christian Boitard

    2011-01-01

    The ideal drug of modern medicine is the one that achieves its therapeutic target with minimal adverse effects. Immune therapy of Type 1 diabetes (T1D) is no exception, and knowledge of the antigens targeted by pathogenic T cells offers a unique opportunity towards this goal. Different antigen formulations are being considered, such as proteins or peptides, either in their native form or modified ad hoc, DNA plasmids, and cell-based agents. Translation from mouse to human should take into acc...

  15. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined.......To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  16. Aspergillus antigen skin test (image)

    Science.gov (United States)

    The aspergillus antigen skin test determines whether or not a person has been exposed to the mold aspergillus. It is performed by injecting an aspergillus antigen under the skin with a needle. After 48 ...

  17. Various Tumor-Mimicking Lesions in the Musculoskeletal System: Causes and Diagnostic Approach

    OpenAIRE

    Kim, Sue Yon; Park, Ji Seon; Ryu, Kyung Nam; Jin, Wook; Park, So Young

    2011-01-01

    Tumor-mimicking lesions in the musculoskeletal system can be defined as lesions mistaken as tumors due to the presence of palpation upon physical examination or a tumor-like appearance upon radiological examination. Moreover, tumor-mimicking lesions show diverse etiologies and anatomic locations. We illustrated the various tumor-mimicking lesions involving bone and soft tissue. In this review, the tumor-mimicking lesions were classified into those based on clinical examination and those based...

  18. Duodenal foreign body mimicking acute pancreatitis

    International Nuclear Information System (INIS)

    Objective: To determine the specificity and sensitivity of plasma and urinary trypsinogen activation peptide (TAP) concentrat. Design: Retrospective analysis of clinical cases. Procedure: Dogs were classified into three groups: healthy animals, dogs with confirmed pancreatitis and dogs with nonpancreatic disease, which clinically or biochemically resembled pancreatitis. This last group was further subdivided into dogs with renal and those with nonrenal disease. The plasma and urinary TAP concentration was determined by a competitive enzyme immunoassay. Clinical cases additionally had serum trypsin-like immunoreactivity concentration measured, as well as radiography and ultrasound of the abdomen and further diagnostic procedures. Nonparametric analysis of variance (Kruskal-Wallis test) was performed using Statistix 4.0 program. Results: There was a wide range of urinary TAP concentration in healthy dogs (mean 52.30 nmol/L, standard deviation 55.25) that made interpretation of urinary TAP concentrations difficult in the other groups. There was a narrow reference range for plasma TAP (mean 2.67 nmol/L, standard deviation 0.93). Plasma and urinary TAP concentrations, as well as urinary TAP to creatinine ratio, were all increased in dogs that died with necrotising pancreatitis. Values were not increased in mild, interstitial pancreatitis. Increased plasma TAP concentrations were also present in dogs with severe renal disease. Conclusion: Plasma TAP concentration isa good prognostic indicator in naturally occurring pancreatitis in dogs. The failure of TAP to increase in mild pancreatitis, and the increase present in severe renal disease, suggests its measurement has limited application as a sole diagnostic tool for canine pancreatitis. Further investigations are required in order to explain the large variability of urinary TAP concentration and the presence of circulating TAP in healthy dogs

  19. Oncocytoma of Oral Cavity Mimicking as Jaw Tumor

    OpenAIRE

    Aloke Bose Majumdar; Shib Shankar Paul; Gautam Sarker; Souradeep Ray

    2014-01-01

    Oncocytoma of major salivary gland is a fairly common benign tumour encountered, but its occurrence in oral minor salivary gland is a rare entity. Here we report a case of a giant minor salivary gland oncocytoma mimicking a jaw tumour which was successfully excised along with a review of literature.

  20. Spinal MRI of vincristine neuropathy mimicking Guillain-Barre syndrome

    International Nuclear Information System (INIS)

    A 4.3-year-old girl with acute leukaemia, who was being treated with chemotherapy (including vincristine), developed paraplegia. Spinal MRI showed diffusely enhancing nerve roots on contrast-enhanced images. Spinal fluid analysis showed a normal protein level. Vincristine neuropathy mimicking Guillain-Barre syndrome is thought to be the cause of the MRI abnormalities. (orig.)

  1. Spinal MRI of vincristine neuropathy mimicking Guillain-Barre syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yun Woo; Yoon, Hye-Kyung; Cho, Jae Min [Department of Radiology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Kangnam-gu, Seoul 135-710 (Korea); Sung, Ki Woong [Department of Paediatrics, Samsung Medical Centre, Seoul 135-710 (Korea)

    2003-11-01

    A 4.3-year-old girl with acute leukaemia, who was being treated with chemotherapy (including vincristine), developed paraplegia. Spinal MRI showed diffusely enhancing nerve roots on contrast-enhanced images. Spinal fluid analysis showed a normal protein level. Vincristine neuropathy mimicking Guillain-Barre syndrome is thought to be the cause of the MRI abnormalities. (orig.)

  2. Bilateral multiple pulmonary tuberculous nodules mimicking metastatic disease

    International Nuclear Information System (INIS)

    We present CT findings of a young woman who has bilateral pulmonary nodules mimicking metastases. Clinical presentation with active multiple pulmonary macronodules without cavitation responsive to treatment is an atypical manifestation of pulmonary tuberculosis. We reviewed the causes of multiple pulmonary nodules, role of radiological findings in differential diagnosis and parenchymal manifestations of pulmonary tuberculosis in this report

  3. Ruptured Ovarian Dermoid Cyst Mimicking Peritoneal Carcinomatosis: CT and MRI

    OpenAIRE

    Gurcan Erbay

    2016-01-01

    Spontaneous rupture of ovarian dermoid cyst and chronic abdominal spillage of its content is a very uncommon condition, which causes granulomatous peritonitis and can be confused with peritoneal carcinomatosis. Here is presented such a case of ruptured dermoid cyst causing chronic granulomatous peritonitis with radiologic findings mimicking peritoneal carcinomatosis.

  4. Peripancreatic Tuberculous Lymphadenopathy Mimicking Pancreatic Neoplasm: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Kyung Eun; Cho, Hyun Sun [Dept. of Radiology, Saggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

    2011-06-15

    Peripancreatic tuberculosis affecting only the lymph nodes is a rare clinical entity which usually raises serious diagnostic problems. We experienced a case of surgically proven peripancreatic tuberculous lymphadenopathy mimicking pancreas cystic neoplasm and report here on the findings of this rare condition along with a literature review.

  5. Peripancreatic Tuberculous Lymphadenopathy Mimicking Pancreatic Neoplasm: A Case Report

    International Nuclear Information System (INIS)

    Peripancreatic tuberculosis affecting only the lymph nodes is a rare clinical entity which usually raises serious diagnostic problems. We experienced a case of surgically proven peripancreatic tuberculous lymphadenopathy mimicking pancreas cystic neoplasm and report here on the findings of this rare condition along with a literature review.

  6. Severe cytomegalovirus colitis with hemolytic anemia mimicking travelers’ diarrhea

    Directory of Open Access Journals (Sweden)

    Nakyoung Hwang

    2015-08-01

    Full Text Available A case of cytomegalovirus (CMV colitis mimicking travelers’ diarrhea following short-term travel is reported. The patient was a Croatian man visiting Korea for work. He presented with fever and severe bloody diarrhea. He was diagnosed with a primary CMV infection complicated with CMV colitis and hemolytic anemia and recovered with antiviral therapy and concomitant steroid therapy.

  7. Xanthogranulomatous Endometritis: An Unusual Pathological Entity Mimicking Endometrial Carcinoma

    OpenAIRE

    Makkar, M; Gill, MK; Singh, DP

    2013-01-01

    Xanthogranulomatous endometritis is an unusual pathological entity mimicking endometrial carcinoma. This shows sheets of foamy histiocytes alongwith other inflammatory cells. We, hereby, report a case of 45 year multigravida female with irregular menstrual history, clinically diagnosed as carcinoma and histopathologically turned out as xanthogranulomatous endometritis. So, this condition should always be dealt with caution, and pathologists and clinicians should be aware of it.

  8. Intracranial Gossypiboma Mimicking a Recurrent Low Grade Astrocytoma : Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Young; Koo, Joon Bum [Dept. of Radiology, Dongguk University Il-San Hospital, Iksan (Korea, Republic of)

    2011-05-15

    Gossypiboma is an inflammatory pseudomass formed by a retained surgical sponge or gauze with reactive tissue after surgery. Gossypiboma has been reported most frequently after abdominal or thoracic surgery. As such, gossypiboma following brain surgery is very rare. We report a case of gossypiboma mimicking tumor recurrence in the brain after a craniotomy and surgical excision of a low grade astrocytoma.

  9. Quantitating protein synthesis, degradation, and endogenous antigen processing.

    Science.gov (United States)

    Princiotta, Michael F; Finzi, Diana; Qian, Shu-Bing; Gibbs, James; Schuchmann, Sebastian; Buttgereit, Frank; Bennink, Jack R; Yewdell, Jonathan W

    2003-03-01

    Using L929 cells, we quantitated the macroeconomics of protein synthesis and degradation and the microeconomics of producing MHC class I associated peptides from viral translation products. To maintain a content of 2.6 x 10(9) proteins, each cell's 6 x 10(6) ribosomes produce 4 x 10(6) proteins min(-1). Each of the cell's 8 x 10(5) proteasomes degrades 2.5 substrates min(-1), creating one MHC class I-peptide complex for each 500-3000 viral translation products degraded. The efficiency of complex formation is similar in dendritic cells and macrophages, which play a critical role in activating T cells in vivo. Proteasomes create antigenic peptides at different efficiencies from two distinct substrate pools: rapidly degraded newly synthesized proteins that clearly represent defective ribosomal products (DRiPs) and a less rapidly degraded pool in which DRiPs may also predominate. PMID:12648452

  10. Stool Test: H. Pylori Antigen

    Science.gov (United States)

    ... All About Food Allergies Stool Test: H. Pylori Antigen KidsHealth > For Parents > Stool Test: H. Pylori Antigen Print A A A Text Size What's in ... sample is used to determine if H. pylori antigens are present in your child's gastrointestinal (GI) system. ...

  11. Peptide/protein vaccine delivery system based on PLGA particles.

    Science.gov (United States)

    Allahyari, Mojgan; Mohit, Elham

    2016-03-01

    Due to the excellent safety profile of poly (D,L-lactide-co-glycolide) (PLGA) particles in human, and their biodegradability, many studies have focused on the application of PLGA particles as a controlled-release vaccine delivery system. Antigenic proteins/peptides can be encapsulated into or adsorbed to the surface of PLGA particles. The gradual release of loaded antigens from PLGA particles is necessary for the induction of efficient immunity. Various factors can influence protein release rates from PLGA particles, which can be defined intrinsic features of the polymer, particle characteristics as well as protein and environmental related factors. The use of PLGA particles encapsulating antigens of different diseases such as hepatitis B, tuberculosis, chlamydia, malaria, leishmania, toxoplasma and allergy antigens will be described herein. The co-delivery of antigens and immunostimulants (IS) with PLGA particles can prevent the systemic adverse effects of immunopotentiators and activate both dendritic cells (DCs) and natural killer (NKs) cells, consequently enhancing the therapeutic efficacy of antigen-loaded PLGA particles. We will review co-delivery of different TLR ligands with antigens in various models, highlighting the specific strengths and weaknesses of the system. Strategies to enhance the immunotherapeutic effect of DC-based vaccine using PLGA particles can be designed to target DCs by functionalized PLGA particle encapsulating siRNAs of suppressive gene, and disease specific antigens. Finally, specific examples of cellular targeting where decorating the surface of PLGA particles target orally administrated vaccine to M-cells will be highlighted. PMID:26513024

  12. PeptideAtlas

    Data.gov (United States)

    U.S. Department of Health & Human Services — PeptideAtlas is a multi-organism, publicly accessible compendium of peptides identified in a large set of tandem mass spectrometry proteomics experiments. Mass...

  13. Peptider holder krabben rask

    DEFF Research Database (Denmark)

    Buchmann, Kurt

    Antimikrobielle Peptider har hos mere primitive dyr en vigtig funktion i organismernes immunforsvar Udgivelsesdato: 1. februar......Antimikrobielle Peptider har hos mere primitive dyr en vigtig funktion i organismernes immunforsvar Udgivelsesdato: 1. februar...

  14. Antiinflammatory properties of a peptide derived from interleukin-4

    DEFF Research Database (Denmark)

    Klementiev, Boris; Enevoldsen, Maj N; Li, Shizhong;

    2013-01-01

    associated with IL-4 signaling. These data collectively show that Ph8 is only a partial agonist of IL-4 mimicking its desirable properties. In agreement, Ph8 treatment of rats with collagen-induced arthritis, a Th1- and antibody- mediated disease of joint, delayed the manifestation of chronic inflammation......Interleukin-4 (IL-4) is a potent antiinflammatory cytokine. However its use in the clinic is hampered by side effects. We here describe the identification of a novel synthetic peptide, termed Ph8, derived from α-helix C of IL-4, which interacts with IL-4 receptor α (IL-4Rα). Employing various...

  15. Peptide Nucleic Acid Synthons

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  16. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  17. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  18. Peptide Nucleic Acids (PNA)

    DEFF Research Database (Denmark)

    2002-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  19. Antimicrobial Peptides in 2014

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2015-03-01

    Full Text Available This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms.

  20. PH dependent adhesive peptides

    Science.gov (United States)

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  1. Immunoassay of antigens

    International Nuclear Information System (INIS)

    A method is described of immunoassay of an antigen in a liquid sample wherein a complex is formed between antigen contained in the said sample and two or more antibody reagents, and the said complex is bound to a solid support by non-covalent bonding as defined herein: and the amount of complex becoming bound to the support is determined; the process employing at least one monoclonal antibody reagent. Labelling methods including radioactive, fluorimetric and enzyme labelling may be used to effect determination of the binding ofthe complex to the solid support. The solid support may take the form of particles, beads, wall-coatings on the reaction vessel or an insert of large surface area. The method is particularly applicable to the assay of TSH, CEA, HCG, alphafeto protein, immunoglobulins, viruses, allergens, bacteria, toxins, drugs and vitamins. Use of monoclonal reagents improves the specificity of the process, and also decreases non-specific binding

  2. Cancer associated aberrant protein o-glycosylation can modify antigen processing and immune response

    DEFF Research Database (Denmark)

    Madsen, Caroline B; Petersen, Cecilie; Lavrsen, Kirstine;

    2012-01-01

    response to a cancer related tumor antigen, Balb/c or B6.Cg(CB)-Tg(HLA-A/H2-D)2Enge/J (HLA-A2 transgenic) mice were immunized with a non-glycosylated or GalNAc-glycosylated MUC1 derived peptide followed by comparison of T cell proliferation, IFN-¿ release, and antibody induction. Gal...... abolished MUC1 specific CD8+ T cell responses in HLA-A2 transgenic mice. GalNAc glycosylation of MUC1 antigen therefore facilitates uptake, MHC class II presentation, and antibody response but might block the antigen presentation to CD8+ T cells....

  3. Competition-based cellular peptide binding assays for 13 prevalent HLA class I alleles using fluorescein-labeled synthetic peptides.

    Science.gov (United States)

    Kessler, Jan H; Mommaas, Bregje; Mutis, Tuna; Huijbers, Ivo; Vissers, Debby; Benckhuijsen, Willemien E; Schreuder, Geziena M Th; Offringa, Rienk; Goulmy, Els; Melief, Cornelis J M; van der Burg, Sjoerd H; Drijfhout, Jan W

    2003-02-01

    We report the development, validation, and application of competition-based peptide binding assays for 13 prevalent human leukocyte antigen (HLA) class I alleles. The assays are based on peptide binding to HLA molecules on living cells carrying the particular allele. Competition for binding between the test peptide of interest and a fluorescein-labeled HLA class I binding peptide is used as read out. The use of cell membrane-bound HLA class I molecules circumvents the need for laborious biochemical purification of these molecules in soluble form. Previously, we have applied this principle for HLA-A2 and HLA-A3. We now describe the assays for HLA-A1, HLA-A11, HLA-A24, HLA-A68, HLA-B7, HLA-B8, HLA-B14, HLA-B35, HLA-B60, HLA-B61, and HLA-B62. Together with HLA-A2 and HLA-A3, these alleles cover more than 95% of the Caucasian population. Several allele-specific parameters were determined for each assay. Using these assays, we identified novel HLA class I high-affinity binding peptides from HIVpol, p53, PRAME, and minor histocompatibility antigen HA-1. Thus these convenient and accurate peptide-binding assays will be useful for the identification of putative cytotoxic T lymphocyte epitopes presented on a diverse array of HLA class I molecules. PMID:12559627

  4. Engineering antigen-specific immunological tolerance.

    Energy Technology Data Exchange (ETDEWEB)

    Kontos, Stephan; Grimm, Alizee J.; Hubbell, Jeffrey A.

    2015-05-01

    Unwanted immunity develops in response to many protein drugs, in autoimmunity, in allergy, and in transplantation. Approaches to induce immunological tolerance aim to either prevent these responses or reverse them after they have already taken place. We present here recent developments in approaches, based on engineered peptides, proteins and biomaterials, that harness mechanisms of peripheral tolerance both prophylactically and therapeutically to induce antigenspecific immunological tolerance. These mechanisms are based on responses of B and T lymphocytes to other cells in their immune environment that result in cellular deletion or ignorance to particular antigens, or in development of active immune regulatory responses. Several of these approaches are moving toward clinical development, and some are already in early stages of clinical testing.

  5. Viral Escape Mutant Epitope Maintains TCR Affinity for Antigen yet Curtails CD8 T Cell Responses

    Science.gov (United States)

    Shorter, Shayla K.; Schnell, Frederick J.; McMaster, Sean R.; Pinelli, David F.; Andargachew, Rakieb; Evavold, Brian D.

    2016-01-01

    T cells have the remarkable ability to recognize antigen with great specificity and in turn mount an appropriate and robust immune response. Critical to this process is the initial T cell antigen recognition and subsequent signal transduction events. This antigen recognition can be modulated at the site of TCR interaction with peptide:major histocompatibility (pMHC) or peptide interaction with the MHC molecule. Both events could have a range of effects on T cell fate. Though responses to antigens that bind sub-optimally to TCR, known as altered peptide ligands (APL), have been studied extensively, the impact of disrupting antigen binding to MHC has been highlighted to a lesser extent and is usually considered to result in complete loss of epitope recognition. Here we present a model of viral evasion from CD8 T cell immuno-surveillance by a lymphocytic choriomeningitis virus (LCMV) escape mutant with an epitope for which TCR affinity for pMHC remains high but where the antigenic peptide binds sub optimally to MHC. Despite high TCR affinity for variant epitope, levels of interferon regulatory factor-4 (IRF4) are not sustained in response to the variant indicating differences in perceived TCR signal strength. The CD8+ T cell response to the variant epitope is characterized by early proliferation and up-regulation of activation markers. Interestingly, this response is not maintained and is characterized by a lack in IL-2 and IFNγ production, increased apoptosis and an abrogated glycolytic response. We show that disrupting the stability of peptide in MHC can effectively disrupt TCR signal strength despite unchanged affinity for TCR and can significantly impact the CD8+ T cell response to a viral escape mutant. PMID:26915099

  6. Viral Escape Mutant Epitope Maintains TCR Affinity for Antigen yet Curtails CD8 T Cell Responses.

    Directory of Open Access Journals (Sweden)

    Shayla K Shorter

    Full Text Available T cells have the remarkable ability to recognize antigen with great specificity and in turn mount an appropriate and robust immune response. Critical to this process is the initial T cell antigen recognition and subsequent signal transduction events. This antigen recognition can be modulated at the site of TCR interaction with peptide:major histocompatibility (pMHC or peptide interaction with the MHC molecule. Both events could have a range of effects on T cell fate. Though responses to antigens that bind sub-optimally to TCR, known as altered peptide ligands (APL, have been studied extensively, the impact of disrupting antigen binding to MHC has been highlighted to a lesser extent and is usually considered to result in complete loss of epitope recognition. Here we present a model of viral evasion from CD8 T cell immuno-surveillance by a lymphocytic choriomeningitis virus (LCMV escape mutant with an epitope for which TCR affinity for pMHC remains high but where the antigenic peptide binds sub optimally to MHC. Despite high TCR affinity for variant epitope, levels of interferon regulatory factor-4 (IRF4 are not sustained in response to the variant indicating differences in perceived TCR signal strength. The CD8+ T cell response to the variant epitope is characterized by early proliferation and up-regulation of activation markers. Interestingly, this response is not maintained and is characterized by a lack in IL-2 and IFNγ production, increased apoptosis and an abrogated glycolytic response. We show that disrupting the stability of peptide in MHC can effectively disrupt TCR signal strength despite unchanged affinity for TCR and can significantly impact the CD8+ T cell response to a viral escape mutant.

  7. Microbially synthesized modular virus-like particles and capsomeres displaying group A streptococcus hypervariable antigenic determinants.

    Science.gov (United States)

    Chuan, Yap P; Wibowo, Nani; Connors, Natalie K; Wu, Yang; Hughes, Fiona K; Batzloff, Michael R; Lua, Linda H L; Middelberg, Anton P J

    2014-06-01

    Effective and low-cost vaccines are essential to control severe group A streptococcus (GAS) infections prevalent in low-income nations and the Australian aboriginal communities. Highly diverse and endemic circulating GAS strains mandate broad-coverage and customized vaccines. This study describes an approach to deliver cross-reactive antigens from endemic GAS strains using modular virus-like particle (VLP) and capsomere systems. The antigens studied were three heterologous N-terminal peptides (GAS1, GAS2, and GAS3) from the GAS surface M-protein that are specific to endemic strains in Australia Northern Territory Aboriginal communities. In vivo data presented here demonstrated salient characteristics of the modular delivery systems in the context of GAS vaccine design. First, the antigenic peptides, when delivered by unadjuvanted modular VLPs or adjuvanted capsomeres, induced high titers of peptide-specific IgG antibodies (over 1 × 10(4) ). Second, delivery by capsomere was superior to VLP for one of the peptides investigated (GAS3), demonstrating that the delivery system relative effectiveness was antigen-dependant. Third, significant cross-reactivity of GAS2-induced IgG with GAS1 was observed using either VLP or capsomere, showing the possibility of broad-coverage vaccine design using these delivery systems and cross-reactive antigens. Fourth, a formulation containing three pre-mixed modular VLPs, each at a low dose of 5 μg (corresponding to <600 ng of each GAS peptide), induced significant titers of IgGs specific to each peptide, demonstrating that a multivalent, broad-coverage VLP vaccine formulation was possible. In summary, the modular VLPs and capsomeres reported here demonstrate, with promising preliminary data, innovative ways to design GAS vaccines using VLP and capsomere delivery systems amenable to microbial synthesis, potentially adoptable by developing countries. PMID:24338691

  8. Vaccine delivery by penetratin: mechanism of antigen presentation by dendritic cells.

    Science.gov (United States)

    Pouniotis, Dodie; Tang, Choon-Kit; Apostolopoulos, Vasso; Pietersz, Geoffrey

    2016-08-01

    Cell-penetrating peptides (CPP) or membrane-translocating peptides such as penetratin from Antennapedia homeodomain or TAT from human immunodeficiency virus are useful vectors for the delivery of protein antigens or their cytotoxic (Tc) or helper (Th) T cell epitopes to antigen-presenting cells. Mice immunized with CPP containing immunogens elicit antigen-specific Tc and/or Th responses and could be protected from tumor challenges. In the present paper, we investigate the mechanism of class I and class II antigen presentation of ovalbumin covalently linked to penetratin (AntpOVA) by bone marrow-derived dendritic cells with the use of biochemical inhibitors of various pathways of antigen processing and presentation. Results from our study suggested that uptake of AntpOVA is via a combination of energy-independent (membrane fusion) and energy-dependent pathways (endocytosis). Once internalized by either mechanism, multiple tap-dependent or independent antigen presentation pathways are accessed while not completely dependent on proteasomal processing but involving proteolytic trimming in the ER and Golgi compartments. Our study provides an understanding on the mechanism of antigen presentation mediated by CPP and leads to greater insights into future development of vaccine formulations. PMID:27138940

  9. Neurotropic and neuroprotective activities of the earthworm peptide Lumbricusin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Hong; Lee, Ik Hwan; Nam, Seung Taek; Hong, Ji; Zhang, Peng [Department of Life Science, College of Natural Science, Daejin University, Pocheon, Gyeonggido 487-711 (Korea, Republic of); Hwang, Jae Sam [Department of Agricultural Biology, National Academy of Agricultural Science, RDA, Suwon 441-707 (Korea, Republic of); Seok, Heon [Department of Biomedical Engineering, Jungwon University, Goesan, Chungcheongbukdo 367-700 (Korea, Republic of); Choi, Hyemin; Lee, Dong Gun [School of Life Sciences, KNU Creative Bioresearch Group (BK21 Plus Program), College of Natural Sciences, Kyungpook National University, Daehak-ro 80, Buk-gu, Daegu 702-701 (Korea, Republic of); Kim, Jae Il [School of Life Sciences, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Kim, Ho, E-mail: hokim@daejin.ac.kr [Department of Life Science, College of Natural Science, Daejin University, Pocheon, Gyeonggido 487-711 (Korea, Republic of)

    2014-06-06

    Highlights: • 11-mer peptide Lumbricusin, a defensin like peptide, is isolated from earthworm. • We here demonstrated that Lumbricusin has neurotropic and neuroprotective effects. • p27 degradation by Lumbricusin mediates effects of Lumbricusin on neuronal cells. - Abstract: We recently isolated a polypeptide from the earthworm Lumbricus terrestris that is structurally similar to defensin, a well-known antibacterial peptide. An 11-mer antibacterial peptide (NH{sub 2}-RNRRWCIDQQA), designated Lumbricusin, was synthesized based on the amino acid sequence of the isolated polypeptide. Since we previously reported that CopA3, a dung beetle peptide, enhanced neuronal cell proliferation, we here examined whether Lumbricusin exerted neurotropic and/or neuroprotective effects. Lumbricusin treatment induced a time-dependent increase (∼51%) in the proliferation of human neuroblastoma SH-SY5Y cells. Lumbricusin also significantly inhibited the apoptosis and decreased viability induced by treatment with 6-hydroxy dopamine, a Parkinson’s disease-mimicking agent. Immunoblot analyses revealed that Lumbricusin treatment increased ubiquitination of p27{sup Kip1} protein, a negative regulator of cell-cycle progression, in SH-SY5Y cells, and markedly promoted its degradation. Notably, adenoviral-mediated over-expression of p27{sup Kip1} significantly blocked the antiapoptotic effect of Lumbricusin in 6-hydroxy dopamine-treated SH-SY5Y cells. These results suggest that promotion of p27{sup Kip1} degradation may be the main mechanism underlying the neuroprotective and neurotropic effects of Lumbricusin.

  10. Toward a network model of MHC class II-restricted antigen processing

    Directory of Open Access Journals (Sweden)

    Laurence C Eisenlohr

    2013-12-01

    Full Text Available The standard model of Major Histocompatibility Complex class II (MHCII-restricted antigen processing depicts a straightforward, linear pathway: Internalized antigens are converted into peptides that load in a chaperone dependent manner onto nascent MHCII in the late endosome, the complexes subsequently trafficking to the cell surface for recognition by CD4+ T cells (TCD4+. Several variations on this theme, both moderate and radical, have come to light but these alternatives have remained peripheral, the conventional pathway generally presumed to be the primary driver of TCD4+ responses. Here we continue to press for the conceptual repositioning of these alternatives toward the center while proposing that MHCII processing be thought of less in terms of discrete pathways and more in terms of a network whose major and minor conduits are variable depending upon many factors, including the epitope, the nature of the antigen, the source of the antigen, and the identity of the antigen-presenting cell.

  11. MULTIPRED2: A computational system for large-scale identification of peptides predicted to bind to HLA supertypes and alleles

    DEFF Research Database (Denmark)

    Zhang, Guang Lan; DeLuca, David S.; Keskin, Derin B.;

    2011-01-01

    MULTIPRED2 is a computational system for facile prediction of peptide binding to multiple alleles belonging to human leukocyte antigen (HLA) class I and class II DR molecules. It enables prediction of peptide binding to products of individual HLA alleles, combination of alleles, or HLA supertypes...

  12. Neuritogenic and Neuroprotective Properties of Peptide Agonists of the Fibroblast Growth Factor Receptor

    Directory of Open Access Journals (Sweden)

    Shizhong Li

    2010-05-01

    Full Text Available Fibroblast growth factor receptors (FGFRs interact with their cognate ligands, FGFs, and with a number of cell adhesion molecules (CAMs, such as the neural cell adhesion molecule (NCAM, mediating a wide range of events during the development and maintenance of the nervous system. Determination of protein structure, in silico modeling and biological studies have recently resulted in the identification of FGFR binding peptides derived from various FGFs and NCAM mimicking the effects of these molecules with regard to their neuritogenic and neuroprotective properties. This review focuses on recently developed functional peptide agonists of FGFR with possible therapeutic potential.

  13. Characterization of BAX inhibitor-1 as a novel leukemia-associated antigen.

    Science.gov (United States)

    Schmidt, S M; König, T; Bringmann, A; Held, S; von Schwarzenberg, K; Heine, A; Holderried, T A W; Stevanovic, S; Grünebach, F; Brossart, P

    2009-10-01

    Using dendritic cells (DCs) electroporated with whole RNA isolated from blasts of a patient with acute myeloid leukemia (AML), we were able to generate leukemia-specific cytotoxic T lymphocytes (CTLs) capable of recognizing the leucemic cells. To identify T-cell epitopes mediating lysis of malignant cells, peptides were eluted from the patient's blasts and analyzed by mass spectrometry (LC/MS)-based peptide sequencing. Using this approach, an HLA-A24-binding peptide derived from Bax inhibitor-1 (BI-1), a regulator of apoptosis pathways, was identified as an epitope recognized by the generated CTLs. To further characterize this novel antigenic peptide, CTLs were induced using DCs electroporated with RNA coding for BI-1 or pulsed with the cognate peptide. These CTLs generated from healthy donors in vitro efficiently lysed the patient's blasts as well as other HLA-matched leukemic cells. In conclusion, we identified a BI-1 peptide as a novel immunogenic tumor-associated antigen (TAA) in AML. In vitro induction of BI-1-specific CTLs by RNA transfection or pulsing of DCs with the synthetically generated peptide was a feasible and highly effective method to generate leukemia-specific CTLs. As BI-1 is (over-) expressed in a broad variety of malignancies, it may represent an interesting novel TAA in the context of cancer vaccines. PMID:19609282

  14. Granuloma inguinale mimicking as squamous cell carcinoma of penis

    Directory of Open Access Journals (Sweden)

    Abhishek Pilani

    2014-01-01

    Full Text Available Granuloma inguinale (GI is an acquired chronic, slowly progressive, mildly contagious disease of venereal origin, characterized by granulomatous ulceration of the genitalia and neighboring sites, with little or no tendency to spontaneous healing caused by Klebsiella (Calymmatobacterium granulomatis. A 55-year-old male presented with fissured, foul smelling, fungating growth over prepuce with phimosis mimicking squamous cell carcinoma (SCC without lymphadenopathy. It started with painless papulonodular showed pseudoepitheliomatous hyperplasia, infiltration in dermis, acanthosis and vacuolated macrophages suggestive of GI and not showing any histopathological features of SCC. Patient was successfully treated by giving cotrimoxazole twice a day for 21 days. Here, we presented a case of GI mimicking SCC of penis, which was diagnosed on basis of histopathology and treated with excision followed by medical therapy with cotrimoxazole.

  15. Rational Design of Pathogen-Mimicking Amphiphilic Materials as Nanoadjuvants

    Science.gov (United States)

    Ulery, Bret D.; Petersen, Latrisha K.; Phanse, Yashdeep; Kong, Chang Sun; Broderick, Scott R.; Kumar, Devender; Ramer-Tait, Amanda E.; Carrillo-Conde, Brenda; Rajan, Krishna; Wannemuehler, Michael J.; Bellaire, Bryan H.; Metzger, Dennis W.; Narasimhan, Balaji

    2011-12-01

    An opportunity exists today for cross-cutting research utilizing advances in materials science, immunology, microbial pathogenesis, and computational analysis to effectively design the next generation of adjuvants and vaccines. This study integrates these advances into a bottom-up approach for the molecular design of nanoadjuvants capable of mimicking the immune response induced by a natural infection but without the toxic side effects. Biodegradable amphiphilic polyanhydrides possess the unique ability to mimic pathogens and pathogen associated molecular patterns with respect to persisting within and activating immune cells, respectively. The molecular properties responsible for the pathogen-mimicking abilities of these materials have been identified. The value of using polyanhydride nanovaccines was demonstrated by the induction of long-lived protection against a lethal challenge of Yersinia pestis following a single administration ten months earlier. This approach has the tantalizing potential to catalyze the development of next generation vaccines against diseases caused by emerging and re-emerging pathogens.

  16. [Plant signaling peptides. Cysteine-rich peptides].

    Science.gov (United States)

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differences among CRP classes, members from each class have striking similarities in their molecular properties and function. The present review presents the recent progress in research on signaling peptides from several families including: EPF/EPFL, SP11/SCR, PrsS, RALF, LURE, and some other peptides belonging to CRP group. There is convincing evidence indicating multiple roles for these CRPs as signaling molecules during the plant life cycle, ranging from stomata development and patterning, self-incompatibility, pollen tube growth and guidance, reproductive processes, and nodule formation. PMID:26281357

  17. Viral sequestration of antigen subverts cross presentation to CD8(+ T cells.

    Directory of Open Access Journals (Sweden)

    Eric F Tewalt

    2009-05-01

    Full Text Available Virus-specific CD8(+ T cells (T(CD8+ are initially triggered by peptide-MHC Class I complexes on the surface of professional antigen presenting cells (pAPC. Peptide-MHC complexes are produced by two spatially distinct pathways during virus infection. Endogenous antigens synthesized within virus-infected pAPC are presented via the direct-presentation pathway. Many viruses have developed strategies to subvert direct presentation. When direct presentation is blocked, the cross-presentation pathway, in which antigen is transferred from virus-infected cells to uninfected pAPC, is thought to compensate and allow the generation of effector T(CD8+. Direct presentation of vaccinia virus (VACV antigens driven by late promoters does not occur, as an abortive infection of pAPC prevents production of these late antigens. This lack of direct presentation results in a greatly diminished or ablated T(CD8+ response to late antigens. We demonstrate that late poxvirus antigens do not enter the cross-presentation pathway, even when identical antigens driven by early promoters access this pathway efficiently. The mechanism mediating this novel means of viral modulation of antigen presentation involves the sequestration of late antigens within virus factories. Early antigens and cellular antigens are cross-presented from virus-infected cells, as are late antigens that are targeted to compartments outside of the virus factories. This virus-mediated blockade specifically targets the cross-presentation pathway, since late antigen that is not cross-presented efficiently enters the MHC Class II presentation pathway. These data are the first to describe an evasion mechanism employed by pathogens to prevent entry into the cross-presentation pathway. In the absence of direct presentation, this evasion mechanism leads to a complete ablation of the T(CD8+ response and a potential replicative advantage for the virus. Such mechanisms of viral modulation of antigen presentation

  18. Osteofibrous dysplasia of clavicle clinically mimicking chronic osteomyelitis

    Directory of Open Access Journals (Sweden)

    Nirmal Raj Gopinathan

    2016-01-01

    Full Text Available Osteofibrous dysplasia or ossifying fibroma is an uncommon benign fibro-osseous lesion of childhood, commonly described in the maxilla and the mandible. Among long bones, it usually presents in the tibia as a painless swelling or anterior bowing. Ossifying fibroma of clavicle has never been reported in English literature, to the best of our knowledge. Here, we would like to present an unusual case of osteofibrous dysplasia of clavicle clinically mimicking chronic osteomyelitis.

  19. Sarcoidosis mimicking metastatic thyroid cancer following radioactive iodine therapy

    OpenAIRE

    Myint, Zin W.; Chow, Robert D.

    2015-01-01

    Introduction: Sarcoidosis is an inflammatory disease characterized by non-caseating granulomas that can be present in diverse organ systems. Sarcoidosis can be associated with malignancy, presenting either preceding, during, or after chemotherapy. We herewith report a case of sarcoidosis mimicking cancer recurrence that developed after radioactive iodine therapy for papillary thyroid cancer.Background: A 68-year-old Caucasian woman was found to have an incidental mediastinal lymph node. She u...

  20. Granuloma inguinale mimicking as squamous cell carcinoma of penis

    OpenAIRE

    Abhishek Pilani; Rita Vora; Gopikrishnan Anjaneyan

    2014-01-01

    Granuloma inguinale (GI) is an acquired chronic, slowly progressive, mildly contagious disease of venereal origin, characterized by granulomatous ulceration of the genitalia and neighboring sites, with little or no tendency to spontaneous healing caused by Klebsiella (Calymmatobacterium) granulomatis. A 55-year-old male presented with fissured, foul smelling, fungating growth over prepuce with phimosis mimicking squamous cell carcinoma (SCC) without lymphadenopathy. It started with painless p...

  1. Heterotopic Pancreas Mimicking Cholangiocarcinoma. Case Report and Literature Review

    OpenAIRE

    Atindriya Biswas; Ehab A. Husain; Roger M Feakins; Abraham, Ajit T

    2007-01-01

    Context Majority of the patients developing obstructive jaundice have an underlying malignancy. Identification of a benign pathology like heterotopic pancreas as an aetiology is uncommon and usually occurs only subsequent to a major operation. Case report We report a case of heterotopic pancreas adjacent to the ampulla of Vater mimicking distal cholangiocarcinoma. A 47- year-old patient presented with abdominal pain and obstructive jaundice. ERCP demonstrated a distal common bile duct strictu...

  2. Traumatic Thumb Radial Sagittal Band Injury Mimicking EPL Rupture.

    Science.gov (United States)

    Dissanayake, Ravi M; Moore, Peter; McCarten, Gregory M

    2016-06-01

    We present the case of a closed traumatic disruption of the thumb radial sagittal band (RSB) that sonographically mimicked rupture of the extensor pollicis longus (EPL) tendon. This injury was treated with primary repair of the RSB and lead to a good functional outcome for the patient. This case report highlights how early recognition and treatment can lead to a good functional outcome. PMID:27454647

  3. A Case of Hidroacanthoma Simplex Mimicking Bowen s Disease

    Directory of Open Access Journals (Sweden)

    Pinar Ozuguz

    2013-10-01

    Full Text Available Hidroacanthoma simplex is a rare benign tumor that originates from eccrine sweet gland ducts. The lesions are characterized by slowly-growing, flat or slightly elevated, skin-colored, brown or erythematous, verrucous papules or plaques. Clinically, plaques may resemble seborrheic keratosis, basal cell carcinoma and Bowen%u2019s disease. Here, we present a case of atypically localized hidroacanthoma simplex mimicking Bowen%u2019s disease.

  4. A Case of Hidroacanthoma Simplex Mimicking Bowen s Disease

    OpenAIRE

    Pinar Ozuguz

    2013-01-01

    Hidroacanthoma simplex is a rare benign tumor that originates from eccrine sweet gland ducts. The lesions are characterized by slowly-growing, flat or slightly elevated, skin-colored, brown or erythematous, verrucous papules or plaques. Clinically, plaques may resemble seborrheic keratosis, basal cell carcinoma and Bowen%u2019s disease. Here, we present a case of atypically localized hidroacanthoma simplex mimicking Bowen%u2019s disease.

  5. Osteolytic nasal polyp of the maxillary sinus mimicking malignancy

    OpenAIRE

    Arvind Karikal; Sampathila Mahalinga Sharma; Anju Gopinath; Arathi Karikal

    2014-01-01

    We present an osteolytic nasal polyp of the maxillary sinus with clinical features and radiographic features mimicking that of a malignancy. Maxillary sinusitis being a common inflammatory condition progressed to cause destruction of the maxillary bone and spread into the facial soft tissue, which is quite a rare occurrence. We have discussed in detail the clinical, radiological, histopathology and management of this uncommon presentation of a common case.

  6. Biliary Ascariasis Mimicking Colonic Tumor Infiltration of the Biliary System.

    Science.gov (United States)

    Sundriyal, Deepak; Mittal, Gyanendra; Kumar, Sushil; Manjunath, Suraj; Sharma, Navneet; Gupta, Mahesh

    2015-09-01

    Ascariasis is a common problem in developing countries with poor hygiene and sanitation. It is endemic in India and usually seen in the northern states. Biliary ascariasis is an uncommon cause of obstructive jaundice. We present a case of carcinoma of hepatic flexure of colon in which the patient developed biliary ascariasis and posed a diagnostic challenge as it mimicked tumor infiltration of the biliary system. PMID:27217679

  7. Bartonella henselae Infection: An Uncommon Mimicker of Autoimmune Disease

    OpenAIRE

    Maritsi, Despoina N.; Diagoras Zarganis; Zoi Metaxa; Georgia Papaioannou; George Vartzelis

    2013-01-01

    We present a case of a seven-year-old immunocompetent female patient who developed systemic symptoms mimicking an autoimmune rather than an infectious disease. The patient presented with rash, biquotidian fever, night sweats, and arthralgias. There was no antecedent history of cat contact. Investigations showed increased inflammatory markers, leukocytosis, thrombocytosis, hypercalcemia, and raised angiotensin-converting enzyme. Interferon-gamma releasing assay for tuberculosis infection was n...

  8. Cytokine Switch and Bystander Suppression of Autoimmune Responses to Multiple Antigens in Experimental Autoimmune Encephalomyelitis by a Single Recombinant T-Cell Receptor Ligand

    OpenAIRE

    Sinha, Sushmita; Subramanian, Sandhya; Miller, Lisa; Proctor, Thomas M.; Roberts, Chris; Burrows, Gregory G.; Vandenbark, Arthur A.; Offner, Halina

    2009-01-01

    Recombinant T-cell receptor ligands (RTLs) can reverse clinical and histological signs of experimental autoimmune encephalomyelitis (EAE) in an antigen-specific manner, and are currently in clinical trials for treatment of subjects with multiple sclerosis (MS). Antigen specificity of RTL raises the question as to whether this treatment would be successful in MS patients where target antigens are unknown. Using spinal cord homogenate or combinations of two different peptides to induce disease,...

  9. Carcino-Embryonic Antigen

    International Nuclear Information System (INIS)

    Tumour marker analysis has increased our understanding of the presence of tumours in the body. Carcino-embryonic antigen, CEA, is one of the best studied tumour markers and has proved an ideal diagnostic adjuvant. It has helped in quantifying the amount of disease present in a patient and thence to make accurate prognosis on the various diagnosed ailments. At UCH, it is observed that there is an increase in cancer related ailments and therefore the need for early diagnosis is more compelling in our environment to mitigate future cost of managing advanced manifestation

  10. An antigen-specific, four-color, B-cell FluoroSpot assay utilizing tagged antigens for detection.

    Science.gov (United States)

    Jahnmatz, Peter; Bengtsson, Theresa; Zuber, Bartek; Färnert, Anna; Ahlborg, Niklas

    2016-06-01

    The FluoroSpot assay, a variant of ELISpot utilizing fluorescent detection, has so far been used primarily for assessment of T cells, where simultaneous detection of several cytokines has allowed a more qualitative analysis of functionally distinct T cells. The potential to measure multiple analytes also presents several advantages when analyzing B cells. Our aim was to develop a B-cell FluoroSpot assay adaptable to studies of a variety of antigens. The assay utilizes anti-IgG antibodies immobilized in 96-well filter membrane plates. During cell culture, IgG antibodies secreted by antibody-secreting cells (ASCs) are captured in the vicinity of each of these cells and the specificity of single ASCs is defined using antigens for detection. The antigens were labeled with biotin or peptide tags enabling secondary detection with fluorophore-conjugated streptavidin or tag-specific antibodies. The assay, utilizing up to four different tag systems and fluorophores simultaneously, was evaluated using hybridomas and immunized splenocytes as ASCs. Assay variants were developed that could: i) identify multiple ASCs with different antigen specificities; ii) detect ASCs showing cross-reactivity with different but related antigens; and iii) define the antigen-specificity and, by including anti-IgG subclass detection reagents, simultaneously determine the IgG subclass of antibodies secreted by ASCs. As demonstrated here, the B-cell FluoroSpot assay using tag-based detection systems provides a versatile and powerful tool to investigate antibody responses by individual cells that can be readily adapted to studies of a variety of antigen-specific ASCs. PMID:26930550

  11. Human leucocyte antigens in tympanosclerosis.

    Science.gov (United States)

    Dursun, G; Acar, A; Turgay, M; Calgüner, M

    1997-02-01

    This study was designed to evaluate the association between certain HLA antigens and tympanosclerosis. The serum concentrations of HLA antigens were measured by a microlymphocytotoxicity technique in patients with tympanosclerosis and compared with a healthy control group. The serum levels of HLA-B35 and -DR3 were significantly higher in the patients with tympanosclerosis. This result suggests that certain types of HLA antigens may play an important role as an indicator or mediator in the pathogenesis of tympanosclerosis. PMID:9088683

  12. Antigenic variants of rabies virus

    OpenAIRE

    Wiktor, TJ; Koprowski, H

    1980-01-01

    Antigenic variants of CVS-11 strain of rabies virus were selected after treatment of virus populations with monoclonal antibodies directed against the glycoprotein antigen of the virus. These variants resisted neutralization by the hybridoma antibody used for their selection. Two independently mutating antigenic sites could be distinguished when five variants were tested with nine hybridoma antibodies. The frequency of single epitope variants in a cloned rabies virus seed was approximately 1:...

  13. The role of FcRn in antigen presentation

    Directory of Open Access Journals (Sweden)

    Kristi eBaker

    2014-08-01

    Full Text Available Immunoglobulins are unique molecules capable of simultaneously recognizing a diverse array of antigens and themselves being recognized by a broad array of receptors. The abundance specifically of the IgG subclass and the variety of signaling receptors to which it binds render this an important immunomodulatory molecule. In addition to the classical Fcγ receptors (FcγR which bind IgG at the cell surface, the neonatal Fc receptor (FcRn is a lifelong resident of the endolysosomal system of most hematopoietic cells where it determines the intracellular fate of both IgG and IgG-containing immune complexes (IgG IC. Crosslinking of FcRn by multivalent IgG IC within antigen presenting cells such as dendritic cells (DC initiates specific mechanisms which result in trafficking of the antigen-bearing IgG IC into compartments from which the antigen can successfully be processed into peptide epitopes compatible with loading onto both MHC class I and II molecules. In turn, this enables the synchronous activation of both CD4+ and CD8+ T cell responses against the cognate antigen, thereby bridging the gap between the humoral and cellular branches of the adaptive immune response. Critically, FcRn-driven T cell priming is efficient at very low doses of antigen due to the exquisite sensitivity of the IgG-mediated antigen delivery system through which it operates. FcRn-mediated antigen presentation has important consequences in tissue compartments replete with IgG and serves not only to determine homeostatic immune activation at a variety of sites but also to induce inflammatory responses upon exposure to antigens perceived as foreign. Therapeutically targeting the pathway by which FcRn enables T cell activation in response to IgG IC is thus a highly attractive prospect not only for the treatment of diseases that are driven by immune complexes but also for manipulating local immune responses against defined antigens such as those present during infections and

  14. Potential of acylated peptides to target the influenza A virus

    Directory of Open Access Journals (Sweden)

    Daniel Lauster

    2015-04-01

    Full Text Available For antiviral drug design, especially in the field of influenza virus research, potent multivalent inhibitors raise high expectations for combating epidemics and pandemics. Among a large variety of covalent and non-covalent scaffold systems for a multivalent display of inhibitors, we created a simple supramolecular platform to enhance the antiviral effect of our recently developed antiviral Peptide B (PeBGF, preventing binding of influenza virus to the host cell. By conjugating the peptide with stearic acid to create a higher-order structure with a multivalent display, we could significantly enhance the inhibitory effect against the serotypes of both human pathogenic influenza virus A/Aichi/2/1968 H3N2, and avian pathogenic A/FPV/Rostock/34 H7N1 in the hemagglutination inhibition assay. Further, the inhibitory potential of stearylated PeBGF (C18-PeBGF was investigated by infection inhibition assays, in which we achieved low micromolar inhibition constants against both viral strains. In addition, we compared C18-PeBGF to other published amphiphilic peptide inhibitors, such as the stearylated sugar receptor mimicking peptide (Matsubara et al. 2010, and the “Entry Blocker” (EB (Jones et al. 2006, with respect to their antiviral activity against infection by Influenza A Virus (IAV H3N2. However, while this strategy seems at a first glance promising, the native situation is quite different from our experimental model settings. First, we found a strong potential of those peptides to form large amyloid-like supramolecular assemblies. Second, in vivo, the large excess of cell surface membranes provides an unspecific target for the stearylated peptides. We show that acylated peptides insert into the lipid phase of such membranes. Eventually, our study reveals serious limitations of this type of self-assembling IAV inhibitors.

  15. Construction of HLA/Peptide Tetramer with Peptide-Linked β2 Microglobulin

    Institute of Scientific and Technical Information of China (English)

    沈传来; ChienchungCHANG; 张建琼; 郭薇; 孟凡岩; 谢维

    2004-01-01

    Analysis of the frequency of antigen-specific cytotoxic T lymphocytes (CTLs) ex vivo is largely dependent on the use of MHC/peptide tetramers. However, the latter reagents have not been widely available, most likely because of their costly and time-consuming production. In this report we utilized an economic strategy to construct HLA/peptide tetramers with recombinant peptide-linked β2 microglobulin (β2m). The HLA-A2-restricted, melanoma antigen MARTl-derived peptide MARTI27-35 (AAGIGILTV) was fused to the N terminus of human β2m through a 15-amino acid (aa)-long linker before being refolded with the recombinant biotinylated HLA-A2 heavy chain ectodomain. The resulted 2-component (2C) monomer was then tetramerized with phycoerythin-labeled streptavidin. The experimental result showed that the 2C HLA-A2/MARTI27-35 monomer was shown to bind to the HLA class Ⅰ complex-specific monoclonal antibody W6/32 and the HLA-A2/MARTI27-35 complex-specific single chain antibody fragment (scFv) 8.3, suggesting the correctness of its specificity. Furthermore, the 2C HLA-A2/MARTI27-35 tetramer detected a specific CD8+ T cell population in HLA-A2-restricted melanoma infiltrating lymphocytes as the conventional 3C HLA-A2/MARTI27-35 tetramer. The yield of 2C HLA-A2/MARTI27-35 monomerwas 2.5 times more than that of the conventional 3C monomer. Taken together, these data indicate that the HLA-A2/MARTI27-35 tetramer can be generated conveniently through the use of MARTI27-35 peptide-β2m fusion proteins, which can facilitate the monitoring of HLA-A2-restricted, MARTl-specific CTL responses in patients with melanoma.

  16. Effects of pre-existing anti-carrier immunity and antigenic element multiplicity on efficacy of a modular virus-like particle vaccine.

    Science.gov (United States)

    Chuan, Yap P; Rivera-Hernandez, Tania; Wibowo, Nani; Connors, Natalie K; Wu, Yang; Hughes, Fiona K; Lua, Linda H L; Middelberg, Anton P J

    2013-09-01

    Modularization of a peptide antigen for presentation on a microbially synthesized murine polyomavirus (MuPyV) virus-like particle (VLP) offers a new alternative for rapid and low-cost vaccine delivery at a global scale. In this approach, heterologous modules containing peptide antigenic elements are fused to and displayed on the VLP carrier, allowing enhancement of peptide immunogenicity via ordered and densely repeated presentation of the modules. This study addresses two key engineering questions pertaining to this platform, exploring the effects of (i) pre-existing carrier-specific immunity on modular VLP vaccine effectiveness and (ii) increase in the antigenic element number per VLP on peptide-specific immune response. These effects were studied in a mouse model and with modular MuPyV VLPs presenting a group A streptococcus (GAS) peptide antigen, J8i. The data presented here demonstrate that immunization with a modular VLP could induce high levels of J8i-specific antibodies despite a strong pre-existing anti-carrier immune response. Doubling of the J8i antigenic element number per VLP did not enhance J8i immunogenicity at a constant peptide dose. However, the strategy, when used in conjunction with increased VLP dose, could effectively increase the peptide dose up to 10-fold, leading to a significantly higher J8i-specific antibody titer. This study further supports feasibility of the MuPyV modular VLP vaccine platform by showing that, in the absence of adjuvant, modularized GAS antigenic peptide at a dose as low as 150 ng was sufficient to raise a high level of peptide-specific IgGs indicative of bactericidal activity. PMID:23532896

  17. PREDICTION OF ANTIGENIC AND BINDING SITES OF NEUROTOXIN 23 OF SCORPION (LYCHASMUCRONACTUS SP.

    Directory of Open Access Journals (Sweden)

    Bharati K Thosare

    2015-07-01

    Full Text Available Identification of antigenic and binding site of protein is highly desirable for the design of vaccines and immunodiagnostics. The present exercise deals with a prediction of antigenic as well as binding sites of neurotoxin 23 of Lychasmucronactus. This species of scorpion having diverse molecules of toxic peptide, the peptide neurotoxin 23 is 96 amino acids long of which 23 to 96 specifically code for neurotoxin. The total of 27 such different ligand binding residue were identified by ConSurf and Raptor X server. The web tool Ellipro which implements Modeller and Jmol viewer, predicted and visualized the linear and discontinuous antibody epitopes ofneurotoxin 23 protein sequence.Thus the information discussed here provides a clue for understanding antigenic site and molecular function of neurotoxin 23.

  18. Plant signalling peptides

    OpenAIRE

    Wiśniewska, Justyna; Trejgell, Alina; Tretyn, Andrzej

    2003-01-01

    Biochemical and genetic studies have identified peptides that play crucial roles in plant growth and development, including defence mechanisms in response to wounding by pests, the control of cell division and expansion, and pollen self-incompatibility. The first two signalling peptides to be described in plants were tomato systemin and phytosulfokine (PSK). There is also biochemical evidence that natriuretic peptide-like molecules, immunologically-relatedt o those found ...

  19. Interaction between a "processed" ovalbumin peptide and Ia molecules

    DEFF Research Database (Denmark)

    Buus, S; Colon, S; Smith, C;

    1986-01-01

    The binding of 125I-labeled immunogenic peptides to purified Ia molecules in detergent solution was examined by equilibrium dialysis. We used the chicken ovalbumin peptide ovalbumin-(323-339)-Tyr, which is immunogenic in the BALB/c mouse and restricted to I-Ad. 125I-labeled ovalbumin-(323-339)-Tyr...... I-Ak but not to I-Ek, I-Ad, or I-Ed. Thus, a specific interaction between Ia and antigen that correlates with the major histocompatibility complex restriction was demonstrated, strongly arguing in favor of a determinant selection hypothesis for such restriction....

  20. Parallel detection of antigen-specific T cell responses by combinatorial encoding of MHC multimers

    DEFF Research Database (Denmark)

    Andersen, Rikke Sick; Kvistborg, Pia; Frøsig, Thomas Mørch;

    2012-01-01

    -dimensional combinatorial matrix, these eight fluorochromes are combined to generate 28 unique two-color codes. By the use of combinatorial encoding, a large number of different T cell populations can be detected in a single sample. The method can be used for T cell epitope mapping, and also for the monitoring of CD8......Fluorescently labeled multimeric complexes of peptide-MHC, the molecular entities recognized by the T cell receptor, have become essential reagents for detection of antigen-specific CD8(+) T cells by flow cytometry. Here we present a method for high-throughput parallel detection of antigen......-specific T cells by combinatorial encoding of MHC multimers. Peptide-MHC complexes are produced by UV-mediated MHC peptide exchange and multimerized in the form of streptavidin-fluorochrome conjugates. Eight different fluorochromes are used for the generation of MHC multimers and, by a two...

  1. Polycyclic peptide therapeutics.

    Science.gov (United States)

    Baeriswyl, Vanessa; Heinis, Christian

    2013-03-01

    Owing to their excellent binding properties, high stability, and low off-target toxicity, polycyclic peptides are an attractive molecule format for the development of therapeutics. Currently, only a handful of polycyclic peptides are used in the clinic; examples include the antibiotic vancomycin, the anticancer drugs actinomycin D and romidepsin, and the analgesic agent ziconotide. All clinically used polycyclic peptide drugs are derived from natural sources, such as soil bacteria in the case of vancomycin, actinomycin D and romidepsin, or the venom of a fish-hunting coil snail in the case of ziconotide. Unfortunately, nature provides peptide macrocyclic ligands for only a small fraction of therapeutic targets. For the generation of ligands of targets of choice, researchers have inserted artificial binding sites into natural polycyclic peptide scaffolds, such as cystine knot proteins, using rational design or directed evolution approaches. More recently, large combinatorial libraries of genetically encoded bicyclic peptides have been generated de novo and screened by phage display. In this Minireview, the properties of existing polycyclic peptide drugs are discussed and related to their interesting molecular architectures. Furthermore, technologies that allow the development of unnatural polycyclic peptide ligands are discussed. Recent application of these technologies has generated promising results, suggesting that polycyclic peptide therapeutics could potentially be developed for a broad range of diseases. PMID:23355488

  2. 9 CFR 113.407 - Pullorum antigen.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Pullorum antigen. 113.407 Section 113... and Reagents § 113.407 Pullorum antigen. Pullorum Antigen shall be produced from a culture of... standard for stained antigen K's and 50 ±10 times McFarland No. 1 standard for tube antigen....

  3. A novel method to measure HLA-DM-susceptibility of peptides bound to MHC class II molecules based on peptide binding competition assay and differential IC(50) determination.

    Science.gov (United States)

    Yin, Liusong; Stern, Lawrence J

    2014-04-01

    HLA-DM (DM) functions as a peptide editor that mediates the exchange of peptides loaded onto MHCII molecules by accelerating peptide dissociation and association kinetics. The relative DM-susceptibility of peptides bound to MHCII molecules correlates with antigen presentation and immunodominance hierarchy, and measurement of DM-susceptibility has been a key effort in this field. Current assays of DM-susceptibility, based on differential peptide dissociation rates measured for individually labeled peptides over a long time base, are difficult and cumbersome. Here, we present a novel method to measure DM-susceptibility based on peptide binding competition assays performed in the presence and absence of DM, reported as a delta-IC(50) (change in 50% inhibition concentration) value. We simulated binding competition reactions of peptides with various intrinsic and DM-catalyzed kinetic parameters and found that under a wide range of conditions the delta-IC(50) value is highly correlated with DM-susceptibility as measured in off-rate assay. We confirmed experimentally that DM-susceptibility measured by delta-IC(50) is comparable to that measured by traditional off-rate assay for peptides with known DM-susceptibility hierarchy. The major advantage of this method is that it allows simple, fast and high throughput measurement of DM-susceptibility for a large set of unlabeled peptides in studies of the mechanism of DM action and for identification of CD4+ T cell epitopes. PMID:24583195

  4. Comparison of melanoma antigens in whole tumor vaccine to those from IIB-MEL-J cells.

    Science.gov (United States)

    McGee, J M; Patten, M R; Malnar, K F; Price, J A; Mayes, J S; Watson, G H

    1999-06-01

    Immunotherapy for melanoma shows promise. Our previous whole tumor (WT) vaccine was noted to have positive clinical effects. We have now developed a new, safer melanoma vaccine that is derived from IIB-MEL-J tissue culture (TC) cells. In this study, we compare by Western blot analyses the antigens in the WT vaccine to antigens in the TC vaccine. Sera from 12 WT vaccine recipients, 8 melanoma patients who received no immunotherapy, and 8 controls served as a source of antibodies to investigate potential antigens in the vaccines. Three major antigenic peptides with approximate molecular weighs of 46, 40, and 36 kDA were present in both vaccines, while two other antigenic peptides with approximate molecular weighs of 68 and 48 kDA were present only in the TC vaccine. The reaction was similar between the patients who received the WT vaccine and those who did not receive the vaccine. Some of the individuals who did not have melanoma showed some reaction, but not to the extent of the melanoma patients. The intensity of immunostaining was greater for the TC vaccine when compared to the WT vaccine, indicating that these proteins are in a higher concentration in the TC vaccine. This new vaccine from IIB-MEL-J tissue culture cells provides a higher yield and a much more consistent source of potentially clinically relevant antigens without risk of infection or contamination by other irrelevant materials. PMID:10850304

  5. THERMODYNAMICS OF PEPTIDE-MHC CLASS II INTERACTIONS: NOT ALL COMPLEXES ARE CREATED EQUAL

    Directory of Open Access Journals (Sweden)

    Andrea eFerrante

    2013-10-01

    Full Text Available The adaptive immune response begins when CD4+ T cells recognize antigenic peptides bound to class II molecules of the Major Histocompatibility Complex (MHCII. The interaction between peptides and MHCII has been historically interpreted as a rigid docking event. However, this model has been challenged by the evidence that conformational flexibility plays an important role in peptide-MHCII complex formation. Thermodynamic analysis of the binding reaction suggests a model of complexation in which the physical-chemical nature of the peptide determines the variability in flexibility of the substates in the peptide-MHC conformational ensemble. This review discusses our understanding of the correlation between thermodynamics of peptide binding and structural features of the resulting complex as well as their impact on HLA-DM activity and on our ability to predict MHCII-restricted epitopes.

  6. Antigen antibody interactions

    CERN Document Server

    DeLisi, Charles

    1976-01-01

    1. 1 Organization of the Immune System One of the most important survival mechanisms of vertebrates is their ability to recognize and respond to the onslaught of pathogenic microbes to which they are conti- ously exposed. The collection of host cells and molecules involved in this recognition­ 12 response function constitutes its immune system. In man, it comprises about 10 cells 20 (lymphocytes) and 10 molecules (immunoglobulins). Its ontogenic development is c- strained by the requirement that it be capable of responding to an almost limitless variety of molecular configurations on foreign substances, while simultaneously remaining inert to those on self components. It has thus evolved to discriminate, with exquisite precision, between molecular patterns. The foreign substances which induce a response, called antigens, are typically large molecules such as proteins and polysaccharides. The portions of these with which immunoglobulins interact are called epitopes or determinants. A typical protein epitope m...

  7. Trypanosoma cruzi: circulating antigens

    Directory of Open Access Journals (Sweden)

    V. Bongertz

    1981-03-01

    Full Text Available Circulating antigens were detected in sera of mice experimentally infected with a high close of Trypanosoma cruzi by reaction with sera from chronically infected mice. The immunodiffusion reaction between homologous acute and chronic sera produced four precipitation lines. By reaction with chronic mouse serum, circulating antingens were detected in sera from heavily infected hamsters, dogs, rabbits and in sera from chagasic patients. A reaction was also found in urine from acutely infected mice and dogs. Trypanosoma cruzi exoantigen was detected in trypanosome culture medium and in the supernatant of infected cell cultures. Attempts to isolate the antigens are described.Antígenos circulantes foram detectados em soros de camundongos infectados experimentalmente com elevadas doses de Trypanosoma cruzi pela reação com soros obtidos de camundongos em fase crônica de infecção. A reação de imunodifusão entre soros homólogos agudo e crônico produziu quatro linhas de precipitação. Por reação com soro crônico de camundongo antígenos circulantes foram detectados em soros de crícetos, cães e coelhos infectados com doses elevadas de Trypanosoma cruzi e em soros de pacientes chagásicos. Uma reação foi também observada com urina de camundongos e cães infectados de forma aguda. Exoantígeno de Trypanosoma cruzi foi detectado em meio de cultura de tripanosomas e em sobrenadantes de culturas de células infectadas. Tentativas de isolamento dos antigenos são descritas.

  8. Antigenic properties of avian hepatitis E virus capsid protein.

    Science.gov (United States)

    Zhao, Qin; Syed, Shahid Faraz; Zhou, En-Min

    2015-10-22

    Avian hepatitis E virus (HEV) is the main causative agent of big liver and spleen disease and hepatitis-splenomegaly syndrome in chickens, and is genetically and antigenically related to mammalian HEVs. HEV capsid protein contains immunodominant epitopes and induces a protective humoral immune response. A better understanding of the antigenic composition of this protein is critically important for the development of effective vaccine and sensitive and specific serological assays. To date, six linear antigenic domains (I-VI) have been characterized in avian HEV capsid protein and analyzed for their applications in the serological diagnosis and vaccine design. Domains I and V induce strong immune response in chickens and are common to avian, human, and swine HEVs, indicating that the shared epitopes hampering differential diagnosis of avian HEV infection. Domains III and IV are not immunodominant and elicit a weak immune response. Domain VI, located in the N-terminal region of the capsid protein, can also trigger an intense immune response, but the anti-domain VI antibodies are transient. The protection analysis showed that the truncated capsid protein containing the C-terminal 268 amino acid residues expressed by the bacterial system can provide protective immunity against avian HEV infection in chickens. However, the synthetic peptides incorporating the different linear antigenic domains (I-VI) and epitopes are non-protective. The antigenic composition of avian HEV capsid protein is altogether complex. To develop an effective vaccine and accurate serological diagnostic methods, more conformational antigenic domains or epitopes are to be characterized in detail. PMID:26340899

  9. Functional Development of the T Cell Receptor for Antigen

    Science.gov (United States)

    Ebert, Peter J.R.; Li, Qi-Jing; Huppa, Johannes B.; Davis, Mark M.

    2016-01-01

    For over three decades now, the T cell receptor (TCR) for antigen has not ceased to challenge the imaginations of cellular and molecular immunologists alike. T cell antigen recognition transcends every aspect of adaptive immunity: it shapes the T cell repertoire in the thymus and directs T cell-mediated effector functions in the periphery, where it is also central to the induction of peripheral tolerance. Yet, despite its central position, there remain many questions unresolved: how can one TCR be specific for one particular peptide-major histocompatibility complex (pMHC) ligand while also binding other pMHC ligands with an immunologically relevant affinity? And how can a T cell’s extreme specificity (alterations of single methyl groups in their ligand can abrogate a response) and sensitivity (single agonist ligands on a cell surface are sufficient to trigger a measurable response) emerge from TCR–ligand interactions that are so low in affinity? Solving these questions is intimately tied to a fundamental understanding of molecular recognition dynamics within the many different contexts of various T cell–antigen presenting cell (APC) contacts: from the thymic APCs that shape the TCR repertoire and guide functional differentiation of developing T cells to the peripheral APCs that support homeostasis and provoke antigen responses in naïve, effector, memory, and regulatory T cells. Here, we discuss our recent findings relating to T cell antigen recognition and how this leads to the thymic development of foreign-antigen-responsive αβT cells. PMID:20800817

  10. Cancer antigen 125 and prognosis

    DEFF Research Database (Denmark)

    Høgdall, Estrid Vilma Solyom

    2008-01-01

    PURPOSE OF REVIEW: This review addresses recently reported progress in cancer antigen 125 as a prognostic marker in patients with ovarian cancer. RECENT FINDINGS: Serum cancer antigen 125 levels measured preoperatively in both early and late stage ovarian cancer may be of prognostic value. Before...... cancer antigen 125 determination may be implemented into clinical practice, cut-off levels must be evaluated and internationally defined. Studies examining serum cancer antigen 125 levels after surgery but before, during, or after treatment confirmed that changes in serum levels are of prognostic value....... Furthermore, recent studies have shown that the level of expression of cancer antigen 125 in tissue may be an independent prognostic indicator in late stage ovarian cancer. SUMMARY: Prognostic markers may potentially help to individualize treatment within subgroups of patients. In a recent study the level of...

  11. Radioimmunological determination of procollagen (type III) and procollagen peptide (type III)

    International Nuclear Information System (INIS)

    The detection of antigens circulating in the blood enables the early recognition of fibrotic processes e.g. liver cirrhosis and hepatitis. One thus uses an anti procollagen (type III) labelled with iodine 125 by the chloramine-T method, or an anti-procollagen peptide (type III) serum which is brought together with a sample of unknown contents. The separation of the antigen-antibody complex is carried out by means of a highly specific antiserum. The procollagen peptide (type III) is produced from calf skin of a foetus or from human aszites fluid. (DG)

  12. Requirements for Peptide-induced T Cell Receptor Downregulation on Naive CD8+ T Cells

    OpenAIRE

    Cai, Zeling; Kishimoto, Hidehiro; Brunmark, Anders; Jackson, Michael R.; Peterson, Per A.; Sprent, Jonathan

    1997-01-01

    The requirements for inducing downregulation of α/β T cell receptor (TCR) molecules on naive major histocompatibility complex class I–restricted T cells was investigated with 2C TCR transgenic mice and defined peptides as antigen. Confirming previous results, activation of 2C T cells in response to specific peptides required CD8 expression on the responder cells and was heavily dependent upon costimulation provided by either B7-1 or ICAM-1 on antigen-presenting cells (APC). These stringent re...

  13. Insulin C-peptide test

    Science.gov (United States)

    C-peptide ... the test depends on the reason for the C-peptide measurement. Ask your health care provider if ... C-peptide is measured to tell the difference between insulin produced by the body and insulin injected ...

  14. A common SNP in ER aminopeptidase 2 induces a specificity switch that leads to altered antigen processing

    OpenAIRE

    Evnouchidou, Irini; Birtley, James; Seregin, Sergey; Papakyriakou, Athanasios; Zervoudi, Efthalia; Samiotaki, Martina; Panayotou, George; Giastas, Petros; Petrakis, Olivia; Georgiadis, Dimitris; Amalfitano, Andrea; Saridakis, Emmanuel; Mavridis, Irene M.; Stratikos, Efstratios

    2012-01-01

    ER aminopeptidases 1 and 2 (ERAP1 and ERAP2) cooperate to trim antigenic peptide precursors for loading onto MHC class I molecules and help regulate the adaptive immune response. Common coding single nucleotide polymorphisms (SNPs) in ERAP1 and ERAP2 have been linked with predisposition to human diseases ranging from viral and bacterial infections to autoimmunity and cancer. It has been hypothesized that altered antigen processing by these enzymes is a causal link to disease etiology but the ...

  15. Lambda-Display: A Powerful Tool for Antigen Discovery

    Directory of Open Access Journals (Sweden)

    Nicola Gargano

    2011-04-01

    Full Text Available Since its introduction in 1985, phage display technology has been successfully used in projects aimed at deciphering biological processes and isolating molecules of practical value in several applications. Bacteriophage lambda, representing a classical molecular cloning and expression system has also been exploited for generating large combinatorial libraries of small peptides and protein domains exposed on its capsid. More recently, lambda display has been consistently and successfully employed for domain mapping, antigen discovery and protein interaction studies or, more generally, in functional genomics. We show here the results obtained by the use of large libraries of cDNA and genomic DNA for the molecular dissection of the human B-cell response against complex pathogens, including protozoan parasites, bacteria and viruses. Moreover, by reviewing the experimental work performed in recent investigations we illustrate the potential of lambda display in the diagnostics field and for identifying antigens useful as targets for vaccine development.

  16. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds known as peptide nucleic acids, bind complementary DNA and RNA strands, and generally do so more strongly than the corresponding DNA or RNA strands while exhibiting increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a...

  17. PNA Peptide chimerae

    DEFF Research Database (Denmark)

    Koch, T.; Næsby, M.; Wittung, P.; Jørgensen, M.; Larsson, C.; Buchardt, O.; Stanly, C.J.; Norden, B.; Nielsen, P.E.; Ørum, H.

    1995-01-01

    Radioactive labelling of PNA has been performed try linking a peptide segment to the PNA which is substrate for protein kinase A. The enzymatic phosphorylation proceeds in almost quantitative yields.......Radioactive labelling of PNA has been performed try linking a peptide segment to the PNA which is substrate for protein kinase A. The enzymatic phosphorylation proceeds in almost quantitative yields....

  18. Gold nanocluster-based vaccines for dual-delivery of antigens and immunostimulatory oligonucleotides

    Science.gov (United States)

    Tao, Yu; Zhang, Yan; Ju, Enguo; Ren, Hui; Ren, Jinsong

    2015-07-01

    We here report a facile one-pot synthesis of fluorescent gold nanoclusters (AuNCs) via the peptide biomineralization method, which can elicit specific immunological responses. The as-prepared peptide-protected AuNCs (peptide-AuNCs) display strong red fluorescence, and more importantly, as compared to the peptide alone, the immune stimulatory ability of the resulting peptide-AuNCs can not only be retained, but can also be efficaciously enhanced. Moreover, through a dual-delivery of antigen peptides and cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (ODNs), the as-prepared peptide-AuNC-CpG conjugates can also act as smart self-vaccines to assist in the generation of high immunostimulatory activity, and be applied as a probe for intracellular imaging. Both in vitro and in vivo studies provide strong evidence that the AuNC-based vaccines may be utilized as safe and efficient immunostimulatory agents that are able to prevent and/or treat a variety of ailments.We here report a facile one-pot synthesis of fluorescent gold nanoclusters (AuNCs) via the peptide biomineralization method, which can elicit specific immunological responses. The as-prepared peptide-protected AuNCs (peptide-AuNCs) display strong red fluorescence, and more importantly, as compared to the peptide alone, the immune stimulatory ability of the resulting peptide-AuNCs can not only be retained, but can also be efficaciously enhanced. Moreover, through a dual-delivery of antigen peptides and cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (ODNs), the as-prepared peptide-AuNC-CpG conjugates can also act as smart self-vaccines to assist in the generation of high immunostimulatory activity, and be applied as a probe for intracellular imaging. Both in vitro and in vivo studies provide strong evidence that the AuNC-based vaccines may be utilized as safe and efficient immunostimulatory agents that are able to prevent and/or treat a variety of ailments. Electronic supplementary information (ESI

  19. Peptide nucleic acids and their potential applications in biotechnology

    DEFF Research Database (Denmark)

    Buchardt, O.; Egholm, M.; Berg, R.H.; Nielsen, P.E.

    1993-01-01

    Peptide nucleic acids (PNAs) are novel DNA mimics in which the sugar-phosphate backbone has been replaced with a backbone based on amino acids1-3. PNAs exhibit sequence-specific binding to DNA and RNA with higher affinities and specificities than unmodified DNA. They,are resistant to nuclease and...... protease attack in serum and cellular extracts and, thus, appear very promising as diagnostic and biomolecular probes, and possibly as antisense and antigene drugs....

  20. Rationally designed inhibitor targeting antigen-trimming aminopeptidases enhances antigen presentation and cytotoxic T-cell responses.

    Science.gov (United States)

    Zervoudi, Efthalia; Saridakis, Emmanuel; Birtley, James R; Seregin, Sergey S; Reeves, Emma; Kokkala, Paraskevi; Aldhamen, Yasser A; Amalfitano, Andrea; Mavridis, Irene M; James, Edward; Georgiadis, Dimitris; Stratikos, Efstratios

    2013-12-01

    Intracellular aminopeptidases endoplasmic reticulum aminopeptidases 1 and 2 (ERAP1 and ERAP2), and as well as insulin-regulated aminopeptidase (IRAP) process antigenic epitope precursors for loading onto MHC class I molecules and regulate the adaptive immune response. Their activity greatly affects the antigenic peptide repertoire presented to cytotoxic T lymphocytes and as a result can regulate cytotoxic cellular responses contributing to autoimmunity or immune evasion by viruses and cancer cells. Therefore, pharmacological regulation of their activity is a promising avenue for modulating the adaptive immune response with possible applications in controlling autoimmunity, in boosting immune responses to pathogens, and in cancer immunotherapy. In this study we exploited recent structural and biochemical analysis of ERAP1 and ERAP2 to design and develop phosphinic pseudopeptide transition state analogs that can inhibit this family of enzymes with nM affinity. X-ray crystallographic analysis of one such inhibitor in complex with ERAP2 validated our design, revealing a canonical mode of binding in the active site of the enzyme, and highlighted the importance of the S2' pocket for achieving inhibitor potency. Antigen processing and presentation assays in HeLa and murine colon carcinoma (CT26) cells showed that these inhibitors induce increased cell-surface antigen presentation of transfected and endogenous antigens and enhance cytotoxic T-cell responses, indicating that these enzymes primarily destroy epitopes in those systems. This class of inhibitors constitutes a promising tool for controlling the cellular adaptive immune response in humans by modulating the antigen processing and presentation pathway. PMID:24248368

  1. Overlapping Synthetic Peptides Encoding TPD52 as Breast Cancer Vaccine in Mice: Prolonged Survival1

    OpenAIRE

    Mirshahidi, Saied; Kramer, Victor G; James B Whitney; Essono, Sosthène; Lee, Sandra; Dranoff, Glenn; Anderson, Karen S.; Ruth M Ruprecht

    2009-01-01

    Peptide-based vaccines, one of several anti-tumor immunization strategies currently under investigation, can elicit both MHC Class I-restricted (CD8+) and Class II-restricted (CD4+) responses. However, the need to identify specific T-cell epitopes in the context of MHC alleles has hampered the application of this approach. We have tested overlapping synthetic peptides (OSP) representing a tumor antigen as a novel approach that bypasses the need for epitope mapping, since OSP contain all possi...

  2. Peptide conjugates for chromosomal gene targeting by triplex-forming oligonucleotides

    OpenAIRE

    Rogers, Faye A.; Manoharan, Muthiah; Rabinovitch, Peter; Ward, David C.; Glazer, Peter M.

    2004-01-01

    Triplex-forming oligonucleotides (TFOs) are DNA-binding molecules, which offer the potential to selectively modulate gene expression. However, the biological activity of TFOs as potential antigene compounds has been limited by cellular uptake. Here, we investigate the effect of cell-penetrating peptides on the biological activity of TFOs as measured in an assay for gene-targeted mutagenesis. Using the transport peptide derived from the third helix of the homeodomain of antennapedia (Antp), we...

  3. Design and Characterization of a Peptide Mimotope of the HIV-1 gp120 Bridging Sheet

    Directory of Open Access Journals (Sweden)

    Guido Poli

    2012-05-01

    Full Text Available The Bridging Sheet domain of HIV-1 gp120 is highly conserved among the HIV-1 strains and allows HIV-1 binding to host cells via the HIV-1 coreceptors. Further, the bridging sheet domain is a major target to neutralize HIV-1 infection. We rationally designed four linear peptide epitopes that mimic the three-dimensional structure of bridging sheet by using molecular modeling. Chemically synthesized peptides BS3 and BS4 showed a fair degree of antigenicity when tested in ELISA with IgG purified from HIV+ broadly neutralizing sera while the production of synthetic peptides BS1 and BS2 failed due to their high degree of hydrophobicity. To overcome this limitation, we linked all four BS peptides to the COOH-terminus of GST protein to test both their antigenicity and immunogenicity. Only the BS1 peptide showed good antigenicity; however, no envelope specific antibodies were elicited upon mice immunization. Therefore we performed further analyses by linking BS1 peptide to the NH2-terminus of the E2 scaffold from the Geobacillus Stearothermophylus PDH complex. The E2-BS1 fusion peptide showed good antigenic results, however only one immunized rabbit elicited good antibody titers towards both the monomeric and oligomeric viral envelope glycoprotein (Env. In addition, moderate neutralizing antibodies response was elicited against two HIV-1 clade B and one clade C primary isolates. These preliminary data validate the peptide mimotope approach as a promising tool to obtain an effective HIV-1 vaccine.

  4. Prediction of peptides binding to MHC class I alleles by partial periodic pattern mining

    OpenAIRE

    Meydan, Cem; Sezerman, Uğur; Sezerman, Ugur; Otu, Hasan

    2009-01-01

    MHC (Major Histocompatibility Complex) is a key player in the immune response of an organism. It is important to be able to predict which antigenic peptides will bind to a spe-cific MHC allele and which will not, creating possibilities for controlling immune response and for the applications of immunotherapy. However a problem encountered in the computational binding prediction methods for MHC class I is the presence of bulges and loops in the peptides, changing the total length. Most machine...

  5. High-sensitivity HLA class I peptidome analysis enables a precise definition of peptide motifs and the identification of peptides from cell lines and patients' sera.

    Science.gov (United States)

    Ritz, Danilo; Gloger, Andreas; Weide, Benjamin; Garbe, Claus; Neri, Dario; Fugmann, Tim

    2016-05-01

    The characterization of peptides bound to human leukocyte antigen (HLA) class I is of fundamental importance for understanding CD8+ T cell-driven immunological processes and for the development of immunomodulatory therapeutic strategies. However, until now, the mass spectrometric analysis of HLA-bound peptides has typically required billions of cells, still resulting in relatively few high-confidence peptide identifications. Capitalizing on the recent developments in mass spectrometry and bioinformatics, we have implemented a methodology for the efficient recovery of acid-eluted HLA peptides after purification with the pan-reactive antibody W6/32 and have identified a total of 27 862 unique peptides with high confidence (1% false discovery rate) from five human cancer cell lines. More than 93% of the identified peptides were eight to 11 amino acids in length and contained signatures that were in excellent agreement with published HLA binding motifs. Furthermore, by purifying soluble HLA class I complexes (sHLA) from sera of melanoma patients, up to 972 high-confidence peptides could be identified, including melanoma-associated antigens already described in the literature. Knowledge of the HLA class I peptidome should facilitate multiplex tetramer technology-based characterization of T cells, and allow the development of patient selection, stratification and immunomodulatory therapeutic strategies. PMID:26992070

  6. Anisotropic microstructured poly(vinyl alcohol) tissue-mimicking phantoms.

    Science.gov (United States)

    Dawson, Andrew; Harris, Paul; Gouws, Gideon

    2010-07-01

    Novel microstructured PVA phantoms mimicking fibrous tissues have been developed using a simple freeze-casting process. Scanning electron micrographs reveal highly anisotropic microstructure with dimensions of the order of 5 to 100 microm. Characterization of an example phantom revealed acoustic properties consistent with those found in fibrous tissues. At 20 MHz, the velocity measured parallel to the microstructure orientation of 1555 ms(-1) was significantly greater than that perpendicular to the microstructure of 1537 ms(-1). The attenuation coefficient was measured to be 5 dBxmm(-1) and proportional to the 1.6 power of frequency, which is in good agreement with that for normal human myocardium. PMID:20639144

  7. Xanthogranulomatous Appendicitis Mimicking Residual Burkitt's Lymphoma After Chemotherapy

    Science.gov (United States)

    Nam, Soomin; Choi, Sung-Eun; Kim, Yu Ri; Baik, Seung Hyuk; Sohn, Seung-Kook

    2016-01-01

    The case of a 23-year-old female treated with aggressive high-dose therapy for Burkitt's lymphoma is reported. A positron emission tomography and computed tomography scan after completion of chemotherapy revealed a residual hypermetabolic lesion in the right pelvic cavity. A pelvic magnetic resonance imaging scan showed circumferential wall thickening at the tip of the appendix. A laparoscopic exploration and appendectomy were performed, and a pathologic examination of the resected appendix revealed xanthogranulomatous appendicitis. This is a rare case of a xanthogranulomatous appendicitis mimicking remnant Burkitt's lymphoma after completion of chemotherapy.

  8. Giant Ectopic Ureter Mimicking Pelvic Organ Prolapse: A Case Report

    OpenAIRE

    Adnan Simsir; Fuat Kizilay; Bilbasar Yildiz; Oktay Nazli

    2011-01-01

    Ectopic ureter is one of the most common urinary tract anomalies. We, herein, present a case of a giant ureter with ectopic orifice, mimicking pelvic organ prolapse, which is the first in the literature. A 59-year-old female patient presenting with frequently recurrent urinary tract infection had grade 3 pelvic organ prolapse. On examination, the organ producing the appearance of prolapse was found to be a right ureter of giant size and was obstructed by a large stone at the distal segment. T...

  9. Primary hepatic tuberculosis mimicking intrahepatic cholangiocarcinoma: report of two cases

    Science.gov (United States)

    2015-01-01

    Hepatic tuberculosis (TB) is usually associated with pulmonary or miliary TB, but primary hepatic TB is very uncommon even in countries with high prevalence of TB. The clinical manifestation of primary hepatic TB is atypical and imaging modalities are unhelpful for differential diagnosis of the liver mass. Image-guided needle biopsy is the best diagnostic method for primary hepatic TB. In the cases presented here, we did not perform liver biopsy because we believed the liver masses were cholangiocarcinoma, but primary hepatic TB was ultimately confirmed by postoperative pathology. Here we report two cases of patients who were diagnosed with primary hepatic TB mimicking mass-forming intrahepatic cholangiocarcinoma. PMID:26236700

  10. A CUTANEOUS HORN MIMICKING POLYDACTYLY: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Funda Tamer

    2015-04-01

    Full Text Available A cutaneous horn is a general name for cornified material protruding from skin. On the other hand, polydactyly is a common congenital anomaly of the hand and foot which is characterized by extra finger or toe. A cutaneous horn might mimick polydactyly by resembling an extra toe. Hereby, we present a 72-year-old white Caucasian male with an extra toe-like projection on his fourth toe. Initially, polydactyly was suspected, however a cutaneous horn was also considered. The lesion was surgically removed. The histopathological examination of the specimen revealed hyperkeratosis, and thus confirmed the  lesion to be a cutaneous horn. 

  11. Xanthogranulomatous Appendicitis Mimicking Residual Burkitt's Lymphoma After Chemotherapy.

    Science.gov (United States)

    Nam, Soomin; Kang, Jeonghyun; Choi, Sung-Eun; Kim, Yu Ri; Baik, Seung Hyuk; Sohn, Seung-Kook

    2016-04-01

    The case of a 23-year-old female treated with aggressive high-dose therapy for Burkitt's lymphoma is reported. A positron emission tomography and computed tomography scan after completion of chemotherapy revealed a residual hypermetabolic lesion in the right pelvic cavity. A pelvic magnetic resonance imaging scan showed circumferential wall thickening at the tip of the appendix. A laparoscopic exploration and appendectomy were performed, and a pathologic examination of the resected appendix revealed xanthogranulomatous appendicitis. This is a rare case of a xanthogranulomatous appendicitis mimicking remnant Burkitt's lymphoma after completion of chemotherapy. PMID:27218100

  12. Epithelioid sarcoma mimicking abscess: review of the MRI appearances

    International Nuclear Information System (INIS)

    A case of epithelioid sarcoma involving the soft tissue of the ankle is presented. The tumor was a hemorrhagic, fluid-filled, multiloculated lesion with inflammatory changes in the surrounding planes. Tuberculous abscess was diagnosed on the basis of the clinical picture, ultrasound and MRI findings. Surgical exploration of the ankle mass was carried out because of lack of local healing while the patient's general and pulmonary status improved on antituberculosis treatment. This was an unusual case of epithelioid sarcoma mimicking a multilocular abscess. (orig.)

  13. Unusual Case of Overt Aortic Dissection Mimicking Aortic Intramural Hematoma.

    Science.gov (United States)

    Disha, Kushtrim; Kuntze, Thomas; Girdauskas, Evaldas

    2016-04-01

    We report an interesting case in which overt aortic dissection mimicked two episodes of aortic intramural hematoma (IMH) (Stanford A, DeBakey I). This took place over the course of four days and had a major influence on the surgical treatment strategy. The first episode of IMH regressed completely within 15 hours after it was clinically diagnosed and verified using imaging techniques. The recurrence of IMH was detected three days thereafter, resulting in an urgent surgical intervention. Overt aortic dissection with evidence of an intimal tear was diagnosed intraoperatively. PMID:27066437

  14. Bulky mediastinal aspergillosis mimicking cancer in an immunocompetent patient.

    Science.gov (United States)

    Stern, Jean-Baptiste; Wyplosz, Benjamin; Validire, Pierre; Angoulvant, Adela; Fregeville, Aude; Caliandro, Raffaele; Gossot, Dominique

    2014-10-01

    We describe the case of a previously healthy 42-year-old woman who presented with a chronic cough and occasional night sweats. Radiologic exploration showed a bulky mediastinal mass surrounding the aortic arch, associated with a left subclavicular lymph node and a cerebral round lesion, mimicking a disseminated lung cancer. Surgical left subclavicular and computed tomography-guided mediastinal biopsy specimens showed granulomatous patterns. Mycologic culture of both samples grew Aspergillus flavus. Resolution was obtained after 9 months of oral voriconazole therapy. PMID:25282220

  15. A huge renal capsular leiomyoma mimicking retroperitoneal sarcoma

    Directory of Open Access Journals (Sweden)

    Lal Anupam

    2009-01-01

    Full Text Available A huge left renal capsular leiomyoma mimicking retroperitoneal sarcoma presented in a patient as an abdominal mass. Computed tomography displayed a large heterogeneous retro-peritoneal mass in the left side of the abdomen with inferior and medial displacement as well as loss of fat plane with the left kidney. Surgical exploration revealed a capsulated mass that was tightly adherent to the left kidney; therefore, total tumor resection with radical left nephrectomy was performed. Histopathology ultimately confirmed the benign nature of the mass. This is the largest leiomyoma reported in literature to the best of our knowledge.

  16. An Adult Gastric Duplication Cyst Mimicking a Gastrointestinal Stromal Tumor.

    Science.gov (United States)

    Yoda, Takenori; Furihata, Makoto; Nagao, Sayaka; Wada, Tomonori

    2016-01-01

    We herein describe a rare case of a 24-year-old man who presented with severe epigastralgia after consuming a considerable amount of broiled meat. Computed tomography revealed a cystic lesion adjacent to the distal stomach, with high intensity on T2-weighted magnetic resonance imaging. Upper endoscopy showed a cystic mass measuring 6 cm in diameter, mimicking a submucosal tumor adjacent to the pyloric valve, with duodenum invagination, characteristic of ball valve syndrome. Endoscopic ultrasonography showed that the lesion was contiguous through the first to the third layer of the stomach. Therefore, we performed distal gastrectomy. Pathology showed that the lesion was a gastric duplication cyst without malignancy. PMID:27580540

  17. Subcutaneous Phaeohyphomycosis Due to Pyrenochaeta romeroi Mimicking a Synovial Cyst

    Science.gov (United States)

    Dinh, Aurélien; Levy, Bruno; Bouchand, Frédérique; Davido, Benjamin; Duran, Clara; Cristi, Marin; Felter, Adrien; Salomon, Jérôme; Ait Ammar, Nawel

    2016-01-01

    Opportunistic subcutaneous fungal infections are increasing nowadays due to the growing number of medical conditions causing immunosuppression, especially organ transplant. The incidence rate of subcutaneous phaeohyphomycosis is very low. Most studies found are case reports. They showed a wide variation of clinical presentations. Pyrenochaeta romeroi, a fungus from the Dematiaceae group is a saprophyte found in soil and plants and a possible causative agent of phaeohyphomycosis. We present a rare case of subcutaneous phaeohyphomycosis caused by P. romeroi mimicking a synovial cyst in a diabetic patient.

  18. Exophytic Atheroma Mimicking Papillary Fibroelastoma Adjacent to the Aortic Valve.

    Science.gov (United States)

    Cho, Tomoki; Tokunaga, Shigehiko; Yasuda, Shota; Izubuchi, Ryo; Masuda, Munetaka

    2015-09-01

    Follow-up echocardiography in a 69-year-old man with alcoholic cardiomyopathy showed a mass above the aortic valve near the left coronary ostium. Transesophageal echocardiography and computed tomography suggested a papillary fibroelastoma with a high risk of embolism. At operation we found an exophytic atheroma adjacent to the left coronary artery orifice. The atheroma was removed, and the patient made an uneventful recovery. We describe this very rare case of an exophytic atheroma mimicking a papillary fibroelastoma situated at the left coronary orifice. PMID:26354633

  19. Hızma Induced Papul of Nose Mimicking Pyogenic Granuloma

    Directory of Open Access Journals (Sweden)

    Mualla Polat

    2014-09-01

    Full Text Available The application of body piercing is popular among young people, who consider it as a sign of marginality, beauty, or group identity. Piercing procedure is observed to cause a large number of complications such as infections, pain, inflammatory reactions, bleeding, dental fractures or fissures, and gingival damage, etc., mostly in young individuals. Hizma is a traditional body ornament worn by Anatolian women via a piercing procedure. Herein, we describe a papule of nose mimicking pyogenic granuloma as an uncommon complication of Hızma.

  20. Common Ewing sarcoma-associated antigens fail to induce natural T cell responses in both patients and healthy individuals.

    Science.gov (United States)

    Altvater, Bianca; Kailayangiri, Sareetha; Theimann, Nadine; Ahlmann, Martina; Farwick, Nicole; Chen, Christiane; Pscherer, Sibylle; Neumann, Ilka; Mrachatz, Gabriele; Hansmeier, Anna; Hardes, Jendrik; Gosheger, Georg; Juergens, Heribert; Rossig, Claudia

    2014-10-01

    Disseminated or relapsed Ewing sarcoma (EwS) has remained fatal in the majority of patients. A promising approach to preventing relapse after conventional therapy is to establish tumor antigen-specific immune control. Efficient and specific T cell memory against the tumor depends on the expansion of rare T cells with native specificity against target antigens overexpressed by the tumor. Candidate antigens in EwS include six-transmembrane epithelial antigen of the prostate-1 (STEAP1), and the human cancer/testis antigens X-antigen family member 1 (XAGE1) and preferentially expressed antigen in melanoma (PRAME). Here, we screened normal donors and EwS patients for the presence of circulating T cells reactive with overlapping peptide libraries of these antigens by IFN-γ Elispot analysis. The majority of 22 healthy donors lacked detectable memory T cell responses against STEAP1, XAGE1 and PRAME. Moreover, ex vivo detection of T cells specific for these antigens in both blood and bone marrow were limited to a minority of EwS patients and required nonspecific T cell prestimulation. Cytotoxic T cells specific for the tumor-associated antigens were efficiently and reliably generated by in vitro priming using professional antigen-presenting cells and optimized cytokine stimulation; however, these T cells failed to interact with native antigen processed by target cells and with EwS cells expressing the antigen. We conclude that EwS-associated antigens fail to induce efficient T cell receptor (TCR)-mediated antitumor immune responses even under optimized conditions. Strategies based on TCR engineering could provide a more effective means to manipulating T cell immunity toward targeted elimination of tumor cells. PMID:24973179

  1. Semi-combinatorial approach for the preparation of linear comb-like glycopeptide dendrimers with Tn antigen using maleimide ligation

    Czech Academy of Sciences Publication Activity Database

    Vepřek, Pavel; Hajdúch, M.; Kelkar, Shripad; Trnka, T.; Ježek, Jan

    Napoli : Edizioni Ziino, 2002 - (Benedetti, E.; Pedone, C.), s. 648-649 ISBN 88-900948-1-8. [Peptides 2002. European Peptide Symposium /27./. Sorrento (IT), 31.08.2002-06.09.2002] R&D Projects: GA ČR GA303/01/0690 Institutional research plan: CEZ:AV0Z4055905 Keywords : Tn antigen * maleimide ligation * glycopeptide dendrimer Subject RIV: CE - Biochemistry

  2. [Antigenic response against PPD and antigen 60 in tubercular patients: single antigen versus the combined test].

    Science.gov (United States)

    Máttar, S; Broquetas, J M; Gea, J; Aran, X; el-Banna, N; Sauleda, J; Torres, J M

    1992-05-01

    We analyze serum samples from 70 patients with pulmonary tuberculosis and 50 healthy individuals. The antigenic activity (IgG) against protein purified antigen (PPD) and antigen 60 (A60) from M. tuberculosis. Thirteen patients were also HIV infected, and three patients had AIDS defined by the presence of disseminated tuberculosis. The test using antigen alone showed a 77% sensitivity and 74% specificity when PPD is used. When A60 was used, both values improved (81% sensitivity, 94% specificity). The use of a combined test (PPD and A60) improves the sensitivity (89%) but reduces the specificity (82%). The HIV infected patients showed similar responses to those of other patients. The combined use of different antigens might be useful for diagnosing tuberculosis. PMID:1390996

  3. CELLULAR VACCINES IN LISTERIOSIS: ROLE OF THE LISTERIA ANTIGEN GAPDH.

    Directory of Open Access Journals (Sweden)

    Ricardo eCalderon-Gonzalez

    2014-02-01

    Full Text Available The use of live Listeria-based vaccines carries serious difficulties when administrated to immunocompromised individuals. However, cellular carriers have the advantage of inducing multivalent innate immunity as well as cell-mediated immune responses, constituting novel and secure vaccine strategies in listeriosis. Here, we compare the protective efficacy of dendritic cells (DCs and macrophages and their safety. We examined the immune response of these vaccine vectors using two Listeria antigens, listeriolysin O (LLO and glyceraldehyde-3-phosphate-dehydrogenase (GAPDH, and several epitopes such as the LLO peptides, LLO189–201 and LLO91–99 and the GAPDH peptide, GAPDH1–22. We discarded macrophages as safe vaccine vectors because they show anti-Listeria protection but also high cytotoxicity. DCs loaded with GAPDH1–22 peptide conferred higher protection and security against listeriosis than the widely explored LLO91–99 peptide. Anti-Listeria protection was related to the changes in DC maturation caused by these epitopes, with high production of interleukin-12 as well as significant levels of other Th1 cytokines such as monocyte chemotactic protein-1, tumor necrosis factor-α, and interferon-γ, and with the induction of GAPDH1–22-specific CD4+ and CD8+ immune responses. This is believed to be the first study to explore the use of a novel GAPDH antigen as a potential DC-based vaccine candidate for listeriosis, whose efficiency appears to highlight the relevance of vaccine designs containing multiple CD4+ and CD8+ epitopes.

  4. Gene transfer strategies for improving radiolabeled peptide imaging and therapy

    International Nuclear Information System (INIS)

    Utilization of molecular biology techniques offers attractive options in nuclear medicine for improving cancer imaging and therapy with radiolabeled peptides. Two of these options include utilization of phage-panning to identify novel tumor specific peptides or single chain antibodies and gene transfer techniques to increase the antibodies and gene transfer techniques to increase the number of antigen/receptor sites expressed on malignant cells. The group has focused on the latter approach for improving radiolabeled peptide imaging and therapy. The most widely used gene transfer vectors in clinical gene therapy trials include retrovirus, cationic lipids and adenovirus. It has been utilized adenovirus vectors for gene transfer because of their ability to accomplish efficient in vivo gene transfer. Adenovirus vectors encoding the genes for a variety of antigens/receptors (carcinoembryonic antigen, gastrin-releasing peptide receptor, somatostatin receptor subtype 2 (SSTr2) have all shown that their expression is increased on cancer cells both in vitro and in vivo following adenovirus infection. Of particular interest has been the adenovirus encoding for SSTr2 (AdCMVSSTr2). Various radioisotopes have been attached to somatostatin analogues for imaging and therapy of SSTr2-positive tumors both clinically and in animal models. The use of these analogues in combination with AdCMVSSTr2 is a promising approach for improving the detection sensitivity and therapeutic efficacy of these radiolabeled peptides against solid tumors. In addition, it has been proposed the use of SSTr2 as a marker for imaging the expression of another cancer therapeutic transgene (e.g. cytosine deaminase, thymidine kinase) encoded within the same vector. This would allow for non-invasive monitoring of gene delivery to tumor sites

  5. Gene transfer strategies for improving radiolabeled peptide imaging and therapy

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, B.E.; Buchsbaum, D.J. [Birmingham University of Alabama, Birmingham, AL (United States). Dept. of Radiation Oncology; Zinn, K.R. [Birmingham University of Alabama, Birmingham, AL (United States). Radiology

    2000-09-01

    Utilization of molecular biology techniques offers attractive options in nuclear medicine for improving cancer imaging and therapy with radiolabeled peptides. Two of these options include utilization of phage-panning to identify novel tumor specific peptides or single chain antibodies and gene transfer techniques to increase the antibodies and gene transfer techniques to increase the number of antigen/receptor sites expressed on malignant cells. The group has focused on the latter approach for improving radiolabeled peptide imaging and therapy. The most widely used gene transfer vectors in clinical gene therapy trials include retrovirus, cationic lipids and adenovirus. It has been utilized adenovirus vectors for gene transfer because of their ability to accomplish efficient in vivo gene transfer. Adenovirus vectors encoding the genes for a variety of antigens/receptors (carcinoembryonic antigen, gastrin-releasing peptide receptor, somatostatin receptor subtype 2 (SSTr2)) have all shown that their expression is increased on cancer cells both in vitro and in vivo following adenovirus infection. Of particular interest has been the adenovirus encoding for SSTr2 (AdCMVSSTr2). Various radioisotopes have been attached to somatostatin analogues for imaging and therapy of SSTr2-positive tumors both clinically and in animal models. The use of these analogues in combination with AdCMVSSTr2 is a promising approach for improving the detection sensitivity and therapeutic efficacy of these radiolabeled peptides against solid tumors. In addition, it has been proposed the use of SSTr2 as a marker for imaging the expression of another cancer therapeutic trans gene (e.g., cytosine deaminase, thymidine kinase) encoded within the same vector. This would allow for non-invasive monitoring of gene delivery to tumor sites.

  6. COLONOSCOPY AND CARCINOEMBRYONIC ANTIGEN VARIATIONS

    Directory of Open Access Journals (Sweden)

    Rita G SOUSA

    2014-03-01

    Full Text Available Context Colonoscopy is essential for synchronous and metachronous cancer detection. Carcinoembryonic antigen is a colorectal cancer tumor marker, important as a follow-up tool in patients with previous colorectal cancer. False-positive carcinoembryonic antigen elevation results in multiples exams and in patient anxiety. In literature, there is reference to transient carcinoembryonic antigen increase with colonoscopy. Objective To evaluate the influence of bowel preparation and colonoscopy in carcinoembryonic antigen blood levels. Methods We prospectively studied subjects that underwent routine colonoscopy in our institution. Blood samples were collected (1 before bowel cleaning, (2 before colonoscopy and (3 immediately after colonoscopy. Blood carcinoembryonic antigen levels were determined by “Sandwich” immunoassay. The statistical methods used were the paired t-test and ANOVA. Results Thirty-seven patients (22M/15F were included; age range 28-84 (mean 56 years. Mean carcinoembryonic antigen values were 1.9, 2 and 1.8 for (1, (2 and (3, respectively. An increase in value (2 compared with (1 was observed in 20/37 patients (P = 0.018, mainly in younger patients and in patients requiring more endoluminal interventions. In 29/37 patients, the CEA value decreased from (2 to (3 (P = 1.3x10-7. Conclusions A trend for carcinoembryonic antigen increase after bowel cleaning was observed, especially in younger patients and in patients with more endoluminal interventions, but without clinical meaning.

  7. Improving therapeutic HPV peptide-based vaccine potency by enhancing CD4+ T help and dendritic cell activation

    Directory of Open Access Journals (Sweden)

    Hung Chien-Fu

    2010-11-01

    Full Text Available Abstract Background Effective vaccination against human papillomavirus (HPV represents an opportunity to control cervical cancer. Peptide-based vaccines targeting HPV E6 and/or E7 antigens while safe, will most likely require additional strategies to enhance the vaccine potency. Methods We tested the HPV-16 E7 peptide-based vaccine in combination with a strategy to enhance CD4+ T help using a Pan HLA-DR epitope (PADRE peptide and a strategy to enhance dendritic cell activation using the toll-like receptor 3 ligand, poly(I:C. Results We observed that mice vaccinated with E7 peptide-based vaccine in combination with PADRE peptide and poly(I:C generated better E7-specific CD8+ T cell immune responses as well as significantly improved therapeutic anti-tumor effects against TC-1 tumors compared to E7 peptide-based vaccine with either PADRE peptide or poly(I:C alone. Furthermore, we found that intratumoral vaccination with the E7 peptide in conjunction with PADRE peptide and poly(I:C generates a significantly higher frequency of E7-specific CD8+ T cells as well as better survival compared to subcutaneous vaccination with the same regimen in treated mice. Conclusions The combination of PADRE peptide and poly(I:C with antigenic peptide is capable of generating potent antigen-specific CD8+ T cell immune responses and antitumor effects in vaccinated mice. Our study has significant clinical implications for peptide-based vaccination.

  8. The internal sequence of the peptide-substrate determines its N-terminus trimming by ERAP1.

    Directory of Open Access Journals (Sweden)

    Irini Evnouchidou

    Full Text Available BACKGROUND: Endoplasmic reticulum aminopeptidase 1 (ERAP1 trims N-terminally extended antigenic peptide precursors down to mature antigenic peptides for presentation by major histocompatibility complex (MHC class I molecules. ERAP1 has unique properties for an aminopeptidase being able to trim peptides in vitro based on their length and the nature of their C-termini. METHODOLOGY/PRINCIPAL FINDINGS: In an effort to better understand the molecular mechanism that ERAP1 uses to trim peptides, we systematically analyzed the enzyme's substrate preferences using collections of peptide substrates. We discovered strong internal sequence preferences of peptide N-terminus trimming by ERAP1. Preferences were only found for positively charged or hydrophobic residues resulting to trimming rate changes by up to 100 fold for single residue substitutions and more than 40,000 fold for multiple residue substitutions for peptides with identical N-termini. Molecular modelling of ERAP1 revealed a large internal cavity that carries a strong negative electrostatic potential and is large enough to accommodate peptides adjacent to the enzyme's active site. This model can readily account for the strong preference for positively charged side chains. CONCLUSIONS/SIGNIFICANCE: To our knowledge no other aminopeptidase has been described to have such strong preferences for internal residues so distal to the N-terminus. Overall, our findings indicate that the internal sequence of the peptide can affect its trimming by ERAP1 as much as the peptide's length and C-terminus. We therefore propose that ERAP1 recognizes the full length of its peptide-substrate and not just the N- and C- termini. It is possible that ERAP1 trimming preferences influence the rate of generation and the composition of antigenic peptides in vivo.

  9. Antibody reactivities to glutamate-rich peptides of Plasmodium falciparum parasites in humans from areas of different malaria endemicity

    DEFF Research Database (Denmark)

    Jakobsen, P.H.; Theander, T.G.; Hvid, L; Morris-Jones, S.; Jensen, J.B.; Bayoumi, R.A.L.; Greenwood, B.M.; Bygbjerg, I.C.; Heegaard, Peter M. H.

    1996-01-01

    individuals from malaria-endemic areas of Sudan, Indonesia and The Gambia to study antibody responses to these peptides in donors living in areas of different malaria endemicity. IgG and IgM reactivities to the peptides increased with malaria endemicity, although there were no differences in reactivities to...... peptides tested were shortlived in most patients. In Gambian children with malaria, IgM reactivities but not IgG antibody reactivities against the ABRA peptide were higher in those with mild malaria than in those with severe malaria. The peptides may be useful in future epidemiological studies, especially......Synthetic P. falciparum peptides were evaluated as tools in epidemiological investigations of malaria. Plasma IgM and IgG antibody reactivities against synthetic peptides covering sequences of glutamate-rich protein (GLURP) and acidic-basic repeat antigen (ABRA) were measured by ELISA in...

  10. Liposome-Based Adjuvants for Subunit Vaccines: Formulation Strategies for Subunit Antigens and Immunostimulators

    Directory of Open Access Journals (Sweden)

    Signe Tandrup Schmidt

    2016-03-01

    Full Text Available The development of subunit vaccines has become very attractive in recent years due to their superior safety profiles as compared to traditional vaccines based on live attenuated or whole inactivated pathogens, and there is an unmet medical need for improved vaccines and vaccines against pathogens for which no effective vaccines exist. The subunit vaccine technology exploits pathogen subunits as antigens, e.g., recombinant proteins or synthetic peptides, allowing for highly specific immune responses against the pathogens. However, such antigens are usually not sufficiently immunogenic to induce protective immunity, and they are often combined with adjuvants to ensure robust immune responses. Adjuvants are capable of enhancing and/or modulating immune responses by exposing antigens to antigen-presenting cells (APCs concomitantly with conferring immune activation signals. Few adjuvant systems have been licensed for use in human vaccines, and they mainly stimulate humoral immunity. Thus, there is an unmet demand for the development of safe and efficient adjuvant systems that can also stimulate cell-mediated immunity (CMI. Adjuvants constitute a heterogeneous group of compounds, which can broadly be classified into delivery systems or immunostimulators. Liposomes are versatile delivery systems for antigens, and they can carefully be customized towards desired immune profiles by combining them with immunostimulators and optimizing their composition, physicochemical properties and antigen-loading mode. Immunostimulators represent highly diverse classes of molecules, e.g., lipids, nucleic acids, proteins and peptides, and they are ligands for pattern-recognition receptors (PRRs, which are differentially expressed on APC subsets. Different formulation strategies might thus be required for incorporation of immunostimulators and antigens, respectively, into liposomes, and the choice of immunostimulator should ideally be based on knowledge regarding the

  11. Leptospirosis mimicking sepsis after orthopedic surgery: a case report

    Directory of Open Access Journals (Sweden)

    C. S. Abboud

    2001-10-01

    Full Text Available We report a case of leptospirosis that occurred after elective surgery involving tendon transfer and shoulder arthroscopy. The disease mimicked hospital infection after orthopedic surgery and was at first misdiagnosed as post-operative sepsis. The patient was 60 year old female that developed sepsis with hypotension, shock, bleeding, jaundice and renal insufficiency 4 hours after surgery. Shock treatment procedures were performed and broad spectrum antibiotic therapy was used with coverage for bacteria acquired in hospitals. A careful investigation was carried out by the Hospital Infection Control Service in search of the possible source of the infection. After clinical evaluation by a specialist in infectious diseases, the hypothesis of leptospirosis was put forward based on clinical and epidemiological data. The hypothesis was later confirmed by the positive result of serological tests with the microagglutination method that yielded 1:800 and then 1:12,600 7 days later. This is the first reported case of leptospirosis manifest directly following surgery, mimicking postoperative sepsis.

  12. New insights into the bioactivity of peptides from probiotics.

    Science.gov (United States)

    Mandal, Santi M; Pati, Bikas R; Chakraborty, Ranadhir; Franco, Octavio L

    2016-01-01

    Probiotics are unique bacteria that offer several therapeutic benefits to human beings when administered in optimum amounts. Probiotics are able to produce antimicrobial substances, which stimulate the body's immune responses. Here, we review in detail the anti-infective peptides derived from probiotics and their potential immunomodulatory and anti-inflammatory activities, including a major role in cross-talk between probiotics and gut microbiota under adverse conditions. Insights from the engineered cell surface of probiotics may provide novel anti-infective therapy by heterologous expression of receptor peptides of bacterial toxins. It may be possible to use antigenic peptides from viral pathogens as live vaccines. Another possibility is to generate antiviral peptides that bind directly to virus particles, while some peptides exert anti-inflammatory and anticancer effects. Some extracellular polymeric substances might serve as anti-infective peptides. These avenues of treatment have remained largely unexplored to date, despite their potential in generating powerful anti-inflammatory and anti-infective products. PMID:27100351

  13. Structural and Functional Studies of Peptide-Carbohydrate Mimicry

    Science.gov (United States)

    Johnson, Margaret A.; Pinto, B. Mario

    Certain peptides act as molecular mimics of carbohydrates in that they are specifically recognized by carbohydrate-binding proteins. Peptides that bind to anti-carbohydrate antibodies, carbohydrate-processing enzymes, and lectins have been identified. These peptides are potentially useful as vaccines and therapeutics; for example, immunologically functional peptide molecular mimics (mimotopes) can strengthen or modify immune responses induced by carbohydrate antigens. However, peptides that bind specifically to carbohydrate-binding proteins may not necessarily show the corresponding biological activity, and further selection based on biochemical studies is always required. The degree of structural mimicry required to generate the desired biological activity is therefore an interesting question. This review will discuss recent structural studies of peptide-carbohydrate mimicry employing NMR spectroscopy, X-ray crystallography, and molecular modeling, as well as relevant biochemical data. These studies provide insights into the basis of mimicry at the molecular level. Comparisons with other carbohydrate-mimetic compounds, namely proteins and glycopeptides, will be drawn. Finally, implications for the design of new therapeutic compounds will also be presented.

  14. Serum peptide reactivities may distinguish neuromyelitis optica subgroups and multiple sclerosis

    Science.gov (United States)

    Metz, Imke; Beißbarth, Tim; Ellenberger, David; Pache, Florence; Stork, Lidia; Ringelstein, Marius; Aktas, Orhan; Jarius, Sven; Wildemann, Brigitte; Dihazi, Hassan; Friede, Tim; Ruprecht, Klemens; Paul, Friedemann

    2016-01-01

    Objective: To assess in an observational study whether serum peptide antibody reactivities may distinguish aquaporin-4 (AQP4) antibody (Ab)–positive and -negative neuromyelitis optica spectrum disorders (NMOSD) and relapsing-remitting multiple sclerosis (RRMS). Methods: We screened 8,700 peptides that included human and viral antigens of potential relevance for inflammatory demyelinating diseases and random peptides with pooled sera from different patient groups and healthy controls to set up a customized microarray with 700 peptides. With this microarray, we tested sera from 66 patients with AQP4-Ab-positive (n = 16) and AQP4-Ab-negative (n = 19) NMOSD, RRMS (n = 11), and healthy controls (n = 20). Results: Differential peptide reactivities distinguished NMOSD subgroups from RRMS in 80% of patients. However, the 2 NMOSD subgroups were not well-discriminated, although those patients are clearly separated by their antibody reactivities against AQP4 in cell-based assays. Elevated reactivities to myelin and Epstein-Barr virus peptides were present in RRMS and to AQP4 and AQP1 peptides in AQP4-Ab-positive NMOSD. Conclusions: While AQP4-Ab-positive and -negative NMOSD subgroups are not well-discriminated by peptide antibody reactivities, our findings suggest that peptide antibody reactivities may have the potential to distinguish between both NMOSD subgroups and MS. Future studies should thus concentrate on evaluating peptide antibody reactivities for the differentiation of AQP4-Ab-negative NMOSD and MS. PMID:26894206

  15. Statistical deconvolution of enthalpic energetic contributions to MHC-peptide binding affinity

    Directory of Open Access Journals (Sweden)

    Drew Michael GB

    2006-03-01

    Full Text Available Abstract Background MHC Class I molecules present antigenic peptides to cytotoxic T cells, which forms an integral part of the adaptive immune response. Peptides are bound within a groove formed by the MHC heavy chain. Previous approaches to MHC Class I-peptide binding prediction have largely concentrated on the peptide anchor residues located at the P2 and C-terminus positions. Results A large dataset comprising MHC-peptide structural complexes was created by re-modelling pre-determined x-ray crystallographic structures. Static energetic analysis, following energy minimisation, was performed on the dataset in order to characterise interactions between bound peptides and the MHC Class I molecule, partitioning the interactions within the groove into van der Waals, electrostatic and total non-bonded energy contributions. Conclusion The QSAR techniques of Genetic Function Approximation (GFA and Genetic Partial Least Squares (G/PLS algorithms were used to identify key interactions between the two molecules by comparing the calculated energy values with experimentally-determined BL50 data. Although the peptide termini binding interactions help ensure the stability of the MHC Class I-peptide complex, the central region of the peptide is also important in defining the specificity of the interaction. As thermodynamic studies indicate that peptide association and dissociation may be driven entropically, it may be necessary to incorporate entropic contributions into future calculations.

  16. Descriptors for antimicrobial peptides

    DEFF Research Database (Denmark)

    Jenssen, Håvard

    2011-01-01

    Introduction: A frightening increase in the number of isolated multidrug resistant bacterial strains linked to the decline in novel antimicrobial drugs entering the market is a great cause for concern. Cationic antimicrobial peptides (AMPs) have lately been introduced as a potential new class of...... antimicrobial drugs, and computational methods utilizing molecular descriptors can significantly accelerate the development of new peptide drug candidates. Areas covered: This paper gives a broad overview of peptide and amino-acid scale descriptors available for AMP modeling and highlights which of these are...

  17. Comprehensive Analysis of Contributions from Protein Conformational Stability and Major Histocompatibility Complex Class II-Peptide Binding Affinity to CD4+ Epitope Immunogenicity in HIV-1 Envelope Glycoprotein

    OpenAIRE

    Li, Tingfeng; Steede, N. Kalaya; Nguyen, Hong-Nam P.; Freytag, Lucy C.; McLachlan, James B.; Mettu, Ramgopal R.; Robinson, James E.; Landry, Samuel J.

    2014-01-01

    Helper T-cell epitope dominance in human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 is not adequately explained by peptide binding to major histocompatibility complex (MHC) proteins. Antigen processing potentially influences epitope dominance, but few, if any, studies have attempted to reconcile the influences of antigen processing and MHC protein binding for all helper T-cell epitopes of an antigen. Epitopes of gp120 identified in both humans and mice occur on the C-te...

  18. Oncogenic cancer/testis antigens

    DEFF Research Database (Denmark)

    Gjerstorff, Morten F; Andersen, Mads H; Ditzel, Henrik J

    2015-01-01

    Recent developments have set the stage for immunotherapy as a supplement to conventional cancer treatment. Consequently, a significant effort is required to further improve efficacy and specificity, particularly the identification of optimal therapeutic targets for clinical testing. Cancer....../testis antigens are immunogenic, highly cancer-specific, and frequently expressed in various types of cancer, which make them promising candidate targets for cancer immunotherapy, including cancer vaccination and adoptive T-cell transfer with chimeric T-cell receptors. Our current understanding of tumor...... immunology and immune escape suggests that targeting oncogenic antigens may be beneficial, meaning that identification of cancer/testis antigens with oncogenic properties is of high priority. Recent work from our lab and others provide evidence that many cancer/testis antigens, in fact, have oncogenic...

  19. Modulation of Backbone Flexibility for Effective Dissociation of Antibacterial and Hemolytic Activity in Cyclic Peptides.

    Science.gov (United States)

    Oddo, Alberto; Thomsen, Thomas T; Britt, Hannah M; Løbner-Olesen, Anders; Thulstrup, Peter W; Sanderson, John M; Hansen, Paul R

    2016-08-11

    Bacterial resistance to antibiotic therapy is on the rise and threatens to evolve into a worldwide emergency: alternative solutions to current therapies are urgently needed. Cationic amphipathic peptides are potent membrane-active agents that hold promise as the next-generation therapy for multidrug-resistant infections. The peptides' behavior upon encountering the bacterial cell wall is crucial, and much effort has been dedicated to the investigation and optimization of this amphipathicity-driven interaction. In this study we examined the interaction of a novel series of nine-membered flexible cyclic AMPs with liposomes mimicking the characteristics of bacterial membranes. Employed techniques included circular dichroism and marker release assays, as well as microbiological experiments. Our analysis was aimed at correlating ring flexibility with their antimicrobial, hemolytic, and membrane activity. By doing so, we obtained useful insights to guide the optimization of cyclic antimicrobial peptides via modulation of their backbone flexibility without loss of activity. PMID:27563396

  20. Isolation and identification of renal cell carcinoma-derived peptides associated with GP96.

    Science.gov (United States)

    Li, H-Z; Li, C-W; Li, C-Y; Zhang, B-F; Li, L-T; Li, J-M; Zheng, J-N; Chang, J-W

    2013-08-01

    We determined the possible associated determinants and analyzed whether gp96-_associated antigenic peptides can be found in renal cell carcinoma (RCC). The gp96-peptide complexes were chromatographically purified from resected tumor tissue of RCC patients. SDS-PAGE and Western blot analysis confirmed gp96 using the gp96 monoclonal antibody, and its concentration was measured using BCA. Approximately 20 to 50 μg gp96-peptide complexes was obtained from 1 g RCC tissue. The mass spectrometry (MS) analysis of the eluted peptides included the initial profiling using matrix-assisted laser desorption/ionization time-of-flight MS. Quadrupole time-of-flight MS combined with the Mascot search engine was used to identify the peptides and find proteins from primary sequence databases. MS analysis results demonstrated that the mass range of peptide associated with gp96 was from 1046.48 to 3501.56 Da. Further research confirmed the sequences of two gp96-associated peptides, namely, LVPLEGWGGNVM and PPVYYVPYVVL. However, the original protein of the two peptides could not be found. The results demonstrated that the gp96-associated peptides are small molecular peptides, and the two peptides are deduced to be RCC-associated peptides. The identified peptides were confirmed to be associated with gp96 using the protocols described above. However, the specificity and relevance of the association to the immunogenicity of gp96 remains to be examined. Further analysis must be accomplished before the findings can be applied in peptide vaccine. PMID:23448575

  1. Sarcocystis neurona Merozoites Express a Family of Immunogenic Surface Antigens That Are Orthologues of the Toxoplasma gondii Surface Antigens (SAGs) and SAG-Related Sequences†

    OpenAIRE

    Howe, Daniel K.; Rajshekhar Y Gaji; Mroz-Barrett, Meaghan; Gubbels, Marc-Jan; Striepen, Boris; Stamper, Shelby

    2005-01-01

    Sarcocystis neurona is a member of the Apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. Analysis of an S. neurona expressed sequence tag (EST) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (SAGs) and SAG-related sequences of Toxoplasma gondii. The primary peptide sequences of the S. neurona proteins are consistent with the two-domain structure that has been describe...

  2. δ-Peptides from RuAAC-Derived 1,5-Disubstituted Triazole Units

    KAUST Repository

    Johansson, Johan R.

    2014-02-14

    Non-natural peptides with structures and functions similar to natural peptides have emerged lately in biomedical as well as nanotechnological contexts. They are interesting for pharmaceutical applications since they can adopt structures with new targeting potentials and because they are generally not prone to degradation by proteases. We report here a new set of peptidomimetics derived from δ-peptides, consisting of n units of a 1,5-disubstituted 1,2,3-triazole amino acid (5Tzl). The monomer was prepared using ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) chemistry using [RuCl2Cp]x as the catalyst, allowing for simpler purification and resulting in excellent yields. This achiral monomer was used to prepare peptide oligomers that are water soluble independent of peptide chain length. Conformational analysis and structural investigations of the oligomers were performed by 2D NOESY NMR experiments, and by quantum chemical calculations using the ωB97X-D functional. These data indicate that several conformations may co-exist with slight energetic differences. Together with their increased hydrophilicity, this feature of homo-5Tzl may prove essential for mimicking natural peptides composed of α-amino acids, where the various secondary structures are achieved by side chain effects and not by the rigidity of the peptide backbone. The improved synthetic method allows for facile variation of the 5Tzl amino acid side chains, further increasing the versatility of these compounds. A new set of non-natural peptides composed of 1,5-disubstituted 1,2,3-triazole amino acids is presented. These peptides benefit from: a) modular synthesis of the monomers, allowing variation of the side chains; b) increased solubility of the oligomers in water, irrespective of peptide length; c) flexibility of the backbone allowing these foldamers to adopt several conformations. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Natural Selection Promotes Antigenic Evolvability

    OpenAIRE

    Graves, C.J.; Ros, V.I.D.; Stevenson, B.; Sniegowski, P. D.; Brisson, D.

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed ‘cassettes...

  4. Discovery of Novel Plasmodium falciparum Pre-Erythrocytic Antigens for Vaccine Development.

    Directory of Open Access Journals (Sweden)

    Joao C Aguiar

    Full Text Available Nearly 100% protection against malaria infection can be achieved in humans by immunization with P. falciparum radiation-attenuated sporozoites (RAS. Although it is thought that protection is mediated by T cell and antibody responses, only a few of the many pre-erythrocytic (sporozoite and liver stage antigens that are targeted by these responses have been identified.Twenty seven P. falciparum pre-erythrocytic antigens were selected using bioinformatics analysis and expression databases and were expressed in a wheat germ cell-free protein expression system. Recombinant proteins were recognized by plasma from RAS-immunized subjects, and 21 induced detectable antibody responses in mice and rabbit and sera from these immunized animals were used to characterize these antigens. All 21 proteins localized to the sporozoite: five localized to the surface, seven localized to the micronemes, cytoplasm, endoplasmic reticulum or nucleus, two localized to the surface and cytoplasm, and seven remain undetermined. PBMC from RAS-immunized volunteers elicited positive ex vivo or cultured ELISpot responses against peptides from 20 of the 21 antigens.These T cell and antibody responses support our approach of using reagents from RAS-immunized subjects to screen potential vaccine antigens, and have led to the identification of a panel of novel P. falciparum antigens. These results provide evidence to further evaluate these antigens as vaccine candidates.ClinicalTrials.gov NCT00870987 ClinicalTrials.gov NCT00392015.

  5. Discovery of Novel Plasmodium falciparum Pre-Erythrocytic Antigens for Vaccine Development

    Science.gov (United States)

    Aguiar, Joao C.; Bolton, Jessica; Wanga, Joyce; Sacci, John B.; Iriko, Hideyuki; Mazeika, Julie K.; Han, Eun-Taek; Limbach, Keith; Patterson, Noelle B.; Sedegah, Martha; Cruz, Ann-Marie; Tsuboi, Takafumi; Hoffman, Stephen L.; Carucci, Daniel; Hollingdale, Michael R.; Villasante, Eileen D.; Richie, Thomas L.

    2015-01-01

    Background Nearly 100% protection against malaria infection can be achieved in humans by immunization with P. falciparum radiation-attenuated sporozoites (RAS). Although it is thought that protection is mediated by T cell and antibody responses, only a few of the many pre-erythrocytic (sporozoite and liver stage) antigens that are targeted by these responses have been identified. Methodology Twenty seven P. falciparum pre-erythrocytic antigens were selected using bioinformatics analysis and expression databases and were expressed in a wheat germ cell-free protein expression system. Recombinant proteins were recognized by plasma from RAS-immunized subjects, and 21 induced detectable antibody responses in mice and rabbit and sera from these immunized animals were used to characterize these antigens. All 21 proteins localized to the sporozoite: five localized to the surface, seven localized to the micronemes, cytoplasm, endoplasmic reticulum or nucleus, two localized to the surface and cytoplasm, and seven remain undetermined. PBMC from RAS-immunized volunteers elicited positive ex vivo or cultured ELISpot responses against peptides from 20 of the 21 antigens. Conclusions These T cell and antibody responses support our approach of using reagents from RAS-immunized subjects to screen potential vaccine antigens, and have led to the identification of a panel of novel P. falciparum antigens. These results provide evidence to further evaluate these antigens as vaccine candidates. Trial Registration ClinicalTrials.gov NCT00870987 ClinicalTrials.gov NCT00392015 PMID:26292257

  6. Antigens linked to synthetic microspheres induce immune responses in primates in the absence of adjuvant.

    Science.gov (United States)

    Sedlik, C; Perraut, R; Bonnemains, B; Leclerc, C

    1996-01-01

    Although most strategies of vaccination require immunopotentiation to induce efficient immune responses, the development of new adjuvants for human vaccines is highly limited by safety problems. In order to overcome this problem, we developed a new vaccine formulation based on the covalent linkage of protein or peptide to synthetic microspheres. In previous experiments performed in mice, we demonstrated that these particulate antigens induce strong antigen-specific CD4+ T cell proliferative responses in the absence of adjuvant. In the present study, we analyzed the immunogenicity in primate Saimiri sciureus monkeys of two different proteins linked to synthetic microspheres. Immune responses induced by these particulate proteins administered without adjuvant were compared to those stimulated by the soluble antigens injected with alum. We currently demonstrated that, in monkeys, particulate antigens administered without adjuvant, induced good PBMC proliferative response and antibody production. Furthermore, the analysis of antibody responses using mAbs specific for different Saimiri sciureus immunoglobulins showed that the antibody response profiles were different in monkeys immunized with soluble versus particulate form of antigens. Results of this study demonstrate that particulate form of antigen may stimulate qualitatively different immune responses as compared to alum and therefore suggest that this new antigen formulation could be an attractive candidate for the development of vaccines. PMID:8852604

  7. Assembly and antigenicity of the Neisseria gonorrhoeae pilus mapped with antibodies.

    Science.gov (United States)

    Forest, K T; Bernstein, S L; Getzoff, E D; So, M; Tribbick, G; Geysen, H M; Deal, C D; Tainer, J A

    1996-02-01

    The relationship between the sequence of Neisseria gonorrhoeae pilin and its quaternary assembly into pilus fibers was studied with a set of site-directed antibody probes and by mapping the specificities of antipilus antisera with peptides. Buried and exposed peptides in assembled pili were identified by competitive immunoassays and immunoelectron microscopy with polyclonal antibodies raised against 11 peptides spanning the pilin sequence. Pili did not compete significantly with pilin subunits for binding to antibodies against residues 13 to 31 (13-31) and 18-36. Pilus fibers competed well with pilin protein subunits for binding to antibodies raised against peptides 37-56, 58-78, 110-120, 115-127, 122-139, and 140-159 and competed weakly for antibodies against residues 79-93 and 94-108. Antibodies to sequence-conserved residues 37-56 and to semiconserved residues 94-108 preferentially bound pilus ends as shown by immunoelectron microscopy. The exposure of pilus regions to the immune system was tested by peptide mapping of antiserum specificities against sets of overlapping peptides representing all possible hexameric or octameric peptides from the N. gonorrhoeae MS11 pilin sequence. The immunogenicity of exposed peptides incorporating semiconserved residues 49-56 and 121-126 was revealed by strong, consistent antigenic reactivity to these regions measured in antipilus sera from rabbits, mice, and human and in sera from human volunteers with gonorrhea. The conservation and variation of antigenic responses among these three species clarify the relevance of immunological studies of other species to the human immune response against pathogens. Overall, our results explain the extreme conservation of the entire N-terminal one-third of the pilin protein by its dominant role in pilus assembly: hydrophobic residues 1-36 are implicated in buried lateral contacts, and polar residues 37-56 are implicated in longitudinal contacts within the pilus fiber. PMID:8550220

  8. Immune response to controlled release of immunomodulating peptides in a murine experimental autoimmune encephalomyelitis (EAE) model

    OpenAIRE

    Zhao, Hong; Kiptoo, Paul; Williams, Todd D.; Siahaan, Teruna J.; Topp, Elizabeth M.

    2009-01-01

    The effects of controlled release on immune response to an immunomodulating peptide were evaluated in a murine experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS). The peptide, Ac-PLP-BPI-NH2-2 (Ac-HSLGKWLGHPDKF-(AcpGAcpGAcp)2-ITDGEATDSG-NH2; Ac = acetyl, Acp = aminocaproic acid) was designed to suppress T-cell activation in response to PLP139–151, an antigenic peptide in MS. Poly-lactide-co-glycolide (PLGA) microparticles containing Ac-PLP-BPI-NH2-2 (8±4 μm, 1.4±...

  9. The inability to process a self-peptide allows autoreactive T cells to escape tolerance

    OpenAIRE

    1993-01-01

    It is now clear that antigen presenting cells (APCs) do not present all the possible peptides of self-proteins to the immune system. When then, is the fate of T cells specific for those self-peptides that escape processing? In this study, the COOH-terminal peptide (residues 81-104) of self cytochrome c (cyt c) elicited strong autoimmune T cells, as well as autoantibodies specific for this immunogen. These T cells did not respond to stimulation with the whole self cyt c molecule, demonstrating...

  10. Structural Determinants of Binding the Seven-transmembrane Domain of the Glucagon-like Peptide-1 Receptor (GLP-1R).

    Science.gov (United States)

    Yang, Dehua; de Graaf, Chris; Yang, Linlin; Song, Gaojie; Dai, Antao; Cai, Xiaoqing; Feng, Yang; Reedtz-Runge, Steffen; Hanson, Michael A; Yang, Huaiyu; Jiang, Hualiang; Stevens, Raymond C; Wang, Ming-Wei

    2016-06-17

    The glucagon-like peptide-1 receptor (GLP-1R) belongs to the secretin-like (class B) family of G protein-coupled receptors. Members of the class B family are distinguished by their large extracellular domain, which works cooperatively with the canonical seven-transmembrane (7TM) helical domain to signal in response to binding of various peptide hormones. We have combined structure-based site-specific mutational studies with molecular dynamics simulations of a full-length model of GLP-1R bound to multiple peptide ligand variants. Despite the high sequence similarity between GLP-1R and its closest structural homologue, the glucagon receptor (GCGR), nearly half of the 62 stably expressed mutants affected GLP-1R in a different manner than the corresponding mutants in GCGR. The molecular dynamics simulations of wild-type and mutant GLP-1R·ligand complexes provided molecular insights into GLP-1R-specific recognition mechanisms for the N terminus of GLP-1 by residues in the 7TM pocket and explained how glucagon-mimicking GLP-1 mutants restored binding affinity for (GCGR-mimicking) GLP-1R mutants. Structural analysis of the simulations suggested that peptide ligand binding mode variations in the 7TM binding pocket are facilitated by movement of the extracellular domain relative to the 7TM bundle. These differences in binding modes may account for the pharmacological differences between GLP-1 peptide variants. PMID:27059958

  11. PNA Peptide chimerae

    DEFF Research Database (Denmark)

    Koch, T.; Næsby, M.; Wittung, P.;

    1995-01-01

    Radioactive labelling of PNA has been performed try linking a peptide segment to the PNA which is substrate for protein kinase A. The enzymatic phosphorylation proceeds in almost quantitative yields....

  12. PreS1 epitope recognition in newborns after vaccination with the third-generation Sci-B-Vac™ vaccine and their relation to the antibody response to hepatitis B surface antigen

    Directory of Open Access Journals (Sweden)

    Madalinski Kazimierz

    2009-01-01

    Full Text Available Abstract Background Sci-B-Vac™ is a recombinant, hepatitis B vaccine derived from a mammalian cell line and containing hepatitis B surface antigen (HBsAg as well as preS1 and preS2 antigens. Few studies have been performed on the antibody responses to preS1 in relation to the antibody to hepatitis B surface antigen (anti-HBs response during immunisation of healthy children with preS-containing vaccines. Results In this study 28 healthy newborns were randomly selected to receive either 2.5 ug or 5.0 ug of the Sci-B-Vac vaccine. Children received three doses of vaccine according to a 0-, 1-, 6-month scheme. Antibodies against the S-protein and three synthetic peptides mimicking three B-cell preS1 epitopes, (21–32 amino acid epitope, (32–47 amino acid epitope and the C-terminal (amino acid epitope 94–117 were determined at 6 and 9 months. Fourteen (50% of the 28 newborns had detectable levels of anti-preS1 (21–32 antibodies; 15 (54% were anti-preS1 (32–47 reactive and 12 (43% were anti-preS1 (94–117 reactive at 6 or 9 months after initiation of the vaccination. Significantly higher levels of anti-HBs were observed in the sera of patients with detectable anti-preS1 (32–47 reactivity (24 550 ± 7375 IU/L, mean ± SEM as compared with the non-reactive sera (5991 ± 1530 IU/L, p Conclusion Recognition of several preS1 epitopes, and in particular, the epitope contained within the second half of the hepatocyte binding site localised in the hepatitis B surface protein of the third-generation hepatitis B vaccine is accompanied by a more pronounced antibody response to the S-gene-derived protein in healthy newborns.

  13. Antigenic and allergenic analysis of psyllium seed components.

    Science.gov (United States)

    Arlian, L G; Vyszenski-Moher, D L; Lawrence, A T; Schrotel, K R; Ritz, H L

    1992-04-01

    The outer portions (husk) of psyllium seeds are a concentrated source of natural fiber used in some bulk-fiber laxatives and cereals. They are known to elicit respiratory allergic reactions after inhalation or ingestion among sensitized individuals. Antigenic and allergenic characterization of three psyllium-seed fractions (husk, endosperm, and embryo) was conducted with crossed immunoelectrophoresis (CIE), crossed radioimmunoelectrophoresis, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis to determine the source of psyllium allergenicity. Homologous CIE demonstrated psyllium endosperm and embryo extracts contained seven and four antigens, respectively. Husk extracts were too gelatinous to react by CIE. However, heterologous CIE profiles of endosperm or embryo extracts, reacted with antihusk antibodies, resulted in antigen-antibody precipitin peaks that matched the heavy staining precipitin lines of homologous reactions for endosperm and embryo, respectively. These results indicated that commercial-grade husk, endosperm, and embryo contained similar antigens. Extracts of all three seed components contained antigens that bound IgE antibodies in the sera of 11 psyllium RAST-positive individuals, as determined by crossed radioimmunoelectrophoresis. The few prominent husk protein/peptide bands resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were common in either embryo or endosperm. Immunoblots revealed common IgE reactive bands in all three seed fractions. Microscopic examination of the powdered commercial-grade psyllium (95% pure) revealed it contained endosperm and embryo particles. These immunologic, biochemical, and microscopic findings suggest that other contaminating seed components are primarily responsible for the allergenicity of commercial-grade psyllium-husk powder rather than the husk itself. PMID:1560169

  14. Anvendelse af prostataspecifikt antigen. En oversigt

    DEFF Research Database (Denmark)

    Brasso, K; Skaarup, P; Roosen, Jens Ulrik; Iversen, Peter

    1998-01-01

    Since it was first introduced, measurement of prostate specific antigen has gained increasing interest, and prostate specific antigen is regarded as being the best tumour marker available. The antigen lacks cancer specificity, limiting the usefulness in early diagnosis, The use of prostate specific...... antigen in early diagnosis, staging, and in monitoring patients with prostate cancer is reviewed....

  15. Tumor penetrating peptides

    Directory of Open Access Journals (Sweden)

    ErkkiRuoslahti

    2013-08-01

    Full Text Available Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC, contains the integrin-binding RGD motif. RGD mediates tumor homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular “zip code” of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is

  16. Introduction to Peptide Synthesis

    OpenAIRE

    Stawikowski, Maciej; Fields, Gregg B.

    2002-01-01

    A number of synthetic peptides are significant commercial or pharmaceutical products, ranging from the dipeptide sugar-substitute aspartame to clinically used hormones, such as oxytocin, adrenocorticotropic hormone, and calcitonin. This unit provides an overview of the field of synthetic peptides and proteins. It discusses selecting the solid support and common coupling reagents. Additional information is provided regarding common side reactions and synthesizing modified residues.

  17. Mimicking unfolding motion of a beetle hind wing

    Institute of Scientific and Technical Information of China (English)

    MUHAMMAD Azhar; PARK Hoon C; HWANG Do Y; BYUN Doyoung; GOO Nam S

    2009-01-01

    This paper presents an experimental research aiming to realize an artificial hind wing that can mimic the wing unfolding motion of Allomyrina dichotoma, an insect in coleopteran order. Based on the understanding of working principles of beetle wing folding/unfolding mechanisms, the hind wing unfolding motion is mimicked by a combination of creative ideas and state-of-art artificial muscle actuator. In this work, we devise two types of artificial wings and the successfully demonstrate that they can be unfolded by actuation of shape memory alloy wires to provide actuation force at the wing base and along the leading edge vein. The folding/unfolding mechanisms may provide an insight for portable nano/micro air vehicles with morphing wings.

  18. Amiodarone-induced pulmonary toxicity mimicking acute pulmonary edema.

    Science.gov (United States)

    Fabiani, Iacopo; Tacconi, Danilo; Grotti, Simone; Brandini, Rossella; Salvadori, Claudia; Caremani, Marcello; Bolognese, Leonardo

    2011-05-01

    Amiodarone is a highly effective antiarrhythmic drug. Its long-term use may, however, lead to several adverse effects, with pulmonary toxicity being the most serious. The article presents the case of a 78-year-old woman with a history of cardiac surgery, who after 2 years of amiodarone therapy for prophylactic treatment of atrial fibrillation developed amiodarone pneumonitis mimicking an acute pulmonary edema. The patient failed to respond to diuretic therapy and several courses of anti-infective therapy. Differential diagnosis of different causes of pulmonary infiltrates did not demonstrate any other abnormality. Lung biopsy findings were consistent with the diagnosis of amiodarone pneumonitis. Given the widespread use of amiodarone as an antiarrhythmic agent, pneumologists and cardiologists should consider this important adverse effect as a differential diagnosis of pulmonary distress refractory to therapy in all patients treated with amiodarone who present with respiratory symptoms and pneumonia-like illness. PMID:19924000

  19. Myelodysplastic changes mimicking MDS following treatment for osteosarcoma

    DEFF Research Database (Denmark)

    Løhmann, Ditte

    -MDS/AML) is a feared long-term complication of paediatric cancer including osteosarcoma. Few develop t-MDS/AML, but it is not known how many have significant haematological changes after finishing treatment for osteosarcoma. In this study we reviewed biochemistry from a consecutive series of children for up....... In one case MDS (refractory anaemia with excess blasts) with monosomy 7 was found and a hematopoietic stem cell transplant was performed. In the other case MDS without excess of blasts was found and a spontaneous normalization of the biochemistry occurred. In conclusion in our study most patients......Myelodysplastic changes mimicking MDS following treatment for osteosarcoma Ditte Juel Adolfsen Løhmann, Department of Pediatrics, Aarhus University Hospital, Skejby, Denmark Authors: Ditte Juel Adolfsen Løhmann and Henrik Hasle. Therapy-related myelodysplastic syndrome/acute myeloid leukaemia (t...

  20. Oral manifestion of Langerhans cell histiocytosis mimicking inflammation

    Directory of Open Access Journals (Sweden)

    K S Divya

    2014-01-01

    Full Text Available Langerhans cell histiocytosis (LCH is a rare idiopathic disease characterized by the clonal proliferation of Langerhans cells. LCH affects five children per million population. The peak incidence is from 1 to 4 years of age. LCH involves the head and neck region quite commonly. Oral soft tissue lesions are also common. The differential diagnosis of oral LCH includes leukemia, neutropenia, prepubertal periodontitis, hypophosphatasia, fibrous dysplasia, and Papillon-Lefevre syndrome. The prognosis of LCH depends on early detection and appropriate management. Surgical management alone is used in 50% of cases with an additional 23% of the lesions being treated with both surgery and radiation therapy. A case of LCH in a 6-year-old girl involving the mid root level of developing first permanent molar with a floating developing tooth bud of permanent second molar mimicking an inflammation is reported.

  1. Giant Ectopic Ureter Mimicking Pelvic Organ Prolapse: A Case Report

    Directory of Open Access Journals (Sweden)

    Adnan Simsir

    2011-01-01

    Full Text Available Ectopic ureter is one of the most common urinary tract anomalies. We, herein, present a case of a giant ureter with ectopic orifice, mimicking pelvic organ prolapse, which is the first in the literature. A 59-year-old female patient presenting with frequently recurrent urinary tract infection had grade 3 pelvic organ prolapse. On examination, the organ producing the appearance of prolapse was found to be a right ureter of giant size and was obstructed by a large stone at the distal segment. The proximal end of the ureter ended blindly. After exploration, the stone was removed, the ureter was detached from the urethra, and the lumen was tied off and cut 5 cm proximally. At 6 months postoperatively, the patient is being followed up without any clinical problems. In such cases with nonfunctioning renal segment draining proximally, the chance of cure can be obtained without a need for a comprehensive intervention such as total abdominal ureterectomy.

  2. Liquid optical phantoms mimicking spectral characteristics of laboratory mouse biotissues

    Science.gov (United States)

    Loginova, D. A.; Sergeeva, E. A.; Krainov, A. D.; Agrba, P. D.; Kirillin, M. Yu

    2016-06-01

    Optical phantoms mimicking optical properties of real biotissues in the visible and IR spectral regions are developed based on measurements of the spectral characteristics of ex vivo samples of laboratory mouse biotissues. The phantoms are composed of aqueous solutions of Lipofundin, Indian ink and red ink with different spectral characteristics. The deviations of the measured absorption and scattering coefficients of phantoms in the wavelength range 480 – 580 nm from the corresponding values for real biotissues do not exceed 25% and 2%, respectively. For phantoms in the wavelength region 580 – 880 nm, the deviations of the absorption coefficient do not exceed 40% and the deviations of the scattering coefficient do not exceed 25%. These values, in general, fall within the range of variations for different individual mice of one strain.

  3. Epineurium-mimicking chitosan conduits for peripheral nervous tissue engineering.

    Science.gov (United States)

    Nawrotek, Katarzyna; Tylman, Michał; Rudnicka, Karolina; Gatkowska, Justyna; Wieczorek, Marek

    2016-11-01

    In this investigation, we report on a fabrication method of epineurium-mimicking tubular conduits based on electrodeposition from chitosan solution. The pre-enrichment of electrodeposition solution with hyaluronic acid and/or collagen components results in structures which structural, morphological, and physicochemical properties can be controlled. In order to determine the optimal composition of the initial chitosan solution resulting in conduits meeting the requirements imposed on peripheral nerve implants, we perform chemical, physical, and biological studies. Both the molecular weight of hyaluronic acid and the concentration of additives are found to be crucial for the final mechanical as well as biological performance of conduits. Because, the obtained structures show biocompatibility when contacting with a mouse hippocampal cell line (mHippoE-18), we further plan to test their application potential on an animal model. PMID:27516256

  4. Impedance of tissue-mimicking phantom material under compression

    Directory of Open Access Journals (Sweden)

    Barry Belmont

    2013-02-01

    Full Text Available The bioimpedance of tissues under compression is a field in need of study. While biological tissues can become compressed in a myriad of ways, very few experiments have been conducted to describe the relationship between the passive electrical properties of a material (impedance/admittance during mechanical deformation. Of the investigations that have been conducted, the exodus of fluid from samples under compression has been thought to be the cause of changes in impedance, though until now was not measured directly. Using a soft tissue-mimicking phantom material (tofu whose passive electrical properties are a function of the conducting fluid held within its porous structure, we have shown that the mechanical behavior of a sample under compression can be measured through bioimpedance techniques.

  5. Hepatic actinomycosis mimicking a malignant tumor: Three case reports

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, O Hyun; Kim, Jae Woon [Dept. of Radiology, Yeungnam University College of Medicine, Daegu (Korea, Republic of)

    2015-05-15

    Various forms of hepatic actinomycosis can be observed on the imaging studies. We report here the imaging findings of three cases of hepatic actinomycosis, which presented as a solid mass mimicking a malignant tumor. With respect to their enhancement pattern on the contrast-enhanced CT and MR images, one case showed homogeneous and persistent enhancement throughout three phases, while the other two cases showed variable degrees of delayed enhancement with their own features during the portal and equilibrium phases, suggesting that they have abundant fibrosis at different stages. Also, normal vascular structures traversing the masses were noted in all three cases. One core needle biopsy and two surgical resections were performed, and the masses were pathologically proven to be hepatic actinomycosis. In conclusion, we need to be aware that a hepatic tumor with abundant fibrosis, in which the normal vasculature is traversing, can be diagnosed as hepatic actinomycosis.

  6. Engineered nanoparticles mimicking cell membranes for toxin neutralization.

    Science.gov (United States)

    Fang, Ronnie H; Luk, Brian T; Hu, Che-Ming J; Zhang, Liangfang

    2015-08-01

    Protein toxins secreted from pathogenic bacteria and venomous animals rely on multiple mechanisms to overcome the cell membrane barrier to inflict their virulence effect. A promising therapeutic concept toward developing a broadly applicable anti-toxin platform is to administer cell membrane mimics as decoys to sequester these virulence factors. As such, lipid membrane-based nanoparticulates are an ideal candidate given their structural similarity to cellular membranes. This article reviews the virulence mechanisms employed by toxins at the cell membrane interface and highlights the application of cell-membrane mimicking nanoparticles as toxin decoys for systemic detoxification. In addition, the implication of particle/toxin nanocomplexes in the development of toxoid vaccines is discussed. PMID:25868452

  7. Malignant fibrous histiocytoma presenting as hemoperitoneum mimicking hepatocellular carcinoma rupture

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Malignant fibrous histiocytoma (MFH) is a pleomorphic mesenchynal sarcoma. It is uncommonly arises primarily from the intra-peritoneal cavity. Primary peritoneal MFH with tumor bleeding and rupture is rare. We describe the imaging features of a 70-year-old patient presenting with ruptured hemorrhagic peritoneal MFH at subhepatic area, accompanied by massive hemoperitoneum,mimicking a ruptured pedunculated hepatocellular carcinoma. Computed tomography (CT) revealed a large heterogeneous enhanced subhepatic mass with adjacent liver, gallbladder and colon invasion. Tumor hemorrhage and rupture complicated with peritoneal seeding and massive bloody ascites were also detected.Angiography showed a hypervascular tumor fed by enlarged right hepatic arteries, cystic artery and omental branches of gastroepiploic artery. The patient underwent laparotomy for tumor resection, but the tumor recurred one month after operation. To our knowledge, the CT appearance of ruptured intraperitoneal MFH complicated by hemoperitoneum has not been previously described.

  8. Hepatic actinomycosis mimicking a malignant tumor: Three case reports

    International Nuclear Information System (INIS)

    Various forms of hepatic actinomycosis can be observed on the imaging studies. We report here the imaging findings of three cases of hepatic actinomycosis, which presented as a solid mass mimicking a malignant tumor. With respect to their enhancement pattern on the contrast-enhanced CT and MR images, one case showed homogeneous and persistent enhancement throughout three phases, while the other two cases showed variable degrees of delayed enhancement with their own features during the portal and equilibrium phases, suggesting that they have abundant fibrosis at different stages. Also, normal vascular structures traversing the masses were noted in all three cases. One core needle biopsy and two surgical resections were performed, and the masses were pathologically proven to be hepatic actinomycosis. In conclusion, we need to be aware that a hepatic tumor with abundant fibrosis, in which the normal vasculature is traversing, can be diagnosed as hepatic actinomycosis.

  9. Primary oral leishmaniasis mimicking oral cancer: a case report.

    Science.gov (United States)

    Celentano, A; Ruoppo, E; Mansueto, G; Mignogna, M D

    2015-04-01

    Primary mucosal leishmaniasis is a rare infectious disease, particularly in immunocompetent patients. We present a 50-year-old patient with a 6-week history of a painful lesion of the left buccal mucosa that mimicked cancer. The exophytic lesion looked invasive, and we took an incisional biopsy specimen to exclude cancer. The diagnosis of leishmaniasis was unexpected, and the patient was successfully treated with amphotericin B for five weeks. After five months the patient had a visceral recurrence. Chronic exophytic and ulcerated mucosal lesions that do not heal within 3-4 weeks should be regarded as the first signs of oral cancer, but primary oral leishmaniasis can easily mimic it. PMID:25701438

  10. Optofluidic phantom mimicking optical properties of porcine livers

    Energy Technology Data Exchange (ETDEWEB)

    Long, Ruiqi [Texas A& M University; King, Travis [Texas A& M University; Akl, Tony [Texas A& M University; Ericson, Milton Nance [ORNL; Wilson, Mark A. [University of Pittsburgh School of Medicine, Pittsburgh PA; Cote, Gerard L. [Texas A& M University; McShane, Michael J. [Texas A& M University

    2011-01-01

    One strategy for assessing efficacy of a liver transplant is to monitor perfusion and oxygenation after transplantation. An implantable optical sensor is being developed to overcome inadequacies of current monitoring approaches. To facilitate sensor design while minimizing animal use, a polydimethylsiloxane (PDMS)-based liver phantom was developed to mimic the optical properties of porcine liver in the 630-1000 nm wavelength range and the anatomical geometry of liver parenchyma. Using soft lithography to construct microfluidic channels in pigmented elastomer enabled the 2D approximation of hexagonal liver lobules with 15mm sinusoidal channels, which will allow perfusion with blood-mimicking fluids to facilitate the development of the liver perfusion and oxygenation monitoring system.

  11. Malignant Mesothelioma Mimicking Invasive Mammary Carcinoma in a Male Breast

    Directory of Open Access Journals (Sweden)

    Mohamed Mokhtar Desouki

    2015-01-01

    Full Text Available Malignant mesothelioma is an uncommon tumor with strong association with asbestos exposure. Few cases of malignant pleural mesothelioma metastatic to the female breast have been reported. Herein, we presented, for the first time, a case of locally infiltrating malignant pleural mesothelioma forming a mass in the breast of a male as the first pathologically confirmed manifestation of the disease. Breast ultrasound revealed an irregular mass in the right breast which involves the pectoralis muscle. Breast core biopsy revealed a proliferation of neoplastic epithelioid cells mimicking an infiltrating pleomorphic lobular carcinoma. IHC studies showed the cells to be positive for calretinin, CK5/6, WT1, and CK7. The cells were negative for MOC-31, BerEp4, ER, and PR. A final diagnosis of malignant mesothelioma, epithelioid type, was rendered. This case demonstrates the importance of considering a broad differential diagnosis in the setting of atypical presentation with application of a panel of IHC markers.

  12. Cytomegalovirus colitis mimicking rectal carcinoma in an immunocompetent elderly woman.

    Science.gov (United States)

    Chidlovskii, Elena; Deroux, Alban; Bernard, Sylvain; Couturier, Pascal

    2016-01-01

    Cytomegalovirus (CMV) colitis is uncommon in immunocompetent patients, despite a high seroprevalence rate of CMV in the general population. CMV infection has been described in individuals with compromised immune systems: in AIDS, under corticosteroid and immune modulating treatment, with cancer or haematological malignancies. Its most frequent clinical presentation is a necrotising ulcerative form; pseudotumoural CMV colitis has been described as highly exceptional. We report a case of CMV colitis mimicking rectal carcinoma in an immunocompetent elderly woman. The immunosenescence and protein-energy malnutrition increase incidence and severity of infectious diseases in elderly individuals. Immunosenescence may affect all aspects of immunity; severe protein malnutrition modifies mostly cellular immunity, growing susceptibility to infections. PMID:27166009

  13. A detailed comparison of peptides presented by different HLA class I loci: an in silico approach

    NARCIS (Netherlands)

    Rao, X.

    2012-01-01

    Human Leukocyte Antigen (HLA) class I is a group of genes located on human chromosome 6 which play a crucial role in initiating potentially protective immune responses, by presenting pathogen-derived peptides to CD8+ T cells and thus targeting infected cells for elimination. Compare to other HLA cla

  14. Pentamers Not Found in the Universal Proteome Can Enhance Antigen Specific Immune Responses and Adjuvant Vaccines

    OpenAIRE

    Ami Patel; Dong, Jessica C.; Brett Trost; Richardson, Jason S.; Sarah Tohme; Shawn Babiuk; Anthony Kusalik; Kung, Sam K. P.; Kobinger, Gary P.

    2012-01-01

    Certain short peptides do not occur in humans and are rare or non-existent in the universal proteome. Antigens that contain rare amino acid sequences are in general highly immunogenic and may activate different arms of the immune system. We first generated a list of rare, semi-common, and common 5-mer peptides using bioinformatics tools to analyze the UniProtKB database. Experimental observations indicated that rare and semi-common 5-mers generated stronger cellular responses in comparison wi...

  15. Acoustical characterization of polysaccharide polymers tissue-mimicking materials.

    Science.gov (United States)

    Cuccaro, Rugiada; Musacchio, Chiara; Giuliano Albo, P Alberto; Troia, Adriano; Lago, Simona

    2015-02-01

    Tissue-mimicking phantoms play a crucial role in medical ultrasound research because they can simulate biological soft tissues. In last years, many types of polymeric tissues have been proposed and characterized from an acoustical and a thermal point of view, but, rarely, a deep discussion about the quality of the measurements, in terms of the uncertainty evaluation, has been reported. In this work, considering the necessity to develop laboratory standards for the measurement of ultrasonic exposure and dose quantities, a detailed description of the experimental apparatuses for the sound speed and the attenuation coefficient measurements is given, focusing the attention on the uncertainty evaluation both of the results and analysis algorithms. In particular, this algorithm reveals a novel empirical relation, fixing a limit to the energy content (therefore limits the number of cycles) of the three parts in which the authors have proposed to divide the acoustical signal. Furthermore, the realisation of multi-components phantoms, Agar and Phytagel based tissue-mimicking gels along with others long chain molecules (dextrane or polyvinyl alcohol) and scattering materials (silicon carbide and kieselguhr) are investigated. This paper reports accurate speed of sound and attenuation coefficient measurements. Speed of sound is measured by a pulse-echo technique in far-field condition, using an optical glass buffer rod; while attenuation coefficient is determined by an insertion technique, using demineralized water as reference material. The experimental sound speed results are subjected to an overall estimated relative uncertainty of about 1.5% and the attenuation coefficient uncertainty is less than 2.5%. For the development of laboratory standards, a detailed analysis of the measurement uncertainty is fundamental to make sample properties comparable. The authors believe this study could represent the right direction to make phantoms characterizations referable and traceable

  16. Mimicking nature: Phosphopeptide enrichment using combinatorial libraries of affinity ligands.

    Science.gov (United States)

    Batalha, Iris L; Zhou, Houjiang; Lilley, Kathryn; Lowe, Christopher R; Roque, Ana C A

    2016-07-29

    Phosphorylation is a reversible post-translational modification of proteins that controls a plethora of cellular processes and triggers specific physiological responses, for which there is a need to develop tools to characterize phosphorylated targets efficiently. Here, a combinatorial library of triazine-based synthetic ligands comprising 64 small molecules has been rationally designed, synthesized and screened for the enrichment of phosphorylated peptides. The lead candidate (coined A8A3), composed of histidine and phenylalanine mimetic components, showed high binding capacity and selectivity for binding mono- and multi-phosphorylated peptides at pH 3. Ligand A8A3 was coupled onto both cross-linked agarose and magnetic nanoparticles, presenting higher binding capacities (100-fold higher) when immobilized on the magnetic support. The magnetic adsorbent was further screened against a tryptic digest of two phosphorylated proteins (α- and β-caseins) and one non-phosphorylated protein (bovine serum albumin, BSA). The MALDI-TOF mass spectra of the eluted peptides allowed the identification of nine phosphopeptides, comprising both mono- and multi-phosphorylated peptides. PMID:27345211

  17. MUC-1 Tumor Antigen Agonist Epitopes for Enhancing T-cell Responses to Human Tumors | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    Scientists at NIH have identified 7 new agonist epitopes of the MUC-1 tumor associated antigen. Compared to their native epitope counterparts, peptides reflecting these agonist epitopes have been shown to enhance the generation of human tumor cells, which in turn have a greater ability to kill human tumor cells endogenously expressing the native MUC-1 epitope.

  18. 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

    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...... not uniformly elicited by natural malaria infection in previously primed donors....

  19. Tumor-associated antigens identified by mRNA expression profiling induce protective anti-tumor immunity

    DEFF Research Database (Denmark)

    Mathiassen, Søren; Lauemøller, S L; Ruhwald, Morten;

    2001-01-01

    to identify TAA, mice were immunized with mixtures of peptides representing putative cytotoxic T cell epitopes derived from one of the gene products. Indeed, such immunized mice were partially protected against subsequent tumor challenge. Despite being immunized with bona fide self antigens, no...

  20. Designing peptidic inhibitors of serum amyloid A aggregation process.

    Science.gov (United States)

    Sosnowska, Marta; Skibiszewska, Sandra; Kamińska, Emilia; Wieczerzak, Ewa; Jankowska, Elżbieta

    2016-04-01

    Amyloid A amyloidosis is a life-threatening complication of a wide range of chronic inflammatory, infectious and neoplastic diseases, and the most common form of systemic amyloidosis worldwide. It is characterized by extracellular tissue deposition of fibrils that are composed of fragments of serum amyloid A protein (SAA), a major acute-phase reactant protein, produced predominantly by hepatocytes. Currently, there are no approved therapeutic agents directed against the formation of fibrillar SAA assemblies. We attempted to develop peptidic inhibitors based on their similarity and complementarity to the regions critical for SAA self-association, which they should interact with and block their assembly into amyloid fibrils. Inh1 and inh4 which are comprised of the residues from the amyloidogenic region of SAA1.1 protein and Aβ peptide, respectively, were found by us as capable to significantly suppress aggregation of the SAA1-12 peptide. It was chosen as an aggregation model that mimicks the amyloidogenic nucleus of SAA protein. We suppose that aromatic interactions may be responsible for inhibitory activity of both compounds. We also recognized that aromatic residues are involved in self-association of SAA1-12. PMID:26759015

  1. Electrospun PELCL membranes loaded with QK peptide for enhancement of vascular endothelial cell growth.

    Science.gov (United States)

    Yang, Yang; Yang, Qingmao; Zhou, Fang; Zhao, Yunhui; Jia, Xiaoling; Yuan, Xiaoyan; Fan, Yubo

    2016-06-01

    One of the major challenges in tissue engineering of small-diameter vascular grafts is to inhibit intimal hyperplasia and keep long-term patency after implantation. Rapid endothelialization of the grafts could be an effective approach. In this study, QK, a peptide mimicking vascular endothelial growth factor, was selected as the bioactive substrate and loaded in electrospun membranes for enhancement of vascular endothelial cell growth. In detail, QK peptide was firstly introduced with poly(ethylene glycol) diacrylate into a thiolated chitosan solution that could transfer into hydrogel. Then, suspensions or emulsions of poly(ethylene glycol)-b-poly(L-lactide-co-ε-caprolactone) (PELCL) containing QK peptide (with or without chitosan hydrogel) were electrospun into fibrous membranes. For comparison, the electrospun PELCL membrane without QK was also fabricated. Results of release behaviors showed that the electrospun membranes, especially that contained chitosan hydrogel prepared by suspension electrospinning, could successfully encapsulate QK peptide and maintain its secondary structure after released. In vitro cell culture studies exhibited that the release of QK peptide could accelerate the proliferation of vascular endothelial cells in the 9 days. It was suggested that the electrospun PELCL membranes loaded with QK peptide might have potential applications in vascular tissue engineering. PMID:27107890

  2. Hepatitis C virus and ethanol alter antigen presentation in liver cells

    Institute of Scientific and Technical Information of China (English)

    Natalia A Osna

    2009-01-01

    Alcoholic patients have a high incidence of hepatitis Cvirus (HCV) infection. Alcohol consumption enhances the severity of the HCV disease course and worsens the outcome of chronic hepatitis C. The accumulation of virally infected cells in the liver is related to the HCVinduced inability of the immune system to recognizeinfected cells and to develop the immune responses. This review covers the effects of HCV proteins and ethanol on major histocompatibility complex (MHC) classⅠ- and class Ⅱ-restricted antigen presentation. Here, we discuss the liver which functions as an immune privilege organ; factors, which affect cleavage and loading of antigenic peptides onto MHC classⅠand class Ⅱ in hepatocytes and dendritic cells, and the modulating effects of ethanol and HCV on antigen presentation by liver cells. Altered antigen presentation in the liver limits the ability of the immune system to clear HCV and infected cells and contributes to disease progression. HCV by itself affects dendritic cell function, switching their cytokine profile to the suppressive phenotype of interleukin-10 (IL-10) and transforming growth factor beta (TGFβ) predominance,preventing cell maturation and allostimulation capacity.The synergistic action of ethanol with HCV results in the suppression of MHC class Ⅱ-restricted antigen presentation. In addition, ethanol metabolism and HCV proteins reduce proteasome function and interferon signaling, thereby suppressing the generation of peptides for MHC classⅠ-restricted antigen presentation.Collectively, ethanol exposure further impairs antigen presentation in HCV-infected liver cells, which may provide a partial explanation for exacerbations and the poor outcome of HCV infection in alcoholics.

  3. Prospects for T cell immunotherapy of tumours by vaccination with immunodominant and subdominant peptides.

    Science.gov (United States)

    Melief, C J; Kast, W M

    1994-01-01

    Immunotherapy of tumours by adoptive transfer of cytotoxic T lymphocytes (CTL) is now feasible in experimental murine systems. These CTL recognize peptide sequences of defined length presented by major histocompatibility complex (MHC) class I molecules. Effective eradication of large tumour masses requires co-administration of interleukin 2. Tumour escape strategies are numerous but in various instances can be counteracted by defined measures. Initiation of CTL responses against poorly immunogenic virally induced tumours and other tumours requires novel strategies to overcome T cell inertia. We propose a strategy in which CTL are raised against target molecules of choice including differentiation antigens of restricted tissue distribution (autoantigens) or mutated/overexpressed oncogene products. The steps proposed include: (1) identification of target molecules of choice. (2) Identification in these target molecules of peptides fitting MHC allele-specific peptide motifs involved in peptide binding to MHC molecules. (3) Evaluation of actual binding of such peptides to specific MHC class I molecules. (4) In vitro CTL response induction by such peptides, presented by highly efficient antigen-presenting cells such as antigen processing-defective cells carrying empty MHC class I molecules loaded with a single peptide or dendritic cells. Both types of cells are capable of primary CTL response induction in vitro. (5) Evaluation of proper processing by the demonstration of tumour cell lysis by these CTL. (6) Adoptive transfer of tumour-specific CTL generated in vitro or vaccination with peptides. These various steps have now been taken for several viruses, virally induced tumours and other types of tumours and the first indications that this strategy is useful have been obtained. PMID:7796678

  4. Time-Frequency Analysis of Peptide Microarray Data: Application to Brain Cancer Immunosignatures.

    Science.gov (United States)

    O'Donnell, Brian; Maurer, Alexander; Papandreou-Suppappola, Antonia; Stafford, Phillip

    2015-01-01

    One of the gravest dangers facing cancer patients is an extended symptom-free lull between tumor initiation and the first diagnosis. Detection of tumors is critical for effective intervention. Using the body's immune system to detect and amplify tumor-specific signals may enable detection of cancer using an inexpensive immunoassay. Immunosignatures are one such assay: they provide a map of antibody interactions with random-sequence peptides. They enable detection of disease-specific patterns using classic train/test methods. However, to date, very little effort has gone into extracting information from the sequence of peptides that interact with disease-specific antibodies. Because it is difficult to represent all possible antigen peptides in a microarray format, we chose to synthesize only 330,000 peptides on a single immunosignature microarray. The 330,000 random-sequence peptides on the microarray represent 83% of all tetramers and 27% of all pentamers, creating an unbiased but substantial gap in the coverage of total sequence space. We therefore chose to examine many relatively short motifs from these random-sequence peptides. Time-variant analysis of recurrent subsequences provided a means to dissect amino acid sequences from the peptides while simultaneously retaining the antibody-peptide binding intensities. We first used a simple experiment in which monoclonal antibodies with known linear epitopes were exposed to these random-sequence peptides, and their binding intensities were used to create our algorithm. We then demonstrated the performance of the proposed algorithm by examining immunosignatures from patients with Glioblastoma multiformae (GBM), an aggressive form of brain cancer. Eight different frameshift targets were identified from the random-sequence peptides using this technique. If immune-reactive antigens can be identified using a relatively simple immune assay, it might enable a diagnostic test with sufficient sensitivity to detect tumors in a

  5. Cell Wall Anchoring of the Campylobacter Antigens to Lactococcus lactis.

    Science.gov (United States)

    Kobierecka, Patrycja A; Olech, Barbara; Książek, Monika; Derlatka, Katarzyna; Adamska, Iwona; Majewski, Paweł M; Jagusztyn-Krynicka, Elżbieta K; Wyszyńska, Agnieszka K

    2016-01-01

    Campylobacter jejuni is the most frequent cause of human food-borne gastroenteritis and chicken meat is the main source of infection. Recent studies showed that broiler chicken immunization against Campylobacter should be the most efficient way to lower the number of human infections by this pathogen. Induction of the mucosal immune system after oral antigen administration should provide protective immunity to chickens. In this work we tested the usefulness of Lactococcus lactis, the most extensively studied lactic acid bacterium, as a delivery vector for Campylobacter antigens. First we constructed hybrid protein - CjaA antigen presenting CjaD peptide epitopes on its surface. We showed that specific rabbit anti-rCjaAD serum reacted strongly with both CjaA and CjaD produced by a wild type C. jejuni strain. Next, rCjaAD and CjaA were fused to the C-terminus of the L. lactis YndF containing the LPTXG motif. The genes expressing these proteins were transcribed under control of the L. lactis Usp45 promoter and their products contain the Usp45 signal sequences. This strategy ensures a cell surface location of both analyzed proteins, which was confirmed by immunofluorescence assay. In order to evaluate the impact of antigen location on vaccine prototype efficacy, a L. lactis strain producing cytoplasm-located rCjaAD was also generated. Animal experiments showed a decrease of Campylobacter cecal load in vaccinated birds as compared with the control group and showed that the L. lactis harboring the surface-exposed rCjaAD antigen afforded greater protection than the L. lactis producing cytoplasm-located rCjaAD. To the best of our knowledge, this is the first attempt to employ Lactic Acid Bacteria (LAB) strains as a mucosal delivery vehicle for chicken immunization. Although the observed reduction of chicken colonization by Campylobacter resulting from vaccination was rather moderate, the experiments showed that LAB strains can be considered as an alternative vector to

  6. MYCN: From Oncoprotein To Tumor-Associated Antigen

    Directory of Open Access Journals (Sweden)

    Vito ePistoia

    2012-11-01

    Full Text Available MYCN is a well known oncogene overexpressed in different human malignancies including neuroblastoma, rhabdomyosarcoma, medulloblastoma, astrocytoma, Wilms’ tumor and small cell lung cancer. In the case of neuroblastoma (NB, MYCN amplification is an established biomarker of poor prognosis. MYCN belongs to a family of transcription factors (the most important of which is CMYC that show a high degree of homology. Downregulation of MYC protein expression leads to tumor regression in animal models, indicating that MYC proteins represent interesting therapeutic targets.Pre-requisites for a candidate tumor-associated antigen (TAA to be targeted by immunotherapeutic approaches are the following, i expression should be tumor-restricted, ii the putative TAA should be up-regulated in cancer cells and iii protein should be processed into immunogenic peptides capable of associating to MHC molecules with high affinity. Indeed, the MYCN protein is not expressed in human adult tissues and upregulated variably in NB cells, and MYCN peptides capable of associating to HLA-A1 or –A2 molecules with high affinity have been identified. Thus the MYCN protein qualifies as putative TAA in NB.Additional issues that determine the feasibility of targeting a putative TAA with cytotoxic T lymphocytes (CTL and will be here discussed are the following, i the inadequacy of tumor cells per se to act as antigen-presenting cells witnessed, in the case of NB cells, by the low to absent expression of HLA- class I molecules, the lack of costimulatory molecules and multiple defects in the HLA class I related antigen processing machinery, and ii the immune evasion mechanisms operated by cancer cells to fool the host immune system, such as up-regulation of soluble immunosuppressive molecules (e.g. soluble MICA and HLA-G in the case of NB or generation of immunosuppressive cells in the tumor microenvironment. A final issue that deserves consideration is the strategy used to generate

  7. HLA-DMA polymorphisms differentially affect MHC class II peptide loading.

    Science.gov (United States)

    Álvaro-Benito, Miguel; Wieczorek, Marek; Sticht, Jana; Kipar, Claudia; Freund, Christian

    2015-01-15

    During the adaptive immune response, MHCII proteins display antigenic peptides on the cell surface of APCs for CD4(+) T cell surveillance. HLA-DM, a nonclassical MHCII protein, acts as a peptide exchange catalyst for MHCII, editing the peptide repertoire. Although they map to the same gene locus, MHCII proteins exhibit a high degree of polymorphism, whereas only low variability has been observed for HLA-DM. As HLA-DM activity directly favors immunodominant peptide presentation, polymorphisms in HLA-DM (DMA or DMB chain) might well be a contributing risk factor for autoimmunity and immune disorders. Our systematic comparison of DMA*0103/DMB*0101 (DMA-G155A and DMA-R184H) with DMA*0101/DMB*0101 in terms of catalyzed peptide exchange and dissociation, as well as direct interaction with several HLA-DR/peptide complexes, reveals an attenuated catalytic activity of DMA*0103/DMB*0101. The G155A substitution dominates the catalytic behavior of DMA*0103/DMB*0101 by decreasing peptide release velocity. Preloaded peptide-MHCII complexes exhibit ∼2-fold increase in half-life in the presence of DMA*0103/DMB*0101 when compared with DMA*0101/DMB*0101. We show that this effect leads to a greater persistence of autoimmunity-related Ags in the presence of high-affinity competitor peptide. Our study therefore reveals that HLA-DM polymorphic residues have a considerable impact on HLA-DM catalytic activity. PMID:25505276

  8. Thyrotropin Receptor Epitope and Human Leukocyte Antigen in Graves' Disease.

    Science.gov (United States)

    Inaba, Hidefumi; De Groot, Leslie J; Akamizu, Takashi

    2016-01-01

    Graves' disease (GD) is an organ-specific autoimmune disease, and thyrotropin (TSH) receptor (TSHR) is a major autoantigen in this condition. Since the extracellular domain of human TSHR (TSHR-ECD) is shed into the circulation, TSHR-ECD is a preferentially immunogenic portion of TSHR. Both genetic factors and environmental factors contribute to development of GD. Inheritance of human leukocyte antigen (HLA) genes, especially HLA-DR3, is associated with GD. TSHR-ECD protein is endocytosed into antigen-presenting cells (APCs), and processed to TSHR-ECD peptides. These peptide epitopes bind to HLA-class II molecules, and subsequently the complex of HLA-class II and TSHR-ECD epitope is presented to CD4+ T cells. The activated CD4+ T cells secrete cytokines/chemokines that stimulate B-cells to produce TSAb, and in turn hyperthyroidism occurs. Numerous studies have been done to identify T- and B-cell epitopes in TSHR-ECD, including (1) in silico, (2) in vitro, (3) in vivo, and (4) clinical experiments. Murine models of GD and HLA-transgenic mice have played a pivotal role in elucidating the immunological mechanisms. To date, linear or conformational epitopes of TSHR-ECD, as well as the molecular structure of the epitope-binding groove in HLA-DR, were reported to be related to the pathogenesis in GD. Dysfunction of central tolerance in the thymus, or in peripheral tolerance, such as regulatory T cells, could allow development of GD. Novel treatments using TSHR antagonists or mutated TSHR peptides have been reported to be effective. We review and update the role of immunogenic TSHR epitopes and HLA in GD, and offer perspectives on TSHR epitope specific treatments. PMID:27602020

  9. Helical 1:1 α/Sulfono-γ-AA Heterogeneous Peptides with Antibacterial Activity.

    Science.gov (United States)

    She, Fengyu; Nimmagadda, Alekhya; Teng, Peng; Su, Ma; Zuo, Xiaobing; Cai, Jianfeng

    2016-05-01

    As one of the greatest threats facing the 21st century, antibiotic resistance is now a major public health concern. Host-defense peptides (HDPs) offer an alternative approach to combat emerging multi-drug-resistant bacteria. It is known that helical HDPs such as magainin 2 and its analogs adopt cationic amphipathic conformations upon interaction with bacterial membranes, leading to membrane disruption and subsequent bacterial cell death. We have previously shown that amphipathic sulfono-γ-AApeptides could mimic magainin 2 and exhibit bactericidal activity. In this article, we demonstrate for the first time that amphipathic helical 1:1 α/sulfono-γ-AA heterogeneous peptides, in which regular amino acids and sulfono-γ-AApeptide building blocks are alternatively present in a 1:1 pattern, display potent antibacterial activity against both Gram-positive and Gram-negative bacterial pathogens. Small angle X-ray scattering (SAXS) suggests that the lead sequences adopt defined helical structures. The subsequent studies including fluorescence microscopy and time-kill experiments indicate that these hybrid peptides exert antimicrobial activity by mimicking the mechanism of HDPs. Our findings may lead to the development of HDP-mimicking antimicrobial peptidomimetics that combat drug-resistant bacterial pathogens. In addition, our results also demonstrate the effective design of a new class of helical foldamer, which could be employed to interrogate other important biological targets such as protein-protein interactions in the future. PMID:27030636

  10. Antimicrobial Peptides from Plants

    Science.gov (United States)

    Tam, James P.; Wang, Shujing; Wong, Ka H.; Tan, Wei Liang

    2015-01-01

    Plant antimicrobial peptides (AMPs) have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs) of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic), lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms. PMID:26580629

  11. Antimicrobial Peptides from Plants

    Directory of Open Access Journals (Sweden)

    James P. Tam

    2015-11-01

    Full Text Available Plant antimicrobial peptides (AMPs have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic, lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms.

  12. Electromembrane extraction of peptides.

    Science.gov (United States)

    Balchen, Marte; Reubsaet, Léon; Pedersen-Bjergaard, Stig

    2008-06-20

    Rapid extraction of eight different peptides using electromembrane extraction (EME) was demonstrated for the first time. During an extraction time of 5 min, the model peptides migrated from a 500 microL aqueous acidic sample solution, through a thin supported liquid membrane (SLM) of an organic liquid sustained in the pores in the wall of a porous hollow fiber, and into a 25 microL aqueous acidic acceptor solution present inside the lumen of the hollow fiber. The driving force of the extraction was a 50 V potential sustained across the SLM, with the positive electrode in the sample and the negative electrode in the acceptor solution. The nature and the composition of the SLM were highly important for the EME process, and a mixture of 1-octanol and 15% di(2-ethylhexyl) phosphate was found to work properly. Using 1mM HCl as background electrolyte in the sample and 100 mM HCl in the acceptor solution, and agitation at 1050 rpm, enrichment up to 11 times was achieved. Recoveries were found to be dependent on the structure of the peptide, indicating that the polarity and the number of ionized groups were important parameters affecting the extraction efficiency. The experimental findings suggested that electromembrane extraction of peptides is possible and may be a valuable tool for future extraction of peptides. PMID:18479691

  13. Peptide secreted by human alveolar macrophages releases neutrophil granule contents

    International Nuclear Information System (INIS)

    A monoclonal antibody was developed against an 8000-kDa enzyme-releasing peptide (ERP) released from human alveolar macrophages. ERP was isolated on an immunoaffinity column containing the antibody bound to staphylococcal protein A-Sepharose, and by autoradiography. Release of ERP from the macrophages is not changed by plastic adherence, phagocytosis, calcium ionophore, or phorbol esters. The peptide was not antigenically similar to interferon-γ, tumor necrosis factor, or interleukin lα or 1β. The release of constituents from azurophilic and specific granules was the main identified biologic function of ERP. ERP was a more effective secretagogue in the untreated neutrophils and f-met-leu-phe was more effective in the cytochalasin B-treated neutrophils. Absorption of ERP from macrophage-conditioned medium removed a small amount of the chemotactic activity; however, the immunopurified peptide was not chemotactic or chemokinetic for neutrophils, and at high concentrations, it suppressed base line chemokinesis. Treatment of washed macrophages with trypsin released active ERP of approximately the same m.w. of spontaneously secreted ERP. These studies showed that human alveolar macrophages release a peptide which is a secretagogue for human neutrophils under conditions which may be encountered in the lungs during certain disease states. Proteolytic enzymes which are free in the lungs may release the peptide and lead to the secretion of neutrophil enzymes

  14. Identification of a Novel UTY‐Encoded Minor Histocompatibility Antigen

    DEFF Research Database (Denmark)

    Mortensen, B. K.; Rasmussen, A. H.; Larsen, Malene Erup; Larsen, Mette Voldby; Lund, Ole; Braendstrup, P.; Harndahl, Mikkel Nors; Rasmussen, M.; Buus, S.; Stryhn, A.; Vindeløv, Lars

    2012-01-01

    Minor histocompatibility antigens (mHags) encoded by the Y‐chromosome (H‐Y‐mHags) are known to play a pivotal role in allogeneic haematopoietic cell transplantation (HCT) involving female donors and male recipients. We present a new H‐Y‐mHag, YYNAFHWAI (UTY139–147), encoded by the UTY gene and...... obtained post‐HCT from male recipients of female donor grafts. In one of these recipients, a CD8+ T cell response was observed against a peptide stretch encoded by the UTY gene. Another bioinformatics tool, HLArestrictor, was used to identify the optimal peptide and HLA‐restriction element. Using peptide...... degranulation (CD107a). In contrast, no responses were seen when the T cells were stimulated with patient tumour cells alone. CD8+ T cells specific for this new H‐Y‐mHag were found in three of five HLA‐A*24:02‐positive male recipients of female donor HCT grafts available for this study....

  15. [Farmer's lung antigens in Germany].

    Science.gov (United States)

    Sennekamp, J; Joest, M; Sander, I; Engelhart, S; Raulf-Heimsoth, M

    2012-05-01

    Recent studies suggest that besides the long-known farmer's lung antigen sources Saccharopolyspora rectivirgula (Micropolyspora faeni), Thermoactinomyces vulgaris, and Aspergillus fumigatus, additionally the mold Absidia (Lichtheimia) corymbifera as well as the bacteria Erwinia herbicola (Pantoea agglomerans) and Streptomyces albus may cause farmer's lung in Germany. In this study the sera of 64 farmers with a suspicion of farmer's lung were examined for the following further antigens: Wallemia sebi, Cladosporium herbarum, Aspergillus versicolor, and Eurotium amstelodami. Our results indicate that these molds are not frequent causes of farmer's lung in Germany. PMID:22477566

  16. Synthetic antibiofilm peptides.

    Science.gov (United States)

    de la Fuente-Núñez, César; Cardoso, Marlon Henrique; de Souza Cândido, Elizabete; Franco, Octavio Luiz; Hancock, Robert E W

    2016-05-01

    Bacteria predominantly exist as multicellular aggregates known as biofilms that are associated with at least two thirds of all infections and exhibit increased adaptive resistance to conventional antibiotic therapies. Therefore, biofilms are major contributors to the global health problem of antibiotic resistance, and novel approaches to counter them are urgently needed. Small molecules of the innate immune system called host defense peptides (HDPs) have emerged as promising templates for the design of potent, broad-spectrum antibiofilm agents. Here, we review recent developments in the new field of synthetic antibiofilm peptides, including mechanistic insights, synergistic interactions with available antibiotics, and their potential as novel antimicrobials against persistent infections caused by biofilms. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert. PMID:26724202

  17. Plasmodium vivax antigen discovery based on alpha-helical coiled coil protein motif.

    Directory of Open Access Journals (Sweden)

    Nora Céspedes

    Full Text Available Protein α-helical coiled coil structures that elicit antibody responses, which block critical functions of medically important microorganisms, represent a means for vaccine development. By using bioinformatics algorithms, a total of 50 antigens with α-helical coiled coil motifs orthologous to Plasmodium falciparum were identified in the P. vivax genome. The peptides identified in silico were chemically synthesized; circular dichroism studies indicated partial or high α-helical content. Antigenicity was evaluated using human sera samples from malaria-endemic areas of Colombia and Papua New Guinea. Eight of these fragments were selected and used to assess immunogenicity in BALB/c mice. ELISA assays indicated strong reactivity of serum samples from individuals residing in malaria-endemic regions and sera of immunized mice, with the α-helical coiled coil structures. In addition, ex vivo production of IFN-γ by murine mononuclear cells confirmed the immunogenicity of these structures and the presence of T-cell epitopes in the peptide sequences. Moreover, sera of mice immunized with four of the eight antigens recognized native proteins on blood-stage P. vivax parasites, and antigenic cross-reactivity with three of the peptides was observed when reacted with both the P. falciparum orthologous fragments and whole parasites. Results here point to the α-helical coiled coil peptides as possible P. vivax malaria vaccine candidates as were observed for P. falciparum. Fragments selected here warrant further study in humans and non-human primate models to assess their protective efficacy as single components or assembled as hybrid linear epitopes.

  18. Cryopreservation of MHC Multimers: Recommendations for Quality Assurance in Detection of Antigen Specific T Cells

    OpenAIRE

    Hadrup, Sine Reker; Maurer, Dominik; Laske, Karoline; Frøsig, Thomas Mørch; Andersen, Sofie Ramskov; Britten, Cedrik M.; Sjoerd H van der Burg; Walter, Steffen; Gouttefangeas, Cécile

    2014-01-01

    Fluorescence-labeled peptide-MHC class I multimers serve as ideal tools for the detection of antigen-specific T cells by flow cytometry, enabling functional and phenotypical characterization of specific T cells at the single cell level. While this technique offers a number of unique advantages, MHC multimer reagents can be difficult to handle in terms of stability and quality assurance. The stability of a given fluorescence-labeled MHC multimer complex depends on both the stability of the pep...

  19. Cellular immune responses in patients with hepatitis B surface antigen seroclearance induced by antiviral therapy

    Directory of Open Access Journals (Sweden)

    Zhu Xiaolin

    2011-02-01

    Full Text Available Abstract Background The mechanisms by which chronic hepatitis B is completely resolved through antiviral therapy are unknown, and the contribution of acquired T cell immunity to hepatitis B surface antigen (HBsAg seroclearance has not been investigated. Therefore, we measured the T-cell responses to core and envelope antigens in patients with HBsAg seroclearance. Methods Fourteen subjects with HBsAg seroclearance following antiviral treatment for chronic hepatitis B, 7 HBeAg-positive immunotolerant HBV carriers and 9 HBeAg-negative inactive HBsAg carriers were recruited. HBV-specific T-cell responses to recombinant HBV core (rHBcAg and envelope (rHBsAg proteins and pools of core and envelope peptides were measured using an ELISPOT assay detecting interferon-gamma and intracellular cytokine staining (ICS assays detecting interferon-gamma or interleukin 2. Results Interferon-gamma ELISPOT assays showed a low frequency of weak responses to the rHBsAg and S peptide pool in the HBsAg seroclearance group, and the response frequency to the rHBcAg and the C peptide pool was higher than to the rHBsAg (P P = 0.001 respectively. A higher response frequency to C than S peptide pools was confirmed in the interferon-gamma ICS assays for both CD4+ (P = 0.033 and CD8+ (P = 0.040 T cells in the HBsAg seroclearance group. The responses to C and S antigens in the inactive carriers were similar. Conclusions There was a low frequency of CD4+ and CD8+ T cell immune responses to envelope antigens in Chinese subjects with HBsAg seroclearance following antiviral therapy. It is unlikely that these immune responses are responsible for HBsAg seroclearance in these subjects.

  20. Phosphorylation patterns of tumour antigens in cells lytically infected or transformed by simian virus 40.

    OpenAIRE

    Roy, F.; Fransen, L; Fiers, W

    1981-01-01

    The phosphorylation sites of simian virus 40 (SV40) large tumor (T) antigens have been analyzed by partial proteolysis peptide mapping and phosphoamino acid analysis of the resulting products. At least four sites were found to be phosphorylated. An amino-terminal part of the molecule contained both phosphoserine and phosphothreonine. One phosphothreonine residue was located in the proline-rich carboxy-terminal end of the molecule, either at position 701 or at position 708. The mutant dl 1265,...

  1. Biomimetic peptide nanosensors.

    Science.gov (United States)

    Cui, Yue; Kim, Sang N; Naik, Rajesh R; McAlpine, Michael C

    2012-05-15

    The development of a miniaturized sensing platform tailored for sensitive and selective detection of a variety of biochemical analytes could offer transformative fundamental and technological opportunities. Due to their high surface-to-volume ratios, nanoscale materials are extremely sensitive sensors. Likewise, peptides represent robust substrates for selective recognition due to the potential for broad chemical diversity within their relatively compact size. Here we explore the possibilities of linking peptides to nanosensors for the selective detection of biochemical targets. Such systems raise a number of interesting fundamental challenges: What are the peptide sequences, and how can rational design be used to derive selective binders? What nanomaterials should be used, and what are some strategies for assembling hybrid nanosensors? What role does molecular modeling play in elucidating response mechanisms? What is the resulting performance of these sensors, in terms of sensitivity, selectivity, and response time? What are some potential applications? This Account will highlight our early attempts to address these research challenges. Specifically, we use natural peptide sequences or sequences identified from phage display as capture elements. The sensors are based on a variety of nanomaterials including nanowires, graphene, and carbon nanotubes. We couple peptides to the nanomaterial surfaces via traditional surface functionalization methods or self-assembly. Molecular modeling provides detailed insights into the hybrid nanostructure, as well as the sensor detection mechanisms. The peptide nanosensors can distinguish chemically camouflaged mixtures of vapors and detect chemical warfare agents with sensitivities as low as parts-per-billion levels. Finally, we anticipate future uses of this technology in biomedicine: for example, devices based on these sensors could detect disease from the molecular components in human breath. Overall, these results provide a

  2. Cross-presentation through langerin and DC-SIGN targeting requires different formulations of glycan-modified antigens.

    Science.gov (United States)

    Fehres, Cynthia M; Kalay, Hakan; Bruijns, Sven C M; Musaafir, Sara A M; Ambrosini, Martino; van Bloois, Louis; van Vliet, Sandra J; Storm, Gert; Garcia-Vallejo, Juan J; van Kooyk, Yvette

    2015-04-10

    Dendritic cells (DCs) and Langerhans cells (LC) are professional antigen presenting cells (APCs) that initiate humoral and cellular immune responses. Targeted delivery of antigen towards DC- or LC-specific receptors enhances vaccine efficacy. In this study, we compared the efficiency of glycan-based antigen targeting to both the human DC-specific C-type lectin receptor (CLR) DC-SIGN and the LC-specific CLR langerin. Since DC-SIGN and langerin are able to recognize the difucosylated oligosaccharide Lewis Y (Le(Y)), we prepared neoglycoconjugates bearing this glycan epitope to allow targeting of both lectins. Le(Y)-modified liposomes, with an approximate diameter of 200nm, were significantly endocytosed by DC-SIGN(+) DCs and mediated efficient antigen presentation to CD4(+) and CD8(+) T cells. Surprisingly, although langerin bound to Le(Y)-modified liposomes, LCs exposed to Le(Y)-modified liposomes could not endocytose liposomes nor mediate antigen presentation to T cells. However, LCs mediated an enhanced cross-presentation when antigen was delivered through langerin using Le(Y)-modified synthetic long peptides. In contrast, Le(Y)-modified synthetic long peptides were recognized by DC-SIGN, but did not trigger antigen internalization nor antigen cross-presentation. These data demonstrate that langerin and DC-SIGN have different size requirements for antigen uptake. Although using glycans remains an interesting option in the design of anti-cancer vaccines targeting multiple CLRs, aspects such as molecule size and conformation need to be taken in consideration. PMID:25656175

  3. Therapeutic HIV Peptide Vaccine

    DEFF Research Database (Denmark)

    Fomsgaard, Anders

    2015-01-01

    Therapeutic vaccines aim to control chronic HIV infection and eliminate the need for lifelong antiretroviral therapy (ART). Therapeutic HIV vaccine is being pursued as part of a functional cure for HIV/AIDS. We have outlined a basic protocol for inducing new T cell immunity during chronic HIV-1...... infection directed to subdominant conserved HIV-1 epitopes restricted to frequent HLA supertypes. The rationale for selecting HIV peptides and adjuvants are provided. Peptide subunit vaccines are regarded as safe due to the simplicity, quality, purity, and low toxicity. The caveat is reduced immunogenicity...

  4. Cationic Antimicrobial Peptide Cytotoxicity

    OpenAIRE

    Laverty, Garry; Gilmore, Brendan

    2014-01-01

    Fluorescence microscopy serves as a valuable tool for assessing the structural integrity and viability of eukaryotic cells. Through the use of calcein AM and the DNA stain 4,6-diamidino-2 phenylindole (DAPI), cell viability and membrane integrity can be qualified. Our group has previously shown the ultra-short cationic antimicrobial peptide H-OOWW-NH2; the amphibian derived 27-mer peptide Maximin-4and the ultra-short lipopeptide C12-OOWW-NH2 to be effective against a range of bacterial biofil...

  5. Identification of a novel SEREX antigen family, ECSA, in esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Murakami Akihiro

    2011-06-01

    Full Text Available Abstract Background Diagnosis of esophageal squamous cell carcinoma (SCC may improve with early diagnosis. Currently it is difficult to diagnose SCC in the early stage because there is a limited number of tumor markers available. Results Fifty-two esophageal SCC SEREX antigens were identified by SEREX (serological identification of antigens by recombinant cDNA expression cloning using a cDNA phage library and sera of patients with esophageal SCC. Sequence analysis revealed that three of these antigens were similar in amino acid sequences, and they were designated as ECSA (esophageal carcinoma SEREX antigen-1, -2 and -3. The ECSA family was also similar to an EST clone, hepatocellular carcinoma-associated antigen 25a (HCA25a. Serum antibody levels to ECSA-1, -2 and -3 were significantly higher in patients with esophageal SCC than in healthy donors. Based on the conserved amino acid sequences, three peptides were synthesized and used for enzyme-linked immunosorbent assays (ELISA. The serum antibody levels against one of these peptides were significantly higher in patients with esophageal SCC. This peptide sequence was also conserved in FAM119A, GOSR1 and BBS5, suggesting that these are also ECSA family members. Reverse transcription followed by quantitative PCR analysis showed that the mRNA expression levels of ECSA-1, -2 and -3 and FAM119A but not of HCA25a, GOSR1 and BBS5 were frequently elevated in esophageal SCC tissues. Conclusions We have identified a new gene family designated ECSA. Serum antibodies against the conserved domain of the ECSA family may be a promising tumor marker for esophageal SCC.

  6. Screening of specific binding peptide targeting blood vessel of human esophageal cancer in vivo in mice

    Institute of Scientific and Technical Information of China (English)

    ZHI Min; WU Kai-chun; HAO Zhi-ming; GUO Chang-cun; YAO Jia-yin

    2011-01-01

    Background Cancer of the esophagus and gastroesophageal junction remains a virulent malignancy with poor prognosis. Rapid progresses were made in chemotherapeutic agents and the development of molecular markers allowed better identification of candidates for targeted therapy. This study aimed to identify the candidate peptides used for anti-angiogenic therapy of esophageal cancer by in vivo screening C7C peptide library for peptides binding specifically to blood vessels of human esophageal cancer.Methods The phage displayed C7C peptide library was injected intravenously into mice bearing human esophageal tumor xenografts under renal capsule. After 5 rounds of screening, 13 clones were picked up individually and sequenced.During each round of screening, titers of phage recovery were calculated from tumor xenograft and control tissues.Homing of these 9 peptides to tumor vessel was detected by calculating phage titers in the tumor xenograft and control tissues (lung and spleen) after each phage was injected into mice model, and compared with the distribution of phage M13 and Ⅷ-related antigen in tumor xenograft by immunohistochemical staining. Comparisons among groups of data were made using one-way analysis of variance (ANOVA), followed by the Bonferroni multiple comparisons test.Results The number of phage recovered from tumor tissue of each round increased gradually in tumor group while decreased in control groups (P <0.01 in tumor and spleen, P <0.05 in lung). Immunohistochemical staining showed similar staining pattern with M13 antibody or Ⅷ-related antigen antibody, suggesting that phages displaying the selected peptides could home to blood vessel of human esophageal cancer. According to their DNA, 9 corresponding peptide sequences were deduced. And the homing ability to blood vessel of phages displaying the selected peptides was confirmed by comparing with their recovery in tumor and control tissues. Two motifs, YSXNXW and PXNXXN, were also obtained by

  7. Diagnosis of tuberculosis with Au NRs biosensor based on the mimic peptide of Mycobacterium tuberculosis antigen%结核分枝杆菌抗原模拟肽纳米金生物传感器诊断结核病

    Institute of Scientific and Technical Information of China (English)

    孙文霞; 袁仕善; 黄昊文; 谭云洪; 黄绍文; 张小萍

    2012-01-01

    Objective To develop a An XRs biosensor bascd on the mimic peptide of Mycobactcrinm tuberculosis an tigen, and explore the diagnostic potwnial of the biosensor for TB. Methods The gold nanorods (An \\Rs) were syntbc sized with seed mcdiatcd method,the An XRs were eonjngated with the synthetie short mimie peptide T1 of Myeobae tcrinm tnbcrenlosis mtigen so as to elemlop a An XRs biosensor,then the diagnostie potcntial of the biosensor were dc tceted by scroanalysis. Results An XRs with good dispcrsity were prcpared with seed mceliated metnod.Tl was eonjn gatcel to Au XRs sneeeasfnlly to develop the biosensor. Scroinilysis showed that the sensitivity and spceifieity of the biosensor were 57. 1% mel 83.9% respectively. Conclusion An XRs immnnosensor bascd on the mimic peptide can be used in the dingnosis of TB.%目的 构建基于结核分枝杆菌抗原模拟肽的纳米金生物传感器,评价其诊断结核病(Tuberculosis,TB)的能力.方法 种子生长法制备金纳米棒,将结核分枝杆菌抗原合成模拟短肽T1包被金纳米棒,构建纳米金生物传感器,血清学分析评价其诊断结核病的能力.结果 种子生长法制备得到分散度良好的金纳米棒,构建成T1-纳米金生物传感器,血清学分析显示敏感性和特异性分别为57.1%和83.9%.结论 基于合成短肽的纳米金生物传感器对结核病有着较好的诊断价值.

  8. Coupling of HIV-1 Antigen to the Selective Autophagy Receptor SQSTM1/p62 Promotes T-Cell-Mediated Immunity

    Science.gov (United States)

    Andersen, Aram Nikolai; Landsverk, Ole Jørgen; Simonsen, Anne; Bogen, Bjarne; Corthay, Alexandre; Øynebråten, Inger

    2016-01-01

    Vaccines aiming to promote T-cell-mediated immune responses have so far showed limited efficacy, and there is a need for novel strategies. Studies indicate that autophagy plays an inherent role in antigen processing and presentation for CD4+ and CD8+ T cells. Here, we report a novel vaccine strategy based on fusion of antigen to the selective autophagy receptor sequestosome 1 (SQSTM1)/p62. We hypothesized that redirection of vaccine antigen from proteasomal degradation into the autophagy pathway would increase the generation of antigen-specific T cells. A hybrid vaccine construct was designed in which the antigen is fused to the C-terminus of p62, a signaling hub, and a receptor that naturally delivers ubiquitinated cargo for autophagic degradation. Fusion of the human immunodeficiency virus-1 antigen Gagp24 to p62 resulted in efficient antigen delivery into the autophagy pathway. Intradermal immunization of mice revealed that, in comparison to Gagp24 delivered alone, fusion to p62 enhanced the number of Gagp24-specific interferon-γ-producing T cells, including CD8+ T cells. The strategy may also have the potential to modulate the antigenic peptide repertoire. Because p62 and autophagy are highly conserved between species, we anticipate this strategy to be a candidate for the development of T-cell-based vaccines in humans.

  9. Antibodies recognizing a variety of different structural motifs on meningococcal Lip antigen fail to demonstrate bactericidal activity.

    Science.gov (United States)

    Tinsley, C R; Virji, M; Heckels, J E

    1992-11-01

    The neisserial Lip antigen is a conserved antigen associated with the pathogenic Neisseria species, and is composed of multiple repeats of a consensus pentapeptide. A series of monoclonal antibodies reacting with meningococcal Lip antigen were subjected to epitope mapping, using solid-phase synthetic peptides based on the consensus repeat sequence. The antibodies were found to recognize different continuous epitopes based on the consensus sequence. One monoclonal antibody was utilized in affinity chromatography to obtain purified Lip antigen and the antigen was used for immunization of mice. The resulting antisera did not recognize Lip antigen on Western blots but reacted specifically with Lip antigen in immune precipitation experiments, indicating that the predominant polyclonal immune response was directed against conformational epitopes. Despite the diversity of both continuous and conformational epitopes recognized by the antibodies produced, none of the antibodies demonstrated the ability to promote complement-mediated bactericidal activity. Thus despite its initial apparent promise as a potential vaccine candidate the case for the inclusion of Lip antigen in vaccine formulation cannot be supported at present. PMID:1282535

  10. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac p...... competent endocrine cells. The structurally related atrial natriuretic peptide will be mentioned where appropriate, whereas C-type natriuretic peptide will not be considered as a cardiac peptide of relevance in mammalian physiology....... characterized. An ongoing characterization of the molecular heterogeneity will help appreciate the biosynthetic capacity of the endocrine heart and could introduce new diagnostic possibilities. Notably, different biosynthetic products may not be equal markers of the same pathophysiological processes. An...... inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...

  11. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac...... inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...... competent endocrine cells. The structurally related atrial natriuretic peptide will be mentioned where appropriate, whereas C-type natriuretic peptide will not be considered as a cardiac peptide of relevance in mammalian physiology....

  12. Study of ultrasound stiffness imaging methods using tissue mimicking phantoms.

    Science.gov (United States)

    Manickam, Kavitha; Machireddy, Ramasubba Reddy; Seshadri, Suresh

    2014-02-01

    A pilot study was carried out to investigate the performance of ultrasound stiffness imaging methods namely Ultrasound Elastography Imaging (UEI) and Acoustic Radiation Force Impulse (ARFI) Imaging. Specifically their potential for characterizing different classes of solid mass lesions was analyzed using agar based tissue mimicking phantoms. Composite tissue mimicking phantom was prepared with embedded inclusions of varying stiffness from 50 kPa to 450 kPa to represent different stages of cancer. Acoustic properties such as sound speed, attenuation coefficient and acoustic impedance were characterized by pulse echo ultrasound test at 5 MHz frequency and they are ranged from (1564 ± 88 to 1671 ± 124 m/s), (0.6915 ± 0.123 to 0.8268 ± 0.755 db cm(-1)MHz(-1)) and (1.61 × 10(6) ± 0.127 to 1.76 × 10(6) ± 0.045 kg m(-2)s(-1)) respectively. The elastic property Young's Modulus of the prepared samples was measured by conducting quasi static uni axial compression test under a strain rate of 0.5mm/min upto 10 % strain, and the values are from 50 kPa to 450 kPa for a variation of agar concentration from 1.7% to 6.6% by weight. The composite phantoms were imaged by Siemens Acuson S2000 (Siemens, Erlangen, Germany) machine using linear array transducer 9L4 at 8 MHz frequency; strain and displacement images were collected by UEI and ARFI. Shear wave velocity 4.43 ± 0.35 m/s was also measured for high modulus contrast (18 dB) inclusion and X.XX m/s was found for all other inclusions. The images were pre processed and parameters such as Contrast Transfer Efficiency and lateral image profile were computed and reported. The results indicate that both ARFI and UEI represent the abnormalities better than conventional US B mode imaging whereas UEI enhances the underlying modulus contrast into improved strain contrast. The results are corroborated with literature and also with clinical patient images. PMID:24083832

  13. Analysis of a cDNA clone expressing a human autoimmune antigen: full-length sequence of the U2 small nuclear RNA-associated B antigen

    International Nuclear Information System (INIS)

    A U2 small nuclear RNA-associated protein, designated B'', was recently identified as the target antigen for autoimmune sera from certain patients with systemic lupus erythematosus and other rheumatic diseases. Such antibodies enabled them to isolate cDNA clone λHB''-1 from a phage λgt11 expression library. This clone appeared to code for the B'' protein as established by in vitro translation of hybrid-selected mRNA. The identity of clone λHB''-1 was further confirmed by partial peptide mapping and analysis of the reactivity of the recombinant antigen with monospecific and monoclonal antibodies. Analysis of the nucleotide sequence of the 1015-base-pair cDNA insert of clone λHB''-1 revealed a large open reading frame of 800 nucleotides containing the coding sequence for a polypeptide of 25,457 daltons. In vitro transcription of the λHB''-1 cDNA insert and subsequent translation resulted in a protein product with the molecular size of the B'' protein. These data demonstrate that clone λHB''-1 contains the complete coding sequence of this antigen. The deduced polypeptide sequence contains three very hydrophilic regions that might constitute RNA binding sites and/or antigenic determinants. These findings might have implications both for the understanding of the pathogenesis of rheumatic diseases as well as for the elucidation of the biological function of autoimmune antigens

  14. Increased Diversity of the HLA-B40 Ligandome by the Presentation of Peptides Phosphorylated at Their Main Anchor Residue*

    OpenAIRE

    Marcilla, Miguel; Alpízar, Adán; Lombardía, Manuel; Ramos-Fernandez, Antonio; Ramos, Manuel; Albar, Juan Pablo

    2013-01-01

    Human leukocyte antigen (HLA) class I molecules bind peptides derived from the intracellular degradation of endogenous proteins and present them to cytotoxic T lymphocytes, allowing the immune system to detect transformed or virally infected cells. It is known that HLA class I–associated peptides may harbor posttranslational modifications. In particular, phosphorylated ligands have raised much interest as potential targets for cancer immunotherapy. By combining affinity purification with high...

  15. The impact of human leukocyte antigen (HLA) micropolymorphism on ligand specificity within the HLA-B*41 allotypic family

    Energy Technology Data Exchange (ETDEWEB)

    Bade-Döding, Christina; Theodossis, Alex; Gras, Stephanie; Kjer-Nielsen, Lars; Eiz-Vesper, Britta; Seltsam, Axel; Huyton, Trevor; Rossjohn, Jamie; McCluskey, James; Blasczyk, Rainer (Springe); (Hannover-MED); (Monash); (Melbourne)

    2011-09-28

    Polymorphic differences between human leukocyte antigen (HLA) molecules affect the specificity and conformation of their bound peptides and lead to differential selection of the T-cell repertoire. Mismatching during allogeneic transplantation can, therefore, lead to immunological reactions. We investigated the structure-function relationships of six members of the HLA-B*41 allelic group that differ by six polymorphic amino acids, including positions 80, 95, 97 and 114 within the antigen-binding cleft. Peptide-binding motifs for B*41:01, *41:02, *41:03, *41:04, *41:05 and *41:06 were determined by sequencing self-peptides from recombinant B*41 molecules by electrospray ionization tandem mass spectrometry. The crystal structures of HLA-B*41:03 bound to a natural 16-mer self-ligand (AEMYGSVTEHPSPSPL) and HLA-B*41:04 bound to a natural 11-mer self-ligand (HEEAVSVDRVL) were solved. Peptide analysis revealed that all B*41 alleles have an identical anchor motif at peptide position 2 (glutamic acid), but differ in their choice of C-terminal p{Omega} anchor (proline, valine, leucine). Additionally, B*41:04 displayed a greater preference for long peptides (>10 residues) when compared to the other B*41 allomorphs, while the longest peptide to be eluted from the allelic group (a 16mer) was obtained from B*41:03. The crystal structures of HLA-B*41:03 and HLA-B*41:04 revealed that both alleles interact in a highly conserved manner with the terminal regions of their respective ligands, while micropolymorphism-induced changes in the steric and electrostatic properties of the antigen-binding cleft account for differences in peptide repertoire and auxiliary anchoring. Differences in peptide repertoire, and peptide length specificity reflect the significant functional evolution of these closely related allotypes and signal their importance in allogeneic transplantation, especially B*41:03 and B*41:04, which accommodate longer peptides, creating structurally distinct peptide

  16. Major histocompatibility complex (MHC) antigens

    Czech Academy of Sciences Publication Activity Database

    Hála, K.; Plachý, Jiří; Kaufman, J.

    New York : Academic Press, 1998 - (Pastoret, P.; Griebel, P.; Bazin, H.; Govaerts, A.), s. 92-95 ISBN 0-12-546401-0 R&D Projects: GA ČR GA523/96/0670 Keywords : chicken MHC * histocompatibility antigens * disease resistance Subject RIV: EB - Genetics ; Molecular Biology

  17. Automated Detection of Conformational Epitopes Using Phage Display Peptide Sequences

    Directory of Open Access Journals (Sweden)

    Surendra S Negi

    2009-01-01

    Full Text Available Background: Precise determination of conformational epitopes of neutralizing antibodies represents a key step in the rational design of novel vaccines. A powerful experimental method to gain insights on the physical chemical nature of conformational epitopes is the selection of linear peptides that bind with high affinities to a monoclonal antibody of interest by phage display technology. However, the structural characterization of conformational epitopes from these mimotopes is not straightforward, and in the past the interpretation of peptide sequences from phage display experiments focused on linear sequence analysis to find a consensus sequence or common sequence motifs.Results: We present a fully automated search method, EpiSearch that predicts the possible location of conformational epitopes on the surface of an antigen. The algorithm uses peptide sequences from phage display experiments as input, and ranks all surface exposed patches according to the frequency distribution of similar residues in the peptides and in the patch. We have tested the performance of the EpiSearch algorithm for six experimental data sets of phage display experiments, the human epidermal growth factor receptor-2 (HER-2/neu, the antibody mAb Bo2C11 targeting the C2 domain of FVIII, antibodies mAb 17b and mAb b12 of the HIV envelope protein gp120, mAb 13b5 targeting HIV-1 capsid protein and 80R of the SARS coronavirus spike protein. In all these examples the conformational epitopes as determined by the X-ray crystal structures of the antibody-antigen complexes, were found within the highest scoring patches of EpiSearch, covering in most cases more than 50% residues of experimental observed conformational epitopes. Input options of the program include mapping of a single peptide or a set of peptides on the antigen structure, and the results of the calculation can be visualized on our interactive web server.Availability: Users can access the EpiSearch from our web

  18. Rapid assessment of the antigenic integrity of tetrameric HLA complexes by human monoclonal HLA antibodies.

    Science.gov (United States)

    Eijsink, Chantal; Kester, Michel G D; Franke, Marry E I; Franken, Kees L M C; Heemskerk, Mirjam H M; Claas, Frans H J; Mulder, Arend

    2006-08-31

    The ability of tetrameric major histocompatibility complex (MHC) class I-peptide complexes (tetramers) to detect antigen-specific T lymphocyte responses has yielded significant information about the generation of in vivo immunity in numerous antigenic systems. Here we present a novel method for rapid validation of tetrameric HLA molecules based on the presence of allodeterminants. Human monoclonal antibodies (mAbs) recognizing polymorphic determinants on HLA class I were immobilized on polystyrene microparticles and used to probe the structural integrity of tetrameric HLA class I molecules by flow cytometry. A total of 22 tetramers, based on HLA-A1, A2, A3, A24, B7 and B8 were reactive with their counterpart mAbs, thus confirming their antigenic integrity. A positive outcome of this mAb test ensures that tetrameric HLA class I can be used with greater confidence in subsequent functional assays. PMID:16973172

  19. Genotyping of human leukocyte antigen (HLA) ancestral haplotypes as prognostic marker in cancer using PCR analysis.

    Science.gov (United States)

    Villabona, Lisa; Andersson, Emilia; Marchesi, Maddalena; Masucci, Giuseppe V

    2014-01-01

    The major histocompatibility complex (MHC) comprises a set of genes that are essential to immunity and surveillance against neoplastic transformation. MHC antigens not only regulate antitumor immune responses in experimental animal models but also directly correlate with survival and prognosis of patients with various types of cancers. Effective recognition of tumor cells by effector T cells may be affected by the genotype and the extent of expression of human leukocyte antigen (HLA)-peptide complexes. Therefore, MHC antigens may serve as potential biomarkers for prognosis and allow selection of cancer patients for specific therapy. We describe PCR-based method to determine the HLA genotype in healthy individuals and patients using blood and tumor tissue as DNA source. PMID:24258987

  20. Delivery of Exogenous Antigens to Induce Cytotoxic CD8+ T Lymphocyte Responses

    Directory of Open Access Journals (Sweden)

    Julia Kim

    2010-01-01

    Full Text Available Vaccines intended to induce a cytotoxic CD8+ T-cell response are highly sought after. However, some of these vaccines can be problematic if they replicate in the host. An alternative strategy is to exploit cross-presentation of exogenous antigens to express peptides on major histocompatibility complex (MHC class I molecules. During cross-presentation, the delivered exogenous antigen can be taken up and processed through diverse mechanisms. Here, we will discuss the recent advances regarding the complex nature of the cross-priming process and the models that reflect its relevance in vivo. Moreover, we summarize current data that explore potential adjuvants and vaccine vectors that deliver antigens to activate CD8+ T cells relying on cross-presentation.