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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

    , 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. Synthetic peptides mimicking lipopolysaccharide as a potential vaccine candidates against Vibrio cholerae serogroup O1.

    Science.gov (United States)

    Ghazi, Fatemeh Mohammad Pour; Gargari, Seyed Latif Mousavi

    2017-08-01

    Cholera is a life-threatening diarrhea caused mainly by Gram-negative marine habitant Vibrio cholerae serogroup O1. Cholera vaccination is limited mainly to developed countries, due to the cumbersome and expensive task of vaccine production. In the present work, the aim was to study the immunogenicity of the synthetic mimotopes through two different routes of injection and oral administration. Lipopolysaccharide (LPS) is one of the immunogenic components in Gram-negative bacteria, which cannot be used as a vaccine candidate, due to its high toxic effect. Three phage-displayed selected peptides, with high affinity to anti-LPS VHH tested in our previous study, were chemically synthesized and used as a potential vaccine candidate. In order to enhance the antigenic properties and safe delivery, these peptides were conjugated to BSA as a carrier and encapsulated with PLGA. Peptides were injected intra-peritoneally or administered orally, alone or in combined form. Mice sera and feces were collected for assessment of humoral and mucosal antibody titers, respectively. ELISA plates were coated with mimotope conjugates and V. cholerae , Shigella sonnei and ETEC were used as target antigens. Antibody titer was measured by adding IgG and IgA as primary antibodies. Mice receiving three selected synthetic peptide conjugates (individually or in combination) showed higher antibody titer compared to control groups. The mice immunized with synthetic peptides were protected against more than 15 LD50 of V. cholerae. These peptides are mimicking LPS and can potentially act as vaccine candidates against V. cholerae.

  3. Defined carriers for synthetic antigens: Hinge Peptides

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Jan; Niederhafner, Petr; Gut, Vladimír; Hulačová, Hana; Maloň, Petr

    2005-01-01

    Roč. 29, č. 1 (2005), s. 68 ISSN 0939-4451. [International Congress on Amino Acids and Proteins /9./. 08.08.2005-12.08.2005, Gert Lubec] R&D Projects: GA ČR(CZ) GA203/03/1362 Institutional research plan: CEZ:AV0Z40550506 Keywords : synthetic carrier * antigen * hinge peptide Subject RIV: CC - Organic Chemistry

  4. Tumor Associated Antigenic Peptides in Prostate Cancer

    National Research Council Canada - National Science Library

    Tiwari, Raj

    2001-01-01

    .... Since this tumor rejection property was specifically mediated by tumor denved and not non-tumor derived gp96-peptide complexes, and that gp96 preparations stripped of its peptides are non-immunogenic...

  5. Oxidative stress can alter the antigenicity of immunodominant peptides

    DEFF Research Database (Denmark)

    Weiskopf, Daniela; Schwanninger, Angelika; Weinberger, Birgit

    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...... of antigenic peptides may affect T cell responses severely by binding T cell clones with different affinity. This may lead to an altered immune response against infectious agents as well as against tumor or autoantigens under oxidative stress conditions....

  6. Conformational analysis of a synthetic fish kisspeptin 1 peptide in membrane mimicking environments.

    Science.gov (United States)

    Thakuria, Dimpal; Shahi, Neetu; Singh, Atul Kumar; Khangembam, Victoria Chanu; Singh, Arvind Kumar; Kumar, Satish

    2017-01-01

    Kisspeptin 1 is a neuropeptide hormone of the RFamide family, which act as an upstream regulator of brain-pituitary-gonad (BPG) axis in most vertebrates including teleosts. In the present study, a 16 amino acid long putative mature bioactive peptide (kiss 1) from preprokisspeptin 1 of golden mahseer, Tor putitora (Hamilton, 1822), was synthesized and characterized using an integrated (experimental and in silico) approach. The far-UV circular dichroism (CD) spectrum of this peptide was evaluated both in aqueous and membrane mimicking solvents (TFE, HFIP and Dioxane). The results indicate that kiss 1 peptide adopted helical, turn and β conformations in membrane like environments. The near-UV CD spectroscopy was also carried out to examine the tertiary packing around aromatic residues of kiss 1 peptide and the peptide-membrane complex. The kiss 1 peptide exhibited little signal in water, but a prominent negative band was observed at around 275 nm when membrane mimetic solution was added. The observed ordered conformations of kiss 1 peptide in the different solvents indicated its potential biological activity which could enhance the secretion of gonadotropin-releasing hormone (GnRH) at BPG axis. The conformational information generated from the present study reinforces the application prospects of bioactive synthetic peptide analogs of kisspeptin 1 in improving the reproductive performances of important cultivable fish species.

  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 effici...... peptide-MHC complexes may have broad significance in the biology of T cell responses, including generation of the T cell repertoire, the specificity of mixed lymphocyte responses, and the immune surveillance of self and nonself antigens in peripheral lymphoid tissues.......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...

  8. Development, Characterization, and Immunotherapeutic Use of Peptide Mimics of the Thomsen-Friedenreich Carbohydrate Antigen

    Directory of Open Access Journals (Sweden)

    Jamie Heimburg-Molinaro

    2009-08-01

    Full Text Available The tumor-associated carbohydrate Thomsen-Friedenreich antigen (TF-Ag; Galß1-3GalNAcα-O-Ser/Thr is overexpressed on the cell surface of several types of tumor cells, contributing to cancer cell adhesion and metastasis to sites containing TF-Ag-binding lectins. A highly specific immunoglobulin G3 monoclonal antibody (Ab developed to TF-Ag (JAA-F11 impedes TF-Ag binding to vascular endothelium, blocking a primary metastatic step and providing a survival advantage. In addition, in patients, even low levels of antibodies to TF-Ag seem to improve prognosis; thus, it is expected that vaccines generating antibodies toward TF-Ag would be clinically valuable. Unfortunately, vaccinations with protein conjugates of carbohydrate tumor-associated Ags have induced clinically inadequate immune responses. However, immunization using peptides that mimic carbohydrate Ags such as Lewis has resulted in both Ab and T-cell responses. Here, we tested the hypothesis that vaccinations with unique TF-Ag peptide mimics may generate immune responses to TF-Ag epitopes on tumor cells, useful for active immunotherapy against relevant cancers. Peptide mimics of TF-Ag were selected by phage display biopanning using JAA-F11 and rabbit anti-TF-Ag Ab and were analyzed in vitro to confirm TF-Ag peptide mimicry. In vitro, TF-Ag peptide mimics bound to TF-Ag-specific peanut agglutinin and blocked TF-Ag-mediated rolling and stable adhesion of cancer cells to vascular endothelium. In vivo, the immunization with TF-Ag-mimicking multiple antigenic peptides induced TFAg- reactive Ab production. We propose that this novel active immunotherapy approach could decrease tumor burden in cancer patients by specifically targeting TF-Ag-positive cancer cells and blocking metastasis.

  9. Synthetic peptides mimicking the binding site of human acetylcholinesterase for its inhibitor fasciculin 2.

    Science.gov (United States)

    Kafurke, Uwe; Erijman, Ariel; Aizner, Yonatan; Shifman, Julia M; Eichler, Jutta

    2015-09-01

    Molecules capable of mimicking protein binding and/or functional sites present useful tools for a range of biomedical applications, including the inhibition of protein-ligand interactions. Such mimics of protein binding sites can currently be generated through structure-based design and chemical synthesis. Computational protein design could be further used to optimize protein binding site mimetics through rationally designed mutations that improve intermolecular interactions or peptide stability. Here, as a model for the study, we chose an interaction between human acetylcholinesterase (hAChE) and its inhibitor fasciculin-2 (Fas) because the structure and function of this complex is well understood. Structure-based design of mimics of the hAChE binding site for Fas yielded a peptide that binds to Fas at micromolar concentrations. Replacement of hAChE residues known to be essential for its interaction with Fas with alanine, in this peptide, resulted in almost complete loss of binding to Fas. Computational optimization of the hAChE mimetic peptide yielded a variant with slightly improved affinity to Fas, indicating that more rounds of computational optimization will be required to obtain peptide variants with greatly improved affinity for Fas. CD spectra in the absence and presence of Fas point to conformational changes in the peptide upon binding to Fas. Furthermore, binding of the optimized hAChE mimetic peptide to Fas could be inhibited by hAChE, providing evidence for a hAChE-specific peptide-Fas interaction. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

  10. Mimicking protein-protein interactions through peptide-peptide interactions: HIV-1 gp120 and CXCR4

    Directory of Open Access Journals (Sweden)

    Andrea eGross

    2013-09-01

    Full Text Available We have recently designed a soluble synthetic peptide that functionally mimics the HIV-1 coreceptor CXCR4, which is a chemokine receptor that belongs to the family of seven-transmembrane GPCRs. This CXCR4 mimetic peptide, termed CX4-M1, presents the three extracellular loops (ECLs of the receptor. In binding assays involving recombinant proteins, as well as in cellular infection assays, CX4-M1 was found to selectively recognize gp120 from HIV-1 strains that use CXCR4 for cell entry (X4 tropic HIV-1. Furthermore, anti-HIV-1 antibodies modulate this interaction in a molecular mechanism related to that of their impact on the gp120-CXCR4 interaction. We could now show that the selectivity of CX4-M1 pertains not only to gp120 from X4 tropic HIV-1, but also to synthetic peptides presenting the V3 loops of these gp120 proteins. The V3 loop is thought to be an essential part of the coreceptor binding site of gp120 that contacts the second ECL of the coreceptor. We were able to experimentally confirm this notion in binding assays using substitution analogs of CX4-M1 and the V3 loop peptides, respectively, as well as in cellular infection assays. These results indicate that interactions of the HIV-1 Env with coreceptors can be mimicked by synthetic peptides, which may be useful to explore these interactions at the molecular level in more detail.

  11. Antigenicity of peptides comprising the immunosuppressive domain of the retroviral envelope glycoprotein [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Bryony Jenkins

    2016-12-01

    Full Text Available To achieve persistent infection of the host, viruses often subvert or suppress host immunity through mechanisms that are not entirely understood. The envelope glycoprotein of several retroviruses is thought to possess potent immunosuppressive activity, mapped to a 17-amino acid residue conserved domain. Synthetic peptides corresponding to this immunosuppressive domain can inhibit lymphocyte activation, whereas mutation of key domain residues can increase the lymphocyte response to linked antigenic epitopes. Using three T cell receptors (TCRs of defined specificity, we examine the effect of the immunosuppressive domain on the T cell response to their respective antigenic peptides. We find that fusion of a T cell epitope to the immunosuppressive domain can greatly modulate its potency. However, the effects heavily depend on the particular combination of TCR and peptide-major histocompatibility complex class II (pMHC II, and are mimicked by sequence-scrambled peptides of similar length, suggesting they operate at the level of TCR-pMHC interaction. These results offer an alternative explanation for the immunogenicity of T cell epitopes comprising the putative immunosuppressive domain, which is more consistent with an effect on peptide antigenicity than true immunosuppressive activity.

  12. Antigenicity of peptides comprising the immunosuppressive domain of the retroviral envelope glycoprotein [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Bryony Jenkins

    2017-02-01

    Full Text Available To achieve persistent infection of the host, viruses often subvert or suppress host immunity through mechanisms that are not entirely understood. The envelope glycoprotein of several retroviruses is thought to possess potent immunosuppressive activity, mapped to a 17-amino acid residue conserved domain. Synthetic peptides corresponding to this immunosuppressive domain can inhibit lymphocyte activation, whereas mutation of key domain residues can increase the lymphocyte response to linked antigenic epitopes. Using three T cell receptors (TCRs of defined specificity, we examine the effect of the immunosuppressive domain on the T cell response to their respective antigenic peptides. We find that fusion of a T cell epitope to the immunosuppressive domain can greatly modulate its potency. However, the effects heavily depend on the particular combination of TCR and peptide-major histocompatibility complex class II (pMHC II, and are mimicked by sequence-scrambled peptides of similar length, suggesting they operate at the level of pMHC formation or TCR-pMHC interaction. These results offer an alternative explanation for the immunogenicity of T cell epitopes comprising the putative immunosuppressive domain, which is more consistent with an effect on peptide antigenicity than true immunosuppressive activity.

  13. Antimicrobial Peptide Mimicking Primary Amine and Guanidine Containing Methacrylamide Copolymers Prepared by Raft Polymerization

    Science.gov (United States)

    Exley, Sarah E.; Paslay, Lea C.; Sahukhal, Gyan S.; Abel, Brooks A.; Brown, Tyler D.; McCormick, Charles L.; Heinhorst, Sabine; Koul, Veena; Choudhary, Veena; Elasri, Mohamed O.; Morgan, Sarah E.

    2016-01-01

    Naturally occurring antimicrobial peptides (AMPs) display the ability to eliminate a wide variety of bacteria, without toxicity to the host eukaryotic cells. Synthetic polymers containing moieties mimicking lysine and arginine components found in AMPs have been reported to show effectiveness against specific bacteria, with the mechanism of activity purported to depend on the nature of the amino acid mimic. In an attempt to incorporate the antimicrobial activity of both amino acids into a single water-soluble copolymer, a series of copolymers containing lysine mimicking aminopropyl methacrylamide (APMA) and arginine mimicking guanadinopropyl methacrylamide (GPMA) were prepared via aqueous RAFT polymerization. Copolymers were prepared with varying ratios of the comonomers, with degree of polymerization of 35–40 and narrow molecular weight distribution to simulate naturally occurring AMPs. Antimicrobial activity was determined against Gram-negative and Gram-positive bacteria under conditions with varying salt concentration. Toxicity to mammalian cells was assessed by hemolysis of red blood cells and MTT assays of MCF-7 cells. Antimicrobial activity was observed for APMA homopolymer and copolymers with low concentrations of GPMA against all bacteria tested, with low toxicity toward mammalian cells. PMID:26558609

  14. Synthetic Peptides as Potential Antigens for Cutaneous Leishmaniosis Diagnosis.

    Science.gov (United States)

    Link, Juliana Seger; Alban, Silvana Maria; Soccol, Carlos Ricardo; Pereira, Gilberto Vinicius Melo; Thomaz Soccol, Vanete

    2017-01-01

    This work's goal was to research new candidate antigens for cutaneous leishmaniosis (CL). In order to reach the goal, we used random peptide phage display libraries screened using antibodies from Leishmania braziliensis patients. After selection, three peptides (P1, P2, and P3) were synthesized using Fmoc chemistry. The peptides individually or a mixture of them (MIX) was subsequently emulsified in complete and incomplete Freund's adjuvant and injected subcutaneously in golden hamsters. Sera from the hamsters administered with P1 presented antibodies that recognized proteins between 76 and 150 kDa from L. braziliensis . Sera from hamsters which had peptides P2 and P3, as well as the MIX, administered presented antibodies that recognized proteins between 52 and 76 kDa of L. braziliensis . The research on the similarity of the peptides' sequences in protein databases showed that they match a 63 kDa glycoprotein. The three peptides and the MIX were recognized by the sera from CL patients by immunoassay approach (ELISA). The peptides' MIX showed the best performance (79% sensitivity) followed by the P1 (72% sensitivity), and the AS presented 91% sensitivity. These results show a new route for discovering molecules for diagnosis or for immunoprotection against leishmaniosis.

  15. Specificities of rabbit antisera to multiple antigen (MAP) peptides.

    Science.gov (United States)

    Chersi, A; di Modugno, F; Falasca, G

    1995-01-01

    Two multiple antigen peptides consisting of 6 and 7 aminoa cid residues, respectively, plus a 12-residue fragment, used as a control, all linked to a polylysine core, were used as immunogens in rabbits in order to obtain an immune response. Rabbit antisera against such polymers were then tested in ELISA against a panel of antigens in order to analyze the specificities of the resulting antibodies. The responses were different for all three immunogens, being partially or totally directed, for two of the three compounds, including the 12-residue control MAP peptide, against the polylysyl core, which is considered as non immunogenic. The third MAP polymer was practically unable to elicit an immune response.

  16. Heterologous expression of antigenic peptides in Bacillus subtilis biofilms.

    Science.gov (United States)

    Vogt, Cédric M; Schraner, Elisabeth M; Aguilar, Claudio; Eichwald, Catherine

    2016-08-11

    Numerous strategies have been developed for the display of heterologous proteins in the surface of live bacterial carriers, which can be used as vaccines, immune-modulators, cancer therapy or bioremediation. Bacterial biofilms have emerged as an interesting approach for the expression of proteins of interest. Bacillus subtilis is a well-described, endospore-forming organism that is able to form biofilms and also used as a probiotic, thus making it a suitable candidate for the display of heterologous proteins within the biofilm. Here, we describe the use of TasA, an important structural component of the biofilms formed by B. subtilis, as a genetic tool for the display of heterologous proteins. We first engineered the fusion protein TasA-mCherry and showed that was widely deployed within the B. subtilis biofilms. A significant enhancement of the expression of TasA-mCherry within the biofilm was obtained when depleting both tasA and sinR genes. We subsequently engineered fusion proteins of TasA to antigenic peptides of the E. granulosus parasite, paramyosin and tropomyosin. Our results show that the antigens were well expressed within the biofilm as denoted by macrostructure complementation and by the detection of the fusion protein in both immunoblot and immunohistochemistry. In addition, we show that the recombinant endospores of B. subtilis preserve their biophysical and morphological properties. In this work we provide strong evidence pointing that TasA is a suitable candidate for the display of heterologous peptides, such as antigens, cytokines, enzymes or antibodies, in the B. subtilis biofilms. Finally, our data portray that the recombinant endospores preserve their morphological and biophysical properties and could be an excellent tool to facilitate the transport and the administration.

  17. Mimicking cellular transport mechanism in stem cells through endosomal escape of new peptide-coated quantum dots.

    Science.gov (United States)

    Narayanan, Karthikeyan; Yen, Swee Kuan; Dou, Qingqing; Padmanabhan, Parasuraman; Sudhaharan, Thankiah; Ahmed, Sohail; Ying, Jackie Y; Selvan, Subramanian Tamil

    2013-01-01

    Protein transport is an important phenomenon in biological systems. Proteins are transported via several mechanisms to reach their destined compartment of cell for its complete function. One such mechanism is the microtubule mediated protein transport. Up to now, there are no reports on synthetic systems mimicking the biological protein transport mechanism. Here we report a highly efficient method of mimicking the microtubule mediated protein transport using newly designed biotinylated peptides encompassing a microtubule-associated sequence (MTAS) and a nuclear localization signaling (NLS) sequence, and their final conjugation with streptavidin-coated CdSe/ZnS quantum dots (QDs). Our results demonstrate that these novel bio-conjugated QDs enhance the endosomal escape and promote targeted delivery into the nucleus of human mesenchymal stem cells via microtubules. Mimicking the cellular transport mechanism in stem cells is highly desirable for diagnostics, targeting and therapeutic applications, opening up new avenues in the area of drug delivery.

  18. Structural mimicry of O-antigen by a peptide revealed in a complex with an antibody raised against Shigella flexneri serotype 2a.

    Science.gov (United States)

    Theillet, François-Xavier; Saul, Frederick A; Vulliez-Le Normand, Brigitte; Hoos, Sylviane; Felici, Franco; Weintraub, Andrej; Mulard, Laurence A; Phalipon, Armelle; Delepierre, Muriel; Bentley, Graham A

    2009-05-15

    The use of carbohydrate-mimicking peptides to induce immune responses against surface polysaccharides of pathogenic bacteria offers a novel approach to vaccine development. Factors governing antigenic and immunogenic mimicry, however, are complex and poorly understood. We have addressed this question using the anti-lipopolysaccharide monoclonal antibody F22-4, which was raised against Shigella flexneri serotype 2a and shown to protect against homologous infection in a mouse model. In a previous crystallographic study, we described F22-4 in complex with two synthetic fragments of the O-antigen, the serotype-specific saccharide moiety of lipopolysaccharide. Here, we present a crystallographic and NMR study of the interaction of F22-4 with a dodecapeptide selected by phage display using the monoclonal antibody. Like the synthetic decasaccharide, the peptide binds to F22-4 with micromolar affinity. Although the peptide and decasaccharide use very similar regions of the antigen-binding site, indicating good antigenic mimicry, immunogenic mimicry by the peptide was not observed. The F22-4-antigen interaction is significantly more hydrophobic with the peptide than with oligosaccharides; nonetheless, all hydrogen bonds formed between the peptide and F22-4 have equivalents in the oligosaccharide complex. Two bridging water molecules are also in common, adding to partial structural mimicry. Whereas the bound peptide is entirely helical, its structure in solution, as shown by NMR, is helical in the central region only. Moreover, docking the NMR structure into the antigen-binding site shows that steric hindrance would occur, revealing poor complementarity between the major solution conformation and the antibody that could contribute to the absence of immunogenic mimicry.

  19. 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.

  20. Peptides containing antigenic and cationic domains have enhanced, multivalent immunogenicity when bound to DNA vaccines.

    Science.gov (United States)

    Riedl, Petra; Reimann, Jörg; Schirmbeck, Reinhold

    2004-02-01

    We explored strategies to codeliver DNA- and peptide-based vaccines in a way that enhances the immunogenicity of both components of the combination vaccine for T cells. Specific CD8(+) T cell responses to an antigenic peptide are primed when the peptide is fused to a cationic peptide domain that is bound to plasmid DNA or oligonucleotides (ODN; with or without CpG motifs). Plasmid DNA mixed with antigenic/cationic peptides or histones forms large complexes with different biological properties depending on the molar ratios of peptide/protein and polynucleotide. Complexes containing high (but not low) molar ratios of cationic peptide to DNA facilitate transfection (DNA uptake and expression of the plasmid-encoded product) of cells. In contrast, complexes containing low (but not high) molar ratios of cationic peptide to DNA prime potent multispecific T cell responses after a single intramuscular injection of the complexes. The general validity of this observation was confirmed mixing different antigenic/cationic peptides with different DNA vaccines. In these vaccine formulations, multispecific CD8(+) T cell responses specific for epitopes of the peptide- as well as the DNA-based vaccine were efficiently coprimed, together with humoral antibody responses to conformational determinants of large viral antigens encoded by the DNA vaccine. The data indicate that mixtures of DNA vaccines with antigenic, cationic peptides are immunogenic vaccine formulations particularly suited for the induction of multispecific T cell responses.

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

    International Nuclear Information System (INIS)

    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 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 [ 35 S]methionine-labeled cells, appears as two discrete bands of ≅72 and 74 kDa after NaDodSO 4 /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

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

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Appella, E

    1990-01-01

    IA(d) and IE(d) molecules and their peptide ligands, we found that some structural characteristics apply to both antigen-MHC interactions. In particular, we found: 1) each MHC molecule is capable of binding many unrelated peptides through the same peptide-binding site; 2) despite this permissiveness......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...... of binding, it is possible to define certain structural features of peptides that are associated with the capacity to bind to a particular MHC specificity (IA(d) or IE(d)); 3) IA(d) and IE(d) molecules recognize different and independent structures on the antigen molecule; 4) only about 10% of the single...

  3. Functional mimicry of a discontinuous antigenic site by a designed synthetic peptide

    NARCIS (Netherlands)

    Villen, J.; Borras, E.; Schaaper, W.M.M.; Meloen, R.H.; Davila, M.; Domingo, E.; Giralt, E.; Andreu, D.

    2002-01-01

    Functional reproduction of the discontinuous antigenic site D of foot-and-mouth disease virus (FMDV) has been achieved by means of synthetic peptide constructions that integrate each of the three protein loops that define the antigenic site into a single molecule. The site D mimics were designed on

  4. Immune response to synthetic peptides representing antigenic sites on the glycoprotein of infectious hematopoietic necrosis virus

    Science.gov (United States)

    Emmenegger, Eveline J.; Huang, C.; LaPatra, S.; Winton, James R.

    1995-01-01

    Summary ― Monoclonal antibodies against infectious hematopoietic necrosis virus have been used to react with recombinant expression products in immunoblots and to select neutralization-resistant mutants for sequence analysis. These strategies identified neutralizing and non-neutralizing antigenic sites on the viral glycoprotein. Synthetic peptides based upon the amino acid sequences of these antigenic sites were synthesized and were injected together with an adjuvant into rainbow trout. The constructs generally failed to stimulate neutralizing antibodies in the fish. These results indicate that we need to understand more about the ability of peptide antigens to stimulate fish immune systems.

  5. 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.

  6. Photochemical Internalization of Peptide Antigens Provides a Novel Strategy to Realize Therapeutic Cancer Vaccination

    Directory of Open Access Journals (Sweden)

    Markus Haug

    2018-04-01

    Full Text Available Effective priming and activation of tumor-specific CD8+ cytotoxic T lymphocytes (CTLs is crucial for realizing the potential of therapeutic cancer vaccination. This requires cytosolic antigens that feed into the MHC class I presentation pathway, which is not efficiently achieved with most current vaccination technologies. Photochemical internalization (PCI provides an emerging technology to route endocytosed material to the cytosol of cells, based on light-induced disruption of endosomal membranes using a photosensitizing compound. Here, we investigated the potential of PCI as a novel, minimally invasive, and well-tolerated vaccination technology to induce priming of cancer-specific CTL responses to peptide antigens. We show that PCI effectively promotes delivery of peptide antigens to the cytosol of antigen-presenting cells (APCs in vitro. This resulted in a 30-fold increase in MHC class I/peptide complex formation and surface presentation, and a subsequent 30- to 100-fold more efficient activation of antigen-specific CTLs compared to using the peptide alone. The effect was found to be highly dependent on the dose of the PCI treatment, where optimal doses promoted maturation of immature dendritic cells, thus also providing an adjuvant effect. The effect of PCI was confirmed in vivo by the successful induction of antigen-specific CTL responses to cancer antigens in C57BL/6 mice following intradermal peptide vaccination using PCI technology. We thus show new and strong evidence that PCI technology holds great potential as a novel strategy for improving the outcome of peptide vaccines aimed at triggering cancer-specific CD8+ CTL responses.

  7. Vesicles mimicking normal and cancer cell membranes exhibit differential responses to the cell-penetrating peptide Pep-1.

    Science.gov (United States)

    Almarwani, Bashiyar; Phambu, Esther Nzuzi; Alexander, Christopher; Nguyen, Ha Aimee T; Phambu, Nsoki; Sunda-Meya, Anderson

    2018-06-01

    The cell-penetrating peptide (CPP) Pep-1 presents a great potential in drug delivery due to its intrinsic property to cross plasma membrane. However, its mechanism of entry into the cell remains unresolved. In this study, we compare the selectivity of Pep-1 towards vesicles mimicking normal and cancer cell membranes. The interaction was performed in a wide range of peptide-to-lipid molar ratios using infrared (IR), fluorescence, scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. At low peptide concentration, fluorescence experiments show that lipid-phosphatidylserine (PS) seems to enable Pep-1 translocation into cancer cell membrane as evidenced by the blue shift of its maximal emission wavelength. DSC data show that Pep-1 induces segregation of lipids. At high peptide concentration, IR data indicate that the interaction of Pep-1 is relatively stronger with normal cell membrane than with cancer cell membrane through the phosphate groups, while the interaction is weaker with normal cell membrane than with cancer cell membrane through the carbonyl groups. TGA and DSC data reveal that vesicles of normal cell membrane are thermally more stable than vesicles of cancer cell membrane. This suggests that the additional lipid PS included in cancer cell membrane has a destabilizing effect on the membrane structure. SEM images reveal that Pep-1 form superstructures including spherical particles and fibrils in the presence of both model membranes. PS seems to enhance peptide transport across cellular membranes. The biophysical techniques in this study provide valuable insights into the properties of CPPs in drug delivery systems. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Diagnosis of tuberculosis infection based on synthetic peptides from Mycobacterium tuberculosis antigen 85 complex.

    Science.gov (United States)

    Kashyap, Rajpal S; Shekhawat, Seema D; Nayak, Amit R; Purohit, Hemant J; Taori, Girdhar M; Daginawala, Hatim F

    2013-06-01

    The laboratory diagnosis of pulmonary tuberculosis (TB) and tuberculous meningitis (TBM) is particularly challenging. The aim of the present work is to develop an immunoassay for the diagnosis of TB infection, using synthetic peptides of antigen (Ag) 85 complex of M. tuberculosis (Mtb) H37Rv. Four peptides (7-10 amino acids long) corresponding to group-specific epitopes of Ag 85 complex of Mtb were synthesized. All peptides were evaluated by enzyme-linked immunosorbent assay (ELISA) for immunoreactivity with sera and CSF samples of TB and TBM patients respectively. The diagnostic value of the four peptides was evaluated in both the samples. It was observed that Ag 85 peptide 1, 3 and 4 had the highest positive rates in the pulmonary patients; however, Ag 85 peptide 1 and 2 had shown good positivity in the TBM subjects. The synthetic peptide based ELISA using Ag 85 complex peptides is a sensitive, specific, rapid and cost effective immunoassay for early diagnosis of pulmonary and extrapulmonary TB. In addition, these synthetic peptides are comparatively easy to produce in a reproducible manner compared with the whole antigen. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Modulation of HIV peptide antigen specific cellular immune response by synthetic α- and β-defensin peptides.

    Science.gov (United States)

    Mohan, Teena; Sharma, Chandresh; Bhat, Ajaz A; Rao, D N

    2013-03-25

    Defensin peptides have their direct role in host defense against microbial infection as innate molecules and also thought to contribute to adaptive immunity by recruiting naïve T-cells and immature dendritic cells at the site of infection through CCR6 receptor. The main aim of the present study is to investigate the efficacy of defensins for the induction of cell mediated immune response against the peptide antigen of HIV-1 encapsulated in PLG microparticles through intranasal (IN) route in mice model. To characterized, we have analyzed T-cell proliferation, Th1/Th2 cytokines, β-chemokines production and IFN-γ/perforin secretion from CD4(+)/CD8(+) T-cells in response to HIV immunogen alone and with defensins at different mucosal site i.e. lamina propria (LP), spleen (SP) and peyer's patches (PP). The cellular immunogenicity of HIV peptide with defensin formulations showed a significantly higher (ppeptide. The enhanced cytokines measurement profile showed mixed Th1 and Th2 type of peptide specific immune response by the incorporation of defensins. In the continuation, enhancement in MIP-1α and RANTES level was also observed in HIV peptide-defensin formulations. The FACS data had revealed that CD4(+)/CD8(+) T-cells showed significantly (ppeptide formulations than HIV antigen alone group. Thus, the study emphasized here that defensin peptides have a potential role as mucosal adjuvant, might be responsible for the induction of cell mediated immunity when administered in mice through IN route with HIV peptide antigen. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. A new model mimicking persistent HBV e antigen-negative infection using covalently closed circular DNA in immunocompetent mice.

    Directory of Open Access Journals (Sweden)

    Lei Wang

    Full Text Available Despite the availability of an effective vaccine, hepatitis B virus (HBV infection remains a major health problem. HBV e antigen (HBeAg-negative strains have become prevalent. Previously, no animal model mimicked the clinical course of HBeAg-negative HBV infection. To establish an HBeAg-negative HBV infection model, the 3.2-kb full-length genome of HBeAg-negative HBV was cloned from a clinical sample and then circularized to form covalently closed circular (cccDNA. The resulting cccDNA was introduced into the liver of C57BL/6J mice through hydrodynamic injection. Persistence of the HBeAg-negative infection was monitored at predetermined time points using HBV-specific markers including HBV surface antigen (HBsAg, HBeAg, and HBV core antigen (HBcAg as well as DNA copies. Throughout the study, pAAV-HBV1.2 was used as a control. In mice injected with HBeAg-negative cccDNA, the HBV infection rate was 100% at the initial stage. HBsAg levels increased up to 1 week, at which point levels peaked and dropped quickly thereafter. In 60% of injected mice, HBsAg and HBcAg persisted for more than 10 weeks. High numbers of HBV DNA copies were detected in the serum and liver. Moreover, cccDNA persisted in the liver tissue of HBeAg-negative mice. In contrast to the pAAV-HBV 1.2 injected mice, no HBeAg was found in mice injected with HBeAg-negative HBV throughout the study period. These results demonstrate the first successful establishment of a model of HBeAg-negative HBV-persistent infection in immunocompetent mice. Compared to pAAV-HBV1.2-injected mice, the infection persistence and levels of serum virological and biochemical markers were approximately equal in the model mice. This model will be useful for mechanistic studies on HBeAg-negative HBV infection and will facilitate the evaluation of new antiviral drugs.

  11. PeMtb: A Database of MHC Antigenic Peptide of Mycobacterium tuberculosis.

    Science.gov (United States)

    Zia, Qamar; Azhar, Asim; Ahmad, Shadab; Afsar, Mohammad; Hasan, Ziaul; Owais, Mohammad; Alam, Mahfooz; Akbar, Shabab; Ganash, Magdah; Ashraf, Ghulam Md; Zubair, Swaleha; Aliev, Gjumrakch

    2017-11-10

    For design of a subunit vaccine for tuberculosis, identification of antigenic Tcell epitope is of utmost importance. Several MHC prediction server are available that can accurately predict antigenic peptide of variable lengths. However, peptides predicted from one server not necessarily are predicted form another server, thus creating a confusing situation for scientists to choose a best epitope. Keeping the above problem in mind, we developed a comprehensive database of peptides of Mycobacterial proteins. Each protein was taken from PubMed and was run through different MHC prediction servers, with the results being compiled into one database. For each protein, PeMtb generates a set of three different mers of variable lengths (12 mer or 13-mer) based on their ranking; with each mer being predicted for a plethora of MHC alleles. Researcher can choose the peptide (mers) that gives best binding affinity from most of the servers. The database relieves the investigators of the painstaking task of searching various MHC prediction servers for the right epitope (T-cell epitope) for a particular Mycobacterial antigen. We trust and anticipate that PeMtb will be a practical platform for trial and computational analyses of antigenic peptides for Mycobacterium tuberculosis. All the resources and information can be accessed by PeMtb home page www.pemtb-amu.org. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Invariant Chain Modulates HLA Class II Protein Recycling and Peptide Presentation in Nonprofessional Antigen Presenting Cells

    OpenAIRE

    Haque, Azizul; Hajiaghamohseni, Laela M.; Li, Ping; Toomy, Katherine; Blum, Janice S.

    2007-01-01

    The expression of MHC class II molecules and the invariant chain (Ii) chaperone, is coordinately regulated in professional antigen presenting cells (APC). Ii facilitates class II subunit folding as well as transit and retention in mature endosomal compartments rich in antigenic peptides in these APC. Yet, in nonprofessional APC such as tumors, fibroblasts and endocrine tissues, the expression of class II subunits and Ii may be uncoupled. Studies of nonprofessional APC indicate class II molecu...

  13. 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

    Synthetic peptides have frequently been used to immunize animals. However, peptides less than about 20 to 30 amino acids long are poor immunogens. In general, to increase its immunogenicity, the presentation of the peptide should be improved, and molecular weight needs to be increased. Many...... attempts have been made to couple peptide immunogens to different carrier proteins [e.g. keyhole limper haemocyanin (KLH) or ovalbumin]. This leads to very complex structures, however. We used a controlled conjugation of a peptide to a single long-chain fatty acid like palmitic acid by a thioester...... or an 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...

  14. Synthetic peptide vaccines: palmitoylation of peptide antigens by an thioester bond increases immunogenicity

    NARCIS (Netherlands)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Tesser, G.I.; Dalsgaard, K.; Langeveld, J.P.M.; Boshuizen, R.S.; Meloen, R.H.

    1997-01-01

    Synthetic peptides have frequently been used to immunize animals. However, peptides less than about 20 to 30 amino acids long are poor immunogens. In general, to increase its immunogenicity, the presentation of the peptide should be improved, and molecular weight needs to be increased. Many attempts

  15. 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.

  16. Inhibition of human immunodeficiency virus type 1 (HIV-1) penetration into target cells by synthetic peptides mimicking the N-terminus of the HIV-1 transmembrane glycoprotein

    NARCIS (Netherlands)

    Slepushkin, V. A.; Kornilaeva, G. V.; Andreev, S. M.; Sidorova, M. V.; Petrukhina, A. O.; Matsevich, G. R.; Raduk, S. V.; Grigoriev, V. B.; Makarova, T. V.; Lukashov, V. V.

    1993-01-01

    To investigate the mechanism of action of the 22-amino-acid HIV fusion peptide on HIV infection, we studied its influence on virus adsorption and HIV-induced syncytium formation. The effect of the peptide preparations on the synthesis of viral antigens in HIV-infected cell cultures was determined by

  17. Interaction of the amyloid β peptide with sodium dodecyl sulfate as a membrane-mimicking detergent.

    NARCIS (Netherlands)

    Hashemi, Shabestari M.; Meeuwenoord, N.J.; Filippov, D.V.; Huber, M.I.

    2016-01-01

    The amyloid β (A β) peptide is important in the context of Alzheimer's disease, since it is one of the major components of the fibrils that constitute amyloid plaques. Agents that can influence fibril formation are important, and of those, membrane mimics are particularly relevant, because the

  18. Immunization with mannosylated peptide induces poor T cell effector functions despite enhanced antigen presentation

    NARCIS (Netherlands)

    Kel, J.M.; Geus, E.D. de; Stipdonk, M.J. van; Drijfhout, J.W.; Koning, F.; Nagelkerken, L.

    2008-01-01

    In this study, we investigated the development of T cell responses in mice after administration of a mannosylated ovalbumin peptide (M-OVA323-339). Immunization with M-OVA323-339 in complete adjuvant resulted in enhanced antigen presentation in draining lymph nodes. Monitoring the fate of

  19. 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

    A plethora of peptides are generated intracellularly, and most peptide-human leukocyte antigen (HLA)-I interactions are of a transient, unproductive nature. Without a quality control mechanism, the HLA-I system would be stressed by futile attempts to present peptides not sufficient for the stable...

  20. 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

  1. Gold nanoparticles functionalized with angiogenin-mimicking peptides modulate cell membrane interactions.

    Science.gov (United States)

    Cucci, Lorena M; Munzone, Alessia; Naletova, Irina; Magrì, Antonio; La Mendola, Diego; Satriano, Cristina

    2018-04-16

    Angiogenin is a protein crucial in angiogenesis, and it is overexpressed in many cancers and downregulated in neurodegenerative diseases, respectively. The protein interaction with actin, through the loop encompassing the 60-68 residues, is an essential step in the cellular cytoskeleton reorganization. This, in turn, influences the cell proliferation and migration processes. In this work, hybrid nanoassemblies of gold nanoparticles with angiogenin fragments containing the 60-68 sequence were prepared and characterized in their interaction with both model membranes of supported lipid bilayers (SLBs) and cellular membranes of cancer (neuroblastoma) and normal (fibroblasts) cell lines. The comparison between physisorption and chemisorption mechanisms was performed by the parallel investigation of the 60-68 sequence and the peptide analogous containing an extra cysteine residue. Moreover, steric hindrance and charge effects were considered with a third analogous peptide sequence, conjugated with a fluorescent carboxyfluorescein (Fam) moiety. The hybrid nanobiointerface was characterized by means of ultraviolet-visible, atomic force microscopy and circular dichroism, to scrutinize plasmonic changes, nanoparticles coverage and conformational features, respectively. Lateral diffusion measurements on SLBs "perturbed" by the interaction with the gold nanoparticles-peptides point to a stronger membrane interaction in comparison with the uncoated nanoparticles. Cell viability and proliferation assays indicate a slight nanotoxicity in neuroblastoma cells and a proliferative activity in fibroblasts. The actin staining confirms different levels of interaction between the hybrid assemblies and the cell membranes.

  2. Multiple antigenic peptide (MAP): a synthetic peptide dendrimer for diagnostic, antiviral and vaccine strategies for emerging and re-emerging viral diseases.

    Science.gov (United States)

    Joshi, Vinay Ganeshrao; Dighe, Vikas D; Thakuria, Dimpal; Malik, Yashpal Singh; Kumar, Satish

    2013-12-01

    The peptide dendrimer provides novel strategies for various biological applications. Assembling of peptide in macromolecular structure is expected to give rational models as drugs, their delivery and diagnostic reagents. Improved understanding of virus structure and their molecular interactions with ligands have paved the way for treatment and control of emerging and re-emerging viral diseases. This review presents a brief account of a synthetic peptide dendrimer used for diagnostic, therapeutic and prophylactic applications. The designs comprise of multiple antigenic peptides which are being used as alternate synthetic antigens for different viruses.

  3. First characterization of Plasmodium vivax liver stage antigen (PvLSA) using synthetic peptides.

    Science.gov (United States)

    Goo, Youn-Kyoung; Seo, Eun-Jeong; Choi, Yeon-Kyung; Shin, Hyun-Il; Sattabongkot, Jetsumon; Ji, So-Young; Chong, Chom-Kyu; Cho, Shin-Hyung; Lee, Won-Ja; Kim, Jung-Yeon

    2014-02-12

    Plasmodium vivax is the most widespread human malaria in tropical and subtropical countries, including the Republic of Korea. Vivax malaria is characterized by hypnozoite relapse and long latency infection by the retained liver stage of P. vivax, and somewhat surprisingly, little is known of the liver stage antigens of this parasite. Here, we report for the first time the characterization of a liver stage antigen of P. vivax (PvLSA). Five peptides located inside PvLSA were synthesized, and specific anti-sera to the respective peptides were used to localize PvLSA on P. vivax parasites in human liver cells by immunofluorescence. Western blotting and enzyme-linked immunosorbent assay were performed using the five peptides and sera collected from vivax malaria patients and from normal healthy controls. PvLSA was localized on P. vivax parasites in human liver cells. Vivax malaria-infected patients were detected using the five peptides by western blotting. Furthermore, the peptides reacted with the sera of vivax malaria patients. These results suggest that PvLSA may function during the liver stage of P. vivax.

  4. Human Leukocyte Antigen F Presents Peptides and Regulates Immunity through Interactions with NK Cell Receptors.

    Science.gov (United States)

    Dulberger, Charles L; McMurtrey, Curtis P; Hölzemer, Angelique; Neu, Karlynn E; Liu, Victor; Steinbach, Adriana M; Garcia-Beltran, Wilfredo F; Sulak, Michael; Jabri, Bana; Lynch, Vincent J; Altfeld, Marcus; Hildebrand, William H; Adams, Erin J

    2017-06-20

    Evidence is mounting that the major histocompatibility complex (MHC) molecule HLA-F (human leukocyte antigen F) regulates the immune system in pregnancy, infection, and autoimmunity by signaling through NK cell receptors (NKRs). We present structural, biochemical, and evolutionary analyses demonstrating that HLA-F presents peptides of unconventional length dictated by a newly arisen mutation (R62W) that has produced an open-ended groove accommodating particularly long peptides. Compared to empty HLA-F open conformers (OCs), HLA-F tetramers bound with human-derived peptides differentially stained leukocytes, suggesting peptide-dependent engagement. Our in vitro studies confirm that NKRs differentiate between peptide-bound and peptide-free HLA-F. The complex structure of peptide-loaded β 2 m-HLA-F bound to the inhibitory LIR1 revealed similarities to high-affinity recognition of the viral MHC-I mimic UL18 and a docking strategy that relies on contacts with HLA-F as well as β 2 m, thus precluding binding to HLA-F OCs. These findings provide a biochemical framework to understand how HLA-F could regulate immunity via interactions with NKRs. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Recognition of Salmonella by Dectin-1 induces presentation of peptide antigen to type B T cells.

    Science.gov (United States)

    Jackson, Nicola; Compton, Evan; Trowsdale, John; Kelly, Adrian P

    2014-04-01

    Type B T cells recognize peptide-MHC class II (pMHCII) isoforms that are structurally distinct from those recognized by conventional type A T cells. These alternative type B conformers result from peptide loading in the absence of HLA-DM. Type A conformers are more stable than type B pMHCII conformers but bind the same peptide in the same register. Here, we show that interaction of Salmonella Typhimurium with bone marrow derived dendritic cells (BMDCs) isolated from C3H/HeNCr1 mice results in enhanced presentation of peptide Ag to type B T cells. The effect could be mimicked by purified PAMPs, the most potent of which were curdlan and zymosan, β-(1,3)-glucan-containing polymers that are recognized by Dectin-1. Blocking of Dectin-1 with Ab and laminarin inhibited the induction of the type B T-cell response by BMDCs, confirming its role as a PRR for S. Typhimurium. Splenic DCs (sDCs) expressed Dectin-1 but were refractive to the induction of type B responses by S. Typhimurium and curdlan. Type B T cells have been shown to escape thymic tolerance and to transfer pathology in an autoimmune disease model. The induction of type B responses by gram-negative bacteria provides a mechanism by which autoreactive T cells may be produced during infection. © 2014 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Crystal structure of a TAPBPR–MHC I complex reveals the mechanism of peptide editing in antigen presentation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Jiansheng; Natarajan, Kannan; Boyd, Lisa F.; Morozov, Giora I.; Mage, Michael G.; Margulies, David H. (NIH); (Hebrew)

    2017-10-12

    Central to CD8+ T cell–mediated immunity is the recognition of peptide–major histocompatibility complex class I (p–MHC I) proteins displayed by antigen-presenting cells. Chaperone-mediated loading of high-affinity peptides onto MHC I is a key step in the MHC I antigen presentation pathway. However, the structure of MHC I with a chaperone that facilitates peptide loading has not been determined. We report the crystal structure of MHC I in complex with the peptide editor TAPBPR (TAP-binding protein–related), a tapasin homolog. TAPBPR remodels the peptide-binding groove of MHC I, resulting in the release of low-affinity peptide. Changes include groove relaxation, modifications of key binding pockets, and domain adjustments. This structure captures a peptide-receptive state of MHC I and provides insights into the mechanism of peptide editing by TAPBPR and, by analogy, tapasin.

  7. 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.

  8. Modulation of the major histocompatibility complex class II-associated peptide repertoire by human histocompatibility leukocyte antigen (HLA)-DO

    NARCIS (Netherlands)

    van Ham, M.; van Lith, M.; Lillemeier, B.; Tjin, E.; Grüneberg, U.; Rahman, D.; Pastoors, L.; van Meijgaarden, K.; Roucard, C.; Trowsdale, J.; Ottenhoff, T.; Pappin, D.; Neefjes, J.

    2000-01-01

    Antigen presentation by major histocompatibility complex class II molecules is essential for antibody production and T cell activation. For most class II alleles, peptide binding depends on the catalytic action of human histocompatibility leukocyte antigens (HLA)-DM. HLA-DO is selectively expressed

  9. Human histocompatibility leukocyte antigen (HLA)-DM edits peptides presented by HLA-DR according to their ligand binding motifs

    NARCIS (Netherlands)

    van Ham, S. M.; Grüneberg, U.; Malcherek, G.; Bröker, I.; Melms, A.; Trowsdale, J.

    1996-01-01

    Human histocompatibility leukocyte antigen (HLA)-DM is a facilitator of antigen presentation via major histocompatibility complex (MHC) class II molecules. In the absence of HLA-DM, MHC class II molecules do not present natural peptides, but tend to remain associated with class II-associated

  10. Efficiency and mechanism of antigen-specific CD8+ T-cell activation using synthetic long peptides.

    Science.gov (United States)

    Zandvliet, Maarten L; Kester, Michel G D; van Liempt, Ellis; de Ru, Arnoud H; van Veelen, Peter A; Griffioen, Marieke; Guchelaar, Henk-Jan; Falkenburg, J H Frederik; Meij, Pauline

    2012-01-01

    Synthetic long peptides that contain immunogenic T-cell epitopes have been used to induce activation of antigen-specific CD8 T cells in vitro for immune monitoring or adoptive transfer, or in vivo after peptide vaccination. However, the efficiency and mechanisms of presentation of exogenous long peptides in human leukocyte antigen (HLA) class I remain to be elucidated. In this study, we demonstrated that the efficiency of antigen-specific CD8 T-cell activation using extended peptide variants of common viral epitopes is variable. We demonstrated that processing and HLA class I presentation of the long peptides were not dependent on the proteasome and transporter associated with antigen processing, illustrating that the classic route of HLA class I presentation was not required for activation of specific CD8 T cells by exogenous synthetic long peptides. Although long peptides were shown to bind to the relevant HLA class I molecules, peptide trimming was likely to be essential for optimal HLA class I presentation and T-cell activation. As the proteasome was not required for processing of exogenous peptides, it is very likely that peptide trimming was mediated by peptidases, which may be located extracellularly at the cell surface, in the cytosol, endoplasmic reticulum, or in endosomal and lysosomal compartments. Furthermore, the results suggested that processing of the correct minimal peptides was facilitated by binding in HLA class I molecules. This mechanism of HLA-guided processing may be important in HLA class I presentation of exogenous long peptides to induce activation of specific CD8 T cells.

  11. 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...

  12. Accurate Structure Prediction of Peptide-MHC Complexes for Identifying Highly Immunogenic Antigens

    Science.gov (United States)

    Park, Min-Sun; Park, Sung Yong; Miller, Keith R.; Collins, Edward J.; Lee, Ha Youn

    2013-01-01

    Designing an optimal HIV-1 vaccine faces the challenge of identifying antigens that induce a broad immune capacity. One factor to control the breadth of T cell responses is the surface morphology of a peptide-MHC complex. Here, we present an in silico protocol for predicting peptide-MHC structure. A robust signature of a conformational transition was identified during all-atom molecular dynamics, which results in a model with high accuracy. A large test set was used in constructing our protocol and we went another step further using a blind test with a wild-type peptide and two highly immunogenic mutants, which predicted substantial conformational changes in both mutants. The center residues at position five of the analogs were configured to be accessible to solvent, forming a prominent surface, while the residue of the wild-type peptide was to point laterally towards the side of the binding cleft. We then experimentally determined the structures of the blind test set, using high resolution of X-ray crystallography, which verified predicted conformational changes. Our observation strongly supports a positive association of the surface morphology of a peptide-MHC complex to its immunogenicity. Our study offers the prospect of enhancing immunogenicity of vaccines by identifying MHC binding immunogens. PMID:23688437

  13. 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.

  14. 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

  15. 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...

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

    Science.gov (United States)

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

    2013-12-03

    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. Twenty-two overlapping synthetic peptides representing the coding sequence of the T. cruzi CRA and FRA proteins were assessed by a Spot-synthesis array analysis using sera donated by patients with Chagas disease. Shorter peptides were selected that represented the determined epitopes and synthesized by solid phase synthesis to evaluate the patterns of cross-reactivities and discrimination through an ELISA-diagnostic assay. The peptide Spot-synthesis array successfully identified two IgG antigenic determinants in the CRA protein and four in FRA. Bioinformatics suggested that the CRA antigens were unique to T. cruzi while the FRA antigen showed similarity with sequences present within various proteins from Leishmania sp. Subsequently, shorter peptides representing the CRA-1, CRA-2 and FRA-1 epitopes were synthesized by solid phase synthesis and assayed by an ELISA-diagnostic assay. The CRA antigens gave a high discrimination between Chagasic, Leishmaniasis and T. cruzi-uninfected serum. A sensitivity and specificity of 100% was calculated for CRA. While the FRA antigen showed a slightly lower sensitivity (91.6%), its specificity was only 60%. The epitopes recognized by human anti-T. cruzi antibodies have been precisely located in two biomarkers of T. cruzi, CRA and FRA. The results from screening a panel of patient sera through an ELISA assay based on peptides representing these epitopes strongly suggest that the sequences from CRA would be useful for the development of diagnostic reagents that could

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

    Science.gov (United States)

    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 Twenty-two overlapping synthetic peptides representing the coding sequence of the T. cruzi CRA and FRA proteins were assessed by a Spot-synthesis array analysis using sera donated by patients with Chagas disease. Shorter peptides were selected that represented the determined epitopes and synthesized by solid phase synthesis to evaluate the patterns of cross-reactivities and discrimination through an ELISA-diagnostic assay. Results The peptide Spot-synthesis array successfully identified two IgG antigenic determinants in the CRA protein and four in FRA. Bioinformatics suggested that the CRA antigens were unique to T. cruzi while the FRA antigen showed similarity with sequences present within various proteins from Leishmania sp. Subsequently, shorter peptides representing the CRA-1, CRA-2 and FRA-1 epitopes were synthesized by solid phase synthesis and assayed by an ELISA-diagnostic assay. The CRA antigens gave a high discrimination between Chagasic, Leishmaniasis and T. cruzi-uninfected serum. A sensitivity and specificity of 100% was calculated for CRA. While the FRA antigen showed a slightly lower sensitivity (91.6%), its specificity was only 60%. Conclusions The epitopes recognized by human anti-T. cruzi antibodies have been precisely located in two biomarkers of T. cruzi, CRA and FRA. The results from screening a panel of patient sera through an ELISA assay based on peptides representing these epitopes strongly suggest that the sequences from CRA would be useful for the

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

    Science.gov (United States)

    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. PMID:24671782

  19. THERMAL STABILITY OF SYNTHETIC PEPTIDES MIMICKING THE SEQUENCE OF THE REGION CONTAINING THE SKIP RESIDUES IN SQUID MYOSIN ROD

    Directory of Open Access Journals (Sweden)

    Yoshihiro Ochiai

    2017-08-01

    Full Text Available Myosin is the major protein in skeletal muscles including those of fish and shellfish. The characteristics of this protein are closely related to the biological function and the quality and physical properties of musclefood. In the myosin rod (the coiled-coil region of myosin, several amino acid residues, known as skip residues, seem to destabilize the ordered structure (heptad repeat. These residues might be responsible for reducing thermal stability. Attempts were thus made to examine the role of these residues in the rod of squid myosin, based on the thermodynamic properties of synthetic peptides which have been designed to mimic the partial sequence of myosin heavy chain from the squid Todarodes pacificus mantle muscle. Five peptides, namely, with the sequence of Trp1343 -Ala1372  having the skip residue Glu1357 at the center (Peptide WT, without the skip residue (Peptide Δ, with the replacements of the skip residue (Glu by Ile, Gln and Pro (Peptides E/I, E/Q, and E/P, respectively to modify the helix forming propensity, were synthesized. The results obtained showed that the stability of the peptides as measured by circular dichroism spectrometry was in the order of Peptide Δ > Peptide WT > Peptide E/Q > Peptide E/P > Peptide E/I. It is suggested that the presence of the skip residues dexterously tunes the stability or flexibility of the coiled-coil structure, thus possibly regulating thick filament formation and further gel formation ability of myosin.

  20. MHC class II-derived peptides can bind to class II molecules, including self molecules, and prevent antigen presentation

    DEFF Research Database (Denmark)

    Rosloniec, E F; Vitez, L J; Buus, S

    1990-01-01

    the alpha k-3 peptide binds slightly less well. These combined data, suggesting that class II-derived peptides can bind to MHC class II molecules, including the autologous molecule from which they are derived, have important implications for the molecular basis of alloreactivity and autoreactivity. Further...... found in the first and third polymorphic regions (PMR) of the A alpha k chain (alpha k-1 and alpha k-3) were capable of inhibiting the presentation of three different HEL-derived peptide antigens to their appropriate T cells. In addition, the alpha k-1 peptide inhibited the presentation of the OVA(323......-339) immunodominant peptide to the I-Ad-restricted T cell hybridomas specific for it. Prepulsing experiments demonstrated that the PMR peptides were interacting with the APC and not with the T cell hybridomas. These observations were confirmed and extended by the demonstration that the alpha k-1 and alpha k-3...

  1. A Molecular Basis for the Presentation of Phosphorylated Peptides by HLA-B Antigens*

    Science.gov (United States)

    Alpízar, Adán; Marino, Fabio; Ramos-Fernández, Antonio; Lombardía, Manuel; Jeko, Anita; Pazos, Florencio

    2017-01-01

    As aberrant protein phosphorylation is a hallmark of tumor cells, the display of tumor-specific phosphopeptides by Human Leukocyte Antigen (HLA) class I molecules can be exploited in the treatment of cancer by T-cell-based immunotherapy. Yet, the characterization and prediction of HLA-I phospholigands is challenging as the molecular determinants of the presentation of such post-translationally modified peptides are not fully understood. Here, we employed a peptidomic workflow to identify 256 unique phosphorylated ligands associated with HLA-B*40, -B*27, -B*39, or -B*07. Remarkably, these phosphopeptides showed similar molecular features. Besides the specific anchor motifs imposed by the binding groove of each allotype, the predominance of phosphorylation at peptide position 4 (P4) became strikingly evident, as was the enrichment of basic residues at P1. To determine the structural basis of this observation, we carried out a series of peptide binding assays and solved the crystal structures of HLA-B*40 in complex with a phosphorylated ligand or its nonphosphorylated counterpart. Overall, our data provide a clear explanation to the common motif found in the phosphopeptidomes associated to different HLA-B molecules. The high prevalence of phosphorylation at P4 is dictated by the presence of the conserved residue Arg62 in the heavy chain, a structural feature shared by most HLA-B alleles. In contrast, the preference for basic residues at P1 is allotype-dependent and might be linked to the structure of the A pocket. This molecular understanding of the presentation of phosphopeptides by HLA-B molecules provides a base for the improved prediction and identification of phosphorylated neo-antigens, as potentially used for cancer immunotherapy. PMID:27920218

  2. 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.

  3. 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

    Major histocompatibility complex (MHC) class I molecules regulate adaptive immune responses through the presentation of antigenic peptides to CD8+ T cells. Polymorphisms in the peptide binding region of class I molecules determine peptide binding affinity and stability during antigen presentation......, and different antigen peptide motifs are associated with specific genetic sequences of class I molecules. Understanding bovine leukocyte antigen (BoLA), peptide-MHC class I binding specificities may facilitate development of vaccines or reagents for quantifying the adaptive immune response to intracellular...... 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...

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

    International Nuclear Information System (INIS)

    Kim, Sun Young; Song, Kyung-A; Kieff, Elliott; Kang, Myung-Soo

    2012-01-01

    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

  5. 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

  6. Studies on associations of antinuclear antibodies with antibodies to an uveitogenic peptide of retinal S antigen in children with uveitis.

    Science.gov (United States)

    Rosenberg, A M; Hauta, S A; Prokopchuk, P A; Romanchuk, K G

    1996-02-01

    To determine if, in children with uveitis, antinuclear antibodies (ANA) are associated with antibodies to an uveitogenic peptide of a soluble retinal antigen and to the homologous nuclear antigen, histone 3 (H3). ANA occur in most children with juvenile rheumatoid arthritis (JRA) and associated uveitis. An uveitogenic segment of retinal soluble antigen (S antigen peptide) is homologous with a similarly uveitogenic peptide of H3. We investigated a possible association between ANA positivity, antibodies to H3, and antibodies to the uveitogenic S antigen peptide. The sera of 31 children with uveitis (20 of whom had associated JRA) were tested for the presence of ANA by indirect immunofluorescence. Antibodies to H3 and to an uveitogenic peptide of S antigen (an 18 mer segment having the amino acid sequence DTNLASSTIIKEGIDKTV) were measured by enzyme immunoassay. 19 of 20 children (95%) with JRA and associated uveitis and none of 11 with uveitis not associated with JRA had positive tests for ANA (X2 = 14.97; p < 0.00001). 16 of 19 ANA positive sera from subjects with JRA (84%) displayed reactivity with the chromosomal regions of metaphase cells. 9 of 20 patients with JRA with uveitis (45%) and 2 of 11 patients (18%) with uveitis not associated with JRA had antibodies to H3. Two uveitic patients with JRA (10%) and 2 non-JRA patients with uveitis (18%) reacted with S antigen peptide. Antibodies to H3 occurred significantly more frequently in children with uveitis than in all adult control subjects (X2 = 12.98; p = 0.003) and in adults with uveitis (X2 = 5.62; p = 0.022). Humoral immune responses to the uveitogenic peptide of S antigen and the homologous H3 antigen appear not to be uniquely important in the immunopathology of uveitis associated with JRA. Antibodies to isolated H3 do not exclusively account for ANA positivity in the uveitic patient with JRA. A unique immunopathogenic mechanism for the development of uveitis associated with JRA is suggested by the

  7. Fluorine substitutions in an antigenic peptide selectively modulate T-cell receptor binding in a minimally perturbing manner

    Energy Technology Data Exchange (ETDEWEB)

    Piepenbrink, Kurt H.; Borbulevych, Oleg Y.; Sommese, Ruth F.; Clemens, John; Armstrong, Kathryn M.; Desmond, Clare; Do, Priscilla; Baker, Brian M.; (Notre Dame)

    2010-08-17

    TCR (T-cell receptor) recognition of antigenic peptides bound and presented by MHC (major histocompatibility complex) molecules forms the basis of the cellular immune response to pathogens and cancer. TCRs bind peptide - MHC complexes weakly and with fast kinetics, features which have hindered detailed biophysical studies of these interactions. Modified peptides resulting in enhanced TCR binding could help overcome these challenges. Furthermore, there is considerable interest in using modified peptides with enhanced TCR binding as the basis for clinical vaccines. In the present study, we examined how fluorine substitutions in an antigenic peptide can selectively impact TCR recognition. Using a structure-guided design approach, we found that fluorination of the Tax peptide [HTLV (human T-cell lymphotropic virus)-1 Tax] enhanced binding by the Tax-specific TCR A6, yet weakened binding by the Tax-specific TCR B7. The changes in affinity were consistent with crystallographic structures and fluorine chemistry, and with the A6 TCR independent of other substitutions in the interface. Peptide fluorination thus provides a means to selectively modulate TCR binding affinity without significantly perturbing peptide composition or structure. Lastly, we probed the mechanism of fluorine's effect on TCR binding and we conclude that our results were most consistent with a 'polar hydrophobicity' mechanism, rather than a purely hydrophobic- or electrostatic-based mechanism. This finding should have an impact on other attempts to alter molecular recognition with fluorine.

  8. 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.

  9. 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

  10. Identification of Bacterial Surface Antigens by Screening Peptide Phage Libraries Using Whole Bacteria Cell-Purified Antisera

    Science.gov (United States)

    Hu, Yun-Fei; Zhao, Dun; Yu, Xing-Long; Hu, Yu-Li; Li, Run-Cheng; Ge, Meng; Xu, Tian-Qi; Liu, Xiao-Bo; Liao, Hua-Yuan

    2017-01-01

    Bacterial surface proteins can be good vaccine candidates. In the present study, we used polyclonal antibodies purified with intact Erysipelothrix rhusiopthiae to screen phage-displayed random dodecapeptide and loop-constrained heptapeptide libraries, which led to the identification of mimotopes. Homology search of the mimotope sequences against E. rhusiopthiae-encoded ORF sequences revealed 14 new antigens that may localize on the surface of E. rhusiopthiae. When these putative surface proteins were used to immunize mice, 9/11 antigens induced protective immunity. Thus, we have demonstrated that a combination of using the whole bacterial cells to purify antibodies and using the phage-displayed peptide libraries to determine the antigen specificities of the antibodies can lead to the discovery of novel bacterial surface antigens. This can be a general approach for identifying surface antigens for other bacterial species. PMID:28184219

  11. Arginine (Di)methylated Human Leukocyte Antigen Class I Peptides Are Favorably Presented by HLA-B*07

    NARCIS (Netherlands)

    Marino, Fabio; Mommen, Geert P M; Jeko, Anita; Meiring, Hugo D; van Gaans-van den Brink, Jacqueline A M; Scheltema, Richard A; van Els, Cécile A C M; Heck, Albert J R

    Alterations in protein post-translational modification (PTM) are recognized hallmarks of diseases. These modifications potentially provide a unique source of disease-related human leukocyte antigen (HLA) class I-presented peptides that can elicit specific immune responses. While phosphorylated HLA

  12. Characterization of murine B-cell epitopes on the Mycobacterium leprae proline-rich antigen by use of synthetic peptides

    NARCIS (Netherlands)

    Klatser, P. R.; de Wit, M. Y.; Kolk, A. H.; Hartskeerl, R. A.

    1991-01-01

    Using synthetic peptides representing overlapping sequences of the 100-amino-acid-long N-terminal region of the proline-rich antigen of Mycobacterium leprae (PRA), we have mapped the epitopes in the primary structure of PRA recognized by four monoclonal antibodies. The M. leprae-specific monoclonal

  13. Analysis of HLA-A24-restricted peptides of carcinoembryonic antigen using a novel structure-based peptide-HLA docking algorithm.

    Science.gov (United States)

    Nakamura, Yoji; Tai, Sachiko; Oshita, Chie; Iizuka, Akira; Ashizawa, Tadashi; Saito, Shuji; Yamaguchi, Shigeki; Kondo, Haruhiko; Yamaguchi, Ken; Akiyama, Yasuto

    2011-04-01

    Carcinoembryonic antigen (CEA) is a very common tumor marker because many types of solid cancer usually produce a variety of CEA and a highly sensitive measuring kit has been developed. However, immunological responses associated with CEA have not been fully characterized, and specifically a weak immunogenicity of CEA protein as a tumor antigen is reported in human leukocyte antigen (HLA)-A24-restricted CEA peptide-based cancer immunotherapy. These observations demonstrated that immunogenic and potent HLA-A24-restricted CTL epitope peptides derived from CEA protein are seemingly difficult to predict using a conventional bioinformatics approach based on primary amino acid sequence. In the present study, we developed an in silico docking simulation assay system of binding affinity between HLA-A24 protein and A24-restricted peptides using two software packages, AutoDock and MODELLER, and a crystal structure of HLA-A24 protein obtained from the Protein Data Bank. We compared the current assay system with HLA-peptide binding predictions of the bioinformatics and molecular analysis section (BIMAS) in terms of the prediction capability using MHC stabilization and peptide-stimulated CTL induction assays for CEA and other HLA-A24 peptides. The MHC stabilization score was inversely correlated with the affinity calculated in the docking simulation alone (r = -0.589, P = 0.015), not with BIMAS score or the IFN-γ production index. On the other hand, BIMAS was not significantly correlated with any other parameters. These results suggested that our in silico assay system has potential advantages in efficiency of epitope prediction over BIMAS and ease of use for bioinformaticians. © 2011 Japanese Cancer Association.

  14. Prostate-related antigen-derived new peptides having the capacity of inducing prostate cancer-reactive CTLs in HLA-A2+ prostate cancer patients.

    Science.gov (United States)

    Harada, Mamoru; Matsueda, Satoko; Yao, Akihisa; Ogata, Rika; Noguchi, Masanori; Itoh, Kyogo

    2004-09-01

    Prostate-related antigens, including prostate-specific membrane antigen (PSMA) and prostatic acid phosphatase (PAP), can be targets in specific immunotherapy for prostate cancer. In this study, we attempted to newly identify epitope peptides from these 2 antigens, which are immunogenic in human histocompatibility leukocyte antigen (HLA)-A2+ prostate cancer patients. Twenty-nine peptides (PSMA with 15 and PAP with 14) were prepared based on the HLA-A2 binding motif. Based on our previous finding that antigenic peptides recognized by both cellular and humoral immune systems are useful for peptide-based immunotherapy, peptide candidates were screened first by their ability to be recognized by immunoglobulin G (IgG), and then by their ability to induce peptide-specific cytotoxic T lymphocytes (CTLs). As a result, PSMA441-450 and PAP112-120 peptides were found to be frequently recognized by IgG in plasma from prostate cancer patients. These 2 candidates effectively induced HLA-A2-restricted and prostate cancer-reactive CTLs in HLA-A2+ prostate cancer patients with several HLA-A2 subtypes. In addition, their cytotoxicity was mainly dependent on peptide-specific and CD8+ T cells. These results indicate that these PSMA441-450 and PAP112-120 peptides could be promising candidates for peptide-based immunotherapy for HLA-A2(+) prostate cancer.

  15. Cutting edge: HLA-B27 acquires many N-terminal dibasic peptides: coupling cytosolic peptide stability to antigen presentation

    NARCIS (Netherlands)

    Herberts, Carla A.; Neijssen, Joost J.; de Haan, Jolanda; Janssen, Lennert; Drijfhout, Jan Wouter; Reits, Eric A.; Neefjes, Jacques J.

    2006-01-01

    Ag presentation by MHC class I is a highly inefficient process because cytosolic peptidases destroy most peptides after proteasomal generation. Various mechanisms shape the MHC class I peptidome. We define a new one: intracellular peptide stability. Peptides with two N-terminal basic amino acids are

  16. Ii-Key/HER-2/neu MHC class-II antigenic epitope vaccine peptide for breast cancer.

    Science.gov (United States)

    Gillogly, Michael E; Kallinteris, Nikoletta L; Xu, Minzhen; Gulfo, Joseph V; Humphreys, Robert E; Murray, James L

    2004-06-01

    Cytotoxic T lymphocytes (CTL)- and T-helper cell-specific, and major histocompatibility complex (MHC) class-I and class-II peptides, respectively, of the HER-2/ neu protein, induce immune responses in patients. A major challenge in developing cancer peptide vaccines is breaking tolerance to tumor-associated antigens which are functionally self-proteins. An adequate CD4+ T-helper response is required for effective and lasting responses. Stimulating anti-cancer CD4+ T cell responses by MHC class-II epitope peptides has been limited by their weak potency, at least compared with tight-binding MHC class-I epitope peptides. Previously, a potent T-cell response to a MHC class-II epitope was engineered by coupling the N-terminus of the pigeon cytochrome C [PGCC(95-104)] MHC class-II epitope to the C-terminus of an immunoregulatory segment of the Ii protein (hIi77-81, the Ii-Key peptide) through a polymethylene spacer. In vitro presentation of the MHC class-II epitope to a T hybridoma was enhanced greatly (>250 times). Now, an Ii-Key/HER-2/neu (777-789) MHC class-II epitope hybrid peptide stimulated lymphocytes from both a healthy donor and a patient with metastatic breast carcinoma. The in vitro primary stimulation with the hybrid peptide strongly activated IFN-gamma release, whereas the epitope-only peptide was weakly active. In fact, the hybrid stimulated IFN-gamma release as well as the wild-type peptide when augmented with IL-12; however, the hybrid was comparable to free peptide in stimulating IL-4 release. This pattern is consistent with preferential activation along a non-tolerogenic Th1 pathway. Such Ii-Key/MHC class-II epitope hybrid peptides have both diagnostic and therapeutic applications.

  17. Antimicrobial peptides at work: interaction of myxinidin and its mutant WMR with lipid bilayers mimicking the P. aeruginosa and E. coli membranes

    Science.gov (United States)

    Lombardi, Lucia; Stellato, Marco Ignazio; Oliva, Rosario; Falanga, Annarita; Galdiero, Massimiliano; Petraccone, Luigi; D'Errico, Geradino; de Santis, Augusta; Galdiero, Stefania; Del Vecchio, Pompea

    2017-03-01

    Antimicrobial peptides are promising candidates as future therapeutics in order to face the problem of antibiotic resistance caused by pathogenic bacteria. Myxinidin is a peptide derived from the hagfish mucus displaying activity against a broad range of bacteria. We have focused our studies on the physico-chemical characterization of the interaction of myxinidin and its mutant WMR, which contains a tryptophan residue at the N-terminus and four additional positive charges, with two model biological membranes (DOPE/DOPG 80/20 and DOPE/DOPG/CL 65/23/12), mimicking respectively Escherichia coli and Pseudomonas aeruginosa membrane bilayers. All our results have coherently shown that, although both myxinidin and WMR interact with the two membranes, their effect on membrane microstructure and stability are different. We further have shown that the presence of cardiolipin plays a key role in the WMR-membrane interaction. Particularly, WMR drastically perturbs the DOPE/DOPG/CL membrane stability inducing a segregation of anionic lipids. On the contrary, myxinidin is not able to significantly perturb the DOPE/DOPG/CL bilayer whereas interacts better with the DOPE/DOPG bilayer causing a significant perturbing effect of the lipid acyl chains. These findings are fully consistent with the reported greater antimicrobial activity of WMR against P. aeruginosa compared with myxinidin.

  18. Phase II Study of Personalized Peptide Vaccination with Both a Hepatitis C Virus-Derived Peptide and Peptides from Tumor-Associated Antigens for the Treatment of HCV-Positive Advanced Hepatocellular Carcinoma Patients

    Directory of Open Access Journals (Sweden)

    Shigeru Yutani

    2015-01-01

    Full Text Available Objective. To evaluate safety and immune responses of personalized peptide vaccination (PPV for hepatitis C virus- (HCV- positive advanced hepatocellular carcinoma (HCC. Patients and Methods. Patients diagnosed with HCV-positive advanced HCC were eligible for this study. A maximum of four HLA-matched peptides were selected based on the preexisting IgG responses specific to 32 different peptides, which consisted of a single HCV-derived peptide at core protein positions 35–44 (C-35 and 31 peptides derived from 15 different tumor-associated antigens (TAAs, followed by subcutaneous administration once per week for 8 weeks. Peptide-specific cytotoxic T lymphocyte (CTL and IgG responses were measured before and after vaccination. Results. Forty-two patients were enrolled. Grade 3 injection site skin reaction was observed in 2 patients, but no other PPV-related severe adverse events were noted. Peptide-specific CTL responses before vaccination were observed in only 3 of 42 patients, but they became detectable in 23 of 36 patients tested after vaccination. Peptide-specific IgG responses were also boosted in 19 of 36 patients. Peptide-specific IgG1 responses to both C-35 and TAA-derived peptides could be potentially prognostic for overall survival. Conclusion. Further clinical study of PPV would be warranted for HCV-positive advanced HCC, based on the safety and strong immune induction.

  19. HLA-A2-restricted glypican-3 peptide-specific CTL clones induced by peptide vaccine show high avidity and antigen-specific killing activity against tumor cells.

    Science.gov (United States)

    Yoshikawa, Toshiaki; Nakatsugawa, Munehide; Suzuki, Shiro; Shirakawa, Hirofumi; Nobuoka, Daisuke; Sakemura, Noriko; Motomura, Yutaka; Tanaka, Yukie; Hayashi, Shin-Ichi; Nakatsura, Tetsuya

    2011-05-01

    Glypican-3 (GPC3) is an onco-fetal antigen that is overexpressed in human hepatocellular carcinoma (HCC), and is only expressed in the placenta and embryonic liver among normal tissues. Previously, we identified an HLA-A2-restricted GPC3(144-152) (FVGEFFTDV) peptide that can induce GPC3-reactive CTLs without inducing autoimmunity in HLA-A2 transgenic mice. In this study, we carried out a phase I clinical trial of HLA-A2-restricted GPC3(144-152) peptide vaccine in 14 patients with advanced HCC. Immunological responses were analyzed by ex vivo γ-interferon enzyme-linked immunospot assay. The frequency of GPC3(144-152) peptide-specific CTLs after vaccination (mean, 96; range, 5-441) was significantly larger than that before vaccination (mean, 6.5; range, 0-43) (P Network number 000001395. © 2011 Japanese Cancer Association.

  20. Modulating gene function with peptide nucleic acids (PNA)

    DEFF Research Database (Denmark)

    Nielsen, Peter E.; Crooke, Stanley T.

    2008-01-01

    A review on peptide nucleic acid (PNA) oligomers as modulators of gene expression ranging from gene silencing at the mRNAor the dsDNA (antigene) level, and redirection of mRNA splicing to gene activation through transcription bubble mimicking. PNA chem., anti-infective agents, cellular delivery...

  1. Generation of rabbit antipeptide antibodies to HLA-class II antigens by the use of synthetic peptides.

    Science.gov (United States)

    Chersi, A; Morganti, M C; Chillemi, F; Houghten, R; Cenciarelli, C

    1988-07-01

    A group of eight synthetic peptides, corresponding in sequence to selected regions of HLA-DQ histocompatibility antigens, was used for rabbit immunization to examine their antigenicity and for localizing exposed regions in the native glycoproteins. Those antibodies were then tested in their ability to recognize the HLA-DQ alloantigens. Seven peptides elicited rabbit antibodies, four of which reacted with human glycoproteins prepared from chronic lymphocytic leukaemia cells. The results indicate that sequence stretches 63 to 79 and probably 82 to 93 of the beta chain correspond to exposed regions in DQw1, DQw2 and DQw3 molecules. However, the specificity of those antipeptide antibodies was low, due to extensive crossreactions with amino acid sequencies of high homology occurring in DQ alloantigens.

  2. Development of a Nucleoprotein-Based Enzyme-Linked Immunosorbent Assay Using a Synthetic Peptide Antigen for Detection of Avian Metapneumovirus Antibodies in Turkey Sera

    Science.gov (United States)

    Alvarez, Rene; Njenga, M. Kariuki; Scott, Melissa; Seal, Bruce S.

    2004-01-01

    Avian metapneumoviruses (aMPV) cause an upper respiratory tract disease with low mortality but high morbidity, primarily in commercial turkeys, that can be exacerbated by secondary infections. There are three types of aMPV, of which type C is found only in the United States. The aMPV nucleoprotein (N) amino acid sequences of serotypes A, B, and C were aligned for comparative analysis. On the basis of the predicted antigenicity of consensus sequences, five aMPV-specific N peptides were synthesized for development of a peptide antigen enzyme-linked immunosorbent assay (aMPV N peptide-based ELISA) to detect aMPV-specific antibodies among turkeys. Sera from naturally and experimentally infected turkeys were used to demonstrate the presence of antibodies reactive to the chemically synthesized aMPV N peptides. Subsequently, aMPV N peptide 1, which had the sequence 10-DLSYKHAILKESQYTIKRDV-29, with variations at only three amino acids among aMPV serotypes, was evaluated as a universal aMPV ELISA antigen. Data obtained with the peptide-based ELISA correlated positively with total aMPV viral antigen-based ELISAs, and the peptide ELISA provided higher optical density readings. The results indicated that aMPV N peptide 1 can be used as a universal ELISA antigen to detect antibodies for all aMPV serotypes. PMID:15013970

  3. Screening of random peptide library of hemagglutinin from pandemic 2009 A(H1N1 influenza virus reveals unexpected antigenically important regions.

    Directory of Open Access Journals (Sweden)

    Wanghui Xu

    Full Text Available The antigenic structure of the membrane protein hemagglutinin (HA from the 2009 A(H1N1 influenza virus was dissected with a high-throughput screening method using complex antisera. The approach involves generating yeast cell libraries displaying a pool of random peptides of controllable lengths on the cell surface, followed by one round of fluorescence-activated cell sorting (FACS against antisera from mouse, goat and human, respectively. The amino acid residue frequency appearing in the antigenic peptides at both the primary sequence and structural level was determined and used to identify "hot spots" or antigenically important regions. Unexpectedly, different antigenic structures were seen for different antisera. Moreover, five antigenic regions were identified, of which all but one are located in the conserved HA stem region that is responsible for membrane fusion. Our findings are corroborated by several recent studies on cross-neutralizing H1 subtype antibodies that recognize the HA stem region. The antigenic peptides identified may provide clues for creating peptide vaccines with better accessibility to memory B cells and better induction of cross-neutralizing antibodies than the whole HA protein. The scheme used in this study enables a direct mapping of the antigenic regions of viral proteins recognized by antisera, and may be useful for dissecting the antigenic structures of other viral proteins.

  4. 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

    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...... leucocyte antigen (HLA) class I binders (K-D...

  5. 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

    2010-01-01

    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.

  6. Multivalent immunity targeting tumor-associated antigens by intra-lymph node DNA-prime, peptide-boost vaccination.

    Science.gov (United States)

    Smith, K A; Qiu, Z; Wong, R; Tam, V L; Tam, B L; Joea, D K; Quach, A; Liu, X; Pold, M; Malyankar, U M; Bot, A

    2011-01-01

    Active immunotherapy of cancer has yet to yield effective therapies in the clinic. To evaluate the translatability of DNA-based vaccines we analyzed the profile of T-cell immunity by plasmid vaccination in a murine model, using transcriptome microarray analysis and flow cytometry. DNA vaccination resulted in specific T cells expressing low levels of co-inhibitory molecules (most notably PD-1), strikingly different from the expression profile elicited by peptide immunization. In addition, the T-cell response primed through this dual-antigen-expressing plasmid (MART-1/Melan-A and tyrosinase) translated into a substantial proliferation capacity and functional conversion to antitumor effector cells after tyrosinase and MART-1/Melan-A peptide analog boost. Furthermore, peptide boost rescued the immune response against the subdominant tyrosinase epitope. This immunization approach could be adapted to elicit potent immunity against multiple tumor antigens, resulting in a broader immune response that was more effective in targeting human tumor cells. Finally, this study sheds light on a novel mechanism of immune homeostasis through synchronous regulation of co-inhibitory molecules on T cells, highly relevant to heterologous prime boost approaches involving DNA vaccines as priming agents.

  7. 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...... separate series of truncated synthetic peptides, it was found that in all three cases the different Ia reactivities mapped to largely overlapping regions of the peptides; although, for two of the peptides, the regions involved in binding the different Ia specificities were distinct. Moreover, subtle...... differences were found to dramatically influence some, but not other, Ia reactivities. Using a large panel of synthetic peptides it was found that a significant correlation exists between the capacity of peptides to interact with different alleles of the same molecule (i.e., IAd and IAk), but no correlation...

  8. Effectiveness of intranasal vaccination against Angiostrongylus costaricensis using a serine/threonine phosphatase 2 A synthetic peptide and recombinant antigens.

    Science.gov (United States)

    Solano-Parada, J; Gonzalez-Gonzalez, G; Torró, L M de Pablos; dos Santos, M F Brazil; Espino, A M; Burgos, M; Osuna, A

    2010-07-19

    Intranasal immunization was assayed in C57BL/6 mice against Angiostrongylus costaricensis using a synthetic and a recombinant peptide belonging to the catalytic region of the serine/threonine phosphatase 2 A (PP2A) of the parasite. Immunization was carried out with the synthetic peptide (SP) polymerized either with itself or with the beta fraction of the cholera toxin (CTB) and then enclosed in nanocapsules of phosphatidyl choline, cholesterol and Quil A (ISCOM). Another group of mice was immunized with recombinant peptide. Immunization consisted of two intranasal inoculations at two-week intervals, and the challenge with L3 larvae was made one month after the last vaccination. The effectiveness of immunization was evaluated 30 days after infection by analysis of the number of parasites in the arteries of the immunized mice, as well as by measuring spleen sizes in the experimental groups. The response induced was determined by identifying the isotypes of IgG as well as the IgE and IgA specific antigen response. The interleukins produced by the splenocyte culture of the different groups were assessed after exposing them to the peptide used in the immunization. From our results, 60%, 80%, and 100% protection against the A. costaricensis challenge was achieved in mice immunized with polymerized synthetic peptide in ISCOM, synthetic peptide polymerized with the CTB in ISCOM and inclusion bodies respectively. Splenomegaly was found to be less evident in the immunized mice than in the controls. A significant increase in IFN gamma and IL-17 levels was observed in the group with 100% protection. The results showed that vaccination through the nasal mucosa may constitute a useful method of immunization and result in a protective immune response against A. costaricensis. (c) 2010 Elsevier Ltd. All rights reserved.

  9. 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.

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

    Science.gov (United States)

    Mattsson, Johanna M; Ravela, Suvi; Hekim, Can; Jonsson, Magnus; Malm, Johan; Närvänen, Ale; Stenman, Ulf-Håkan; Koistinen, Hannu

    2014-01-01

    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.

  11. Proteolytic Activity of Prostate-Specific Antigen (PSA) towards Protein Substrates and Effect of Peptides Stimulating PSA Activity

    Science.gov (United States)

    Mattsson, Johanna M.; Ravela, Suvi; Hekim, Can; Jonsson, Magnus; Malm, Johan; Närvänen, Ale; Stenman, Ulf-Håkan; Koistinen, Hannu

    2014-01-01

    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. PMID:25237904

  12. Trogocytosis of peptide-MHC class II complexes from dendritic cells confers antigen-presenting ability on basophils.

    Science.gov (United States)

    Miyake, Kensuke; Shiozawa, Nozomu; Nagao, Toshihisa; Yoshikawa, Soichiro; Yamanishi, Yoshinori; Karasuyama, Hajime

    2017-01-31

    Th2 immunity plays important roles in both protective and allergic responses. Nevertheless, the nature of antigen-presenting cells responsible for Th2 cell differentiation remains ill-defined compared with the nature of the cells responsible for Th1 and Th17 cell differentiation. Basophils have attracted attention as a producer of Th2-inducing cytokine IL-4, whereas their MHC class II (MHC-II) expression and function as antigen-presenting cells are matters of considerable controversy. Here we revisited the MHC-II expression on basophils and explored its functional relevance in Th2 cell differentiation. Basophils generated in vitro from bone marrow cells in culture with IL-3 plus GM-CSF displayed MHC-II on the cell surface, whereas those generated in culture with IL-3 alone did not. Of note, these MHC-II-expressing basophils showed little or no transcription of the corresponding MHC-II gene. The GM-CSF addition to culture expanded dendritic cells (DCs) other than basophils. Coculture of basophils and DCs revealed that basophils acquired peptide-MHC-II complexes from DCs via cell contact-dependent trogocytosis. The acquired complexes, together with CD86, enabled basophils to stimulate peptide-specific T cells, leading to their proliferation and IL-4 production, indicating that basophils can function as antigen-presenting cells for Th2 cell differentiation. Transfer of MHC-II from DCs to basophils was also detected in draining lymph nodes of mice with atopic dermatitis-like skin inflammation. Thus, the present study defined the mechanism by which basophils display MHC-II on the cell surface and appears to reconcile some discrepancies observed in previous studies.

  13. Structural and computational investigations of the conformation of antigenic peptide fragments of human polymorphic epithelial mucin.

    OpenAIRE

    Scanlon, M J; Morley, S D; Jackson, D E; Price, M R; Tendler, S J

    1992-01-01

    Human polymorphic epithelial mucins (PEM) are complex glycoproteins that are associated with breast and ovarian carcinomas. The PEM core protein consists of variable numbers of a tandem repeat sequence which contains a short antigenic hydrophilic region (Pro1-Asp-Thr-Arg-Pro-Ala-Pro7). High-field n.m.r. studies undertaken on antigenic 20- and 11-amino acid fragments of the PEM core protein in dimethyl sulphoxide have identified a type-I beta-turn to be present in the region Pro1-Asp-Thr-Arg4....

  14. 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. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

  15. Identification of Lck-derived peptides applicable to anti-cancer vaccine for patients with human leukocyte antigen-A3 supertype alleles

    OpenAIRE

    Naito, M; Komohara, Y; Ishihara, Y; Noguchi, M; Yamashita, Y; Shirakusa, T; Yamada, A; Itoh, K; Harada, M

    2007-01-01

    The identification of peptide vaccine candidates to date has been focused on human leukocyte antigen (HLA)-A2 and -A24 alleles. In this study, we attempted to identify cytotoxic T lymphocyte (CTL)-directed Lck-derived peptides applicable to HLA-A11+, -A31+, or -A33+ cancer patients, because these HLA-A alleles share binding motifs, designated HLA-A3 supertype alleles, and because the Lck is preferentially expressed in metastatic cancer. Twenty-one Lck-derived peptides were prepared based on t...

  16. A molecular basis for the presentation of phosphorylated peptides by HLA-B antigens

    NARCIS (Netherlands)

    Alpízar, Adán; Marino, Fabio; Ramos-Fernández, Antonio; Lombardía, Manuel; Jeko, Anita; Pazos, Florencio; Paradela, Alberto; Santiago, César; Heck, Albert J R; Marcilla, Miguel

    2017-01-01

    As aberrant protein phosphorylation is a hallmark of tumor cells, the display of tumor-specific phosphopeptides by Human Leukocyte Antigen (HLA) class I molecules can be exploited in the treatment of cancer by T-cell-based immunotherapy. Yet, the characterization and prediction of HLA-I

  17. Peptide and nucleotide sequences of rat CD4 (W3/25) antigen: evidence for derivation from a structure with four immunoglobulin-related domains

    International Nuclear Information System (INIS)

    Clark, S.J.; Jefferies, W.A.; Barclay, A.N.; Gagnon, J.; Williams, A.F.

    1987-01-01

    The rat W3/25 antigen was the first marker antigen of helper T lymphocytes to be identified. Subsequently, the human OKT4 antigen (now called CD4) was described, and cell distribution and functional data suggested that W3/25 and OKT4 antigens were homologous. This is now confirmed by the matching of peptide sequences from W3/25 antigen with sequence predicted from rat cDNA clones detected by cross-hybridization with a cDNA probe for human CD4. Analysis of the two sequences suggests an evolutionary origin from a structure with four immunoglobulin-related domains, although only domain 1 at the NH 2 terminus meets the standard criteria for an immunoglobulin-related sequence. CD4 domains 2 and 4 contain disulfide bonds but seem like truncated immunoglobulin domains, whereas domain 3 may have a pattern of β-strands like an immunoglobulin variable domain, but without the disulfide bond

  18. Structural requirements for the interaction between peptide antigens and I-Ed molecules

    DEFF Research Database (Denmark)

    Sette, A; Adorini, L; Appella, E

    1989-01-01

    We have analyzed the structural characteristics of the interaction between I-Ed molecules and their peptide ligands. It was found that unrelated good I-Ed binders share structurally similar "core" regions that were experimentally demonstrated to be crucial for binding to I-Ed molecules. Single am...

  19. Inhibition of multidrug resistance by SV40 pseudovirion delivery of an antigene peptide nucleic acid (PNA in cultured cells.

    Directory of Open Access Journals (Sweden)

    Benjamin Macadangdang

    Full Text Available Peptide nucleic acid (PNA is known to bind with extraordinarily high affinity and sequence-specificity to complementary nucleic acid sequences and can be used to suppress gene expression. However, effective delivery into cells is a major obstacle to the development of PNA for gene therapy applications. Here, we present a novel method for the in vitro delivery of antigene PNA to cells. By using a nucleocapsid protein derived from Simian virus 40, we have been able to package PNA into pseudovirions, facilitating the delivery of the packaged PNA into cells. We demonstrate that this system can be used effectively to suppress gene expression associated with multidrug resistance in cancer cells, as shown by RT-PCR, flow cytometry, Western blotting, and cell viability under chemotherapy. The combination of PNA with the SV40-based delivery system is a method for suppressing a gene of interest that could be broadly applied to numerous targets.

  20. Novel biotechnological platform based on baculovirus occlusion bodies carrying Babesia bovis small antigenic peptides for the design of a diagnostic enzyme-linked immunosorbent assay (ELISA).

    Science.gov (United States)

    López, M G; Pallarés, H M; Alfonso, V; Carmona, S J; Farber, M; Taboga, O; Wilkowsky, S E

    2018-01-01

    Baculoviruses are large DNA virus of insects principally employed in recombinant protein expression. Its ability to form occlusion bodies (OBs), which are composed mainly of polyhedrin protein (POLH), makes them biotechnologically attractive, as these crystals (polyhedra) can incorporate foreign peptides and can be easily isolated. On the other hand, peptide microarrays allow rapid and inexpensive high-throughput serological screening of new candidates to be incorporated to OBs. To integrate these 2 biotechnological approaches, we worked on Babesia bovis, one of the causative agents of bovine babesiosis. Current molecular diagnosis of infection with B. bovis includes enzyme-linked immunosorbent assay (ELISA) techniques, which use merozoite lysate obtained from infected bovine erythrocytes. However, it is important to produce recombinant antigens that replace the use of crude antigens. Here, we describe a new biotechnological platform for the design of indirect ELISAs based on 5 antigenic peptides of 15 amino acid residues of B. bovis (ApBb), selected from a peptide microarray and expressed as a fusion to POLH. An Sf9POLH E44G packaging cell line infected with recombinant baculoviruses carrying POLH-ApBb fusions yielded higher levels of chimeric polyhedra, highlighting the advantage of a trans-contribution of a mutant copy of polyhedrin. Finally, the use of dissolved recombinant polyhedra as antigens was successful in an ELISA assay, as B. bovis-positive sera recognized the fusion POLH-ApBb. Thus, the use of this platform resulted in a promising alternative for molecular diagnosis of relevant infectious diseases.

  1. Recognition of HLA class II molecules by antipeptide antibodies elicited by synthetic peptides selected from regions of HLA-DP antigens.

    Science.gov (United States)

    Chersi, A; Houghten, R A; Morganti, M C; Muratti, E

    1987-01-01

    Repeated immunizations of rabbits with chemically synthesized peptides from selected regions of HLA-DP histocompatibility antigens resulted in the production of specific antibodies that were then isolated from the immune sera by chromatography on Sepharose-peptide immunoadsorbents. The purified antibodies, when tested with an enzyme-linked immunosorbent assay, specifically bound to the inciting fragments; moreover, two of them recognized glycoproteins extracted by nonionic detergents from human chronic lymphocytic leukemia cells, as revealed by binding assays. The results suggest that amino acid stretches 51-61 of the alpha chain and 80-90 of the beta chain of HLA-DP histocompatibility antigens are likely exposed on the surface of the protein molecule. The specific recognition of DP regions is strongly suggested by the difference in the binding of those antibodies to soluble membrane proteins, as compared to the binding of monomorphic anti-Class II monoclonal antibodies to the same antigens.

  2. Synthetic peptide antigens derived from long-chain alpha-neurotoxins: Immunogenicity effect against elapid venoms.

    Science.gov (United States)

    de la Rosa, Guillermo; Pastor, Nina; Alagón, Alejandro; Corzo, Gerardo

    2017-02-01

    Three-finger toxins (3FTXs), especially α-neurotoxins, are the most poorly neutralized elapid snake toxins by current antivenoms. In this work, the conserved structural similarity and motif arrangements of long-chain α-neurotoxins led us to design peptides with consensus sequences. Eight long-chain α-neurotoxins (also known as Type II) were used to generate a consensus sequence from which two peptides were chemically synthesized, LCP1 and LCP2. Rabbit sera raised against them were able to generate partially-neutralizing antibodies, which delayed mice mortality in neutralization assays against Naja haje, Dendrospis polylepis and Ophiophagus hannah venoms. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. The HIV-1 Integrase α4-Helix Involved in LTR-DNA Recognition Is also a Highly Antigenic Peptide Element

    Science.gov (United States)

    Azzi, Sandy; Parissi, Vincent; Maroun, Richard G.; Eid, Pierre; Mauffret, Olivier; Fermandjian, Serge

    2010-01-01

    Monoclonal antibodies (MAbas) constitute remarkable tools to analyze the relationship between the structure and the function of a protein. By immunizing a mouse with a 29mer peptide (K159) formed by residues 147 to 175 of the HIV-1 integrase (IN), we obtained a monoclonal antibody (MAba4) recognizing an epitope lying in the N-terminal portion of K159 (residues 147–166 of IN). The boundaries of the epitope were determined in ELISA assays using peptide truncation and amino acid substitutions. The epitope in K159 or as a free peptide (pep-a4) was mostly a random coil in solution, while in the CCD (catalytic core domain) crystal, the homologous segment displayed an amphipathic helix structure (α4-helix) at the protein surface. Despite this conformational difference, a strong antigenic crossreactivity was observed between pep-a4 and the protein segment, as well as K156, a stabilized analogue of pep-a4 constrained into helix by seven helicogenic mutations, most of them involving hydrophobic residues. We concluded that the epitope is freely accessible to the antibody inside the protein and that its recognition by the antibody is not influenced by the conformation of its backbone and the chemistry of amino acids submitted to helicogenic mutations. In contrast, the AA →Glu mutations of the hydrophilic residues Gln148, Lys156 and Lys159, known for their interactions with LTRs (long terminal repeats) and inhibitors (5 CITEP, for instance), significantly impaired the binding of K156 to the antibody. Moreover, we found that in competition ELISAs, the processed and unprocessed LTR oligonucleotides interfered with the binding of MAba4 to IN and K156, confirming that the IN α4-helix uses common residues to interact with the DNA target and the MAba4 antibody. This also explains why, in our standard in vitro concerted integration assays, MAba4 strongly impaired the IN enzymatic activity. PMID:21209864

  4. Activation of monocytic cells by immunostimulatory lipids conjugated to peptide antigens.

    Science.gov (United States)

    Galdiero, Stefania; Vitiello, Mariateresa; Finamore, Emiliana; Mansi, Rosalba; Galdiero, Marilena; Morelli, Giancarlo; Tesauro, Diego

    2012-10-30

    Bacterial derived lipoproteins constitute potent macrophage activators in vivo and are effective stimuli, enhancing the immune response especially with respect to low or non-immunogenic compounds. In the present study we have prepared branched lipopeptide constructs in which different (B- and T-cell) epitopes of Herpes simplex virus type 1, derived from glycoproteins B (gB) and D (gD), are linked to a synthetic lipid core. The ability of the lipid core peptide (LCP) constructs (LCP-gB and LCP-gD) to induce cytokine expression and activate the mitogen-activated protein kinase cascade has been evaluated and compared with the behaviour of the isolated epitopes and the lipid core. In this respect, the use of LCP technology coupled with the use of three different gB or gD peptide epitopes in the same branched constructs could represent an interesting approach in order to obtain efficient delivery systems in the development of a synthetic multiepitopic vaccine for the prevention of viral infections.

  5. Mass spectrometry measurements of prostate-specific antigen (PSA) peptides derived from immune-extracted PSA provide a potential strategy for harmonizing immunoassay differences.

    Science.gov (United States)

    Klee, Eric W; Bondar, Olga P; Goodmanson, Marcia K; Trushin, Sergey A; Singh, Ravinder J; Anderson, N Leigh; Klee, George G

    2014-04-01

    Harmonization of prostate-specific antigen (PSA) immunoassays is important for good patient care. The specificity of the antibodies used to detect circulating PSA could cause differences in the PSA measurements. We used mass spectrometry (MS) to quantitate the concentration of five peptides cleaved from trypsin digestion of PSA and compared these measurements with six automated immunoassays. Linear regression and a mixed-effects model were used to analyze the results. PSA measurements from the immunoassays and the five MS peptide assays were highly correlated (R(2) > 0.99), but the recovery of the World Health Organization standard and the regression slopes differed across assays. The same relative patterns of immunoassay differences were seen in comparing their results with each of the five MS peptide measurements from different parts of the circulating PSA molecules. Mass spectrometry quantitation of peptides derived from trypsin digestion of immune-extracted PSA could be used to harmonize PSA immunoassays.

  6. Enhanced Class I Tumor Antigen Presentation via Cytosolic Delivery of Exosomal Cargos by Tumor-Cell-Derived Exosomes Displaying a pH-Sensitive Fusogenic Peptide.

    Science.gov (United States)

    Morishita, Masaki; Takahashi, Yuki; Nishikawa, Makiya; Ariizumi, Reiichi; Takakura, Yoshinobu

    2017-11-06

    Tumor-cell-derived exosomes contain endogenous tumor antigens and can be used as a potential cancer vaccine without requiring identification of the tumor-specific antigen. To elicit an effective antitumor effect, efficient tumor antigen presentation by MHC class I molecules on dendritic cells (DC) is desirable. Because DC endocytose exosomes, an endosomal escape mechanism is required for efficient MHC class I presentation of exosomal tumor antigens. In the present study, efficient cytosolic delivery of exosomal tumor antigens was performed using genetically engineered tumor-cell-derived exosomes and pH-sensitive fusogenic GALA peptide. Murine melanoma B16BL6 cells were transfected with a plasmid vector encoding a streptavidin (SAV; a protein that binds to biotin with high affinity)-lactadherin (LA; an exosome-tropic protein) fusion protein to obtain SAV-LA-modified exosomes (SAV-exo). SAV-exo was mixed with biotinylated GALA to obtain GALA-modified exosomes (GALA-exo). Fluorescent microscopic observation using fluorescent-labeled GALA showed that the exosomes were modified with GALA. GALA-exo exerted a membrane-lytic activity under acidic conditions and efficiently delivered exosomal cargos to the cytosol. Moreover, DC treated with GALA-exo showed enhanced tumor antigen presentation capacity by MHC class I molecules. Thus, genetically engineered GALA-exo are effective in controlling the intracellular traffic of tumor-cell-derived exosomes and for enhancing tumor antigen presentation capacity.

  7. Myeloid dendritic cells loaded with dendritic tandem multiple antigenic telomerase reverse transcriptase (hTERT) epitope peptides: a potentially promising tumor vaccine.

    Science.gov (United States)

    Niu, Bai-lin; Du, Hui-min; Shen, Hua-ping; Lian, Zheng-rong; Li, Jin-zheng; Lai, Xing; Wei, Si-dong; Zou, Li-quan; Gong, Jian-ping

    2012-05-14

    Human telomerase reverse transcriptase (hTERT) has been identified as an ideal tumor-associated antigen (TAA). Use of a synthetic hTERT epitope peptide to pulse dendritic cells can induce autologous T cell anti-tumor immune responses, but such responses induced by a single epitope peptide have been shown to be weak and a narrow-spectrum. Here, we designed dendritic tandem multiple antigenic peptides (MAPs) containing the following three hTERT epitope peptides: I540, V461 and L766, which are HLA-A*02-, HLA-A*24- and HLA-RDB1*04/11/15-restricted, respectively. The MAPs and their three single-epitope peptides were obtained through solid-phase synthesis. Healthy volunteers that were HLA-A*02(+)/HLA-DRB1*04(+) and HLA-A*24(+)/HLA-DRB1*15(+) were recruited. Myeloid dendritic cells were isolated by magnetic activated cell sorting and were divided into a MAP-stimulated group (MAP-DC), a group in which the three epitope peptides were mixed and used to stimulate the DCs (MixP-DC) and a no peptide-stimulated group (NoP-DC, control group). All of the DCs were cultured in serum-free medium, pulsed with the corresponding peptides on the 3rd, 5th and 7th days, and co-cultured with autologous lymphocytes when they were mature. The related cytokines were measured via ELISA. The killing effects of cytotoxic T lymphocytes (CTLs) on SW480/A549 tumor cells expressing HLA-A*02(+), HepG2/SMMC-7721 cells expressing HLA-A*24(+) and SKOV3 cells negative for HLA-A*02/A*24 were detected by flow cytometry. Our results indicated that the CTLs induced by the MAP-DCs had the greatest anti-tumor effect. Therefore, the dendritic tandem multiple antigenic hTERT epitope peptides combined with MDCs may represent a powerful, broad-spectrum anti-tumor vaccine. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Juzentaihoto Failed to Augment Antigen-Specific Immunity but Prevented Deterioration of Patients’ Conditions in Advanced Pancreatic Cancer under Personalized Peptide Vaccine

    Directory of Open Access Journals (Sweden)

    Shigeru Yutani

    2013-01-01

    Full Text Available Juzentaihoto (JTT is a well-known Japanese herbal medicine, which has been reported to modulate immune responses and enhance antitumor immunity in animal models. However, it is not clear whether JTT has similar effects on humans. In particular, there is little information on the effects of JTT in antigen-specific immunity in cancer patients. Here we conducted a randomized clinical study to investigate whether combined usage of JTT could affect antigen-specific immunity and clinical findings in advanced pancreatic cancer patients undergoing personalized peptide vaccination (PPV, in which HLA-matched vaccine antigens were selected based on the preexisting host immunity. Fifty-seven patients were randomly assigned to receive PPV with (n=28 or without (n=29 JTT. Unexpectedly, JTT did not significantly affect cellular or humoral immune responses specific to the vaccine antigens, which were determined by antigen-specific interferon-γ secretion in T cells and antigen-specific IgG titers in plasma, respectively. Nevertheless, JTT prevented deterioration of patients’ conditions, such as anemia, lymphopenia, hypoalbuminemia, plasma IL-6 elevation, and reduction of performance status, which are frequently observed in advanced cancers. To our knowledge, this is the first clinical study that examined the immunological and clinical effects of JTT in cancer patients undergoing immunotherapy in humans.

  9. 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

  10. 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

  11. 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.

  12. 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: 3.687, year: 2015

  13. Tumor antigen-specific FOXP3+ CD4 T cells identified in human metastatic melanoma: peptide vaccination results in selective expansion of Th1-like counterparts.

    Science.gov (United States)

    Jandus, Camilla; Bioley, Gilles; Dojcinovic, Danijel; Derré, Laurent; Baitsch, Lukas; Wieckowski, Sébastien; Rufer, Nathalie; Kwok, William W; Tiercy, Jean-Marie; Luescher, Immanuel F; Speiser, Daniel E; Romero, Pedro

    2009-10-15

    We have previously shown that vaccination of HLA-A2 metastatic melanoma patients with the analogue Melan-A(26-35(A27L)) peptide emulsified in a mineral oil induces ex vivo detectable specific CD8 T cells. These are further enhanced when a TLR9 agonist is codelivered in the same vaccine formulation. Interestingly, the same peptide can be efficiently recognized by HLA-DQ6-restricted CD4 T cells. We used HLA-DQ6 multimers to assess the specific CD4 T-cell response in both healthy individuals and melanoma patients. We report that the majority of melanoma patients carry high frequencies of naturally circulating HLA-DQ6-restricted Melan-A-specific CD4 T cells, a high proportion of which express FOXP3 and proliferate poorly in response to the cognate peptide. Upon vaccination, the relative frequency of multimer+ CD4 T cells did not change significantly. In contrast, we found a marked shift to FOXP3-negative CD4 T cells, accompanied by robust CD4 T-cell proliferation upon in vitro stimulation with cognate peptide. A concomitant reduction in TCR diversity was also observed. This is the first report on direct ex vivo identification of antigen-specific FOXP3+ T cells by multimer labeling in cancer patients and on the direct assessment of the impact of peptide vaccination on immunoregulatory T cells.

  14. 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

    1998-01-01

    as demonstrated by flow cytometry analysis. The peptide, EBA(aa1076-96), also bound to desialylated glycophorin A and glycophorin B when tested by ELISA. The peptide blocked parasite multiplication in vitro. The glycophorin A binding sequence was further delineated to a 12-aa sequence, EBA(aa1085-96), by testing...

  15. 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.

    1998-01-01

    as demonstrated by flow cytometry analysis. The peptide, EBA(aa1076-96), also bound to desialylated glycophorin A and glycophorin B when tested by ELISA, The peptide blocked parasite multiplication in vitro. The glycophorin A binding sequence was further delineated to a 12-aa sequence, EBA(aa1085-96), by testing...

  16. 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

    2009-01-01

    presented by a non-self human leucocyte antigen (HLA) molecule and transferred to cancer patients expressing that HLA molecule. Obtaining allo-restricted CTL of high-avidity and low cross-reactivity has, however, proven difficult. Here, we show that dendritic cells transfected with mRNA encoding HLA-A*0201......, 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-HLA...

  17. [STUDY OF HUMORAL IMMUNE RESPONSE FEATURES BASED ON MODELLING OF ANTIGEN DETERMINANTS OF HEPATITIS C VIRUS BY SYNTHETIC PEPTIDES AND GENETICALLY ENGINEERED POLYPEPTIDES].

    Science.gov (United States)

    Kruglov, I V

    2015-01-01

    Study of humoral immune response features in patients with acute hepatitis C (AHC) with various disease outcomes based on modelling of antigen determinants of hepatitis C virus (HCV) by synthetic peptides and genetically engineered polypeptides. 20 patients with icteric form of AHC based on clinical-biochemical presentation and HCV RNA detection by PCR in blood sera during 12 months from the disease onset were included into the study. Antibody seroconversion study was carried out by EIA. Genetically engineered proteins and synthetic peptides were used as antigens. Similarity and differences of humoral immune response against the HCV antigens used in this study depending on the disease outcome (convalescence or chronicity) were shown. Significant difference of the humoral immune response to both HCV core protein and various fragments of the immune dominant region of this protein were detected, that indicates on a link of these features of immune response with perspectives of a more or less favorable disease development. The regularities of seroconversion detected allow to consider anti-NS5 IgG as a prognostic marker of the disease chronicity. Such marker, as anti-NS3 IgG, is important for diagnostics, but not for disease outcome prognosis.

  18. 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

  19. NOG-hIL-4-Tg, a new humanized mouse model for producing tumor antigen-specific IgG antibody by peptide vaccination.

    Directory of Open Access Journals (Sweden)

    Yoshie Kametani

    Full Text Available Immunodeficient mice transplanted with human peripheral blood mononuclear cells (PBMCs are promising tools to evaluate human immune responses to vaccines. However, these mice usually develop severe graft-versus-host disease (GVHD, which makes estimation of antigen-specific IgG production after antigen immunization difficult. To evaluate antigen-specific IgG responses in PBMC-transplanted immunodeficient mice, we developed a novel NOD/Shi-scid-IL2rγnull (NOG mouse strain that systemically expresses the human IL-4 gene (NOG-hIL-4-Tg. After human PBMC transplantation, GVHD symptoms were significantly suppressed in NOG-hIL-4-Tg compared to conventional NOG mice. In kinetic analyses of human leukocytes, long-term engraftment of human T cells has been observed in peripheral blood of NOG-hIL-4-Tg, followed by dominant CD4+ T rather than CD8+ T cell proliferation. Furthermore, these CD4+ T cells shifted to type 2 helper (Th2 cells, resulting in long-term suppression of GVHD. Most of the human B cells detected in the transplanted mice had a plasmablast phenotype. Vaccination with HER2 multiple antigen peptide (CH401MAP or keyhole limpet hemocyanin (KLH successfully induced antigen-specific IgG production in PBMC-transplanted NOG-hIL-4-Tg. The HLA haplotype of donor PBMCs might not be relevant to the antibody secretion ability after immunization. These results suggest that the human PBMC-transplanted NOG-hIL-4-Tg mouse is an effective tool to evaluate the production of antigen-specific IgG antibodies.

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

    Science.gov (United States)

    Witschas, Katja; Jobin, Marie-Lise; Korkut, Dursun Nizam; Vladan, Maria Magdalena; Salgado, Gilmar; Lecomte, Sophie; Vlachova, Viktorie; Alves, Isabel D

    2015-05-01

    The transient receptor potential ankyrin 1 channel (TRPA1) belongs to the TRP cation channel superfamily that responds to a panoply of stimuli such as changes in temperature, calcium levels, reactive oxygen and nitrogen species and lipid mediators among others. The TRP superfamily has been implicated in diverse pathological states including neurodegenerative disorders, kidney diseases, inflammation, pain and cancer. The intracellular C-terminus is an important regulator of TRP channel activity. Studies with this and other TRP superfamily members have shown that the C-terminus association with lipid bilayer alters channel sensitivity and activation, especially interactions occurring through basic residues. Nevertheless, it is not yet clear how this process takes place and which regions in the C-terminus would be responsible for such membrane recognition. With that in mind, herein the first putative membrane interacting region of the C-terminus of human TRPA1, (corresponding to a 29 residue peptide, IAEVQKHASLKRIAMQVELHTSLEKKLPL) named H1 due to its potential helical character was chosen for studies of membrane interaction. The affinity of H1 to lipid membranes, H1 structural changes occurring upon this interaction as well as effects of this interaction in lipid organization and integrity were investigated using a biophysical approach. Lipid models systems composed of zwitterionic and anionic lipids, namely those present in the lipid membrane inner leaflet, where H1 is prone to interact, where used. The study reveals a strong interaction and affinity of H1 as well as peptide structuration especially with membranes containing anionic lipids. Moreover, the interactions and peptide structure adoption are headgroup specific. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Effect of conformational propensity of peptide antigens in their interaction with MHC class II molecules. Failure to document the importance of regular secondary structures

    DEFF Research Database (Denmark)

    Sette, A; Lamont, A; Buus, S

    1989-01-01

    In an attempt to define some of the conformational requirements for binding of the antigenic peptide OVA 323-336 to purified IAd molecules, three distinct experimental approaches were applied. First, the effect of introducing proline or glycine residues within the region of OVA 323-336 crucial...... for its IAd binding capacity was analyzed. In most instances these substitutions had little or no effect, suggesting that neither alpha-helical nor beta-sheet regular structures may be strictly required for productive interaction with MHC molecules. Some of the same substitutions were also found to have...... no effect on the capacity of the peptide to stimulate OVA 323-336 specific T cell hybridomas, suggesting that regular structures such as alpha-helices or beta-sheets may not be strictly required for T cell stimulation, either. Second, we introduced, within the OVA 323-336 molecule, structural modifications...

  2. The putative natural killer decoy early gene m04 (gp34) of murine cytomegalovirus encodes an antigenic peptide recognized by protective antiviral CD8 T cells.

    Science.gov (United States)

    Holtappels, R; Thomas, D; Podlech, J; Geginat, G; Steffens, H P; Reddehase, M J

    2000-02-01

    Several early genes of murine cytomegalovirus (MCMV) encode proteins that mediate immune evasion by interference with the major histocompatibility complex class I (MHC-I) pathway of antigen presentation to cytolytic T lymphocytes (CTL). Specifically, the m152 gene product gp37/40 causes retention of MHC-I molecules in the endoplasmic reticulum (ER)-Golgi intermediate compartment. Lack of MHC-I on the cell surface should activate natural killer (NK) cells recognizing the "missing self." The retention, however, is counteracted by the m04 early gene product gp34, which binds to folded MHC-I molecules in the ER and directs the complex to the cell surface. It was thus speculated that gp34 might serve to silence NK cells and thereby complete the immune evasion of MCMV. In light of these current views, we provide here results demonstrating an in vivo role for gp34 in protective antiviral immunity. We have identified an antigenic nonapeptide derived from gp34 and presented by the MHC-I molecule D(d). Besides the immunodominant immediate-early nonapeptide consisting of IE1 amino acids 168-176 (IE1(168-176)), the early nonapeptide m04(243-251) is the second antigenic peptide described for MCMV. The primary immune response to MCMV generates significant m04-specific CD8 T-cell memory. Upon adoptive transfer into immunodeficient recipients, an m04-specific CTL line controls MCMV infection with an efficacy comparable to that of an IE1-specific CTL line. Thus, gp34 is the first noted early protein of MCMV that escapes viral immune evasion mechanisms. These data document that MCMV is held in check by a redundance of protective CD8 T cells recognizing antigenic peptides in different phases of viral gene expression.

  3. 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.

  4. Large-scale detection of antigen-specific T cells using peptide-MHC-I multimers labeled with DNA barcodes

    DEFF Research Database (Denmark)

    Bentzen, Amalie Kai; Marquard, Andrea Marion; Lyngaa, Rikke Birgitte

    2016-01-01

    Identification of the peptides recognized by individual T cells is important for understanding and treating immune-related diseases. Current cytometry-based approaches are limited to the simultaneous screening of 10-100 distinct T-cell specificities in one sample. Here we use peptide-major histoc...

  5. 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

    ) class I molecules, which are highly polymorphic peptide receptors which select and present endogenously derived peptides to circulating CTLs. Peptides that are recognized by CTLs in the context of MHC are epitopes, and represent a small sample of the pathogen proteome, making it possible for the immune...... fingerprint” of an individual can be identified by defining MHC alleles. This is classically called “tissue typing” and is done by analyzing the reactivity of peripheral blood cells with sera unique to MHC alleles. Such knowledge is paramount to analysis of the immune response regarding MHC restriction...... within a species makes immune escape almost impossible for any intruding pathogen. Characterization of the SLA class I and class II gene products and their peptide binding capacity defines the T cell epitopes of any given pathogen proteome. To date the analysis of MHC peptide interactions, strength...

  6. Expression, purification and preliminary X-ray crystallographic analysis of the human major histocompatibility antigen HLA-B*1402 in complex with a viral peptide and with a self-peptide

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pravin [Institut für Immungenetik, Charité - Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Thielallee 73, 14195 Berlin (Germany); Vahedi-Faridi, Ardeschir [Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin, Takustrasse 6, 14195 Berlin (Germany); Merino, Elena; López de Castro, José A. [Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Cientificas, Universidad Autónoma de Madrid, Facultad de Ciencias, Universidad Autónoma, 28049 Madrid (Spain); Volz, Armin; Ziegler, Andreas [Institut für Immungenetik, Charité - Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Thielallee 73, 14195 Berlin (Germany); Saenger, Wolfram, E-mail: saenger@chemie.fu-berlin.de [Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin, Takustrasse 6, 14195 Berlin (Germany); Uchanska-Ziegler, Barbara, E-mail: saenger@chemie.fu-berlin.de [Institut für Immungenetik, Charité - Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Thielallee 73, 14195 Berlin (Germany)

    2007-07-01

    The crystallization of HLA-B*1402 in complex with two peptides is reported. The product of the human major histocompatibility (HLA) class I allele HLA-B*1402 only differs from that of allele HLA-B*1403 at amino-acid position 156 of the heavy chain (Leu in HLA-B*1402 and Arg in HLA-B*1403). However, both subtypes are known to be differentially associated with the inflammatory rheumatic disease ankylosing spondylitis (AS) in black populations in Cameroon and Togo. HLA-B*1402 is not associated with AS, in contrast to HLA-B*1403, which is associated with this disease in the Togolese population. The products of these alleles can present peptides with Arg at position 2, a feature shared by a small group of other HLA-B antigens, including HLA-B*2705, the prototypical AS-associated subtype. Complexes of HLA-B*1402 with a viral peptide (RRRWRRLTV, termed pLMP2) and a self-peptide (IRAAPPPLF, termed pCatA) were prepared and were crystallized using polyethylene glycol as precipitant. The complexes crystallized in space groups P2{sub 1} (pLMP2) and P2{sub 1}2{sub 1}2{sub 1} (pCatA) and diffracted synchrotron radiation to 2.55 and 1.86 Å resolution, respectively. Unambiguous solutions for both data sets were obtained by molecular replacement using a peptide-complexed HLA-B*2705 molecule (PDB code) as a search model.

  7. 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

    2011-06-01

    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. 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. Copyright © 2011 American Association for the Study of Liver Diseases.

  8. 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.

  9. Structural and antigenic features of the synthetic SF23 peptide corresponding to the receptor binding fragment of diphtheria toxin.

    Science.gov (United States)

    Khrustaleva, Tatyana Aleksandrovna; Khrustalev, Vladislav Victorovich; Barkovsky, Eugene Victorovich; Kolodkina, Valentina Leonidovna; Astapov, Anatoly Archipovich

    2015-02-01

    The SF23 peptide corresponding to the receptor binding fragment of diphtheria toxin (residues 508-530) has been synthesized. This fragment forming a protruding beta hairpin has been chosen because it is the less mutable B-cell epitope. Affine chromatography and ELISA show that antibodies from the sera of persons infected by toxigenic Corynebacterium diphtheriae and those immunized by diphtheria toxoid are able to bind the synthetic SF23 peptide. There are antibodies recognizing the SF23 peptide in the serum of horses hyperimmunized with diphtheria toxoid. Analysis of circular dichroism spectra show formation of beta hairpin by the peptide. Taken together, the results showed that the structure of the less mutable epitope of C. diphtheriae toxin was reproduced by the short SF23 peptide. Since antibodies against that epitope should block its interactions with cellular receptor (heparin-binding epidermal growth factor), the SF23 peptide can be considered as a promising candidate for synthetic vaccine development. Fluorescence quenching studies showed the existence of chloride and phosphate binding sites on the SF23 molecule. Phosphate containing adjuvants (aluminum hydroxyphosphate or aluminum hydroxyphosphate sulfate) are recommended to increase the SF23 immunogenic properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Antigenic Peptides Capable of Inducing Specific Antibodies for Detection of the Major Alterations Found in Type 2B Von Willebrand Disease

    Directory of Open Access Journals (Sweden)

    Marina de Oliveira Paro

    2013-01-01

    Full Text Available Von Willebrand disease (VWD is an inherited hemorrhagic disorder promoted by either quantitative or qualitative defects of the von Willebrand factor (VWF. The disease represents the most common human coagulopathy afflicting 1.3% of the population. Qualitative defects are subdivided into four subtypes and classified according to the molecular dysfunction of the VWF. The differential diagnosis of the VWD is a difficult task, relying on a panel of tests aimed to assess the plasma levels and function of the VWF. Here, we propose biochemical approaches for the identification of structural variants of the VWF. A bioinformatic analysis was conducted to design seven peptides among which three were representatives of specific amino acid sequences belonging to normal VWF and four encompassed sequences found in the most common VWD subtype 2B. These peptides were used to immunize mice, after which, peptide-specific immunoglobulins were purified. This resulted in four Ig preparations capable of detecting alterations in the subtype 2B VWD plus additional three antibody fractions targeting the normal VWF. The panel of antibodies could serve many applications among them (1 assessment of VWF: antigen interaction, (2 VWF multimer analysis, and (3 production of monoclonal antibodies against VWF for therapeutic purposes as in thrombotic thrombocytopenic purpura.

  11. Antigenic Peptides Capable of Inducing Specific Antibodies for Detection of the Major Alterations Found in Type 2B Von Willebrand Disease

    Science.gov (United States)

    Paro, Marina de Oliveira; Ferreira, Cyntia Silva; Vieira, Fernanda Silva; de Santana, Marcos Aurélio; Namen-Lopes, Maria Sueli Silva; Leclercq, Sophie Yvette; Velloso-Rodrigues, Cibele; Guerra de Andrade, Milton Hércules

    2013-01-01

    Von Willebrand disease (VWD) is an inherited hemorrhagic disorder promoted by either quantitative or qualitative defects of the von Willebrand factor (VWF). The disease represents the most common human coagulopathy afflicting 1.3% of the population. Qualitative defects are subdivided into four subtypes and classified according to the molecular dysfunction of the VWF. The differential diagnosis of the VWD is a difficult task, relying on a panel of tests aimed to assess the plasma levels and function of the VWF. Here, we propose biochemical approaches for the identification of structural variants of the VWF. A bioinformatic analysis was conducted to design seven peptides among which three were representatives of specific amino acid sequences belonging to normal VWF and four encompassed sequences found in the most common VWD subtype 2B. These peptides were used to immunize mice, after which, peptide-specific immunoglobulins were purified. This resulted in four Ig preparations capable of detecting alterations in the subtype 2B VWD plus additional three antibody fractions targeting the normal VWF. The panel of antibodies could serve many applications among them (1) assessment of VWF: antigen interaction, (2) VWF multimer analysis, and (3) production of monoclonal antibodies against VWF for therapeutic purposes as in thrombotic thrombocytopenic purpura. PMID:23970904

  12. Specific Antibodies Reacting with SV40 Large T Antigen Mimotopes in Serum Samples of Healthy Subjects.

    Directory of Open Access Journals (Sweden)

    Mauro Tognon

    Full Text Available Simian Virus 40, experimentally assayed in vitro in different animal and human cells and in vivo in rodents, was classified as a small DNA tumor virus. In previous studies, many groups identified Simian Virus 40 sequences in healthy individuals and cancer patients using PCR techniques, whereas others failed to detect the viral sequences in human specimens. These conflicting results prompted us to develop a novel indirect ELISA with synthetic peptides, mimicking Simian Virus 40 capsid viral protein antigens, named mimotopes. This immunologic assay allowed us to investigate the presence of serum antibodies against Simian Virus 40 and to verify whether Simian Virus 40 is circulating in humans. In this investigation two mimotopes from Simian Virus 40 large T antigen, the viral replication protein and oncoprotein, were employed to analyze for specific reactions to human sera antibodies. This indirect ELISA with synthetic peptides from Simian Virus 40 large T antigen was used to assay a new collection of serum samples from healthy subjects. This novel assay revealed that serum antibodies against Simian Virus 40 large T antigen mimotopes are detectable, at low titer, in healthy subjects aged from 18-65 years old. The overall prevalence of reactivity with the two Simian Virus 40 large T antigen peptides was 20%. This new ELISA with two mimotopes of the early viral regions is able to detect in a specific manner Simian Virus 40 large T antigen-antibody responses.

  13. [Development of an antigen 'sandwich' enzyme immunoassay for the detection of antibodies against HIV-2 by using a biotinylated synthetic peptide of gp36 protein].

    Science.gov (United States)

    Delahanty-Fernández, Aurora; Bequer-Ariza, Dunia Clara; Hernández-Marín, Milenen; Zulueta-Rodríguez, Orlando; Pozo-Peña, Lilliam; Hernández-Spengler, Idialis; Ramos-Martínez, Grisell; Valdespino-Díaz, Marcos Antonio; Ventura-Paz, Julio

    2015-01-01

    Among the several existing methods for the detection of antibodies to HIV, the 'sandwich' ELISA is currently the most used. This study aims to assess a biotinylated monomeric synthetic peptide of the glycoprotein trans-membrane gp36 from HIV-2, in a sandwich assay, for the detection of antibodies against this HIV-2 protein. To perform the assay, plates coated with recombinant protein gp36 at 0.5μg/mL and synthetic peptide gp36(5) at 1μg/mL were used. The concentration of the biotinylated synthetic peptide (gp36(5)-B) used was 0.1μg/mL prepared with a Tris-BSA-NaCl buffer solution and the Streptavidin- Alkaline Phosphatase conjugate diluted 1:30000 prepared with a PBS-Sucrose-BSA solution. Positive serum samples to antibodies against HIV-1 and HIV-2 viruses (88 and 34, respectively) were tested, with 483 negative samples from blood donors and 96 serum samples to assess the analytical specificity. All the samples were tested using the UMELISA HIV 1+2 RECOMBINANT assay, and all positives were confirmed using a DAHIV-BLOT assay. Thirty four samples with antibodies against HIV-2 were assessed as positive for both coating variants. The highest specificity was obtained with the variant using the synthetic peptide gp36(5) in its coating. The antigen 'sandwich' assay developed by using gp36(5)-B enables the detection of antibodies against gp36 protein of HIV-2. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  14. 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

    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...... 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....... 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...

  15. 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

    ten dines at two-weeks intervals with low doses of the eight conjugates, Blood samples collected between each immunisation were analysed by ELISA for specific antibody titres and relative affinities. With both types of conjugations, the anti-peptide antibody titres increased in response to increasing...... the 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...

  16. Polymeric nanoparticles for co-delivery of synthetic long peptide antigen and poly IC as therapeutic cancer vaccine formulation

    NARCIS (Netherlands)

    Rahimian, Sima; Fransen, Marieke F.; Kleinovink, Jan Willem; Christensen, Jonatan Riis; Amidi, Maryam|info:eu-repo/dai/nl/304834912; Hennink, Wim E.|info:eu-repo/dai/nl/070880409; Ossendorp, Ferry

    2015-01-01

    The aim of the current study was to develop a cancer vaccine formulation for treatment of human papillomavirus (HPV)-induced malignancies. Synthetic long peptides (SLPs) derived from HPV16 E6 and E7 oncoproteins have been used for therapeutic vaccination in clinical trials with promising results. In

  17. A study of the liver of goats immunized with a synthetic peptide of the Sm14 antigen and challenged with Fasciola hepatica.

    Science.gov (United States)

    Zafra, R; Buffoni, L; Martínez-Moreno, A; Pérez-Ecija, A; Martinez-Moreno, F J; Pérez, J

    2008-11-01

    A synthetic peptide of the Sm14 antigen of Schistosoma mansoni was used to immunize goats against experimental challenge with Fasciola hepatica. The goats used consisted of: group 1 (unimmunized and uninfected [controls]); group 2 (unimmunized and infected); group 3 (immunized and infected). Compared with group 2, the animals of group 3 showed at necropsy a reduction in hepatic worm burden; however, because of variability in the two groups this reduction was not statistically significant. A gross morphometric study of the hepatic changes revealed a correlation between lesions and worm burdens in group 3. No significant differences in damaged areas were found between groups 2 and 3, except that group 2 had more severe bile duct hyperplasia. A striking hepatic inflammatory infiltration of CD3+ T lymphocytes and IgG+ plasma cells was found in both groups 2 and 3, especially the latter.

  18. [Use of a synthetic peptide of HIV-2 glycoprotein 36 in antigen mixtures for the immunodiagnosis of HIV types 1 and 2].

    Science.gov (United States)

    Ramos Martínez, Grisell; Valdespino-Díaz, Marcos Antonio; Hernández Marín, Milenen; Valle Carvajal, Elizabeth; Selles León, María Elena; Pozo Peña, Lilliam

    2015-12-01

    The HIV-2 glycoprotein 36 (gp36) is often used in ELISA. An evaluation of the diagnostic indexes of antigen mixtures with a synthetic peptide of HIV2 gp36 (5) is performed in this study. Five mixtures of gp36 (5) and the recombinant proteins of HIV1/2 were prepared. A total of 1306 samples were evaluated with UMELISA HIV1+2 RECOMBINANT used as reference. The variant (V-1) showed very good agreement as regards the reference method. The V-1 variant was shown to be highly effective in the immunodiagnosis of HIV 1/2. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  19. Effective clinical-scale production of dendritic cell vaccines by monocyte elutriation directly in medium, subsequent culture in bags and final antigen loading using peptides or RNA transfection.

    Science.gov (United States)

    Erdmann, Michael; Dörrie, Jan; Schaft, Niels; Strasser, Erwin; Hendelmeier, Martin; Kämpgen, Eckhart; Schuler, Gerold; Schuler-Thurner, Beatrice

    2007-09-01

    Dendritic cell (DC) vaccination approaches are advancing fast into the clinic. The major obstacle for further improvement is the current lack of a simple functionally "closed" system to generate standardized monocyte-derived (mo) DC vaccines. Here, we significantly optimized the use of the Elutra counterflow elutriation system to enrich monocytic DC precursors by (1) developing an algorithm to avoid red blood cell debulking and associated monocyte loss before elutriation, and (2) by elutriation directly in culture medium rather than phosphate-buffered saline. Upon elutriation the bags containing the collected monocytes are simply transferred into the incubator to generate DC progeny as the final "open" washing step is no longer required. Elutriation resulted in significantly more (> or = 2-fold) and purer DC than the standard gradient centrifugation/adherence-based monocyte enrichment, whereas morphology, maturation markers, viability, migratory capacity, and T cell stimulatory capacity were identical. Subsequently, we compared RNA transfection, as this is an increasingly used approach to load DC with antigen. Elutra-derived and adherence-derived DC could be electroporated with similar, high efficiency (on average >85% green fluorescence protein positive), and appeared also equal in antigen expression kinetics. Both Elutra-derived and adherence-derived DC, when loaded with the MelanA peptide or electroporated with MelanA RNA, showed a high T cell stimulation capacity, that is, priming of MelanA-specific CD8+ T cells. Our optimized Elutra-based procedure is straightforward, clearly superior to the standard gradient centrifugation/plastic adherence protocol, and now allows the generation of large numbers of peptide-loaded or RNA-transfected DC in a functionally closed system.

  20. 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

  1. 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)

    Wang, Yanying; Qu, Ying; Li, Chunya; Wu, Kangbing; Liu, Guishen; Hou, Xiaodong; Huang, Yina; Wu, Wangze

    2015-01-01

    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)

  2. Serum concentrations of prostate-specific antigen measured using immune extraction, trypsin digestion, and tandem mass spectrometry quantification of LSEPAELTDAVK peptide.

    Science.gov (United States)

    Klee, Eric W; Bondar, Olga P; Goodmanson, Marcia K; Trushin, Sergey A; Bergstralh, Eric J; Singh, Ravinder J; Anderson, N Leigh; Klee, George G

    2014-10-01

    Prostate-specific antigen (PSA) is a 34-kDa glycoprotein with chymotrypsin-like enzyme activity that circulates both in free forms and complexed to various enzyme inhibitors including antichymotrypsin and α2-macroglobulin. Prostate-specific antigen bound to α2-macroglobulin is not detected by commercial PSA immunoassays. To develop a mass spectrometry assay that detects the same forms of PSA as the immunoassays, which could serve as a reference for harmonizing PSA immunoassays. Prostate-specific antigen was immune extracted from serum, trypsin was digested, and the LSEPAELTDAVK peptide was quantitated on an API 5000 spectrometer. Calibrators were made by adding 10% free and 90% antichymotrypsin-bound PSA to female sera. The assay was standardized to the World Health Organization 96/670 reference standard. Validation of clinical utility and comparisons with 2 immunoassays (Roche cobas and Beckman Access) were performed using frozen sera aliquots from 100 men undergoing prostate biopsy (50 negative, 50 with cancer) and 5 serial samples collected over time from 5 men with advanced prostate cancer. The antibody extraction efficiency was greater than 99%. The assay has an analytic range from 1.2 to 76 ng/mL, with precision ranging from 8.6% at 1.5 ng/mL to 5.4% at 27 ng/mL. The mass spectrometry assay correlated well with 2 immunoassays. All 3 assays showed statistically equivalent separation of prostate cancer from benign disease using receiver operating characteristic curve analysis. This mass spectrometry assay can reliably measure PSA concentrations in human serum and could serve as a reference standard for harmonizing PSA immunoassays.

  3. 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

  4. Vaccination with M2e-based multiple antigenic peptides: characterization of the B cell response and protection efficacy in inbred and outbred mice.

    Directory of Open Access Journals (Sweden)

    Amaya I Wolf

    Full Text Available The extracellular domain of the influenza A virus protein matrix protein 2 (M2e is remarkably conserved between various human isolates and thus is a viable target antigen for a universal influenza vaccine. With the goal of inducing protection in multiple mouse haplotypes, M2e-based multiple antigenic peptides (M2e-MAP were synthesized to contain promiscuous T helper determinants from the Plasmodium falciparum circumsporozoite protein, the hepatitis B virus antigen and the influenza virus hemagglutinin. Here, we investigated the nature of the M2e-MAP-induced B cell response in terms of the distribution of antibody (Ab secreting cells (ASCs and Ab isotypes, and tested the protective efficacy in various mouse strains.Immunization of BALB/c mice with M2e-MAPs together with potent adjuvants, CpG 1826 oligonucleotides (ODN and cholera toxin (CT elicited high M2e-specific serum Ab titers that protected mice against viral challenge. Subcutaneous (s.c. and intranasal (i.n. delivery of M2e-MAPs resulted in the induction of IgG in serum and airway secretions, however only i.n. immunization induced anti-M2e IgA ASCs locally in the lungs, correlating with M2-specific IgA in the bronchio-alveolar lavage (BAL. Interestingly, both routes of vaccination resulted in equal protection against viral challenge. Moreover, M2e-MAPs induced cross-reactive and protective responses to diverse M2e peptides and variant influenza viruses. However, in contrast to BALB/c mice, immunization of other inbred and outbred mouse strains did not induce protective Abs. This correlated with a defect in T cell but not B cell responsiveness to the M2e-MAPs.Anti-M2e Abs induced by M2e-MAPs are highly cross-reactive and can mediate protection to variant viruses. Although synthetic MAPs are promising designs for vaccines, future constructs will need to be optimized for use in the genetically heterogeneous human population.

  5. Glomerulopathy induced by immunization with a peptide derived from the goodpasture antigen α3IV-NC1.

    Science.gov (United States)

    Hopfer, Helmut; Hünemörder, Stefanie; Treder, Julia; Turner, Jan-Eric; Paust, Hans-Joachim; Meyer-Schwesinger, Catherine; Hopfer, Ulrike; Sachs, Marlies; Peters, Anett; Bucher-Kocaoglu, Biranda; Ahrens, Stefanie; Panzer, Ulf; Mittrücker, Hans-Willi

    2015-04-15

    Mouse experimental autoimmune glomerulonephritis, a model of human antiglomerular basement membrane disease, depends on both Ab and T cell responses to the Goodpasture Ag noncollagenous domain 1 of the α3-chain of type IV collagen (α3IV-NC1). The aim of our study was to further characterize the T cell-mediated immune response. Repeated immunization with mouse α3IV-NC1 caused fatal glomerulonephritis in DBA/1 mice. Although two immunizations were sufficient to generate high α3IV-NC1-specific IgG titers, Ab and complement deposition along the glomerular basement membranes, and a nephrotic syndrome, two additional immunizations were needed to induce a necrotizing/crescentic glomerulonephritis. Ten days after the first immunization, α3IV-NC1-specific CD4(+) cells producing TNF-α, IFN-γ, or IL-17A were detected in the spleen. With the emergence of necrotizing/crescentic glomerulonephritis, ∼0.15% of renal CD4(+) cells were specific for α3IV-NC1. Using peptides spanning the whole α3IV-NC1 domain, three immunodominant T cell epitopes were identified. Immunization with these peptides did not lead to clinical signs of experimental autoimmune glomerulonephritis or necrotizing/crescentic glomerulonephritis. However, mice immunized with one of the peptides (STVKAGDLEKIISRC) developed circulating Abs against mouse α3IV-NC1 first detected at 8 wk, and 50% of the mice showed mild proteinuria at 18-24 wk due to membranous glomerulopathy. Taken together, our results suggest that autoreactive T cells are able to induce the formation of pathologic autoantibodies. The quality and quantity of α3IV-NC1-specific Ab and T cell responses are critical for the phenotype of the glomerulonephritis. Copyright © 2015 by The American Association of Immunologists, Inc.

  6. The same self-peptide selects conventional and regulatory CD4+ T cells with identical antigen receptors

    OpenAIRE

    Wojciech, Lukasz; Ignatowicz, Alicja; Seweryn, Michal; Rempala, Grzegorz; Pabla, Simarjot Singh; McIndoe, Richard A.; Kisielow, Pawel; Ignatowicz, Leszek

    2014-01-01

    The role of the T cell receptor (TCR) in commitment of thymocytes to regulatory CD4+Foxp3+ and conventional CD4?Foxp3? T cell lineages remains controversial. According to the prevailing view, commitment to the former lineage, in contrast to the latter, requires that high affinity TCRs bind rare class II MHC/peptide complexes presented in ?thymic niches?, which could explain differences between their TCR repertoires. Here we challenge this view and show that the binding of identical TCRs to th...

  7. Identification and characterization of HLA-A24-specific XBP1, CD138 (Syndecan-1) and CS1 (SLAMF7) peptides inducing antigens-specific memory cytotoxic T lymphocytes targeting multiple myeloma.

    Science.gov (United States)

    Bae, J; Hideshima, T; Zhang, G L; Zhou, J; Keskin, D B; Munshi, N C; Anderson, K C

    2018-03-01

    X-box binding protein 1 (XBP1), CD138 (Syndecan-1) and CS1 (SLAMF7) are highly expressed antigens in cancers including multiple myeloma (MM). Here, we identify and characterize immunogenic HLA-A24 peptides derived from these antigens for potential vaccination therapy of HLA-A24+ patients with MM. The identified immunogenic HLA-A24-specific XBP1 unspliced (UN) 185-193 (I S P W I L A V L), XBP1 spliced (SP) 223-231 (V Y P E G P S S L), CD138 265-273 (I F A V C L V G F) and CS1 240-248 (L F V L G L F L W) peptides induced antigen-specific CTL with anti-MM activity in an HLA-A24 restricted manner. Furthermore, a cocktail containing the four HLA-A24 peptides evoked MM-specific CTL with distinct phenotypic profiles (CD28, CD40L, 41BB, CD38, CD69) and anti-tumor activities, evidenced by perforin upregulation, CD107a degranulation (cytotoxicity) and Th1-type cytokines (IFN-γ/IL-2/TNF-α) production in response to HLA-A24 + MM cells. The multipeptide-specific CTL included antigen-specific memory CD8 + T cells expressing both T-cell activation (CD38, CD69) and immune checkpoints antigens (CTLA, PD-1, LAG-3, TIM-3). These results provide the framework for a multipeptide vaccination therapy to induce tumor-specific CTL in HLA-A24-positive patients with myeloma and other cancers expressing these antigens.

  8. Administration of sulfosuccinimidyl-4-[N-maleimidomethyl] cyclohexane-1-carboxylate conjugated GP100{sub 25–33} peptide-coupled spleen cells effectively mounts antigen-specific immune response against mouse melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Xiaoli [Department of Hematology, Xuanwu Hospital, Capital Medical University, Beijing (China); Xia, Chang-Qing, E-mail: cqx65@yahoo.com [Department of Hematology, Xuanwu Hospital, Capital Medical University, Beijing (China); Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL32610 (United States)

    2015-12-04

    It remains a top research priority to develop immunotherapeutic approaches to induce potent antigen-specific immune responses against tumors. However, in spite of some promising results, most strategies are ineffective because they generate low numbers of tumor-reactive cytotoxic T lymphocytes (CTLs). Here we designed a strategy to enhance antigen-specific immune response via administering sulfosuccinimidyl-4-[N-maleimidomethyl] cyclohexane-1-carboxylate (sulfo-SMCC)-conjugated melanoma tumor antigen GP100{sub 25–33} peptide-coupled syngeneic spleen cells in a mouse model of melanoma. We found that infusion of GP100{sub 25–33} peptide-coupled spleen cells significantly attenuated the growth of melanoma in prophylactic and therapeutic immunizations. Consistent with these findings, the adoptive transfer of spleen cells from immunized mice to naïve syngeneic mice was able to transfer anti-tumor effect, suggesting that GP100{sub 25–33} peptide-specific immune response was induced. Further studies showed that, CD8+ T cell proliferation and the frequency of interferon (IFN)-γ-producing CD8+ T cells upon ex vivo stimulation by GP100{sub 25–33} were significantly increased compared to control groups. Tumor antigen, GP100{sub 25–23} specific immune response was also confirmed by ELISpot and GP100-tetramer assays. This approach is simple, easy-handled, and efficiently delivering antigens to lymphoid tissues. Our study offers an opportunity for clinically translating this approach into tumor immunotherapy. - Highlights: • Infusion of GP100{sub 25–33}-coupled spleen cells leads to potent anti-melanoma immunity. • GP100{sub 25–33}-coupled spleen cell treatment induces antigen-specific IFN-γ-producing CD8 T cells. • This approach takes advantage of homing nature of immune cells.

  9. Identification of a second T-cell antigen receptor in human and mouse by an anti-peptide γ-chain-specific monoclonal antibody

    International Nuclear Information System (INIS)

    Ioannides, C.G.; Itoh, K.; Fox, F.E.; Pahwa, R.; Good, R.A.; Platsoucas, C.D.

    1987-01-01

    The authors developed a monoclonal antibody (mAb) (9D7) against a synthetic peptide (P13K) selected from the deduced amino acid sequence of the constant region of the λ chain of the murine T-cell antigen receptor (TCR) (amino acids 118-130). Using this mAb, they identified a putative second TCR expressed on peripheral blood lymphocytes from a patient with severe combined immunodeficiency (SCID) that were propagated in culture with recombinant interleukin 2 (rIL-2) and Con A. This mAb immunoprecipitated two polypeptide chains of 40 and 58 kDa under nonreducing conditions and of 40 and 56 kDa under reducing conditions from 125 I-labeled denatured lysates of T3 + WT31 - lymphocytes expanded in culture from a SCID patient. Chemical crosslinking of 125 I-labeled cells followed by immunoprecipitation with anti-Leu-4 mAb under nonreducing or reducing conditions revealed that the 40- and 56-kDa polypeptide chains were associated with the T3 differentiation antigen. These experiments were done with polyclonal cell populations. Cloned T3 + WT31 - cell populations are required to determine whether the TCR contains two λ polypeptide chains. Using the same 9D7 anti-P18K mAb and immunoblotting analysis, they identified a 35 kDa γ-chain polypeptide under reducing conditions expressed on purified L3T4 - Lyt2 - BALB/c mouse thymocytes. This γ-chain TCR is disulfide linked and has a molecular mass of 80 kDa under nonreducing conditions

  10. Immune events associated with protection in C57BL/6 mice immunized with anti-idiotypic antibodies mimicking protective antigens shared between gamma-irradiated cercariae vaccine and human resistance model of Schistosoma haematobium.

    Science.gov (United States)

    Abdeen, Sherif H

    2010-01-01

    Immunoregulation is central for successful manipulation of schistosomiasis. Unlike schistosome vaccine development strategies that relied on direct selection of antigens from crude responses leading to selection of mildly protective antigens, the present study tested the utility of selection of potentially protective antigens encompassed rounds of immunoregulation via idiotypic network. Anti-idiotypic antibodies (Ab2) were purified from sera of New Zealand white rabbits multiply immunized with gamma-irradiated cercariae of S. haematobium, using adult worm specific idiotypes (Ab1) purified from sera of subjects resistant to reinfection. Ab2 was used for immunization of C57BL/6 mice and consequences of immunization were monitored before and after challenge infection with S. haematobium. Results showed an increase of splenic T cell expression of intercellular adhesion molecule-1 (ICAM-1) and very late antigen-4 (VLA-4) upon immunization (average % stimulated cells 54.9 vs. 20.4, P anti-anti-ids (Ab3) reactivity against antigens of approximate molecular weight 40, 80 and 160 kDa of adult worms, which were also recognized by Ab1. However, in contrast to Ab1, Ab3 showed no surface binding to 3 hr schistosomula. Strikingly, mice immunized with Ab2 showed strong resistance to challenge infection (approximately 82% reduction in worm burden, P vaccine development strategy appears to filter out non-protective antigens. Indeed Ab3 recognizes much fewer numbers of antigens, which passed through two rounds of immune regulation. These antigens appear to represent a significant proportion of the protective response in the gamma-irradiated cercariae vaccine and human resistance model as well, providing the basis for an alternative vaccine for schistosomiasis.

  11. Study of the local immune response to Fasciola hepatica in the liver and hepatic lymph nodes of goats immunised with a peptide of the Sm14 antigen.

    Science.gov (United States)

    Zafra, R; Buffoni, L; Pérez-Ecija, R A; Mendes, R E; Martínez-Moreno, A; Martínez-Moreno, F J; Pérez, J

    2009-10-01

    The nature of the local immune response was assessed studying the distribution of CD2(+), CD4(+), CD8(+), gammadelta(+) T lymphocytes, IgM(+) B cells, IL-4(+) and IFN-gamma(+) cells in the liver and hepatic lymph nodes (HLN) of goats immunised with a synthetic peptide of the Sm14 antigen from Schistosoma mansoni and challenged with Fasciola hepatica. A morphometric study of HLN was also carried out in order to evaluate the hyperplasia of lymphoid follicles. Despite the decrease in fluke burdens found in the immunised group (45.9%) respect to the infected control group, this difference was not statistically significant due to the high individual variability. In liver, a significant increase of CD2(+), CD4(+), CD8(+), gammadelta(+) T lymphocytes was found in the infected groups respect to the uninfected control and in the infected control respect to the immunised group. HLN showed a significant enlargement due to the hyperplasia of lymphoid follicles and infiltration of CD2(+), CD4(+), CD8(+), gammadelta(+) T lymphocytes in both infected groups respect to the uninfected control, with no significant differences between the infected control and immunised group. IFN-gamma(+) lymphoid cells was absent or very occasional in HLN where the number of IL-4(+) cells was higher than that of IFN-gamma, suggesting a polarized Th2 response in immunised and in infected control group.

  12. Deletion of fusion peptide or destabilization of fusion core of HIV gp41 enhances antigenicity and immunogenicity of 4E10 epitope

    International Nuclear Information System (INIS)

    Li Jing; Chen Xi; Jiang Shibo; Chen Yinghua

    2008-01-01

    The human monoclonal antibody 4E10 against the membrane-proximal external region (MPER) of HIV-1 gp41 demonstrates broad neutralizing activity across various strains, and makes its epitope an attractive target for HIV-1 vaccine development. Although the contiguous epitope of 4E10 has been identified, attempts to re-elicit 4E10-like antibodies have failed, possibly due to the lack of proper conformation of the 4E10 epitope. Here we used pIg-tail expression system to construct a panel of eukaryotic cell-surface expression plasmids encoding the extracellular domain of gp41 with deletion of fusion peptide and/or introduction of L568P mutation that may disrupt the gp41 six-helix bundle core conformation as DNA vaccines for immunization of mice. We found that these changes resulted in significant increase of the antigenicity and immunogenicity of 4E10 epitope. This information is thus useful for rational design of vaccines targeting the HIV-1 gp41 MPER

  13. Identification of a dengue virus type 2 (DEN-2) serotype-specific B-cell epitope and detection of DEN-2-immunized animal serum samples using an epitope-based peptide antigen.

    Science.gov (United States)

    Wu, Han-Chung; Jung, Mei-Ying; Chiu, Chien-Yu; Chao, Ting-Ting; Lai, Szu-Chia; Jan, Jia-Tsrong; Shaio, Men-Fang

    2003-10-01

    In this study, a serotype-specific monoclonal antibody (mAb), D(2) 16-1 (Ab4), against dengue virus type 2 (DEN-2) was generated. The specificity of Ab4, which recognized DEN-2 non-structural protein 1, was determined by ELISA, immunofluorescence and immunoblotting analyses. The serotype-specific B-cell epitope of Ab4 was identified further from a random phage-displayed peptide library; selected phage clones reacted specifically with Ab4 and did not react with other mAbs. Immunopositive phage clones displayed a consensus motif, His-Arg/Lys-Leu/Ile, and a synthetic peptide corresponding to the phage-displayed peptide bound specifically to Ab4. The His and Arg residues in this epitope were found to be crucial for peptide binding to Ab4 and binding activity decreased dramatically when these residues were changed to Leu. The epitope-based synthetic peptide not only identified serum samples from DEN-2-immunized mice and rabbits by ELISA but also differentiated clearly between serum samples from DEN-2- and Japanese encephalitis virus-immunized mice. This mAb and its epitope-based peptide antigen will be useful for serologic diagnosis of DEN-2 infection. Furthermore, DEN-2 epitope identification makes it feasible to dissect antibody responses to DEN and to address the role of antibodies in the pathogenesis of primary and secondary DEN-2 infections.

  14. 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.

  15. Effect of Fatty Acid Conjugation on Antimicrobial Peptide Activity

    National Research Council Canada - National Science Library

    Chu-Kung, Alexander F; Bozzelli, Kristen N; Nguyen, Rose; Tirrell, Matthew V

    2004-01-01

    .... In the presence of bacteria-mimicking phospholipid vesicles fatty acid conjugates of the amphipathic peptide, AKK, show a larger change in helical structure than either of the unmodified peptides...

  16. 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

  17. Enhanced suppression of polyclonal CD8+25+regulatory T cells via exosomal arming of antigen-specific peptide/MHC complexes.

    Science.gov (United States)

    Mu, Chuanyong; Zhang, Xueshu; Wang, Lu; Xu, Aizhang; Ahmed, Khawaja Ashfaque; Pang, Xueqin; Chibbar, Rajni; Freywald, Andrew; Huang, Jianan; Zhu, Yehan; Xiang, Jim

    2017-05-01

    Compared with CD4 + 25 + regulatory T cells (T regs ), the mechanisms for natural, polyclonal CD8 + 25 + T reg immune suppression have been significantly less studied. We previously showed that polyclonal T cells can acquire antigen-specific targeting activity through arming with exosomal peptide-MHC (pMHC). In this study, we assessed the suppressive effect of CD8 + 25 + T regs or CD8 + 25 + T regs armed with ovalbumin (OVA)-specific exosomes on other immune cells and OVA-specific dendritic cell (DC OVA )-stimulated antitumor immunity. We demonstrate that CD8 + 25 + T regs inhibit T cell proliferation in vitro in a cell contact-dependent fashion but independent of the expression of immunosuppressive IL-10, TGF-β, and CTLA-4. CD8 + 25 + T regs anergize naïve T cells upon stimulation by up-regulating T cell anergy-associated Egr2 and down-regulating IL-2 production. T regs also anergize DCs by preventing DC maturation through the down-regulation of Ia b , CD80, CD86, and inflammatory cytokines, leading to defects in T cell stimulation. Moreover, CD8 + 25 + T regs inhibit CTLs through inducing CTL death via perforin-mediated apoptosis and through reducing effector CTL cytotoxic activity via down-regulating CTL perforin-production and degranulation. In addition, we show that CD8 + 25 + T regs suppress DC OVA -stimulated CTL responses in priming and effector phases and inhibit immunity against OVA-expressing CCL OVA lung cancer. Remarkably, polyclonal CD8 + 25 + T regs armed with OVA-specific exosomal pMHC class-II (pMHC-II), or pMHC class-I (pMHC-I) complexes exert their enhanced inhibition of CTL responses in the priming and the effector phases, respectively. Taken together, our investigation reveals that assigning antigen specificity to nonspecific polyclonal CD8 + 25 + T regs for enhanced immune suppression can be achieved through exosomal pMHC arming. This principle may have a great effect on T reg -mediated immunotherapy of autoimmune diseases. © Society for

  18. Effect of the human leukocyte antigen HLA-DRB1 and anti-cyclic citrullinated peptide on the outcome of rheumatoid arthritis patients

    Directory of Open Access Journals (Sweden)

    H.M. Farouk

    2009-09-01

    Full Text Available Our objective was to determine whether the presence of the human leukocyte antigen HLA-DRB1 locus is associated with production of anti-cyclic citrullinated peptide antibodies (anti-CCP Abs and to what extent they are associated with increased susceptibility to and severity of rheumatoid arthritis (RA in Egyptian patients. Twenty-nine RA patients gave informed consent to participate in a case-control study that was approved by the Ain Shams University Medical Ethics Committee. RA disease activity and severity were determined using the simplified disease activity index and Larsen scores, respectively. We used a wide scale national study on the pattern of HLA typing in normal Egyptians as a control study. Anti-CCP Abs and HLA-DRB1 typing were determined for all subjects. The alleles most strongly associated with RA were HLA-DRB1 [*01 , *04 and *06] (41.4%. RA patients with serum anti-CCP Ab titers above 60 U/mL had a significantly higher frequency of HLA-DRB1*01 (58.3% and HLA-DRB1*04 alleles (83.3%. Significant positive correlations were found between serum and synovial anti-CCP Ab titer, RA disease activity, and severity (r = 0.87, 0.66 and 0.63, respectively; P < 0.05. HLA-DRB1 SE+ alleles [*01 and *04] were highly expressed among Egyptian RA patients. The presence of these alleles was associated with higher anti-CCP Ab titer, active and severe RA disease. Early determination of HLA-DRB1 SE+ alleles and serum anti-CCP Ab could facilitate the prediction of the clinical course and prognosis of RA when first evaluated leading to better disease control.

  19. Mimicking of Arginine by Functionalized N(ω)-Carbamoylated Arginine As a New Broadly Applicable Approach to Labeled Bioactive Peptides: High Affinity Angiotensin, Neuropeptide Y, Neuropeptide FF, and Neurotensin Receptor Ligands As Examples.

    Science.gov (United States)

    Keller, Max; Kuhn, Kilian K; Einsiedel, Jürgen; Hübner, Harald; Biselli, Sabrina; Mollereau, Catherine; Wifling, David; Svobodová, Jaroslava; Bernhardt, Günther; Cabrele, Chiara; Vanderheyden, Patrick M L; Gmeiner, Peter; Buschauer, Armin

    2016-03-10

    Derivatization of biologically active peptides by conjugation with fluorophores or radionuclide-bearing moieties is an effective and commonly used approach to prepare molecular tools and diagnostic agents. Whereas lysine, cysteine, and N-terminal amino acids have been mostly used for peptide conjugation, we describe a new, widely applicable approach to peptide conjugation based on the nonclassical bioisosteric replacement of the guanidine group in arginine by a functionalized carbamoylguanidine moiety. Four arginine-containing peptide receptor ligands (angiotensin II, neurotensin(8-13), an analogue of the C-terminal pentapeptide of neuropeptide Y, and a neuropeptide FF analogue) were subject of this proof-of-concept study. The N(ω)-carbamoylated arginines, bearing spacers with a terminal amino group, were incorporated into the peptides by standard Fmoc solid phase peptide synthesis. The synthesized chemically stable peptide derivatives showed high receptor affinities with Ki values in the low nanomolar range, even when bulky fluorophores had been attached. Two new tritiated tracers for angiotensin and neurotensin receptors are described.

  20. An H5N1 M2e-based multiple antigenic peptide vaccine confers heterosubtypic protection from lethal infection with pandemic 2009 H1N1 virus

    Directory of Open Access Journals (Sweden)

    Yu Hong

    2010-07-01

    Full Text Available Abstract Background A 2009 global influenza pandemic caused by a novel swine-origin H1N1 influenza A virus has posted an increasing threat of a potential pandemic by the highly pathogenic avian influenza (HPAI H5N1 virus, driving us to develop an influenza vaccine which confers cross-protection against both H5N1 and H1N1 viruses. Previously, we have shown that a tetra-branched multiple antigenic peptide (MAP vaccine based on the extracellular domain of M2 protein (M2e from H5N1 virus (H5N1-M2e-MAP induced strong immune responses and cross-protection against different clades of HPAI H5N1 viruses. In this report, we investigated whether such M2e-MAP presenting the H5N1-M2e consensus sequence can afford heterosubtypic protection from lethal challenge with the pandemic 2009 H1N1 virus. Results Our results demonstrated that H5N1-M2e-MAP plus Freund's or aluminum adjuvant induced strong cross-reactive IgG antibody responses against M2e of the pandemic H1N1 virus which contains one amino acid variation with M2e of H5N1 at position 13. These cross-reactive antibodies may maintain for 6 months and bounced back quickly to the previous high level after the 2nd boost administered 2 weeks before virus challenge. H5N1-M2e-MAP could afford heterosubtypic protection against lethal challenge with pandemic H1N1 virus, showing significant decrease of viral replications and obvious alleviation of histopathological damages in the challenged mouse lungs. 100% and 80% of the H5N1-M2e-MAP-vaccinated mice with Freund's and aluminum adjuvant, respectively, survived the lethal challenge with pandemic H1N1 virus. Conclusions Our results suggest that H5N1-M2e-MAP has a great potential to prevent the threat from re-emergence of pandemic H1N1 influenza and possible novel influenza pandemic due to the reassortment of HPAI H5N1 virus with the 2009 swine-origin H1N1 influenza virus.

  1. 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

    Characterization of the peptide‐binding specificity of swine leukocyte antigen (SLA) class I and II molecules is critical to the understanding of adaptive immune responses of swine toward infectious pathogens. Here, we describe the complete binding motif of the SLA‐2*0401 molecule based on a posi......Characterization of the peptide‐binding specificity of swine leukocyte antigen (SLA) class I and II molecules is critical to the understanding of adaptive immune responses of swine toward infectious pathogens. Here, we describe the complete binding motif of the SLA‐2*0401 molecule based...... 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...

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

    NARCIS (Netherlands)

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

    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

  3. Isolation of an HIV-1 neutralizing peptide mimicking the CXCR4 and CCR5 surface from the heavy-chain complementary determining region 3 repertoire of a viremic controller.

    Science.gov (United States)

    Chevigne, Andy; Delhalle, Sylvie; Counson, Manuel; Beaupain, Nadia; Rybicki, Arkadiusz; Verschueren, Charlène; Staub, Thérèse; Schmit, Jean-Claude; Seguin-Devaux, Carole; Deroo, Sabrina

    2016-01-28

    The recent identification of neutralizing antibodies able to prevent viral rebound reemphasized the interest in humoral immune responses to control HIV-1 infection. In this study, we characterized HIV-1-inhibiting sequences from heavy-chain complementary determining region 3 (HCDR3) repertoires of a viremic controller. IgM and IgG-derived HCDR3 repertoires of a viremic controller presenting plasma-neutralizing activity and characterized by over 20 years of infection with a stable CD4 T-cell count were displayed on filamentous phage to identify HCDR3 repertoire-derived peptides inhibiting HIV-1 entry. Screening of phage libraries against recombinant gp120 led to the identification of an HCDR3-derived peptide sequence (LRTV-1) displaying antiviral properties against both X4 and R5 viruses. The interaction of LRTV-1 with gp120 was enhanced upon CD4 binding and sequence comparison revealed homology between LRTV-1 and the second extracellular loop of C-X-C chemokine receptor type 4 (CXCR4) (11/23) and the N-terminus of C-C chemokine receptor type 5 (CCR5) (7/23). Alanine scanning experiments identified different clusters of residues critical for interaction with the viral envelope protein. LRTV-1 peptide is to date the smallest human HCDR3 repertoire-derived peptide identified by phage display inhibiting HIV entry of R5 and X4 viruses. This peptide recognizes a CD4-dependent gp120 epitope critical for coreceptor binding and mimics the surface of CXCR4 and CCR5. Our data emphasize the potential of human HCDR3 immune repertoires as sources of small biologically active peptides for HIV cure.

  4. 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)

    Kwun, Hyun Jin; Ramos da Silva, Suzane; Qin Huilian; Ferris, Robert L.; Tan Rusung; Chang Yuan; Moore, Patrick S.

    2011-01-01

    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.

  5. The Semi-Synthetic Peptide Lin-SB056-1 in Combination with EDTA Exerts Strong Antimicrobial and Antibiofilm Activity against Pseudomonas aeruginosa in Conditions Mimicking Cystic Fibrosis Sputum.

    Science.gov (United States)

    Maisetta, Giuseppantonio; Grassi, Lucia; Esin, Semih; Serra, Ilaria; Scorciapino, Mariano A; Rinaldi, Andrea C; Batoni, Giovanna

    2017-09-16

    Pseudomonas aeruginosa is a major cause of chronic lung infections in cystic fibrosis (CF) patients. The ability of the bacterium to form biofilms and the presence of a thick and stagnant mucus in the airways of CF patients largely contribute to antibiotic therapy failure and demand for new antimicrobial agents able to act in the CF environment. The present study investigated the anti- P. aeruginosa activity of lin-SB056-1, a recently described semi-synthetic antimicrobial peptide, used alone and in combination with the cation chelator ethylenediaminetetraacetic acid (EDTA). Bactericidal assays were carried out in standard culture conditions and in an artificial sputum medium (ASM) closely resembling the CF environment. Peptide's structure and interaction with large unilamellar vesicles in media with different ionic strengths were also investigated through infrared spectroscopy. Lin-SB056-1 demonstrated fast and strong bactericidal activity against both mucoid and non-mucoid strains of P. aeruginosa in planktonic form and, in combination with EDTA, caused significant reduction of the biomass of P. aeruginosa mature biofilms. In ASM, the peptide/EDTA combination exerted a strong bactericidal effect and inhibited the formation of biofilm-like structures of P. aeruginosa . Overall, the results obtained highlight the potential of the lin-SB056-1/EDTA combination for the treatment of P. aeruginosa lung infections in CF patients.

  6. Identification of Common Bacterial Antigenic Markers From Bovine Digital Dermatitis Lesions Using Meta-Transcriptomics in Combination With High-Density Peptide-Microarrays

    DEFF Research Database (Denmark)

    Nielsen, Martin W.; Marcatili, Paoli; Sicheritz-Ponten, Thomas

    of collagenous and connective tissues. Multiple Treponema species, many of which are not-yet-cultivable, are strongly implicated in disease progression. Despite the economic and welfare importance of this disease, no effective vaccine is available; and there is presently very little knowledge concerning...... efficacious immunoprophylactic antigens against DD. It is highly likely that DD-associated treponemes possess considerable antigenic variation, as cows exhibit a variable humoral response against different isolates of Treponema. Hence, combinations of antigens from multiple Treponema species should be used...... response directed at the site of infection. By metatranscriptomics we measured the in situ genome-wide transcriptome of the bacterial population in DD-affected skin lesions from 21 dairy cows. From the transcriptome data, we identified a panel of Treponema genes that were highly expressed in multiple...

  7. Amino acid substitutions in the melanoma antigen recognized by T cell 1 peptide modulate cytokine responses in melanoma-specific T cells

    DEFF Research Database (Denmark)

    Nielsen, M B; Kirkin, A F; Loftus, D

    2000-01-01

    enhances the production of mRNA for interleukin (IL)-5, IL-10, IL-13, IL-15, and interferon-gamma and significantly enhances release of IL-13 and IL-10 from anti-MART-1 cytotoxic T cells. Another heteroclitic peptide, 1L, with an A to L substitution in MART-1(27-35), also enhances the tyrosine...... phosphorylation response in anti-MART-1 cytotoxic CD8+ T cells. Yet, 1L does not enhance the production of T helper cell type 2-like cytokines (IL-10 and IL-13). Together these data show that minor amino acid modifications of immunodominant melanoma peptides profoundly influence the cytokine response in melanoma...

  8. The N-Terminal Flanking Region of the Invariant Chain Peptide Augments the Immunogenicity of a Cryptic “Self” Epitope from a Tumor-Associated Antigen

    NARCIS (Netherlands)

    Hess, A.D.; Thoburn, C.; Chen, W.; Miura, Y.; Wall, E. van der

    2001-01-01

    The N-terminal flanking region of the invariant chain peptide termed CLIP appears to have superagonistic properties interacting with the T cell receptor and the MHC class II molecule at or near the binding site for the bacterial superantigen Staphylococcal enterotoxin B (SEB). The present studies

  9. A combination of autoantibodies to cyclic citrullinated peptide (CCP) and HLA-DRB1 locus antigens is strongly associated with future onset of rheumatoid arthritis

    NARCIS (Netherlands)

    Berglin, E.; Padyukov, L.; Sundin, U.; Hallmans, G.; Stenlund, H.; Venrooij, W.J.W. van; Klareskog, L.; Dahlqvist, S.R.

    2004-01-01

    Antibodies against cyclic citrullinated peptide (CCP) and rheumatoid factors (RFs) have been demonstrated to predate the onset of rheumatoid arthritis ( RA) by years. A nested case control study was performed within the Northern Sweden Health and Disease study cohort to analyse the presence of

  10. Systemic lupus erythematosus: molecular mimicry between anti-dsDNA CDR3 idiotype, microbial and self peptides as antigens for Th cells

    Directory of Open Access Journals (Sweden)

    Kristin eAas-Hanssen

    2015-07-01

    Full Text Available Systemic lupus erythematosus (SLE is marked by a T helper (Th cell dependent B cell hyperresponsiveness, with frequent germinal center reactions, and gammaglobulinemia. A hallmark of SLE is the finding of IgG autoantibodies specific for dsDNA. The specificity of the Th cells that drive the expansion of anti-dsDNA B cells is unresolved. However, anti-microbial, anti-histone and anti-idiotype Th cell responses have been hypothesized to play a role. It has been entirely unclear if these seemingly disparate Th cell responses and hypotheses could be related or unified. Here we describe that H chain CDR3 idiotypes from IgG+ B cells of lupus mice have sequence similarities with both microbial and other self peptides, matched sequences were increased within the mutated CDR3 repertoire and when sequences were derived from lupus mice with expanded anti-dsDNA B cells. Analyses of histone sequences showed that particular histone peptides were similar to VDJ junctions. Moreover, lupus mice had Th cell responses towards histone peptides similar to anti-dsDNA CDR3 sequences. The results suggest that Th cell in lupus may have multiple cross-reactive specificities linked to the IgVH CDR3 Id-peptide sequences as well as similar DNA-associated protein motifs.

  11. Immunoglobulin (Ig)G purified from human sera mirrors intravenous Ig human leucocyte antigen (HLA) reactivity and recognizes one's own HLA types, but may be masked by Fab complementarity-determining region peptide in the native sera.

    Science.gov (United States)

    Ravindranath, M H; Terasaki, P I; Maehara, C Y; Jucaud, V; Kawakita, S; Pham, T; Yamashita, W

    2015-02-01

    Intravenous immunoglobulin (IVIg) reacted with a wide array of human leucocyte antigen (HLA) alleles, in contrast to normal sera, due possibly to the purification of IgG from the pooled plasma. The reactivity of IgG purified from normal sera was compared with that of native sera to determine whether any serum factors mask the HLA reactivity of anti-HLA IgG and whether IgG purified from sera can recognize the HLA types of the corresponding donors. The purified IgG, unlike native sera, mirrored IVIg reactivity to a wide array of HLA-I/-II alleles, indicating that anti-HLA IgG may be masked in normal sera - either by peptides derived from soluble HLA or by those from antibodies. A HLA peptides) masked HLA recognition by the purified IgG. Most importantly, some of the anti-HLA IgG purified from normal sera - and serum IgG from a few donors - indeed recognized the HLA types of the corresponding donors, confirming the presence of auto-HLA antibodies. Comparison of HLA types with the profile of HLA antibodies showed auto-HLA IgG to the donors' HLA antigens in this order of frequency: DPA (80%), DQA (71%), DRB345 (67%), DQB (57%), Cw (50%), DBP (43%), DRB1 (21%), A (14%) and B (7%). The auto-HLA antibodies, when unmasked in vivo, may perform immunoregulatory functions similar to those of therapeutic preparations of IVIg. © 2014 British Society for Immunology.

  12. Functional Mechanism(s) of the Inhibition of Disease Progression by Combination Treatment with Fingolimod Plus Pathogenic Antigen in a Glucose-6-phosphate Isomerase Peptide-Induced Arthritis Mouse Model.

    Science.gov (United States)

    Yoshida, Yuya; Mikami, Norihisa; Matsushima, Yuki; Otani, Fumiya; Miyawaki, Mai; Takatsuji, Miku; Banno, Rie; Tsuji, Takumi; Fujita, Tetsuro; Tsujikawa, Kazutake; Kohno, Takeyuki

    2015-01-01

    We previously reported that combination treatment with fingolimod (FTY720) plus antigenic peptide of glucose-6-phosphate isomerase (residues 325-339) (GPI325-339) from the onset of symptoms significantly inhibited disease progression in a mouse model of GPI325-339-induced arthritis. In this study, we investigated the mechanism(s) involved. The model mice were treated from arthritis onset with FTY720 alone, GPI325-339 alone, or the combination of FTY720 plus GPI325-339. At the end of treatment, inguinal lymph nodes (LNs) were excised and examined histologically and in flow cytometry. Levels of apoptotic cells, programmed death-1-expressing CD4(+)forkhead box P3(-) nonregulatory T cells (non-Tregs), and cytotoxic T-lymphocyte antigen 4-expressing non-Tregs in inguinal LNs were markedly increased in the combination treatment group mice. Regulatory T cells (Tregs) were also increased. These results indicate that combination treatment with FTY720 plus GPI325-339 inhibits the progression of arthritis by inducing clonal deletion and anergy of pathogenic T cells and also by immune suppression via Tregs.

  13. Antibody Production with Synthetic Peptides.

    Science.gov (United States)

    Lee, Bao-Shiang; Huang, Jin-Sheng; Jayathilaka, Lasanthi P; Lee, Jenny; Gupta, Shalini

    2016-01-01

    Peptides (usually 10-20 amino acid residues in length) can be used as effectively as proteins in raising antibodies producing both polyclonal and monoclonal antibodies routinely with titers higher than 20,000. Peptide antigens do not function as immunogens unless they are conjugated to proteins. Production of high quality antipeptide antibodies is dependent upon peptide sequence selection, the success of peptide synthesis, peptide-carrier protein conjugation, the humoral immune response in the host animal, the adjuvant used, the peptide dose administered, the injection method, and the purification of the antibody. Peptide sequence selection is probably the most critical step in the production of antipeptide antibodies. Although the process for designing peptide antigens is not exact, several guidelines and computational B-cell epitope prediction methods can help maximize the likelihood of producing antipeptide antibodies that recognize the protein. Antibodies raised by peptides have become essential tools in life science research. Virtually all phospho-specific antibodies are now produced using phosphopeptides as antigens. Typically, 5-20 mg of peptide is enough for antipeptide antibody production. It takes 3 months to produce a polyclonal antipeptide antibody in rabbits that yields ~100 mL of serum which corresponds to ~8-10 mg of the specific antibody after affinity purification using a peptide column.

  14. Cancer testis antigen and immunotherapy

    Directory of Open Access Journals (Sweden)

    Krishnadas DK

    2013-04-01

    Full Text Available Deepa Kolaseri Krishnadas, Fanqi Bai, Kenneth G Lucas Department of Pediatrics, Division of Hematology/Oncology, University of Louisville, KY, USA Abstract: The identification of cancer testis (CT antigens has been an important advance in determining potential targets for cancer immunotherapy. Multiple previous studies have shown that CT antigen vaccines, using both peptides and dendritic cell vaccines, can elicit clinical and immunologic responses in several different tumors. This review details the expression of melanoma antigen family A, 1 (MAGE-A1, melanoma antigen family A, 3 (MAGE-A3, and New York esophageal squamous cell carcinoma-1 (NY-ESO-1 in various malignancies, and presents our current understanding of CT antigen based immunotherapy. Keywords: cancer testis antigens, immunotherapy, vaccine

  15. The Putative Natural Killer Decoy Early Gene m04 (gp34) of Murine Cytomegalovirus Encodes an Antigenic Peptide Recognized by Protective Antiviral CD8 T Cells

    OpenAIRE

    Holtappels, Rafaela; Thomas, Doris; Podlech, Jürgen; Geginat, Gernot; Steffens, Hans-Peter; Reddehase, Matthias J.

    2000-01-01

    Several early genes of murine cytomegalovirus (MCMV) encode proteins that mediate immune evasion by interference with the major histocompatibility complex class I (MHC-I) pathway of antigen presentation to cytolytic T lymphocytes (CTL). Specifically, the m152 gene product gp37/40 causes retention of MHC-I molecules in the endoplasmic reticulum (ER)-Golgi intermediate compartment. Lack of MHC-I on the cell surface should activate natural killer (NK) cells recognizing the “missing self.” The re...

  16. Vaccination with NY-ESO-1 overlapping peptides mixed with Picibanil OK-432 and montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

    Science.gov (United States)

    Wada, Hisashi; Isobe, Midori; Kakimi, Kazuhiro; Mizote, Yu; Eikawa, Shingo; Sato, Eiichi; Takigawa, Nagio; Kiura, Katsuyuki; Tsuji, Kazuhide; Iwatsuki, Keiji; Yamasaki, Makoto; Miyata, Hiroshi; Matsushita, Hirokazu; Udono, Heiichiro; Seto, Yasuyuki; Yamada, Kazuhiro; Nishikawa, Hiroyoshi; Pan, Linda; Venhaus, Ralph; Oka, Mikio; Doki, Yuichiro; Nakayama, Eiichi

    2014-01-01

    We conducted a clinical trial of an NY-ESO-1 cancer vaccine using 4 synthetic overlapping long peptides (OLP; peptides #1, 79-108; #2, 100-129; #3, 121-150; and #4, 142-173) that include a highly immunogenic region of the NY-ESO-1 molecule. Nine patients were immunized with 0.25 mg each of three 30-mer and a 32-mer long NY-ESO-1 OLP mixed with 0.2 KE Picibanil OK-432 and 1.25 mL Montanide ISA-51. The primary endpoints of this study were safety and NY-ESO-1 immune responses. Five to 18 injections of the NY-ESO-1 OLP vaccine were well tolerated. Vaccine-related adverse events observed were fever and injection site reaction (grade 1 and 2). Two patients showed stable disease after vaccination. An NY-ESO-1-specific humoral immune response was observed in all patients and an antibody against peptide #3 (121-150) was detected firstly and strongly after vaccination. NY-ESO-1 CD4 and CD8 T-cell responses were elicited in these patients and their epitopes were identified. Using a multifunctional cytokine assay, the number of single or double cytokine-producing cells was increased in NY-ESO-1-specific CD4 and CD8 T cells after vaccination. Multiple cytokine-producing cells were observed in PD-1 (-) and PD-1 (+) CD4 T cells. In conclusion, our study indicated that the NY-ESO-1 OLP vaccine mixed with Picibanil OK-432 and Montanide ISA-51 was well tolerated and elicited NY-ESO-1-specific humoral and CD4 and CD8 T-cell responses in immunized patients.

  17. Xanthogranulomatous cholecystitis mimicking gallbladder cancer.

    Science.gov (United States)

    Ewelukwa, Ofor; Ali, Omair; Akram, Salma

    2014-05-08

    Xanthogranulomatous cholecystitis (XGC) is a benign, uncommon variant of chronic cholecystitis characterised by focal or diffuse destructive inflammatory process of the gallbladder (GB). Macroscopically, it appears like yellowish tumour-like masses in the wall of the GB. This article reports on a 74-year-old woman with XGC mimicking GB cancer.

  18. Cell-penetrating peptides (CPPs): From delivery of nucleic acids and antigens to transduction of engineered nucleases for application in transgenesis.

    Science.gov (United States)

    Rádis-Baptista, Gandhi; Campelo, Iana S; Morlighem, Jean-Étienne R L; Melo, Luciana M; Freitas, Vicente J F

    2017-06-20

    Cell-penetrating peptides (CPPs) have been studied for their capacity to translocate across the lipid membrane of several cell types. In membrane translocation, these peptides can remarkably transport biologically active hydrophilic molecules, such as pharmaceuticals, nucleic acids (DNA and RNA) and even high-molecular-weight proteins, Fig. 3 into the cell cytoplasm and organelles. The development of CPPs as transduction agents includes the modification of gene and protein expression, the reprogramming and differentiation of induced pluripotent stem cells and the preparation of cellular vaccines. A relatively recent field of CPP application is the transduction of plasmid DNA vectors and CPP-fusion proteins to modify genomes and introduce new traits in cells and organisms. CPP-mediated transduction of components for genome editing is an advantageous alternative to viral DNA vectors. Engineered site-specific nucleases, such as Cre recombinase, ZFN, TALENs and CRISPR associated protein (Cas), have been coupled to CPPs, and the fused proteins have been used to permeate targeted cells and tissues. The functionally active fusion CPP-nucleases subsequently home to the nucleus, incise genomic DNA at specific sites and induce repair and recombination. This review has the objective of discussing CPPs and elucidating the prospective use of CPP-mediated transduction technology, particularly in genome modification and transgenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. A fusion protein consisting of IL-16 and the encephalitogenic peptide of myelin basic protein constitutes an antigen-specific tolerogenic vaccine that inhibits experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Mannie, Mark D; Abbott, Derek J

    2007-08-01

    To test a novel concept for the generation of tolerogenic vaccines, fusion proteins were constructed encompassing a tolerogenic or biasing cytokine and the major encephalitogenic peptide of guinea pig myelin basic protein (GPMBP; i.e., neuroantigen or NAg). The cytokine domain was predicted to condition APC while simultaneously targeting the covalently linked encephalitogenic peptide to the MHC class II Ag processing pathway of those conditioned APC. Rats were given three s.c. injections of cytokine-NAg in saline 1-2 wk apart and then at least 1 wk later were challenged with NAg in CFA. The rank order of tolerogenic activity in the Lewis rat model of EAE was NAgIL16 > IL2NAg > IL1RA-NAg, IL13NAg >or= IL10NAg, GPMBP, GP69-88, and saline. NAgIL16 was also an effective inhibitor of experimental autoimmune encephalomyelitis when administered after an encephalitogenic challenge during the onset of clinical signs. Covalent linkage of the NAg and IL-16 was required for inhibition of experimental autoimmune encephalomyelitis. These data identify IL-16 as an optimal cytokine partner for the generation of tolerogenic vaccines and indicate that such vaccines may serve as Ag-specific tolerogens for the treatment of autoimmune disease.

  20. PRDM1/BLIMP-1 modulates IFN-gamma-dependent control of the MHC class I antigen-processing and peptide-loading pathway.

    Science.gov (United States)

    Doody, Gina M; Stephenson, Sophie; McManamy, Charles; Tooze, Reuben M

    2007-12-01

    A diverse spectrum of unique peptide-MHC class I complexes guides CD8 T cell responses toward viral or stress-induced Ags. Multiple components are required to process Ag and facilitate peptide loading in the endoplasmic reticulum. IFN-gamma, a potent proinflammatory cytokine, markedly up-regulates transcription of genes involved in MHC class I assembly. Physiological mechanisms which counteract this response are poorly defined. We demonstrate that promoters of functionally linked genes on this pathway contain conserved regulatory elements that allow antagonistic regulation by IFN-gamma and the transcription factor B lymphocyte-induced maturation protein-1 (also known as PR domain-containing 1, with ZNF domain (PRDM1)). Repression of ERAP1, TAPASIN, MECL1, and LMP7 by PRDM1 results in failure to up-regulate surface MHC class I in response to IFN-gamma in human cell lines. Using the sea urchin prdm1 ortholog, we demonstrate that the capacity of PRDM1 to repress the IFN response of such promoters is evolutionarily ancient and that dependence on the precise IFN regulatory factor element sequence is highly conserved. This indicates that the functional interaction between PRDM1 and IFN-regulated pathways antedates the evolution of the adaptive immune system and the MHC, and identifies a unique role for PRDM1 as a key regulator of Ag presentation by MHC class I.

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

    Science.gov (United States)

    Nomura, Wataru; Mizuguchi, Takaaki; Tamamura, Hirokazu

    2016-11-04

    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. © 2015 Wiley Periodicals, Inc.

  2. THE THEORETICAL AND PRACTICAL ASPECTS OF THE RECOMBINANT ANTIGENS FOR THE DIAGNOSIS OF BOVINE LEUKEMIA PRODUCTION

    Directory of Open Access Journals (Sweden)

    Shapovalova OV

    2016-12-01

    sequence construction. The efficiency of BLV gp51 and p24 encoding regions fusion-sequence integration was confirmed by the screening with the specially designed oligonucleotides. The recombinant antigen expression was induced by addition of IPTG. To isolate the antigen bacterial mass was destroyed by defrostation and ultrasonic disintegration in the experimentally selected modes. The activity and specificity of the antigen was determined by AGID with the use of the bovine fetal serum, positive and negative reference diagnostic serum by unified method in comparison with the standardized cultural BLV antigen in AGID. The antigen specificity was increased by adsorption with commercial anticolibacillosis serum. The antigen activity was confirmed by AGID. Conclusions. Nowadays the most promising BLV antigens expressing genetic constructions with E. coli and baculovirus. E. coli recombinant strains are the most available and effective using expressing system, which allows to get an active and specific antigenic product if an optimal vector constructions and commercially available systems of metal affinity chromatography purification and control with appropriate Mab are used. As an cultural and recombinant antigens alternative the mimicking critical BLV antigenic epitopes synthetic peptides were tested. In recent times many scientific works formed the basis for the bovine leukemia diagnostic test systems’ creation, which are now widely available on the biotechnological products market. Although the majority of manufacturers prefer the recombinant antigens of the pathogen, pilot studies on more improved and cheaper ways to obtain different diagnostic antigens preparations shall not lose relevance.

  3. Preparation of polypeptides comprising multiple TAA peptides.

    Science.gov (United States)

    Ni, Bing; Jia, Zhengcai; Wu, Yuzhang

    2014-01-01

    Polypeptides consisting of multiple tumor-associated antigen epitopes (multiepitope peptides) are commonly used as therapeutic peptide cancer vaccines in experimental studies and clinical trials. These methods include polypeptides composed of multiple major histocompatibility complex (MHC) class I-restricted cytotoxic T cell (CTL) epitopes and those containing multiple CTL epitopes and one T helper (Th) epitope. This chapter describes a complete set of methods for preparing multiepitope peptides and branched multiple antigen peptides (MAPs), including sequence design, peptide synthesis, purification, preservation, and the preparation of polypeptide solutions.

  4. 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.

  5. Application of Antigen Cross-Presentation Research into Patient Care

    NARCIS (Netherlands)

    The activation of adaptive immune responses requires the processing and presentation of protein antigens to lymphocytes. Especially dendritic cells are effective at display of antigen-derived peptides in the form of immunogenic peptide/MHC complexes to CD4 and CD8-positive T cells, and can stimulate

  6. Comparison of bovine lymphocyte antigen DRB3.2 allele ...

    African Journals Online (AJOL)

    The bovine lymphocyte antigen (BoLA-DRB3) gene encodes cell surface glycoproteins that initiate immune responses by presenting processed antigenic peptides to CD4 T helper cells. DRB3 is the most polymorphic bovine MHC class II gene which encodes the peptide-binding groove. Since different alleles favor the ...

  7. rOv-ASP-1, a recombinant secreted protein of the helminth Onchocercavolvulus, is a potent adjuvant for inducing antibodies to ovalbumin, HIV-1 polypeptide and SARS-CoV peptide antigens.

    Science.gov (United States)

    MacDonald, Angus J; Cao, Long; He, Yuxian; Zhao, Qian; Jiang, Shibo; Lustigman, Sara

    2005-05-16

    We studied the adjuvanticity of recombinant Onchocerca volvulus activation associated protein-1 (rOv-ASP-1) for ovalbumin (OVA) in mice. After a single immunization and one boost, rOv-ASP-1 exceeded the efficacy of alum or MPL + TDM adjuvants in terms of end-point total IgG or IgG1 and IgG2a anti-OVA titres. Using the helminth-derived adjuvant, IgG isotype responses to OVA were of a mixed Th1/Th2 profile and spleen cell cytokines exclusively Th1-type. The potent adjuvanticity of rOv-ASP-1 was confirmed in mice vaccinated with a 37-mer peptide from the S protein of SARS-CoV and an HIV-1 gp120-CD4 chimeric polypeptide antigen. Unusually for a helminth product, the rOv-ASP-1 adjuvant augmented not only Th2 but also Th1 responses, the latter property being of potential utility in stimulating anti-viral immune responses.

  8. Filamentous bacteriophage fd as an antigen delivery system in vaccination.

    Science.gov (United States)

    Prisco, Antonella; De Berardinis, Piergiuseppe

    2012-01-01

    Peptides displayed on the surface of filamentous bacteriophage fd are able to induce humoral as well as cell-mediated immune responses, which makes phage particles an attractive antigen delivery system to design new vaccines. The immune response induced by phage-displayed peptides can be enhanced by targeting phage particles to the professional antigen presenting cells, utilizing a single-chain antibody fragment that binds dendritic cell receptor DEC-205. Here, we review recent advances in the use of filamentous phage fd as a platform for peptide vaccines, with a special focus on the use of phage fd as an antigen delivery platform for peptide vaccines in Alzheimer's Disease and cancer.

  9. Carbohydrate Mimicking Peptides as Inhibitors of Angiogenesis and Metastasis

    Science.gov (United States)

    1998-06-01

    leukocyte trafficking, thrombosis , acute and chronic inflammation and ischemia reperfusion injury (5-7). Selectins support the adhesion of leukocytes to...in lung, liver and mesenteric lymph nodes, and died much faster than wild-type animals (28). These data imply that similar molecular mechanisms do

  10. Propionic acidemia mimicking diabetic ketoacidosis.

    Science.gov (United States)

    Dweikat, Imad M; Naser, Enas N; Abu Libdeh, Abdulsalam I; Naser, Osama J; Abu Gharbieh, Najwan N; Maraqa, Nizar F; Abu Libdeh, Bassam Y

    2011-05-01

    Propionic acidemia manifesting with hyperglycemia is rare. Few cases have been reported mainly of the neonatal-onset form associated with high mortality. We report a 9-month-old Palestinian boy who manifested with coma, severe hyperglycemia and ketoacidosis mimicking diabetic ketoacidosis. Family history of unexplained infant deaths was helpful in reaching the correct diagnosis. In response to therapy, the patient regained consciousness without neurologic deficits and had normal examination. This is, to our knowledge, the first case report of late-onset propionic acidemia that had this presentation and survived. Copyright © 2010 The Japanese Society of Child Neurology. All rights reserved.

  11. Histoplasmosis mimicking metastatic spinal tumour.

    Science.gov (United States)

    Liu, Bing; Qu, Liyan; Zhu, Jian; Yang, Zhengming; Yan, Shigui

    2017-08-01

    Histoplasmosis is an infection caused by a fungus called Histoplasma. Diagnosis of histoplasmosis is based on the culture of biological samples and detection of fungus in tissues. Histoplasmosis can mimic malignant lesions. We report a 65-year-old, immunocompetent, male patient with back pain. We describe the main clinical and radiological characteristics in our patient who had vertebral histoplasmosis that mimicked cancer. A computed tomography scan showed lytic lesions of the right side of T4, T5, and T6 vertebral bodies. Magnetic resonance imaging displayed abnormal marrow signals in T4, T5, and T6 vertebral bodies (low signal on T1, high on T2 and short time inversion recovery (STIR)). Which was mimicking malignancy, such as haematological malignancy and metastatic bone cancer. Therefore, thoracic spinal surgery using the anterior approach was performed. An intraoperative frozen section examination and routine postoperative pathology showed thoracic histoplasmosis infection. Treatment of histoplasmosis was performed with oral itraconazole. The lesions did not progress and the patient symptomatically improved at a follow-up of 26 months.

  12. 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...

  13. Peptide Vaccine Against Paracoccidioidomycosis.

    Science.gov (United States)

    Taborda, Carlos P; Travassos, Luiz R

    2017-01-01

    The chapter reviews methods utilized for the isolation and characterization of a promising immunogen candidate, aiming at a human vaccine against paracoccidioidomycosis. Peptide P10 carries a T-CD4+ epitope and was identified as an internal sequence of the major diagnostic antigen known as gp43 glycoprotein. It successfully treated massive intratracheal infections by virulent Paracoccidioides brasiliensis in combination with chemotherapy.An introduction about the systemic mycosis was found essential to understand the various options that were considered to design prophylactic and therapeutic vaccine protocols using peptide P10.

  14. The interaction of beta 2-microglobulin (beta 2m) with mouse class I major histocompatibility antigens and its ability to support peptide binding. A comparison of human and mouse beta 2m

    DEFF Research Database (Denmark)

    Pedersen, L O; Stryhn, A; Holter, T L

    1995-01-01

    The function of major histocompatibility complex (MHC) class I molecules is to sample peptides derived from intracellular proteins and to present these peptides to CD8+ cytotoxic T lymphocytes. In this paper, biochemical assays addressing MHC class I binding of both peptide and beta 2-microglobul...

  15. 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...... not seem to increase the end point titre as tested in direct ELISA. The specificity of the antiserum was determined by competitive ELISA and histochemistry on pancreas sections. Only the synthetic C-peptide 2, but not the homologous synthetic C-peptide 1 from mouse and rat competed efficiently in ELISA...... for antibody binding to the immunizing antigen. Antisera to C-peptide 2, stained islet beta-cells on mouse and rat, but not monkey pancreas sections in immunocytochemical analysis. Preabsorption to the synthetic C-peptide 2, but not the synthetic mouse and rat C-peptide 1 abolished staining. In conclusion we...

  16. Herpes viral proteins manipulating the peptide transporter TAP

    NARCIS (Netherlands)

    Reits, E.; Griekspoor, A.; Neefjes, J.

    2002-01-01

    The peptide transporter associated with antigen processing (TAP) is crucial for class I-restricted antigen presentation because it transfers cytosolic peptides into the endoplasmic reticulum (ER) lumen for class I binding. It is therefore not surprising that TAP is targeted for inactivation by many

  17. Granulomatous prostatitis after intravesical immunotherapy mimicking prostate cancer

    Directory of Open Access Journals (Sweden)

    Waldemar Białek

    2016-12-01

    Full Text Available Intravesical immunotherapy with attenuated strains of Mycobacterium bovis is a widely used therapeutic option in patients with non-muscle-invasive transitional cell carcinoma of the bladder. A rare complication of intravesical therapy with the Bacillus Calmette-Guérin vaccine is granulomatous prostatitis, which due to increasing levels of prostate-specific antigen and abnormalities found in transrectal examination of the prostate may suggest concomitant prostate cancer. A case of extensive granulomatous prostatitis in a 61-year-old patient which occurred after the first course of a well-tolerated Bacillus Calmette-Guérin therapy is presented. Due to abnormalities found in rectal examination and an abnormal transrectal ultrasound image of the prostate with extensive infiltration mimicking neoplastic hyperplasia a core biopsy of the prostate was performed. Histopathological examination revealed inflammatory infiltration sites of tuberculosis origin.

  18. Hyaluronidase allergy mimicking orbital cellulitis.

    Science.gov (United States)

    Raichura, Nirav D; Alam, Md Shahid; Jaichandran, V V; Mistry, Saurabh; Mukherjee, Bipasha

    2017-10-20

    Hyaluronidase enzyme is a common additive with local anesthetic agent to facilitate faster permeation of the anesthetic in periocular tissues during ophthalmic surgery. We report a series of five subjects presenting with clinical features mimicking orbital cellulitis following peribulbar anesthesia and consequently diagnosed with hyaluronidase hypersensitivity. The study was conducted at a tertiary eye care center in Southern India. It was a retrospective interventional case series. We retrospectively reviewed the case records of patients diagnosed as and treated for hyaluronidase allergy from 2011 to 2015. The presenting features included periocular edema, proptosis, and restriction of ocular movements. The symptoms appeared immediately after the injection to as late as 6 days after the surgery. All patients underwent comprehensive ophthalmic evaluation, relevant investigations, and dermal allergy tests. All five patients tested positive for hyaluronidase. Patients were treated with antihistaminics, systemic steroids, and emergency orbital decompression, when required. In majority of the patients, symptoms resolved in 3-5 days. Clinically, hyaluronidase allergy may mimic orbital cellulitis, which in the context of a recent intraocular surgery may be alarming for both the patient and the surgeon. However, with prompt intervention, the prognosis is extremely favorable in cases of hyaluronidase allergy. It is important for ophthalmic surgeons and anesthetists to recognize and differentiate this entity from the more serious vision threatening conditions.

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

    NARCIS (Netherlands)

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

    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

  20. Synthetic peptides for diagnostic use

    NARCIS (Netherlands)

    Meloen, R.H.; Langedijk, J.P.M.; Langeveld, J.P.M.

    1997-01-01

    Synthetic peptides representing relevant B-cell epitopes are, potentially, ideal antigens to be used in diagnostic assays because of their superior properties with respect to quality control as compared to those of biologically derived molecules and the much higher specificity that sometimes can be

  1. Study of the antigenic cross reactivity between carcinoembryonic antigen and "nonspecific cross reacting antigens" (NCA and NCA 2).

    Science.gov (United States)

    Neveu, T.; Staebler, D.; Chavanel, G.; Burtin, P.

    1975-01-01

    The immunochemical relationship between CEA, NCA and NCA 2 was studied in guinea-pigs. Strong cross reactions were found between these antigens, either in delayed or anaphylactic reactions. Some specific determinants for each antigen could still be demonstrated. Delayed hypersensitivity is likely to be due to the protein moiety of the molecules while anaphylactic reactivity could probably be related to their glucidic parts. Consequently, CEA and NCA have common antigenic determinants on their glucidic and peptidic moieties, perhaps more on the latter ones. PMID:50854

  2. Primary Hepatic Lymphoma Mimicking Cholangiocarcinoma

    Directory of Open Access Journals (Sweden)

    Foroogh Forghani1,

    2017-07-01

    Full Text Available Primary hepatic lymphoma (PHL presenting with obstructive jaundice is rare and can mimic a preoperative diagnosis of cholangiocarcinoma. We should consider PHL in patients with radiological hepatic disease with normal serum alpha-fetoprotein and carcinoembryonic antigen levels, and elevated lactate dehydrogenase. We present the case of a 67-year-old male with no significant medical history presented with abdominal pain, jaundice, fever, and abnormal liver function tests. Abdominal sonography and computed tomography scan suggested a diagnosis of obstructive jaundice and cholangitis due to cholangiocarcinoma (Klatskin tumor. A subsequent liver biopsy diagnosed PHL, and the patient was treated with combination chemotherapy, including rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP. PHL should be considered in patients presenting with biliary obstruction.

  3. Set Theory Applied to the Mathematical Characterization of HLA Class II Binding Peptides

    Directory of Open Access Journals (Sweden)

    Javier Rodríguez Velásquez, MD, esp.1

    2008-04-01

    Full Text Available Antigen presentation contains the molecularbasis for antigenic identification and immuneresponses. The set theory and experimental datawere used in order to develop an union core regionmathematic characterization through the definitionof 8 laws associated to HLA class II binding.The laws were applied to 4 promiscuous peptides,25 natural peptides sequences of core region: 13binding peptides and 12 no binding peptides; and19 synthetic peptides looking to differentiate peptides.Only one peptide was not rightly characterized.This methodology may be used to choose keypeptides in the development of vaccine.

  4. Identification and Characterization of Ovarian Carcinoma Peptide Epitopes Recognized by Cylotoxic T Lymphocytes

    Science.gov (United States)

    2008-11-01

    cell line CEA Carcinoembryonic antigen CTL Cytotoxic T lymphocyte Ck Cytokeratin FBP Folate binding protein FBS Fetal bovine serum GAPDH Glyceraldehyde-3...MHC molecules, and for their expres- sion of the tumor antigens carcinoembryonic antigen (CEA), FBP, Her-2/neu, MAGE-A1, MAGE-A2, MAGE- A3, MAGE-A4... carcinoembryonic antigen .27 We have applied that approach to the cancer/testis antigen TAG and have attempted to identify new peptide antigens presented

  5. Class II-associated invariant chain peptide expression on myeloid leukemic blasts predicts poor clinical outcome.

    NARCIS (Netherlands)

    Chamuleau, M.E.D.; Souwer, Y; Ham, van S.M.; Zevenbergen, A.; Westers, T.M.; Berkhof, J.; Meijer, C.J.L.M.; Loosdrecht, van de A.A.; Ossenkoppele, G.J.

    2004-01-01

    Effective antitumor responses need the activation of CD4+ T cells. MHC class II antigen presentation requires the release of class II-associated invariant chain peptide (CLIP) from the antigen-binding site. In antigen-presenting cells, human leukocyte antigen DM (HLA-DM; abbreviated DM in this

  6. A phase I study of vaccination with NY-ESO-1f peptide mixed with Picibanil OK-432 and Montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

    Science.gov (United States)

    Kakimi, Kazuhiro; Isobe, Midori; Uenaka, Akiko; Wada, Hisashi; Sato, Eiichi; Doki, Yuichiro; Nakajima, Jun; Seto, Yasuyuki; Yamatsuji, Tomoki; Naomoto, Yoshio; Shiraishi, Kenshiro; Takigawa, Nagio; Kiura, Katsuyuki; Tsuji, Kazuhide; Iwatsuki, Keiji; Oka, Mikio; Pan, Linda; Hoffman, Eric W; Old, Lloyd J; Nakayama, Eiichi

    2011-12-15

    We conducted a phase I clinical trial of a cancer vaccine using a 20-mer NY-ESO-1f peptide (NY-ESO-1 91-110) that includes multiple epitopes recognized by antibodies, and CD4 and CD8 T cells. Ten patients were immunized with 600 μg of NY-ESO-1f peptide mixed with 0.2 KE Picibanil OK-432 and 1.25 ml Montanide ISA-51. Primary end points of the study were safety and immune response. Subcutaneous injection of the NY-ESO-1f peptide vaccine was well tolerated. Vaccine-related adverse events observed were fever (Grade 1), injection-site reaction (Grade 1 or 2) and induration (Grade 2). Vaccination with the NY-ESO-1f peptide resulted in an increase or induction of NY-ESO-1 antibody responses in nine of ten patients. The sera reacted with recombinant NY-ESO-1 whole protein as well as the NY-ESO-1f peptide. An increase in CD4 and CD8 T cell responses was observed in nine of ten patients. Vaccine-induced CD4 and CD8 T cells responded to NY-ESO-1 91-108 in all patients with various HLA types with a less frequent response to neighboring peptides. The findings indicate that the 20-mer NY-ESO-1f peptide includes multiple epitopes recognized by CD4 and CD8 T cells with distinct specificity. Of ten patients, two with lung cancer and one with esophageal cancer showed stable disease. Our study shows that the NY-ESO-1f peptide vaccine was well tolerated and elicited humoral, CD4 and CD8 T cell responses in immunized patients. Copyright © 2011 UICC.

  7. 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.

    2015-01-01

    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, 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 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 dendritic cells. 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 antigen presenting cells and provide foundational information for the rational design of targeted nanovaccines against HIV-1. PMID:25068589

  8. HLA-DO is a negative modulator of HLA-DM-mediated MHC class II peptide loading

    NARCIS (Netherlands)

    van Ham, S. M.; Tjin, E. P.; Lillemeier, B. F.; Grüneberg, U.; van Meijgaarden, K. E.; Pastoors, L.; Verwoerd, D.; Tulp, A.; Canas, B.; Rahman, D.; Ottenhoff, T. H.; Pappin, D. J.; Trowsdale, J.; Neefjes, J.

    1997-01-01

    Class II molecules of the major histocompatibility complex become loaded with antigenic peptides after dissociation of invariant chainderived peptides (CLIP) from the peptide-binding groove. The human leukocyte antigen (HLA)-DM is a prerequisite for this process, which takes place in specialised

  9. Identification of an immunodominant epitope in glycoproteins B and G of herpes simplex viruses (HSVs) using synthetic peptides as antigens in assay of antibodies to HSV in herpes simplex encephalitis patients.

    Science.gov (United States)

    Bhullar, S S; Chandak, N H; Baheti, N N; Purohit, H J; Taori, G M; Daginawala, H F; Kashyap, R S

    2014-01-01

    Herpes simplex encephalitis (HSE) is a severe viral infection of the central nervous system (CNS). Assay of antibody response is widely used in diagnostics of HSE. The aim of this study was to identify an immunodominant epitope determining the antibody response to herpes simplex viruses (HSVs) in cerebrospinal fluid (CSF) of HSE patients. The synthetic peptides that resembled type-common as well as type-specific domains of glycoproteins B (gB) and G (gG) of these viruses were evaluated for binding with IgM and IgG antibodies in CSF samples from HSE and non-HSE patients in ELISA. The QLHDLRF peptide, derived from gB of HSV was found to be an immunodominant epitope in the IgM and IgG antibody response. The patients with confirmed and suspected HSE showed in ELISA against this peptide 26% and 23% positivities for IgM, 43% and 37% positivities for IgG and 17% and 15% for both IgM and IgG antibodies, respectively. The total positivities of 86% and 75% for both IgM and IgG antibodies were obtained in the patients with confirmed and suspected HSE, respectively. These results demonstrate that a synthetic peptide-based diagnostics of HSE can be an efficient and easily accessible alternative. This is the first report describing the use of synthetic peptides derived from HSVs in diagnostics of HSE using patientsʹ CSF samples.

  10. Isolated ovarian tuberculosis mimicking ovarian carcinoma: Case ...

    African Journals Online (AJOL)

    Although genitourinary tuberculosis is common, reports of isolated ovarian tuberculosis are rare. However, its presentation can mimick that of an ovarian tumour, leading to diagnostic difficulties. A woman of 17 years presented with chronic pelvic pain, weight loss, a right ovarian mass on ultrasound, and a significantly ...

  11. Uncomplicated bifid Meckle's diverticulum mimicking recurrent ...

    African Journals Online (AJOL)

    It was excised with V shaped ileal wall. Histopathology showed features of Meckel's diverticulum without any Gastric or pancreatic tissue in mucosa. Clinicians should be wary of a bifid meckel's diverticulum as a very rare anomaly that can be symptomatic mimicking appendicitis. Keywords: Bifid, Meckel's, Diverticulitis ...

  12. Right paratesticular abscess mimicking neonatal testicular torsion ...

    African Journals Online (AJOL)

    U.O. Ezomike

    Right paratesticular abscess mimicking neonatal testicular torsion and caused by Proteus mirabilis. U.O. Ezomikea,∗. , M.A. Ituena, S.C. Ekpemoa, S.O. Ekenzeb a Department of Surgery, Federal Medical Centre Umuahia, Abia State, Nigeria b Sub-Department of Pediatric Surgery, University of Nigeria Teaching Hospital, ...

  13. Acute dystonia mimicking angioedema of the tongue

    DEFF Research Database (Denmark)

    Rasmussen, Eva Rye; Pallesen, Kristine A U; Bygum, Anette

    2013-01-01

    We report a case of acute dystonia of the face, jaw and tongue caused by metoclopramide and mimicking angioedema. The patient had attacks for several years before the correct diagnosis was made and we present the first ever published video footage of an attack. This adverse drug reaction is known...

  14. 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.)

  15. Iliacus Abscess with Radiculopathy Mimicking Herniated Nucleus ...

    African Journals Online (AJOL)

    2016-05-02

    May 2, 2016 ... radiculopathy mimicking herniated nucleus pulposus: Aadditional diagnostic value of magnetic resonance imaging. Niger J Clin Pract. 2017;20:392-3. This is an open access article distributed under the terms of the Creative Commons. Attribution-Non Commercial-Share Alike 3.0 License, which allows ...

  16. Characterization of a single peptide derived from cytochrome P4501B1 that elicits spontaneous human leukocyte antigen (HLA)-A1 as well as HLA-B35 restricted CD8 T-cell responses in cancer patients

    DEFF Research Database (Denmark)

    Kvistborg, P.; Hadrup, S.R.; Andersen, M.H.

    2008-01-01

    Cytochrome P450 1B1 (CYP1B1) is widely expressed in human malignancies, but silent in most normal tissues. Importantly, the protein is believed to play an important role in the survival and growth of cancer cells in a stressed environment, e.g., as a result of hypoxia or chemotherapy. Thus......, targeting of CYP1B1 represents a potentially successful strategy in the treatment of metastatic cancer, e.g., by therapeutic vaccination. Herein, we describe the characterization of a novel peptide from the CYP1B1 protein (CYP240), which is spontaneously recognized by CD8 T cells in cancer patients....... Rare but strong responses were detected in HLA-A1-positive patients, and more frequent responses were detected in HLA-B35-positive patients. No reactivity against the peptide could be detected in healthy donors. Furthermore, we demonstrated that peptide-specific T cells were able to lyze target cells...

  17. A Conserved Epitope Mapped with a Monoclonal Antibody against the VP3 Protein of Goose Parvovirus by Using Peptide Screening and Phage Display Approaches.

    Science.gov (United States)

    Li, Chenxi; Liu, Hongyu; Li, Jinzhe; Liu, Dafei; Meng, Runze; Zhang, Qingshan; Shaozhou, Wulin; Bai, Xiaofei; Zhang, Tingting; Liu, Ming; Zhang, Yun

    2016-01-01

    Waterfowl parvovirus (WPV) infection causes high mortality and morbidity in both geese (Anser anser) and Muscovy ducks (Cairina moschata), resulting in significant losses to the waterfowl industries. The VP3 protein of WPV is a major structural protein that induces neutralizing antibodies in the waterfowl. However, B-cell epitopes on the VP3 protein of WPV have not been characterized. To understand the antigenic determinants of the VP3 protein, we used the monoclonal antibody (mAb) 4A6 to screen a set of eight partially expressed overlapping peptides spanning VP3. Using western blotting and an enzyme-linked immunosorbent assay (ELISA), we localized the VP3 epitope between amino acids (aa) 57 and 112. To identify the essential epitope residues, a phage library displaying 12-mer random peptides was screened with mAb 4A6. Phage clone peptides displayed a consensus sequence of YxRFHxH that mimicked the sequence 82Y/FNRFHCH88, which corresponded to amino acid residues 82 to 88 of VP3 protein of WPVs. mAb 4A6 binding to biotinylated fragments corresponding to amino acid residues 82 to 88 of the VP3 protein verified that the 82FxRFHxH88 was the VP3 epitope and that amino acids 82F is necessary to retain maximal binding to mAb 4A6. Parvovirus-positive goose and duck sera reacted with the epitope peptide by dot blotting assay, revealing the importance of these amino acids of the epitope in antibody-epitope binding reactivity. We identified the motif FxRFHxH as a VP3-specific B-cell epitope that is recognized by the neutralizing mAb 4A6. This finding might be valuable in understanding of the antigenic topology of VP3 of WPV.

  18. A Conserved Epitope Mapped with a Monoclonal Antibody against the VP3 Protein of Goose Parvovirus by Using Peptide Screening and Phage Display Approaches.

    Directory of Open Access Journals (Sweden)

    Chenxi Li

    Full Text Available Waterfowl parvovirus (WPV infection causes high mortality and morbidity in both geese (Anser anser and Muscovy ducks (Cairina moschata, resulting in significant losses to the waterfowl industries. The VP3 protein of WPV is a major structural protein that induces neutralizing antibodies in the waterfowl. However, B-cell epitopes on the VP3 protein of WPV have not been characterized.To understand the antigenic determinants of the VP3 protein, we used the monoclonal antibody (mAb 4A6 to screen a set of eight partially expressed overlapping peptides spanning VP3. Using western blotting and an enzyme-linked immunosorbent assay (ELISA, we localized the VP3 epitope between amino acids (aa 57 and 112. To identify the essential epitope residues, a phage library displaying 12-mer random peptides was screened with mAb 4A6. Phage clone peptides displayed a consensus sequence of YxRFHxH that mimicked the sequence 82Y/FNRFHCH88, which corresponded to amino acid residues 82 to 88 of VP3 protein of WPVs. mAb 4A6 binding to biotinylated fragments corresponding to amino acid residues 82 to 88 of the VP3 protein verified that the 82FxRFHxH88 was the VP3 epitope and that amino acids 82F is necessary to retain maximal binding to mAb 4A6. Parvovirus-positive goose and duck sera reacted with the epitope peptide by dot blotting assay, revealing the importance of these amino acids of the epitope in antibody-epitope binding reactivity.We identified the motif FxRFHxH as a VP3-specific B-cell epitope that is recognized by the neutralizing mAb 4A6. This finding might be valuable in understanding of the antigenic topology of VP3 of WPV.

  19. 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.

  20. Carcinoma-associated antigens

    International Nuclear Information System (INIS)

    Bartorelli, A.; Accinni, R.

    1981-01-01

    This invention relates to novel antigens associated with breast carcinoma, anti-sera specific to said antigens, 125 I-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)

  1. Identification of MHC class I H-2 Kb/Db-restricted immunogenic peptides derived from retinal proteins

    DEFF Research Database (Denmark)

    Wang, Mingjun; Bai, Fang; Pries, Mette

    2006-01-01

    -antigen), recoverin, phosducin, and pigment epithelium-derived factor (PEDF). The affinity of the peptides was analyzed by their abilities to upregulate the expression of major histocompatibility complex (MHC) class I on TAP-deficient cells (RMA-S cells) with flow cytometry. C57BL/6 mice were immunized subcutaneously......-397, PEDF139-147, and PEDF272-279, induced specific CTL responses in vivo, whereas the remaining 16 peptides, including 5 IRBP-derived peptides, 5 S-antigen-derived peptides, 1 recoverin-derived peptide, 1 phosducin-derived peptide, and 4 PEDF-derived peptides, did not induce specific CTL reactivity...

  2. ANTIGENIC PROMOTION

    Science.gov (United States)

    Wu, Chin-Yu; Cinader, Bernard

    1971-01-01

    Rabbits were immunized with p-azobenzene arsonic acid derivatives of human serum albumin (HA-As) or of dissociated keyhole limpet hemocyanin. The IgM response to the hapten was evaluated in terms of the number of hapten-specific plaque-forming cells in the lymph node draining the injection site. In some experiments, antibody was measured by agglutination of tanned and sensitized erythrocytes. The hapten response of animals immunized with HA-As was increased (promoting effect) when the animals were injected with one of several structurally unrelated macromolecules: keyhole limpet hemocyanin (KLH), horse spleen ferritin (HSF), lysozyme (Lys), alum-precipitated human gamma globulin (alum-precipitated HGG). Different macromolecules differed in the magnitude of the promoting effect they induced, e.g., promotion by the associated form of KLH was greater than that by the dissociated form; alum-precipitated HGG was a better promoter than was soluble HGG. The relative magnitude of promotion by different macromolecules (associated vs. dissociated KLH, alum-precipitated vs. soluble HGG) correlated with the relative magnitude of the carrier effect, as judged by the hapten response induced by p-azobenzene arsonic acid conjugated to various proteins. Promotion was detected by agglutination assay of circulating antibody, by plaque assay of cells from the popliteal lymph node draining the site of preinjection, but not by plaque assay of cells from the contralateral lymph node. Promotion was dependent on the dose of the promoting macromolecule and on the dose of the hapten-protein conjugate. It was not observed in animals tolerant to the promoting macromolecule. Inhibition (i.e. antigenic competition), rather than promotion, was observed upon a secondary response to the preinjected macromolecule or when the hapten-protein conjugate was incorporated in Freund's adjuvant. PMID:15776570

  3. Intracranial capillary hemangioma mimicking a dissociative disorder

    Directory of Open Access Journals (Sweden)

    Alexander Lacasse

    2012-01-01

    Full Text Available Capillary hemangiomas, hamartomatous proliferation of vascular endothelial cells, are rare in the central nervous system (CNS. Intracranial capillary hemangiomas presenting with reversible behavioral abnormalities and focal neurological deficits have rarely been reported. We report a case of CNS capillary hemangioma presenting with transient focal neurological deficits and behavioral abnormalities mimicking Ganser’s syndrome. Patient underwent total excision of the vascular malformation, resulting in complete resolution of his symptoms.

  4. Giant chondroid syringoma radiologically mimicking malignancy

    Directory of Open Access Journals (Sweden)

    Belkiz Uyar

    2013-01-01

    Full Text Available Chondroid syringoma, or mixed tumor of skin, is a relatively rare, usually benign sweat gland tumor, most often seen in the head-and-neck region. Rare malignant examples have been reported, commonly involving the extremities. We report here a case radiologically mimicking a malignant neoplasm, but histologically-proven benign subcutaneous chondroid syringoma, arising in the anterior aspect of the upper thigh of a 59-year-old male.

  5. Hydroxychloroquine-Associated Hyperpigmentation Mimicking Elder Abuse

    OpenAIRE

    Cohen, Philip R.

    2013-01-01

    Background Hydroxychloroquine may result in cutaneous dyschromia. Older individuals who are the victims of elder abuse can present with bruising and resolving ecchymoses. Purpose The features of hydroxychloroquine-associated hyperpigmentation are described, the mucosal and skin manifestations of elder abuse are reviewed, and the mucocutaneous mimickers of elder abuse are summarized. Case Report An elderly woman being treated with hydroxychloroquine for systemic lupus erythematosus developed d...

  6. Photochromic crystalline systems mimicking bio-functions.

    Science.gov (United States)

    Uchida, Kingo; Nishimura, Ryo; Hatano, Eri; Mayama, Hiroyuki; Yokojima, Satoshi

    2018-01-31

    Photoresponsive crystalline systems mimicking bio-functions are prepared using photochromic diarylethenes. Upon UV irradiation to a diarylethene crystal, the self-aggregated and needle-shaped crystals of photogenerated colored closed-ring isomer were generated on the surface. The rough surface showed the superhydrophobic lotus effect. By controlling the heating procedures, UV irradiation processes, and molecular structural modification, rose-petal effects of wetting, anti-reflective moth eye effect, and double-roughness structure mimicking the surface of lotus leaf were observed. By changing the molecular structure, superhydrophilic surface mimicking snail shell was photogenerated. We also found a derivative to form hollow crystals by sublimation. The crystals showed photosalient effect and the photo-response similar to impatiens was observed after small beads were packed in the hollow. These photoresponsive functions are unique, and they demonstrate a macroscopic response by assembling microscopic molecular movement of light. In the future, such a molecular assembly system will be a promising candidate for fabricating photoresponsive architectures and soft robots. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. TAPBPR alters MHC class I peptide presentation by functioning as a peptide exchange catalyst

    Science.gov (United States)

    Hermann, Clemens; van Hateren, Andy; Trautwein, Nico; Neerincx, Andreas; Duriez, Patrick J; Stevanović, Stefan; Trowsdale, John; Deane, Janet E; Elliott, Tim; Boyle, Louise H

    2015-01-01

    Our understanding of the antigen presentation pathway has recently been enhanced with the identification that the tapasin-related protein TAPBPR is a second major histocompatibility complex (MHC) class I-specific chaperone. We sought to determine whether, like tapasin, TAPBPR can also influence MHC class I peptide selection by functioning as a peptide exchange catalyst. We show that TAPBPR can catalyse the dissociation of peptides from peptide-MHC I complexes, enhance the loading of peptide-receptive MHC I molecules, and discriminate between peptides based on affinity in vitro. In cells, the depletion of TAPBPR increased the diversity of peptides presented on MHC I molecules, suggesting that TAPBPR is involved in restricting peptide presentation. Our results suggest TAPBPR binds to MHC I in a peptide-receptive state and, like tapasin, works to enhance peptide optimisation. It is now clear there are two MHC class I specific peptide editors, tapasin and TAPBPR, intimately involved in controlling peptide presentation to the immune system. DOI: http://dx.doi.org/10.7554/eLife.09617.001 PMID:26439010

  8. TAPBPR alters MHC class I peptide presentation by functioning as a peptide exchange catalyst.

    Science.gov (United States)

    Hermann, Clemens; van Hateren, Andy; Trautwein, Nico; Neerincx, Andreas; Duriez, Patrick J; Stevanović, Stefan; Trowsdale, John; Deane, Janet E; Elliott, Tim; Boyle, Louise H

    2015-10-06

    Our understanding of the antigen presentation pathway has recently been enhanced with the identification that the tapasin-related protein TAPBPR is a second major histocompatibility complex (MHC) class I-specific chaperone. We sought to determine whether, like tapasin, TAPBPR can also influence MHC class I peptide selection by functioning as a peptide exchange catalyst. We show that TAPBPR can catalyse the dissociation of peptides from peptide-MHC I complexes, enhance the loading of peptide-receptive MHC I molecules, and discriminate between peptides based on affinity in vitro. In cells, the depletion of TAPBPR increased the diversity of peptides presented on MHC I molecules, suggesting that TAPBPR is involved in restricting peptide presentation. Our results suggest TAPBPR binds to MHC I in a peptide-receptive state and, like tapasin, works to enhance peptide optimisation. It is now clear there are two MHC class I specific peptide editors, tapasin and TAPBPR, intimately involved in controlling peptide presentation to the immune system.

  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

    2016-06-13

    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.

  10. Liposome-based synthetic long peptide vaccines for cancer immunotherapy

    NARCIS (Netherlands)

    Varypataki, E.M.

    2016-01-01

    Synthetic long peptides (SLP) derived from cancer-associated antigens hold great promise as well-defined antigens for cancer immunotherapy. Clinical studies showed that SLP vaccines have functional potency when applied to pre-malignant stage patients, but need to be improved for use as a therapeutic

  11. Nucleic Acid Backbone Structure Variations: Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    Nielsen, Peter E.

    2010-01-01

    Synthetic analogues and mimics of the natural genetic material deoxyribonucleic acid (DNA) are potential gene therapeutic (antisense or antigene) drugs. One of these mimics, peptide nucleic acids (PNAs), are chemically closer to peptides and proteins than to DNA, but nonetheless have retained many...

  12. Peptide-MHC class I stability is a stronger predictor of CTL immunogenicity than peptide affinity

    DEFF Research Database (Denmark)

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

    2012-01-01

    of antigen processing and presentation in defining cytotoxic T lymphocyte (CTL) immunogenicity Assarsson et al., 2007. Using an affinity-balanced approach, we demonstrated that immunogenic peptides tend to be more stably bound to MHC-I molecules compared with non-immunogenic peptides. We also developed......Peptide-MHC class I stability is a stronger predictor of CTL immunogenicity than peptide affinity Mikkel Harndahla, Michael Rasmussena, Morten Nielsenb, Soren Buusa,∗ a Laboratory of Experimental Immunology, Faculty of Health Sciences, University of Copenhagen, Denmark b Center for Biological...... Sequence Analysis, Department of Systems Biology, Technical University of Denmark, Denmark Efficient presentation of peptide-MHC class I (pMHC-I) complexes to immune T cells should benefit from a stable peptide- MHC-I interaction. However, it has been difficult to distinguish stability from other...

  13. Unusual presentation of chondroblastoma mimicking Trevor's disease

    Directory of Open Access Journals (Sweden)

    Y Karkhur

    2017-01-01

    Full Text Available Chondroblastoma is a benign bone tumor, represents 1%–2% of all primary bone tumors, typically seen in patients 10–25-year-old and more common in males. It occurs most frequently in the distal femur, proximal tibia, and proximal humerus. Soft tissue extension is extremely rare. Adjacent joints may develop effusions, but the tumor mass protruding into the joint has never been seen in case of chondroblastoma. We report a rare case of intra-articular chondroblastoma arising from proximal tibia in a 16-year-old boy and growing into the knee joint mimicking an intra-articular osteochondroma.

  14. Acute Myelogenous Leukemia Mimicking Fulminant Periorbital Cellulitis

    Directory of Open Access Journals (Sweden)

    Abbas Bagheri

    2013-01-01

    Full Text Available Purpose: To report a patient who was referred for orbital cellulitis but was finally diagnosed with acute leukemia. Case Report: A 17-year-old boy presented with fever, periorbital erythema and swelling mimicking periorbital cellulitis. He underwent empiric antibiotic therapy. Complete blood counts revealed leukocytosis with a predominance of immature blast cells. Bone marrow aspiration confirmed the diagnosis of acute myelogenous leukemia. Chemotherapy was initiated resulting in resolution of signs and symptoms. Conclusion: Acute leukemia may mimic periorbital cellulitis and must be considered in the differential diagnosis.

  15. Central skeletal sarcoidosis mimicking metastatic disease

    International Nuclear Information System (INIS)

    Talmi, Danit; Smith, Stacy; Mulligan, Michael E.

    2008-01-01

    Sarcoidosis is a systemic disease that histologically typically shows non-caseating granulomas. The most common radiologic finding is hilar and mediastinal adenopathy. Patients with widely disseminated disease may show involvement of the peripheral appendicular skeleton in 1-13% of such cases. A primary skeletal presentation without other manifestations typical of the disease is rare. We present a case of sarcoidosis in a middle-aged Caucasian man in whom the disease presented with widespread lytic lesions in the axial skeleton and long bones, mimicking metastatic disease. There was no involvement of the peripheral skeleton, skin or lungs. (orig.)

  16. Pigmented poroid neoplasm mimicking nodular melanoma.

    Science.gov (United States)

    Mitsuishi, Tsuyoshi; Ansai, Shin-ichi; Ueno, Takashi; Kawana, Seiji

    2010-06-01

    We reported the case of a 92-year-old woman with a pigmented and non-pigmented surface of the pedunculated nodule on her lower leg. Microscopic examination revealed that this nodule consisted of a component of small, dark, homogenous, poroid cells and cuticular cells in the dermis. The histopathological features of the lesion were consistent with poroid neoplasm. Immunohistochemistry showed that HMB-45 and Melan-A were positive in malanocytes and melanophages of the pigmented areas. Unlike most poroid neoplasms, this case showed pigmented lesion mimicked nodular melanoma.

  17. Disseminated peritoneal leiomyomatosis mimicking ovarian torsion

    Directory of Open Access Journals (Sweden)

    Chau-Yang Tyan

    2015-01-01

    Full Text Available The presentation of disseminated peritoneal leiomyomatosis (DPL can be misleading. Herein, we present the case of a 42-year-old nulliparous female who had previously undergone a total hysterectomy and presented with an acute abdomen. A presumptive diagnosis of ovarian torsion was made based on the clinical findings and an ultrasonographic examination. A diagnostic laparoscopy was performed immediately. DPL was subsequently diagnosed based on an intra-operative frozen section during surgical exploration and the final histopathologic examination. This case illustrates an atypical presentation of DPL mimicking ovarian torsion.

  18. 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.

  19. Dural Metastasis Mimicking Meningioma: An Interesting Case

    Directory of Open Access Journals (Sweden)

    Hamzaini Abdul Hamid

    2009-01-01

    Full Text Available Dural metastasis is a rare entity in clinical practice. We report a case of dural metastasis secondary to thyroid carcinoma, which on both preoperative CT and MRI and at surgery had the typical appearance of a meningioma. Histopathological findings confirmed metastatic follicular thyroid carcinoma as a primary site. Although rare, dural metastases can mimic a meningioma. Our experience in this case has led us to consider metastasis as a differential diagnosis even when a meningioma is suspected. We believe that reporting of the case of dural metastasis mimicking a meningioma may help clinicians in future.

  20. Giant Spermatocele Mimicking Hydrocele: A Case Report

    Directory of Open Access Journals (Sweden)

    Hsin-Chih Yeh

    2007-07-01

    Full Text Available Spermatoceles are usually asymptomatic and often found incidentally during physical examination. We report a case of giant spermatocele that mimicked a hydrocele. A 55-year-old man suffered from right scrotal enlargement for several years. As the heavy sensation and scrotal soreness worsened in recent months, he came to our outpatient clinic for help. Hydrocele was suspected due to transilluminating appearance of the scrotal content. Surgical exploration was arranged and a giant spermatocele was found. Total excision of the spermatocele was performed and the patient recovered well. The specimen was sent for pathology and spermatocele with spermatozoa was noted.

  1. Presentation of phagocytosed antigens by MHC class I and II

    Science.gov (United States)

    Mantegazza, Adriana R.; Magalhaes, Joao G.; Amigorena, Sebastian; Marks, Michael S.

    2012-01-01

    Phagocytosis provides innate immune cells with a mechanism to take up and destroy pathogenic bacteria, apoptotic cells and other large particles. In some cases, however, peptide antigens from these particles are preserved for presentation in association with major histocompatibility complex (MHC) class I or class II molecules in order to stimulate antigen-specific T cells. Processing and presentation of antigens from phagosomes presents a number of distinct challenges relative to antigens internalized by other means; While bacterial antigens were among the first discovered to be presented to T cells, analyses of the cellular mechanisms by which peptides from phagocytosed antigens assemble with MHC molecules and by which these complexes are then expressed at the plasma membrane have lagged behind those of conventional model soluble antigens. In this review, we cover recent advances in our understanding of these processes, including the unique cross-presentation of phagocytosed antigens by MHC class I molecules, and in their control by signaling modalities in phagocytic cells. PMID:23127154

  2. Clinical and Histologic Mimickers of Celiac Disease.

    Science.gov (United States)

    Kamboj, Amrit K; Oxentenko, Amy S

    2017-08-17

    Celiac disease is an autoimmune disorder of the small bowel, classically associated with diarrhea, abdominal pain, and malabsorption. The diagnosis of celiac disease is made when there are compatible clinical features, supportive serologic markers, representative histology from the small bowel, and response to a gluten-free diet. Histologic findings associated with celiac disease include intraepithelial lymphocytosis, crypt hyperplasia, villous atrophy, and a chronic inflammatory cell infiltrate in the lamina propria. It is important to recognize and diagnose celiac disease, as strict adherence to a gluten-free diet can lead to resolution of clinical and histologic manifestations of the disease. However, many other entities can present with clinical and/or histologic features of celiac disease. In this review article, we highlight key clinical and histologic mimickers of celiac disease. The evaluation of a patient with serologically negative enteropathy necessitates a carefully elicited history and detailed review by a pathologist. Medications can mimic celiac disease and should be considered in all patients with a serologically negative enteropathy. Many mimickers of celiac disease have clues to the underlying diagnosis, and many have a targeted therapy. It is necessary to provide patients with a correct diagnosis rather than subject them to a lifetime of an unnecessary gluten-free diet.

  3. A classic mimicker of systemic vasculitis.

    Science.gov (United States)

    Moreno-Ariño, Marc; Ortiz-Santamaria, Vera; Deudero Infante, Aída; Ayats Delgado, Montserrat; Novell Teixidó, Francesc

    2016-01-01

    Embolic and constitutional manifestations of intracavitary cardiac tumors are included within the classic mimickers of systemic vasculitis, especially in those in which there are no cardiac manifestations. We present a case report of atrial myxoma in which the patient only presented systemic symptoms and in whom an initial diagnostic approach of systemic vasculitis was made. We also performed a literature search of the cases described. A case report of atrial myxoma with atypical presentation manifested as a systemic disease with no concomitant cardiac symptoms is described. The case report is discussed and 11 cases of atrial myxoma pseudovasculitis described in the literature are reviewed, emphasizing their similarities and differences. Constitutional symptoms and cutaneous manifestations were the most common. Most of the cases showed partial response to glucococorticosteroid treatment, reinforcing the theory of the inflammatory role in its pathogenesis. Mean delayed time to diagnosis was 12.27 months. Atrial myxoma is a systemic vasculitis mimicker, this being difficult to diagnose in the absence of cardiac manifestations. This delay in diagnosis entails serious complications. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

  4. Imaging findings of mimickers of hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Tae Kyoung Kim

    2015-12-01

    Full Text Available Radiological imaging plays a crucial role in the diagnosis of hepatocellular carcinoma (HCC as the noninvasive diagnosis of HCC in high-risk patients by typical imaging findings alone is widely adopted in major practice guidelines for HCC. While imaging techniques have markedly improved in detecting small liver lesions, they often detect incidental benign liver lesions and non-hepatocellular malignancy that can be misdiagnosed as HCC. The most common mimicker of HCC in cirrhotic liver is nontumorous arterioportal shunts that are seen as focal hypervascular liver lesions on dynamic contrast-enhanced cross-sectional imaging. Rapidly enhancing hemangiomas can be easily misdiagnosed as HCC especially on MR imaging with liver-specific contrast agent. Focal inflammatory liver lesions mimic HCC by demonstrating arterial-phase hypervascularity and subsequent washout on dynamic contrast-enhanced imaging. It is important to recognize the suggestive imaging findings for intrahepatic cholangiocarcinoma (CC as the management of CC is largely different from that of HCC. There are other benign mimickers of HCC such as angiomyolipomas and focal nodular hyperplasia-like nodules. Recognition of their typical imaging findings can reduce false-positive HCC diagnosis.

  5. Ultrasound artifacts mimicking pleural sliding after pneumonectomy.

    Science.gov (United States)

    Cavaliere, Franco; Zamparelli, Roberto; Soave, Maurizio P; Gargaruti, Riccardo; Scapigliati, Andrea; De Paulis, Stefano

    2014-03-01

    To determine the presence of pleural sliding on chest ultrasonography (US) in a series of patients admitted to a surgical intensive care unit (SICU). Prospective, observational study. 16-bed SICU of a University hospital. 8 patients (7 men, 1 woman), aged 64 - 73 years (mean 67.5 yrs). Seven patients underwent pneumonectomy for pulmonary neoplasms; one patient underwent an atypical lung resection after having undergone a pneumonectomy one year before. None. Chest ultrasounds were performed during mechanical ventilation and spontaneous ventilation after endotracheal tube removal. In both examinations, pleural sliding was searched bilaterally in brightness mode (B-mode) and motion mode (M-mode) on the anterior thoracic wall in the least gravitationally dependent areas. During mechanical ventilation, pleural sliding was always absent on the side of the pneumonectomy and present on the other side. During spontaneous ventilation, some artifacts mimicking pleural sliding were noted on the side of the pneumonectomy both in B-mode and M-mode (presence of the seashore sign) in all patients, except for the one patient who had undergone a pneumonectomy one year earlier. Those artifacts became more pronounced during deep breaths. Ultrasound artifacts mimicking pleural sliding may be observed in the absence of the lung and may originate from the activity of intercostal muscles since they become more evident during deep breathing. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Identification of Immunodominant Peptides from Gnathostoma binucleatum

    Science.gov (United States)

    Campista-León, Samuel; Delgado-Vargas, Francisco; Landa, Abraham; Willms, Kaethe; López-Moreno, Hector Samuel; Mendoza-Hernández, Guillermo; Ríos-Sicairos, Julian; Bojórquez-Contreras, Ángel Noel; Díaz-Camacho, Sylvia Páz

    2012-01-01

    Gnathostomiasis is now recognized as a zoonosis with a worldwide distribution. In the Americas, it is caused by the third-stage larvae of Gnathostoma binucleatum and in Asia mainly by G. spinigerum. The availability and preparation of specific antigens are among the main obstacles for developing reliable immunodiagnostic tests. In this study, six immunodominant peptides were identified and characterized from G. binucleatum, somatic antigens (AgS: 24, 32, and 40 kDa) and excretory-secretory antigens (AgES: 42, 44, and 56 kDa) by two-dimensional immunoblot analysis. Among those immunodominant peptides, two AgS spots were characterized by mass spectrometric analysis (32 kDa; pI 6.3 and 6.5) and identified as type 1 galectins. In accordance with this finding, a fraction of AgS exhibited affinity to lactose and displayed a 100% specificity and sensitivity for the diagnosis of human gnathostomiasis. PMID:22949520

  7. Antigen processing and remodeling of the endosomal pathway: requirements for antigen cross-presentation.

    Directory of Open Access Journals (Sweden)

    Ewoud Bernardus Compeer

    2012-03-01

    Full Text Available The cross-presentation of endocytosed antigen as peptide/class I MHC complexes plays a central role in the elicitation of CD8+ T cell clones that mediate anti-viral and anti-tumor immune responses. While it has been clear that there are specific subsets of professional antigen presenting cells (APC capable of antigen cross-presentation, description of mechanisms involved is still ongoing. Especially amongst dendritic cells (DC, there are specialized subsets that are highly proficient at antigen cross-presentation. We here present a focused survey on the cell biological processes in the endosomal pathway that support antigen cross-presentation. This review highlight DC-intrinsic mechanisms that facilitate the cross-presentation of endocytosed antigen, including receptor-mediated uptake, recycling and maturation including the sorting of membrane proteins, dynamic remodeling of endosomal structures and cell-surface directed endosomal trafficking. We will conclude with description of pathogen-induced deviation of endosomal processing, and discuss how immune evasion strategies pertaining endosomal trafficking may preclude antigen cross-presentation.

  8. Limited density of an antigen presented by RMA-S cells requires B7-1/CD28 signaling to enhance T-cell immunity at the effector phase.

    Directory of Open Access Journals (Sweden)

    Xiao-Lin Li

    Full Text Available The association of B7-1/CD28 between antigen presenting cells (APCs and T-cells provides a second signal to proliferate and activate T-cell immunity at the induction phase. Many reports indicate that tumor cells transfected with B7-1 induced augmented antitumor immunity at the induction phase by mimicking APC function; however, the function of B7-1 on antitumor immunity at the effector phase is unknown. Here, we report direct evidence of enhanced T-cell antitumor immunity at the effector phase by the B7-1 molecule. Our experiments in vivo and in vitro indicated that reactivity of antigen-specific monoclonal and polyclonal T-cell effectors against a Lass5 epitope presented by RMA-S cells is increased when the cells expressed B7-1. Use of either anti-B7-1 or anti-CD28 antibodies to block the B7-1/CD28 association reduced reactivity of the T effectors against B7-1 positive RMA-S cells. Transfection of Lass5 cDNA into or pulse of Lass5 peptide onto B7-1 positive RMA-S cells overcomes the requirement of the B7-1/CD28 signal for T effector response. To our knowledge, the data offers, for the first time, strong evidence that supports the requirement of B7-1/CD28 secondary signal at the effector phase of antitumor T-cell immunity being dependent on the density of an antigenic peptide.

  9. Applications of plastic embedding to electron microscopic immunocytochemistry and in situ hybridization in observations of production and secretion of peptide hormones.

    Science.gov (United States)

    Osamura, R Y; Itoh, Y; Matsuno, A

    2000-07-01

    Plastic embedding has been used to localize various antigens in conjunction with immunohistochemistry. Peptide hormones have been among the antigens that have been studied extensively. Recent application of water-soluble plastics such as LR White and Lowicryl has extended the ranges of detectable antigens and enabled the observation of antigen-antigen or mRNA-antigen combinations. This review article deals with technical aspects, procedures, and applications in endocrine cells.

  10. Antigen storage compartments in mature dendritic cells facilitate prolonged cytotoxic T lymphocyte cross-priming capacity.

    Science.gov (United States)

    van Montfoort, Nadine; Camps, Marcel G; Khan, Selina; Filippov, Dmitri V; Weterings, Jimmy J; Griffith, Janice M; Geuze, Hans J; van Hall, Thorbald; Verbeek, J Sjef; Melief, Cornelis J; Ossendorp, Ferry

    2009-04-21

    Dendritic cells (DCs) are crucial for priming of naive CD8(+) T lymphocytes to exogenous antigens, so-called "cross-priming." We report that exogenous protein antigen can be conserved for several days in mature DCs, coinciding with strong cytotoxic T lymphocyte cross-priming potency in vivo. After MHC class I peptide elution, protein antigen-derived peptide presentation is efficiently restored, indicating the presence of an intracellular antigen depot. We characterized this depot as a lysosome-like organelle, distinct from MHC class II compartments and recently described early endosomal compartments that allow acute antigen presentation in MHC class I. The storage compartments we report here facilitate continuous supply of MHC class I ligands. This mechanism ensures sustained cross-presentation by DCs, despite the short-lived expression of MHC class I-peptide complexes at the cell surface.

  11. Whole-Inactivated Influenza Virus Is a Potent Adjuvant for Influenza Peptides Containing CD8+ T Cell Epitopes

    Directory of Open Access Journals (Sweden)

    Peter C. Soema

    2018-03-01

    Full Text Available Influenza peptide antigens coding for conserved T cell epitopes have the capacity to induce cross-protective influenza-specific immunity. Short peptide antigens used as a vaccine, however, often show poor immunogenicity. In this study, we demonstrate that whole-inactivated influenza virus (WIV acts as an adjuvant for influenza peptide antigens, as shown by the induction of peptide-specific CD8+ T cells in HLA-A2.1 transgenic mice upon vaccination with the influenza-M1-derived GILGFVFTL peptide (GIL, formulated with WIV. By screening various concentrations of GIL and WIV, we found that both components contributed to the GIL-specific T cell response. Whereas co-localization of the peptide antigen and WIV adjuvant was found to be important, neither physical association between peptide and WIV nor fusogenic activity of WIV were relevant for the adjuvant effect of WIV. We furthermore show that WIV may adjuvate T cell responses to a variety of peptides, using pools of either conserved wild-type influenza peptides or chemically altered peptide ligands. This study shows the potential of WIV as an adjuvant for influenza peptides. The simple formulation process and the solid safety record of WIV make this an attractive adjuvant for T cell peptides, and may also be used for non-influenza antigens.

  12. The relation between major histocompatibility complex (MHC) restriction and the capacity of Ia to bind immunogenic peptides

    DEFF Research Database (Denmark)

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

    1987-01-01

    The capacity of purified I-Ad, I-Ed, I-Ak, and I-Ek to bind to protein derived peptides that have been previously reported to be T cell immunogens has been examined. For each of the 12 peptides studied strong binding to the relevant Ia restriction element was observed. All the peptides bound more...... than one Ia molecule; however, for 11 of 12 peptides, the dominant binding was to the restriction element, whereas in one instance the dominant binding was to a nonrestriction element. When the peptides were used to inhibit the presentation of antigen by prefixed accessory cells to T cells......, an excellent correlation was found between the capacity of a peptide to inhibit the binding of an antigen to purified Ia and the capacity of the peptide to inhibit accessory cell presentation of the antigen. Thus, the binding of peptide to purified Ia is immunologically relevant, and Ia seems to be the only...

  13. Codelivery of antigen and an immune cell adhesion inhibitor is necessary for efficacy of soluble antigen arrays in experimental autoimmune encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Joshua O Sestak

    2014-01-01

    Full Text Available Autoimmune diseases such as multiple sclerosis (MS are typified by the misrecognition of self-antigen and the clonal expansion of autoreactive T cells. Antigen-specific immunotherapies (antigen-SITs have long been explored as a means to desensitize patients to offending self-antigen(s with the potential to retolerize the immune response. Soluble antigen arrays (SAgAs are composed of hyaluronic acid (HA cografted with disease-specific autoantigen (proteolipid protein peptide and an ICAM-1 inhibitor peptide (LABL. SAgAs were designed as an antigen-SIT that codeliver peptides to suppress experimental autoimmune encephalomyelitis (EAE, a murine model of MS. Codelivery of antigen and cell adhesion inhibitor (LABL conjugated to HA was essential for SAgA treatment of EAE. Individual SAgA components or mixtures thereof reduced proinflammatory cytokines in cultured splenocytes from EAE mice; however, these treatments showed minimal to no in vivo therapeutic effect in EAE mice. Thus, carriers that codeliver antigen and a secondary “context” signal (e.g., LABL in vivo may be an important design criteria to consider when designing antigen-SIT for autoimmune therapy.

  14. HLA-DR-presented peptide repertoires derived from human monocyte-derived dendritic cells pulsed with blood coagulation factor VIII

    NARCIS (Netherlands)

    van Haren, Simon D.; Herczenik, Eszter; ten Brinke, Anja; Mertens, Koen; Voorberg, Jan; Meijer, Alexander B.

    2011-01-01

    Activation of T-helper cells is dependent upon the appropriate presentation of antigen-derived peptides on MHC class II molecules expressed on antigen presenting cells. In the current study we explored the repertoire of peptides presented on MHC class II molecules on human monocyte derived dendritic

  15. Antigen-B Cell Receptor Complexes Associate with Intracellular major histocompatibility complex (MHC) Class II Molecules*

    Science.gov (United States)

    Barroso, Margarida; Tucker, Heidi; Drake, Lisa; Nichol, Kathleen; Drake, James R.

    2015-01-01

    Antigen processing and MHC class II-restricted antigen presentation by antigen-presenting cells such as dendritic cells and B cells allows the activation of naïve CD4+ T cells and cognate interactions between B cells and effector CD4+ T cells, respectively. B cells are unique among class II-restricted antigen-presenting cells in that they have a clonally restricted antigen-specific receptor, the B cell receptor (BCR), which allows the cell to recognize and respond to trace amounts of foreign antigen present in a sea of self-antigens. Moreover, engagement of peptide-class II complexes formed via BCR-mediated processing of cognate antigen has been shown to result in a unique pattern of B cell activation. Using a combined biochemical and imaging/FRET approach, we establish that internalized antigen-BCR complexes associate with intracellular class II molecules. We demonstrate that the M1-paired MHC class II conformer, shown previously to be critical for CD4 T cell activation, is incorporated selectively into these complexes and loaded selectively with peptide derived from BCR-internalized cognate antigen. These results demonstrate that, in B cells, internalized antigen-BCR complexes associate with intracellular MHC class II molecules, potentially defining a site of class II peptide acquisition, and reveal a selective role for the M1-paired class II conformer in the presentation of cognate antigen. These findings provide key insights into the molecular mechanisms used by B cells to control the source of peptides charged onto class II molecules, allowing the immune system to mount an antibody response focused on BCR-reactive cognate antigen. PMID:26400081

  16. The latest developments in synthetic peptides with immunoregulatory activities.

    Science.gov (United States)

    Zhou, Chun-lei; Lu, Rong; Lin, Gang; Yao, Zhi

    2011-02-01

    In the past few years, many researches have provided us with much data demonstrating the abilities of synthetic peptides to impact immune response in vitro and in vivo. These peptides were designed according to the structure of some important protein molecules which play a key role in immune response, so they act with specific targets. The class I and II MHC-derived peptides inhibit the TCR recognition of antigen peptide-MHC complex. Rationally designed CD80 and CD154-binding peptides block the interaction between cell surface costimulatory molecules on antigen-presenting cells (APCs) and T cells. Some peptides were designed to inhibit the activities of cell signal proteins, including JNK, NF-κB and NFAT. Some peptide antagonists competitively bind to important cytokines and inhibit their activities, such as TNF-α, TGF-β and IL-1β inhibitory peptides. Adhesion molecule ICAM-1 derived peptides block the T cell adhesion and activation. These immunoregulatory peptides showed therapeutic effect in several animal models, including collagen-induced arthritis (CIA), autoimmune cystitis model, murine skin transplant model and cardiac allograft model. These results give us important implications for the development of a novel therapy for immune mediated diseases. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. Clinicopathological characteristics of lung cancer mimicking organizing pneumonia on computed tomography-a novel radiological entity of pulmonary malignancy.

    Science.gov (United States)

    Ichikawa, Tomohiro; Hattori, Aritoshi; Suzuki, Kazuhiro; Matsunaga, Takeshi; Takamochi, Kazuya; Oh, Shiaki; Suzuki, Kenji

    2016-07-01

    Lung cancer could be misdiagnosed as benign due to its atypical radiological findings or difficulty in the histological diagnosis. We intended to elucidate the clinicopathological features of such lung cancers. Between 2008 and 2011, we performed surgical resection for 564 consecutive patients with lung adenocarcinoma. Findings on thin-section computed tomography were reviewed for all patients, 13 of whom were found to have lung cancer mimicking organizing pneumonia. The radiological and clinicopathological features of lung cancer mimicking organizing pneumonia and other adenocarcinomas were evaluated. Among 13 patients with lung cancer mimicking organizing pneumonia, 4 were men. The median age was 70 years (range 62-81 years). Six patients were followed up for more than 1 year (range 1-108 months) as their lesions were misdiagnosed as organizing pneumonia. Preoperative carcinoembryonic antigen was significantly high (P = 0.025), and maximum tumor dimension was significantly large for lung cancer mimicking organizing pneumonia (30 vs. 23.6 mm, P = 0.001). Pathologically, there was no vascular invasion (P = 0.012) and only one lymphatic invasion (P = 0.064). One case of lymph node metastasis to the N2 node was found due to misdiagnosis as organizing pneumonia for 9 years. Basically, lung cancer mimicking organizing pneumonia was less invasive and showed slow growth. However, nodal metastasis could be found. Thus, radiological diagnosis based on the findings of thin-section computed tomography is valuable to avoid delay in diagnosis. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Probing protein sequences as sources for encrypted antimicrobial peptides.

    Science.gov (United States)

    Brand, Guilherme D; Magalhães, Mariana T Q; Tinoco, Maria L P; Aragão, Francisco J L; Nicoli, Jacques; Kelly, Sharon M; Cooper, Alan; Bloch, Carlos

    2012-01-01

    Starting from the premise that a wealth of potentially biologically active peptides may lurk within proteins, we describe here a methodology to identify putative antimicrobial peptides encrypted in protein sequences. Candidate peptides were identified using a new screening procedure based on physicochemical criteria to reveal matching peptides within protein databases. Fifteen such peptides, along with a range of natural antimicrobial peptides, were examined using DSC and CD to characterize their interaction with phospholipid membranes. Principal component analysis of DSC data shows that the investigated peptides group according to their effects on the main phase transition of phospholipid vesicles, and that these effects correlate both to antimicrobial activity and to the changes in peptide secondary structure. Consequently, we have been able to identify novel antimicrobial peptides from larger proteins not hitherto associated with such activity, mimicking endogenous and/or exogenous microorganism enzymatic processing of parent proteins to smaller bioactive molecules. A biotechnological application for this methodology is explored. Soybean (Glycine max) plants, transformed to include a putative antimicrobial protein fragment encoded in its own genome were tested for tolerance against Phakopsora pachyrhizi, the causative agent of the Asian soybean rust. This procedure may represent an inventive alternative to the transgenic technology, since the genetic material to be used belongs to the host organism and not to exogenous sources.

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

    Science.gov (United States)

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

    2013-11-01

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

  20. 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...... 100-fold; from 8.5 x 101 CFU/ml to 5.2 x 103 CFU/ml, whereas addition of AHLs did not improve culturability on any of the media.The substitution of agar with gellan gum shows great promise for increasing culturability of marine bacteria, and further studies are ongoing. The AHLs used in this study...... were selected based on a previous study determining the most common AHLs produced by marine strains of the Vibrionaceae family. However, their effect on culturability could not be fully explained, so also here further studies are being carried out....

  1. Case report. Pityriasis versicolor mimicking Pityriasis rotunda.

    Science.gov (United States)

    Aste, Nicola; Pau, Monica; Aste, Natalia; Biggio, P

    2002-04-01

    Pityriasis versicolor is a common dermatomycosis, occurring throughout the world, characterized by irregular, slightly scaly patches, varying in color from red/light brown to white. Pityriasis rotunda, on the other hand, is an uncommon disease, reported in specific ethnic groups, and characterized by perfectly round or oval patches of varying color, with a scaly surface. The histologic pattern is that of ichthyosis vulgaris. We report here the case of a male patient, aged 31, from Sardinia (Italy), affected by Pityriasis versicolor mimicking Pityriasis rotunda. Mycological examination allowed us to formulate the correct diagnosis, and ensuing treatment with antifungal drugs was entirely successful. The authors, while pointing out the rarity of this case, stress the possibility that Pityriasis versicolor mimics Pityriasis rotunda and vice-versa, especially in those countries in which the two diseases are endemic. More widespread recourse to microscopic examination can help avoid the risk of mistaken diagnosis and consequent incorrect treatment.

  2. Orbital Lymphoma Mimicking Lacrimal Gland Pleomorphic Adenoma

    Directory of Open Access Journals (Sweden)

    Diego Strianese

    2013-09-01

    Full Text Available Purpose: To describe the case of a patient affected by orbital lymphoma mimicking pleomorphic adenoma of the lacrimal gland. Methods: This was a retrospective case report. Results: We present the case of a patient with 15-year history of slowly progressive left proptosis and inferomedial bulbar dislocation who had the presumptive diagnosis of lacrimal gland pleomorphic adenoma based on clinical and radiological features. The patient underwent lateral orbitotomy and lacrimal gland excision. Postoperative histological features were consistent with low-grade B-cell non-Hodgkin lymphoma. Conclusion: The accepted clinico-radiological criteria used for the diagnosis of lacrimal gland fossa lesions might have a certain false-positive rate, even in recent years. The initial surgical approach with the appropriate choice between fine-needle aspiration biopsies, intraoperative biopsies and lacrimal gland excisions might be a challenge.

  3. Orbital roof encephalocele mimicking a destructive neoplasm.

    Science.gov (United States)

    Alsuhaibani, Adel H; Hitchon, Patrick W; Smoker, Wendy R K; Lee, Andrew G; Nerad, Jeffrey A

    2011-01-01

    The purpose of this case report is to report an orbital roof encephalocele mimicking a destructive orbital neoplasm. Orbital roof encephalocele is uncommon but can mimic neoplasm. One potential mechanism for the orbital roof destruction is a post-traumatic "growing orbital roof fracture." The growing fracture has been reported mostly in children but can occur in adults. Alternative potential etiologies for the encephalocele are discussed, including Gorham syndrome. Orbital roof encephalocele is uncommon in adults, and the findings can superficially resemble an orbital neoplasm. Radiographic and clinical features that might suggest the correct diagnosis include a prior history of trauma, overlying frontal lobe encephalomalacia without significant mass effect or edema, and an orbital roof defect. The "growing fracture" mechanism may be a potential explanation for the orbital roof destruction in some cases.

  4. Development of tissue mimicking ultrasound phantom materials

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Sang Chul [Shinheung College, Uijeongbu (Korea, Republic of); Kong, Young Kun [Kyonggi University, Suwon (Korea, Republic of); Park, Ki Jung [Korea Food Drug Administration, Seoul (Korea, Republic of); Lee, Suk [Yonsei Medical Center, Seoul (Korea, Republic of)

    2003-06-15

    We carried out studies on develop of the ultrasound tissue mimicking materials (TMM) by synthesis of polymer urethane (C, CCR, TiO{sub 2}, tungsten, graphite, silver type). The major finding were as follows; (1) C type TMM was shown good homogeneity, penetration, gray scale like as liver tissue and propagated speed 1,540 m/s, attenuation 0.5 {approx} 0.7 dB/cm/MHz. (2) TiO{sub 2} type TMM was shown heterogeneous dot echo pattern. (3) Silver type TMM was appear good homogeneous echo pattern like as echo texture of thyroid gland. Therefor, C type TMM will be useful for ultrasound Q/A phantom materials and previous phantom materials.

  5. Contiguous spinal metastasis mimicking infectious spondylodiscitis

    International Nuclear Information System (INIS)

    Lee, Chul Min; Lee, Seung Hun; Bae, Ji Yoon

    2015-01-01

    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

  6. 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.

  7. Acute perimyocarditis mimicking transmural myocardial infarction

    Directory of Open Access Journals (Sweden)

    Omar Hesham R

    2009-12-01

    Full Text Available Abstract Although acute pericarditis has charachteristic electrocardiographic (ECG findings that differentiate it from acute ST segment elevation myocardial infarction (MI; in certain cases diagnosis is somewhat difficult especially when the ECG reveals focal instead of diffuse changes and moreover when pericarditis is associated with an underlying myocarditis causing elevation of the cardiac biomarkers therefore increasing the difficulty in differentiating between both enteties. This is especially important because adverse lethal side effect can occur if thrombolytic therapy is administered for a patient with acute pericarditis, or if a diagnosis of transmural MI is missed. In this case report we are describing an 18 year old male patient who presented with an acute onset of severe chest pain associated with focal ECG changes and elevated cardiac enzymes mimicking transmural MI. This report aims to sensitize readers to this debate and create awareness among cardiologists and intensivists with both presentations and how to reach an accurate diagnosis.

  8. Pelvic-peritoneal tuberculosis mimicking ovarian cancer

    International Nuclear Information System (INIS)

    Imtiaz, S.; Siddiqui, N.

    2012-01-01

    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)

  9. Viral interference with antigen presentation: trapping TAP.

    Science.gov (United States)

    Ressing, Maaike E; Luteijn, Rutger D; Horst, Daniëlle; Wiertz, Emmanuel J

    2013-09-01

    Following primary infection, herpesviruses persist for life in their hosts, even when vigorous anti-viral immunity has been induced. Failure of the host immune system to eliminate infected cells is facilitated by highly effective immune evasion strategies acquired by these herpesviruses during millions of years of co-evolution with their hosts. Here, we review the mechanisms of action of viral gene products that lead to cytotoxic T cell evasion through interference with the function of the transporter associated with antigen processing, TAP. The viral TAP inhibitors impede transport of peptides from the cytosol into the ER lumen, thereby preventing peptide loading onto MHC class I complexes. Recent insights have revealed a pattern of functional convergent evolution. In every herpesvirus subfamily, inhibitors of TAP function have been identified that are, surprisingly, unrelated in genome location, structure, and mechanism of action. Recently, cowpox virus has also been found to encode a TAP inhibitor. Expanding our knowledge on how viruses perturb antigen presentation, in particular by targeting TAP, not only provides information on viral pathogenesis, but also reveals novel aspects of the cellular processes corrupted by these viruses, notably the translocation of peptides by the ATP-binding cassette (ABC) transporter TAP. As the various TAP inhibitors are anticipated to impede discrete conformational transitions it is expected that crystal structures of TAP-inhibitor complexes will reveal valuable structural information on the actual mechanism of peptide translocation by TAP. Viral TAP inhibitors are also used for various (clinical) applications, for example, as effective tools in antigen presentation studies and as immunomodulators in immunotherapy for cancer, heterologous vaccination, and transplant protection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Antigen-dependent fluorescence response of anti-c-Myc Quenchbody studied by molecular dynamics simulations

    Science.gov (United States)

    Mori, Yoshiharu; Okumura, Hisashi; Watanabe, Takayoshi; Hohsaka, Takahiro

    2018-04-01

    We performed metadynamics molecular dynamics simulations to reveal mechanism of antigen-dependent fluorescence response observed for site-specifically fluorescent-labeled single-chain antibody against c-Myc peptide antigen. We found that VH and VL bind with each other only when the antigen exists and that the fluorophore labeled at the N-terminus of VH interacts with Trp103 most stably. These results support the mechanism proposed from previous experiments: In the absence of antigen, Trp residues are partially exposed at the interface of VH and quench the fluorophore. In the presence of antigen, the Trp residues are buried between VH and VL , and the quenching is eliminated.

  11. Rapid screening and identification of dominant B cell epitopes of HBV surface antigen by quantum dot-based fluorescence polarization assay

    Science.gov (United States)

    Meng, Zhongji; Song, Ruihua; Chen, Yue; Zhu, Yang; Tian, Yanhui; Li, Ding; Cui, Daxiang

    2013-03-01

    A method for quickly screening and identifying dominant B cell epitopes was developed using hepatitis B virus (HBV) surface antigen as a target. Eleven amino acid fragments from HBV surface antigen were synthesized by 9-fluorenylmethoxy carbonyl solid-phase peptide synthesis strategy, and then CdTe quantum dots were used to label the N-terminals of all peptides. After optimizing the factors for fluorescence polarization (FP) immunoassay, the antigenicities of synthetic peptides were determined by analyzing the recognition and combination of peptides and standard antibody samples. The results of FP assays confirmed that 10 of 11 synthetic peptides have distinct antigenicities. In order to screen dominant antigenic peptides, the FP assays were carried out to investigate the antibodies against the 10 synthetic peptides of HBV surface antigen respectively in 159 samples of anti-HBV surface antigen-positive antiserum. The results showed that 3 of the 10 antigenic peptides may be immunodominant because the antibodies against them existed more widely among the samples and their antibody titers were higher than those of other peptides. Using three dominant antigenic peptides, 293 serum samples were detected for HBV infection by FP assays; the results showed that the antibody-positive ratio was 51.9% and the sensitivity and specificity were 84.3% and 98.2%, respectively. In conclusion, a quantum dot-based FP assay is a very simple, rapid, and convenient method for determining immunodominant antigenic peptides and has great potential in applications such as epitope mapping, vaccine designing, or clinical disease diagnosis in the future.

  12. Analysis of Tn antigenicity with a panel of new IgM and IgG1 monoclonal antibodies raised against leukemic cells

    DEFF Research Database (Denmark)

    Blixt, Klas Ola; Lavrova, Olga I; Mazurov, Dmitriy V

    2012-01-01

    NAc residue of the Tn antigen irrespective of the peptide context or with low selectivity to the glycoproteins. In contrast, IgG mAbs recognized the Tn antigen in the context of a specific peptide motif. Particularly, JA3 mAb reacted to the GSPP or GSPAPP, and JA5 mAb recognized specifically the GSP motif...

  13. Locus-specific detection of HLA-DQ and -DR antigens by antibodies against synthetic N-terminal octapeptides of the beta chain

    DEFF Research Database (Denmark)

    Deufel, T; Grove, A; Kofod, Hans

    1985-01-01

    Antibodies against synthetic peptides representing the class-II antigen HLA-DR and -DQ beta chain N-terminal sequences were prepared in rabbits. The two octapeptides only share two amino acids and enzyme-linked immuno-assays showed the antisera only to bind to its own antigen. Both peptide antisera...

  14. 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

  15. De nonklassiske humant leukocyt-antigen (HLA)-vaevstyper--fra implantation til transplantation

    DEFF Research Database (Denmark)

    Hviid, Thomas Vauvert F

    2006-01-01

    The classical and extremely polymorphic human leukocyte antigens (HLA) classes Ia and II have been studied in great detail and have significant importance in organ transplantation, autoimmune diseases and presentation of antigen peptides. However, in the human major histocompatibility complex (MHC...... of rejection episodes in heart and kidney/liver transplants....

  16. Antigen loading of MHC class I molecules in the endocytic tract

    NARCIS (Netherlands)

    M.J. Kleijmeer (Monique); J.M. Escola; F.G.C.M. Uytdehaag (Fons); E. Jakobson (Eva); J.M. Griffith (Janice); A.D.M.E. Osterhaus (Albert); W. Stoorvogel (Willem); C.J.M. Melief (Cornelis); C. Rabouille (Catherine); H.J. Geuze (Hans)

    2001-01-01

    textabstractMajor histocompatibility complex (MHC) class I molecules bind antigenic peptides that are translocated from the cytosol into the endoplasmic reticulum by the transporter associated with antigen processing. MHC class I loading independent of this transporter also exists and involves

  17. Application of synthetic peptides for detection of anti-citrullinated peptide antibodies

    DEFF Research Database (Denmark)

    Trier, Nicole Hartwig; Holm, Bettina Eide; Slot, Ole

    2016-01-01

    Anti-citrullinated protein antibodies (ACPAs) are a hallmark of rheumatoid arthritis (RA) and represent an important tool for the serological diagnosis of RA. In this study, we describe ACPA reactivity to overlapping citrullinated Epstein-Barr virus nuclear antigen-1 (EBNA-1)-derived peptides and...

  18. Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Ali Adem Bahar

    2013-11-01

    Full Text Available The rapid increase in drug-resistant infections has presented a serious challenge to antimicrobial therapies. The failure of the most potent antibiotics to kill “superbugs” emphasizes the urgent need to develop other control agents. Here we review the history and new development of antimicrobial peptides (AMPs, a growing class of natural and synthetic peptides with a wide spectrum of targets including viruses, bacteria, fungi, and parasites. We summarize the major types of AMPs, their modes of action, and the common mechanisms of AMP resistance. In addition, we discuss the principles for designing effective AMPs and the potential of using AMPs to control biofilms (multicellular structures of bacteria embedded in extracellular matrixes and persister cells (dormant phenotypic variants of bacterial cells that are highly tolerant to antibiotics.

  19. Virtual models of the HLA class I antigen processing pathway.

    Science.gov (United States)

    Petrovsky, Nikolai; Brusic, Vladimir

    2004-12-01

    Antigen recognition by cytotoxic CD8 T cells is dependent upon a number of critical steps in MHC class I antigen processing including proteosomal cleavage, TAP transport into the endoplasmic reticulum, and MHC class I binding. Based on extensive experimental data relating to each of these steps there is now the capacity to model individual antigen processing steps with a high degree of accuracy. This paper demonstrates the potential to bring together models of individual antigen processing steps, for example proteosome cleavage, TAP transport, and MHC binding, to build highly informative models of functional pathways. In particular, we demonstrate how an artificial neural network model of TAP transport was used to mine a HLA-binding database so as to identify HLA-binding peptides transported by TAP. This integrated model of antigen processing provided the unique insight that HLA class I alleles apparently constitute two separate classes: those that are TAP-efficient for peptide loading (HLA-B27, -A3, and -A24) and those that are TAP-inefficient (HLA-A2, -B7, and -B8). Hence, using this integrated model we were able to generate novel hypotheses regarding antigen processing, and these hypotheses are now capable of being tested experimentally. This model confirms the feasibility of constructing a virtual immune system, whereby each additional step in antigen processing is incorporated into a single modular model. Accurate models of antigen processing have implications for the study of basic immunology as well as for the design of peptide-based vaccines and other immunotherapies.

  20. The systems biology of MHC class II antigen presentation

    NARCIS (Netherlands)

    Paul, Petra

    2012-01-01

    Major histocompatibility class II molecules (MHC class II) are one of the key regulators of adaptive immunity because of their specific expression by professional antigen presenting cells (APC). They present peptides derived from endocytosed material to T helper lymphocytes. Consequently, MHC class

  1. 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...

  2. Viral immune evasion : Lessons in MHC class I antigen presentation

    NARCIS (Netherlands)

    van de Weijer, Michael L.; Luteijn, Rutger D.; Wiertz, EJHJ

    2015-01-01

    The MHC class I antigen presentation pathway enables cells infected with intracellular pathogens to signal the presence of the invader to the immune system. Cytotoxic T lymphocytes are able to eliminate the infected cells through recognition of pathogen-derived peptides presented by MHC class I

  3. Advances in synthetic peptides reagent discovery

    Science.gov (United States)

    Adams, Bryn L.; Sarkes, Deborah A.; Finch, Amethist S.; Stratis-Cullum, Dimitra N.

    2013-05-01

    Bacterial display technology offers a number of advantages over competing display technologies (e.g, phage) for the rapid discovery and development of peptides with interaction targeted to materials ranging from biological hazards through inorganic metals. We have previously shown that discovery of synthetic peptide reagents utilizing bacterial display technology is relatively simple and rapid to make laboratory automation possible. This included extensive study of the protective antigen system of Bacillus anthracis, including development of discovery, characterization, and computational biology capabilities for in-silico optimization. Although the benefits towards CBD goals are evident, the impact is far-reaching due to our ability to understand and harness peptide interactions that are ultimately extendable to the hybrid biomaterials of the future. In this paper, we describe advances in peptide discovery including, new target systems (e.g. non-biological materials), advanced library development and clone analysis including integrated reporting.

  4. Advancement and applications of peptide phage display technology in biomedical science.

    Science.gov (United States)

    Wu, Chien-Hsun; Liu, I-Ju; Lu, Ruei-Min; Wu, Han-Chung

    2016-01-19

    Combinatorial phage library is a powerful research tool for high-throughput screening of protein interactions. Of all available molecular display techniques, phage display has proven to be the most popular approach. Screening phage-displayed random peptide libraries is an effective means of identifying peptides that can bind target molecules and regulate their function. Phage-displayed peptide libraries can be used for (i) B-cell and T-cell epitope mapping, (ii) selection of bioactive peptides bound to receptors or proteins, disease-specific antigen mimics, peptides bound to non-protein targets, cell-specific peptides, or organ-specific peptides, and (iii) development of peptide-mediated drug delivery systems and other applications. Targeting peptides identified using phage display technology may be useful for basic research and translational medicine. In this review article, we summarize the latest technological advancements in the application of phage-displayed peptide libraries to applied biomedical sciences.

  5. 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.

  6. Antigen processing and immune regulation in the response to tumours.

    Science.gov (United States)

    Reeves, Emma; James, Edward

    2017-01-01

    The MHC class I and II antigen processing and presentation pathways display peptides to circulating CD8 + cytotoxic and CD4 + helper T cells respectively to enable pathogens and transformed cells to be identified. Once detected, T cells become activated and either directly kill the infected / transformed cells (CD8 + cytotoxic T lymphocytes) or orchestrate the activation of the adaptive immune response (CD4 + T cells). The immune surveillance of transformed/tumour cells drives alteration of the antigen processing and presentation pathways to evade detection and hence the immune response. Evasion of the immune response is a significant event tumour development and considered one of the hallmarks of cancer. To avoid immune recognition, tumours employ a multitude of strategies with most resulting in a down-regulation of the MHC class I expression at the cell surface, significantly impairing the ability of CD8 + cytotoxic T lymphocytes to recognize the tumour. Alteration of the expression of key players in antigen processing not only affects MHC class I expression but also significantly alters the repertoire of peptides being presented. These modified peptide repertoires may serve to further reduce the presentation of tumour-specific/associated antigenic epitopes to aid immune evasion and tumour progression. Here we review the modifications to the antigen processing and presentation pathway in tumours and how it affects the anti-tumour immune response, considering the role of tumour-infiltrating cell populations and highlighting possible future therapeutic targets. © 2016 John Wiley & Sons Ltd.

  7. pH dependence of MHC class I-restricted peptide presentation

    DEFF Research Database (Denmark)

    Stryhn, A; Pedersen, L O; Romme, T

    1996-01-01

    The function of MHC class I molecules is to bind and present antigenic peptides to cytotoxic T cells. Here, we report that class I-restricted peptide presentation is strongly pH dependent. The presentation of some peptides was enhanced at acidic pH, whereas the presentation of others was inhibited....... Biochemical peptide-MHC class I binding assays demonstrated that peptide-MHC class I complexes are more stable at neutral pH than at acidic pH. We suggest that acid-dependent peptide dissociation can generate empty class I molecules and that the resulting binding potential can be exploited by a subset...

  8. Neuritogenic and neuroprotective properties of peptide agonists of the fibroblast growth factor receptor

    DEFF Research Database (Denmark)

    Li, Shizhong; Bock, Elisabeth Marianne; Berezin, Vladimir

    2010-01-01

    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...

  9. 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....

  10. AntigenMap 3D: an online antigenic cartography resource.

    Science.gov (United States)

    Barnett, J Lamar; Yang, Jialiang; Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2012-05-01

    Antigenic cartography is a useful technique to visualize and minimize errors in immunological data by projecting antigens to 2D or 3D cartography. However, a 2D cartography may not be sufficient to capture the antigenic relationship from high-dimensional immunological data. AntigenMap 3D presents an online, interactive, and robust 3D antigenic cartography construction and visualization resource. AntigenMap 3D can be applied to identify antigenic variants and vaccine strain candidates for pathogens with rapid antigenic variations, such as influenza A virus. http://sysbio.cvm.msstate.edu/AntigenMap3D

  11. Antigens of Streptococcus sanguis

    Science.gov (United States)

    Rosan, Burton

    1973-01-01

    An antigenic analysis of the alpha-hemolytic streptococci isolated from dental plaque was performed by use of antisera against a strain of Streptococcus sanguis (M-5) which was isolated from dental plaque. Immunoelectrophoretic and Ouchterlony tests of Rantz and Randall extracts of 45 strains gave positive reactions with the M-5 antisera. These strains represented 60% of the strains tested. The number of antigens which could be identified in these extracts varied from one to five and were designated a to e. The a antigen was found in 36 of the strains tested, including reference strains of S. sanguis and the group H streptococci. The strains reacting with the M-5 antisera were divided into two majors types: type I consisted of 23 strains in which the a antigen was found alone or with one or more of the c, d, and e antigens; type II consisted of 13 strains in which both the a and b antigens were found with or without one or more of the c, d, and e antigens. The remaining strains contained, either singly or in combination, the b, c, d, and e antigens but not the a antigen. Biochemical tests of representatives of each serotype and reference strains indicated that strains reacting with M-5 antisera were S. sanguis. These findings suggest that S. sanguis strains share common physiological and serological properties. Images PMID:4633291

  12. Molecular mechanisms of viral immune evasion proteins to inhibit MHC class I antigen processing and presentation.

    Science.gov (United States)

    Zhou, Fang

    2009-01-01

    Viral products inhibit MHC class I antigen processing and presentation via three major pathways: inhibition of major histocompatibility complex (MHC) class I expression on cells, blockade of peptide trafficking and loading on MHC class I molecules, and inhibition of peptide generation in host cells. Viral products also interfere with IFN-gamma -mediated JAK/STAT signal transduction in cells. These results imply that viral proteins probably inhibit the function of IFN-gamma in MHC class I antigen presentation via inactivation of JAK/STAT signal transduction in host cells. Mechanisms of viral products to inhibit IFN-gamma -mediated MHC class I antigen presentation were summarized in this literature review.

  13. 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.

    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

  14. [Infestation with Enterobius vermicularis mimicking appendicitis].

    Science.gov (United States)

    Levens, Afra M A; Schurink, Maarten; Koetse, Harma A; van Baren, Robertine

    2014-01-01

    Gastrointestinal infestation with the parasite Enterobius vermicularis is common in humans and is usually harmless. Anal pruritus is the most characteristic symptom, but the parasites can cause severe abdominal pain mimicking appendicitis. Early recognition can prevent an unnecessary appendectomy. A six-year-old girl reported to the accident and emergency department with pain in the lower right abdominal region. She was admitted and treated for suspected perforated appendix, following physical examination supplemented with an abdominal CT scan. After antibiotic treatment the symptoms disappeared as did the abscess, apart from a minor amount of residual infiltrate. She was then readmitted twice with recurrent abdominal pain without radiological evidence of an abdominal focus. We decided to conduct a diagnostic laparoscopy and an elective appendectomy à froid. During this procedure living worms were found in the appendix. Treatment with the anthelminthicum mebendazol was effective. Gastro-intestinal infestation with E. vermicularis is very common, especially in young children. This infestation is usually harmless, but can mimic appendicitis. This infestation is easily treatable with mebendazol.

  15. 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.

  16. Microfabricated adhesive mimicking gecko foot-hair

    Science.gov (United States)

    Geim, A. K.; Dubonos, S. V.; Grigorieva, I. V.; Novoselov, K. S.; Zhukov, A. A.; Shapoval, S. Yu.

    2003-07-01

    The amazing climbing ability of geckos has attracted the interest of philosophers and scientists alike for centuries. However, only in the past few years has progress been made in understanding the mechanism behind this ability, which relies on submicrometre keratin hairs covering the soles of geckos. Each hair produces a miniscule force ~10-7 N (due to van der Waals and/or capillary interactions) but millions of hairs acting together create a formidable adhesion of ~10 N cm-2: sufficient to keep geckos firmly on their feet, even when upside down on a glass ceiling. It is very tempting to create a new type of adhesive by mimicking the gecko mechanism. Here we report on a prototype of such 'gecko tape' made by microfabrication of dense arrays of flexible plastic pillars, the geometry of which is optimized to ensure their collective adhesion. Our approach shows a way to manufacture self-cleaning, re-attachable dry adhesives, although problems related to their durability and mass production are yet to be resolved.

  17. Enhanced Direct Major Histocompatibility Complex Class I Self-Antigen Presentation Induced by Chlamydia Infection.

    Science.gov (United States)

    Cram, Erik D; Simmons, Ryan S; Palmer, Amy L; Hildebrand, William H; Rockey, Daniel D; Dolan, Brian P

    2016-02-01

    The direct major histocompatibility complex (MHC) class I antigen presentation pathway ensures intracellular peptides are displayed at the cellular surface for recognition of infected or transformed cells by CD8(+) cytotoxic T lymphocytes. Chlamydia spp. are obligate intracellular bacteria and, as such, should be targeted by CD8(+) T cells. It is likely that Chlamydia spp. have evolved mechanisms to avoid the CD8(+) killer T cell responses by interfering with MHC class I antigen presentation. Using a model system of self-peptide presentation which allows for posttranslational control of the model protein's stability, we tested the ability of various Chlamydia species to alter direct MHC class I antigen presentation. Infection of the JY lymphoblastoid cell line limited the accumulation of a model host protein and increased presentation of the model-protein-derived peptides. Enhanced self-peptide presentation was detected only when presentation was restricted to defective ribosomal products, or DRiPs, and total MHC class I levels remained unaltered. Skewed antigen presentation was dependent on a bacterial synthesized component, as evidenced by reversal of the observed phenotype upon preventing bacterial transcription, translation, and the inhibition of bacterial lipooligosaccharide synthesis. These data suggest that Chlamydia spp. have evolved to alter the host antigen presentation machinery to favor presentation of defective and rapidly degraded forms of self-antigen, possibly as a mechanism to diminish the presentation of peptides derived from bacterial proteins. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  18. Huge desmoid tumor of the anterior abdominal wall mimicking an ...

    African Journals Online (AJOL)

    Huge desmoid tumor of the anterior abdominal wall mimicking an intraabdominal mass in a postpartum woman: a case report. Khaled Trigui, Mahdi Bouassida, Houda Kilani, Mohamed Mongi Mighri, Selim Sassi, Fathi Chebbi, Hassen Touinsi, Sadok Sassi ...

  19. A systems approach to designing next generation vaccines: combining α-galactose modified antigens with nanoparticle platforms

    Science.gov (United States)

    Phanse, Yashdeep; Carrillo-Conde, Brenda R.; Ramer-Tait, Amanda E.; Broderick, Scott; Kong, Chang Sun; Rajan, Krishna; Flick, Ramon; Mandell, Robert B.; Narasimhan, Balaji; Wannemuehler, Michael J.

    2014-01-01

    Innovative vaccine platforms are needed to develop effective countermeasures against emerging and re-emerging diseases. These platforms should direct antigen internalization by antigen presenting cells and promote immunogenic responses. This work describes an innovative systems approach combining two novel platforms, αGalactose (αGal)-modification of antigens and amphiphilic polyanhydride nanoparticles as vaccine delivery vehicles, to rationally design vaccine formulations. Regimens comprising soluble αGal-modified antigen and nanoparticle-encapsulated unmodified antigen induced a high titer, high avidity antibody response with broader epitope recognition of antigenic peptides than other regimen. Proliferation of antigen-specific CD4+ T cells was also enhanced compared to a traditional adjuvant. Combining the technology platforms and augmenting immune response studies with peptide arrays and informatics analysis provides a new paradigm for rational, systems-based design of next generation vaccine platforms against emerging and re-emerging pathogens.

  20. MHC class I-presented tumor antigen appraisable for T-cell responses against ovarian cancer

    Directory of Open Access Journals (Sweden)

    Jing Yao Wang

    2015-08-01

    Full Text Available The purpose of this study is to assess whether MHC class I-presented tumor antigen is appraisable for T-cell responses against ovarian cancer. In ovarian cancer cell, human leukocyte antigen A2 (HLA-A2 associated with peptides was used to promote the activation of naive T cells so as to activate antigen-specific T cells. 7 or 4 patients were observed grade 1 or 2 injection site reactions, respectively. 5, 2 or 1 patients were observed grade 1, 2 or 3 pain reactions, respectively. 4 or 1 patients were observed grade 1 or 2 induration reactions. Total number mean value of patients experiencing response to the particular peptide was 7.73, and total number mean value of peptides to which the patients responded was 7.45. MHC class I-presented tumor antigen is appraisable for T-cell responses against ovarian cancer in China.

  1. Eosinofil Sel Penyaji Antigen

    Directory of Open Access Journals (Sweden)

    Safari Wahyu Jatmiko

    2015-04-01

    Full Text Available Sel eosinofil merupakan jenis sel lekosit yang terlibat dalam berbagai patogenesis penyakit. Sel eosinofil pada awalnya dikenal sebagai sel efektor  dari sistem imunitas alamiah. Akan tetapi, kemampuan sel eosinofil dalam memfagositosis patogen menimbulkan dugaan bahwa sel eosinofil ikut berperan sebagai sel penyaji antigen. Hal ini dianalogikan dengan sel makrofag dan sel dendritik yang bisa memfagositosis dan menyajikan antigen sebagai hasil dari degradasi patogen yang difagositosis. Untuk menjawab permasalahan ini, penulis melakukan penelusuran artikel tentang eosinofil sebagai sel penyaji antigen melalui US National Library of Medicine National Institute of Healthdengan kata kunci eoshinophil dan antigen presenting cell. Hasil penelusuran adalah ditemukannya 10 artikel yang relevan dengan topik. Hasil dari sintesis kesepuluh jurnal tersebut adalah sel eosinofil mampu berperan sebagai sel penyaji antigen yang profesional (professionalantigenpresentng cell

  2. Synthetic antifreeze peptide

    OpenAIRE

    1991-01-01

    A synthetic antifreeze peptide and a synthetic gene coding for the antifreeze peptide have been produced. The antifreeze peptide has a greater number of repeating amino acid sequences than is present in the native antifreeze peptides from winter flounder upon which the synthetic antifreeze peptide was modeled. Each repeating amino acid sequence has two polar amino acid residues which are spaced a controlled distance apart so that the antifreeze peptide may inhibit ice formation. The synthetic...

  3. Therapeutic Antibodies against Intracellular Tumor Antigens

    Directory of Open Access Journals (Sweden)

    Iva Trenevska

    2017-08-01

    Full Text Available Monoclonal antibodies are among the most clinically effective drugs used to treat cancer. However, their target repertoire is limited as there are relatively few tumor-specific or tumor-associated cell surface or soluble antigens. Intracellular molecules represent nearly half of the human proteome and provide an untapped reservoir of potential therapeutic targets. Antibodies have been developed to target externalized antigens, have also been engineered to enter into cells or may be expressed intracellularly with the aim of binding intracellular antigens. Furthermore, intracellular proteins can be degraded by the proteasome into short, commonly 8–10 amino acid long, peptides that are presented on the cell surface in the context of major histocompatibility complex class I (MHC-I molecules. These tumor-associated peptide–MHC-I complexes can then be targeted by antibodies known as T-cell receptor mimic (TCRm or T-cell receptor (TCR-like antibodies, which recognize epitopes comprising both the peptide and the MHC-I molecule, similar to the recognition of such complexes by the TCR on T cells. Advances in the production of TCRm antibodies have enabled the generation of multiple TCRm antibodies, which have been tested in vitro and in vivo, expanding our understanding of their mechanisms of action and the importance of target epitope selection and expression. This review will summarize multiple approaches to targeting intracellular antigens with therapeutic antibodies, in particular describing the production and characterization of TCRm antibodies, the factors influencing their target identification, their advantages and disadvantages in the context of TCR therapies, and the potential to advance TCRm-based therapies into the clinic.

  4. Enzymatic Activation of Proteasome Inhibitor Prodrugs by Prostate-Specific Antigen as Targeted Therapy for Prostate Cancer

    National Research Council Canada - National Science Library

    Denmeade, Samuel

    2002-01-01

    ... significant toxicity, To achieve targeted cytotoxicity the TG analogs were converted to inactive prodrugs by coupling to a peptide carrier that is a substrate for the serine protease activity of Prostate-Specific Antigen (PSA...

  5. Ruptured ectopic pregnancy mimicking acute pancreatitis.

    Science.gov (United States)

    Mitura, Kryspin; Romanczuk, Mikolaj

    2009-05-01

    Ectopic pregnancy may lead to massive haemorrhage, infertility or death. Prompt diagnosis and treatment are crucial to save patients who would otherwise die. Serum amylase and lipase measurements are known biochemical markers of pancreatic inflammation and a recognized finding that may help diagnose acute pancreatitis. To the best of our knowledge (Medline, Pubmed, Cochrane Library have been researched) the following study presents the first case of ruptured ectopic pregnancy accompanied by markedly elevated amylase and lipase levels mimicking acute pancreatitis ever reported. A previously healthy, nulliparous 35-year-old woman was admitted to hospital with a 2-day history of abdominal pain and vomiting. Her last menstrual period was 7 weeks before presentation. At the admission, the patient was hemodynamically stable. The abdomen was soft with tenderness in its mesogastric area. Blood tests revealed markedly elevated activities of the pancreatic enzymes. Acute pancreatitis was the early clinical diagnosis and subsequent therapy was initiated. After 12 hours the condition of the patient suddenly worsened. She was clinically shocked with pallor, hypotension and tachycardia. Laboratory tests revealed anaemia and increased activities of pancreatic enzymes. An ultrasound examination demonstrated an accumulation of intraperitoneal fluid in the pelvis. Subsequently, the patient was subjected to immediate laparotomy. The peritoneal cavity contained large amount of blood. A cystic mass was found and extracted from the ruptured and bleeding right fallopian tube. Histological examination confirmed a rupture of an ectopic pregnancy of a 6-week-old foetus with an intact gestational sac. The patient made an uneventful recovery and was discharged from hospital after 8 days. Our case proves that a misdiagnosed ruptured ectopic pregnancy in the event of elevated activities of pancreatic enzymes may lead to delayed diagnosis of haemorrhage to peritoneum, resulting in hemodynamic

  6. Vaccination and the TAP-independent antigen processing pathways.

    Science.gov (United States)

    López, Daniel; Lorente, Elena; Barriga, Alejandro; Johnstone, Carolina; Mir, Carmen

    2013-09-01

    The cytotoxic CD8(+) T lymphocyte-mediated cellular response is important for the elimination of virus-infected cells and requires the prior recognition of short viral peptide antigens previously translocated to the endoplasmic reticulum by the transporter associated with antigen processing (TAP). However, individuals with nonfunctional TAP complexes or infected cells with TAP molecules blocked by specific viral proteins, such as the cowpoxvirus, a component of the first source of early empirical vaccination against smallpox, are still able to present several HLA class I ligands generated by the TAP-independent antigen processing pathways to specific cytotoxic CD8(+) T lymphocytes. Currently, bioterrorism and emerging infectious diseases have renewed interest in poxviruses. Recent works that have identified HLA class I ligands and epitopes in virus-infected TAP-deficient cells have implications for the study of both the effectiveness of early empirical vaccination and the analysis of HLA class I antigen processing in TAP-deficient subjects.

  7. Cancer Immunotherapy Utilized Bubble Liposomes and Ultrasound as Antigen Delivery System

    Science.gov (United States)

    Oda, Yusuke; Otake, Shota; Suzuki, Ryo; Otake, Shota; Nishiie, Norihito; Hirata, Keiichi; Taira, Yuichiro; Utoguchi, Naoki; Maruyama, Kazuo

    2010-03-01

    In dendritic cells (DCs)-based cancer immunotherapy, it is important to present the epitope peptide derived from tumor associated antigens (TAAs) on MHC class I in order to induce tumor specific cytotoxic T lymphocytes (CTLs). However, MHC class I molecules generally present the epitope peptides derived from endogenous antigens for DCs but not exogenous ones such as TAAs. Recently, we developed the novel liposomal bubbles (Bubble liposomes) encapsulating perfluoropropane nanobubbles. In this study, we attempted to establish the novel antigen delivery system to induce MHC class I presentation using the combination of ultrasound and Bubble liposomes. Using ovalbumin (OVA) as model antigen, the combination of Bubble liposomes and ultrasound exposure for the DC could induce MHC class I presentation. In addition, the viability of DCs was more than 80%. These results suggest that Bubble liposomes might be a novel ultrasound enhanced antigen delivery tool in DC-based cancer immunotherapy.

  8. Advances in synthetic peptide immuno-regulatory epitopes.

    Science.gov (United States)

    Creticos, Peter Socrates

    2014-01-01

    Synthetic peptide immuno-regulatory epitopes (SPIRE) represent a new class of therapeutics for allergen immunotherapy that offer the potential to suppress the IgE-mediated allergic disease process through induction of T-cell tolerance. These synthetic T-cell-tolerizing peptides have been designed to induce immunologic tolerance via binding to MHC class II molecules on antigen presenting cells, with subsequent upregulation of regulatory T-cells.

  9. Carcinoembryonic antigen (CEA)

    International Nuclear Information System (INIS)

    Ephraim, K.H.; Cox, P.H.; Hamer, C.J.A. v.d.; Berends, W.; Delhez, H.

    1977-01-01

    The carcinoembryonic antigen (CEA) is a complex of antigen determinants and also the carrier of these determinants. Chemically it is a glycoprotein. Its occurrence in blood serum or urine is correlated with malignant disease. Several radioimmunoassays (RIA) have been developed, one by Hoffmann-Laroche and one by the Rotterdam Radiotherapeutic Institute. Both methods and the Hoffmann assay kit are tested. Specifications are given for isolation of the antigen, preparation of the antiserum, and the execution of the RIA. Biochemical and clinical aspects are discussed

  10. 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.

  11. Proofreading of Peptide-MHC Complexes through Dynamic Multivalent Interactions.

    Science.gov (United States)

    Thomas, Christoph; Tampé, Robert

    2017-01-01

    The adaptive immune system is able to detect and destroy cells that are malignantly transformed or infected by intracellular pathogens. Specific immune responses against these cells are elicited by antigenic peptides that are presented on major histocompatibility complex class I (MHC I) molecules and recognized by cytotoxic T lymphocytes at the cell surface. Since these MHC I-presented peptides are generated in the cytosol by proteasomal protein degradation, they can be metaphorically described as a window providing immune cells with insights into the state of the cellular proteome. A crucial element of MHC I antigen presentation is the peptide-loading complex (PLC), a multisubunit machinery, which contains as key constituents the transporter associated with antigen processing (TAP) and the MHC I-specific chaperone tapasin (Tsn). While TAP recognizes and shuttles the cytosolic antigenic peptides into the endoplasmic reticulum (ER), Tsn samples peptides in the ER for their ability to form stable complexes with MHC I, a process called peptide proofreading or peptide editing. Through its selection of peptides that improve MHC I stability, Tsn contributes to the hierarchy of immunodominant peptide epitopes. Despite the fact that it concerns a key event in adaptive immunity, insights into the catalytic mechanism of peptide proofreading carried out by Tsn have only lately been gained via biochemical, biophysical, and structural studies. Furthermore, a Tsn homolog called TAP-binding protein-related (TAPBPR) has only recently been demonstrated to function as a second MHC I-specific chaperone and peptide proofreader. Although TAPBPR is PLC-independent and has a distinct allomorph specificity, it is likely to share a common catalytic mechanism with Tsn. This review focuses on the current knowledge of the multivalent protein-protein interactions and the concomitant dynamic molecular processes underlying peptide-proofreading catalysis. We do not only derive a model that

  12. Protection against Cutaneous Leishmaniasis in Outbred Vervet Monkeys, Using a Recombinant Histone H1 Antigen

    OpenAIRE

    Masina, Slavica; M. Gicheru, Michael; Demotz, Stéphane O.; Fasel, Nicolas J.

    2017-01-01

    Infection with Leishmania major parasites results in the development of cutaneous ulcerative lesions on the skin. We investigated the protective potential of a single, recombinant histone H1 antigen against cutaneous leishmaniasis in an outbred population of vervet monkeys, using Montanide adjuvant. Protection was assessed by challenging the animals with a mixture of vector sand fly salivary-gland lysate and a low dose of in vitro-derived parasites, thus more closely mimicking natural infecti...

  13. 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.

  14. Potent antigen-specific immune response induced by infusion of spleen cells coupled with succinimidyl-4-(N-maleimidomethyl cyclohexane)-1-carboxylate (SMCC) conjugated antigens.

    Science.gov (United States)

    Guo, Yixian; Werbel, Tyler; Wan, Suigui; Wu, Haitao; Li, Yaohua; Clare-Salzler, Michael; Xia, Chang-Qing

    2016-02-01

    In the present study, we report our recently developed new approach to inducing antigen-specific immune response. We use two nucleophilic substitution "click" chemistry processes to successfully couple protein antigens or peptides to mouse spleen cells or T cells by a heterobifunctional crosslinker, succinimidyl-4-(N-maleimidomethyl cyclohexane)-1-carboxylate (SMCC) or sulfo-SMCC. SMCC and its water-soluble analog sulfo-SMCC contain N-hydroxysuccinimide (NHS) ester and maleimide groups, which allow stable covalent conjugation of amine- and sulfhydryl-containing molecules in trans. Protein coupling to cells relies on the free sulfhydryls (thiols) on cell surfaces and the free amines on protein antigens. Although the amount of protein coupled to cells is limited due to the limited number of cell surface thiols, the injection of spleen cells coupled with antigenic proteins, such as keyhole limpet hemocyanin (KLH) or ovalbumin (OVA), induces a potent antigen-specific immune response in vivo, which is even stronger than that induced by the injection of a large dose of protein plus adjuvants. In addition, short peptides coupled to purified splenic T cells also potently elicit peptide-specific T cell proliferation in vivo after injection. Further studies show that antigen-coupled spleen cell treatment leads to augmented IFN-γ-producing T cells. Our study provides a unique antigen delivery method that efficiently distributes antigen to the entire immune system, subsequently eliciting a potent antigen-specific immune response with enhanced IFN-γ production. The findings in the present study suggest that this antigen-cell coupling strategy could be employed in immunotherapy for cancers, infectious diseases as well as immune-mediated disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Restless legs syndrome mimicking S1 radiculopathy.

    Science.gov (United States)

    Zambelis, Th; Wolgamuth, B R; Papoutsi, S N; Economou, N T

    2016-01-01

    mimicking several pathological conditions, Restless Legs Syndrome prevalence on general population according to various large epidemiological studies and pathogenic hypotheses on the issue of Restless Legs Syndrome are discussed. Finally, by presenting another possible "RLS-mimic" our aim is to highlight the common misdiagnosis of Restless Legs Syndrome, which can mimic a variety of disorders, some of which are very common, such as an S1 radiculopathy, thus raising concern among doctors of various specialties addressed to by Restless Legs Syndrome sufferers, on the importance of proper diagnosis of the syndrome.

  16. 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...

  17. [SYNTHETIC PEPTIDE VACCINES].

    Science.gov (United States)

    Sergeyev, O V; Barinsky, I F

    2016-01-01

    An update on the development and trials of synthetic peptide vaccines is reviewed. The review considers the successful examples of specific protection as a result of immunization with synthetic peptides using various protocols. The importance of conformation for the immunogenicity of the peptide is pointed out. An alternative strategy of the protection of the organism against the infection using synthetic peptides is suggested.

  18. Peptide fragments induce a more rapid immune response than intact proteins in earthworms.

    Science.gov (United States)

    Hanusová, R; Tucková, L; Halada, P; Bezouska, K; Bilej, M

    1999-01-01

    The effect of in vivo proteolytic processing of protein antigen was studied in Eisenia foetida earthworms. Parenteral administration of the protein antigen induces elevated levels of an antigen-binding protein (ABP) which recognizes the protein used for stimulation. When the protein antigen is administered simultaneously with nontoxic serine proteinase inhibitor, ABP levels remain close to background. On the other hand, the in vivo adaptive response of earthworms to peptide fragments obtained by coelomic fluid digestion of the foreign antigen occurs even in the presence of proteinase inhibitor and, moreover, is significantly faster as compared to the response to intact antigen. These findings confirm the role of proteolytic processing in earthworms. MALDI mass spectrometric analysis of the fragments after coelomic fluid digestion has revealed the presence of the peptide fragments with molecular weights in the mass range 700-1100 Da.

  19. Towards patient-specific tumor antigen selection for vaccination.

    Science.gov (United States)

    Rammensee, Hans-Georg; Weinschenk, Toni; Gouttefangeas, Cécile; Stevanović, Stefan

    2002-10-01

    In this review, we discuss the possibilities for combining the power of molecular analysis of the antigens expressed in a given individual tumor with the design of a tailored vaccine containing defined antigens. Step 1 is a differential gene expression analysis of tumor and corresponding normal tissue. Step 2 is the analysis of human leukocyte antigen (HLA) ligands on tumor cells. Step 3 is data mining with the aim to select those antigens that might be suitable for tumor attack by the adaptive immune system. Step 4 is the on-the-spot clinical grade production of the constituents of the patient tailored vaccine, e.g. peptides. Step 5 is then vaccination and monitoring. Although it will not be possible to cover all relevant antigens expressed in a tumor, the antigens that can be identified with our present technical possibilities might be enough for improved immunotherapy. The scope of the present review is to explore the possibilities and the formidable technical and logistical challenge for such individual patient-oriented antigen definition to be used for therapeutic immunization.

  20. Comparative characteristic of the methods of protein antigens epitope mapping

    Directory of Open Access Journals (Sweden)

    O. Yu. Galkin

    2014-08-01

    Full Text Available Comparative analysis of experimental methods of epitope mapping of protein antigens has been carried out. The vast majority of known techniques are involved in immunochemical study of the interaction of protein molecules or peptides with antibodies of corresponding specifici­ty. The most effective and widely applicable metho­dological techniques are those that use synthetic and genetically engineered peptides. Over the past 30 years, these groups of methods have travelled a notable evolutionary path up to the maximum automation and the detection of antigenic determinants of various types (linear and conformational epitopes, and mimotopes. Most of epitope searching algorithms were integrated into a computer program, which greatly facilitates the analysis of experimental data and makes it possible to create spatial models. It is possible to use comparative epitope mapping for solving the applied problems; this less time-consuming method is based on the analysis of competition between different antibodies interactions with the same antigen. The physical method of antigenic structure study is X-ray analysis of antigen-antibody complexes, which may be applied only to crystallizing­ proteins, and nuclear magnetic resonance.

  1. Selection of ligand peptides with the ability to detect antibodies in ...

    African Journals Online (AJOL)

    ... contributing directly to disease control. The selections enabled the choice of clones which can be used as potential antigens in the diagnoses of diseases. The synthetic peptide produced from the selected sequences may be considered as an alternative for antigens in the serologic diagnosis of enzootic bovine leukosis.

  2. A casein-kinase-2-related protein kinase is tightly associated with the large T antigen of simian virus 40

    DEFF Research Database (Denmark)

    Götz, C; Koenig, M G; Issinger, O G

    1995-01-01

    The simian virus 40 (SV40) large T antigen is a multifunctional protein involved in SV40 cell transformation and lytic virus infection. Some of its activities are regulated by interaction with cellular proteins and/or by phosphorylation of T antigen by various protein kinases. In this study, we...... of T antigen by the associated kinase is reduced whereas a p34cdc2-kinase-specific peptide has no influence. In addition, the T-antigen-associated protein kinase can use GTP and ATP as phosphate donors. These properties together with the observation that immunopurified T antigen can be phosphorylated...

  3. Interaction of Serum Antibodies from Breast Cancer Patients with Synthetic Peptides.

    Science.gov (United States)

    Podlesnykh, S V; Kolosova, E A; Shcherbakov, D N; Shaidurov, A A; Anisimov, D S; Ryazanov, M A; Johnston, S A; Shoikhet, Ya N; Petrova, V D; Lazarev, A F; Chapoval, A I

    2016-10-01

    The blood serum of tumor patients contains antibodies recognizing tumor-associated antigens and other molecular products of tumor growth. We studied the interaction of blood antibodies from breast cancer patients with synthetic peptides that were applied on the microchip surface. The serum from healthy volunteers and breast cancer patients was shown to contain antibodies that interact with various peptides. Statistically significant between-group differences were observed in the level of binding with 122 informative peptides (0.01% of the total number of peptides on a microchip). Analysis of antibodies that interact with the peptide panel holds much promise for the diagnostics of breast cancer.

  4. 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

  5. Human pathogen subversion of antigen presentation.

    Science.gov (United States)

    Brodsky, F M; Lem, L; Solache, A; Bennett, E M

    1999-04-01

    Many pathogens have co-evolved with their human hosts to develop strategies for immune evasion that involve disruption of the intracellular pathways by which antigens are bound by class I and class II molecules of the major histocompatibility complex (MHC) for presentation to T cells. Here the molecular events in these pathways are reviewed and pathogen interference is documented for viruses, extracellular and intracellular bacteria and intracellular parasites. In addition to a general review, data from our studies of adenovirus, Chlamydia trachomatis and Coxiella burnetii are summarized. Adenovirus E19 is the first viral gene product described that affects class I MHC molecule expression by two separate mechanisms, intracellular retention of the class I heavy chain by direct binding and by binding to the TAP transporter involved in class I peptide loading. Coxiella and Chlamydia both affect peptide presentation by class II MHC molecules as a result of their residence in endocytic compartments, although the properties of the parasitophorous vacuoles they form are quite different. These examples of active interference with antigen presentation by viral gene products and passive interference by rickettsiae and bacteria are typical of the strategies used by these different classes of pathogens, which need to evade different types of immune responses. Pathogen-host co-evolution is evident in these subversion tactics for which the pathogen crime seems tailored to fit the immune system punishment.

  6. 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.

  7. Novel antigens used to detect cell-mediated immune responses over time in Mycobacterium avium subsp. paratuberculosis infected cattle

    DEFF Research Database (Denmark)

    Mikkelsen, Heidi; Aagaard, Claus; Nielsen, Søren Saxmose

    consisting of undefined antigens with possible cross reactions toward other environmental bacteria. The objective of the study was to optimize the IFN-γ test using different types of novel antigens for stimulation. Fourteen novel antigen candidates were selected for testing, including 4 peptides of the ESAT...... on the same 30 heifers from a known MAP infected herd. Determination of cut-off for each antigen was based on samples from a non-infected herd, including 60 heifers. Based on PPDj stimulations, more than 50% of the heifers tested MAP positive at the first two samplings, whereas only 20% tested positive...... at third sampling. The resulted showed that PPDj detect a high percentage as MAP positive animals, as this crude antigen mixture is expected to induce non-specific IFN-γ production. However, the tested latency antigens, some secreted proteins and some peptides of the ESAT-6 family detected a comparable...

  8. Identification of a Highly Antigenic Linear B Cell Epitope within Plasmodium vivax Apical Membrane Antigen 1 (AMA-1)

    Science.gov (United States)

    Bueno, Lilian Lacerda; Lobo, Francisco Pereira; Morais, Cristiane Guimarães; Mourão, Luíza Carvalho; de Ávila, Ricardo Andrez Machado; Soares, Irene Silva; Fontes, Cor Jesus; Lacerda, Marcus Vinícius; Olórtegui, Carlos Chavez; Bartholomeu, Daniella Castanheira; Fujiwara, Ricardo Toshio; Braga, Érika Martins

    2011-01-01

    Apical membrane antigen 1 (AMA-1) is considered to be a major candidate antigen for a malaria vaccine. Previous immunoepidemiological studies of naturally acquired immunity to Plasmodium vivax AMA-1 (PvAMA-1) have shown a higher prevalence of specific antibodies to domain II (DII) of AMA-1. In the present study, we confirmed that specific antibody responses from naturally infected individuals were highly reactive to both full-length AMA-1 and DII. Also, we demonstrated a strong association between AMA-1 and DII IgG and IgG subclass responses. We analyzed the primary sequence of PvAMA-1 for B cell linear epitopes co-occurring with intrinsically unstructured/disordered regions (IURs). The B cell epitope comprising the amino acid sequence 290–307 of PvAMA-1 (SASDQPTQYEEEMTDYQK), with the highest prediction scores, was identified in domain II and further selected for chemical synthesis and immunological testing. The antigenicity of the synthetic peptide was identified by serological analysis using sera from P. vivax-infected individuals who were knowingly reactive to the PvAMA-1 ectodomain only, domain II only, or reactive to both antigens. Although the synthetic peptide was recognized by all serum samples specific to domain II, serum with reactivity only to the full-length protein presented 58.3% positivity. Moreover, IgG reactivity against PvAMA-1 and domain II after depletion of specific synthetic peptide antibodies was reduced by 18% and 33% (P = 0.0001 for both), respectively. These results suggest that the linear epitope SASDQPTQYEEEMTDYQK is highly antigenic during natural human infections and is an important antigenic region of the domain II of PvAMA-1, suggesting its possible future use in pre-clinical studies. PMID:21713006

  9. Unusual antigen presentation offers new insight into HIV vaccine design.

    Science.gov (United States)

    McMichael, Andrew J; Picker, Louis J

    2017-06-01

    Recent findings with a rhesus monkey cytomegalovirus based simian immunodeficiency virus vaccine have identified strong CD8+ T cell responses that are restricted by MHC-E. Also mycobacteria specific CD8+ T cells, that are MHC-E restricted, have been identified. MHC-E therefore can present a wide range of epitope peptides to CD8+ T cells, alongside its well defined role in presenting a conserved MHC-class I signal peptide to the NKG2A/C-CD94 receptor on natural killer cells. Here we explore the antigen processing pathways involved in these atypical T cell responses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Ocular surface foreign bodies: novel findings mimicking ocular malignant melanoma.

    Science.gov (United States)

    Maudgil, A; Wagner, B E; Rundle, P; Rennie, I G; Mudhar, H S

    2014-11-01

    Malignant melanoma of the eye is an uncommon condition that is important to recognise. We describe three cases in which ocular foreign bodies have masqueraded as ocular malignant melanoma. Interventional case reports. Case 1 describes diathermy-induced carbon particle implantation, during plaque therapy for the treatment of uveal melanoma, mimicking recurrence with extra-scleral invasion. Case 2 shows a foreign body called 'mullite' mimicking conjunctival melanoma. Case 3 demonstrates a conjunctival foreign body called 'illite' that mimicked a limbal melanocytic lesion, clinically thought to be either melanocytoma or melanoma. This report highlights the importance of careful history taking, examination, and appropriate biopsy in cases of suspected malignant melanoma, to prevent unnecessary and potentially radical treatment.

  11. Impact of the NCAM derived mimetic peptide plannexin on the acute cellular consequences of a status epilepticus

    DEFF Research Database (Denmark)

    Zellinger, Christina; Hadamitzky, Martin; Bock, Elisabeth

    2011-01-01

    Plannexin represents a NCAM-derived peptide mimicking trans-homophilic NCAM interaction, which proved to exert neuroprotective effects in vitro. The effect of plannexin was evaluated in a rat status epilepticus model. As expected, prolonged seizure activity resulted in a pronounced cell loss in h...

  12. Proteasomal targeting and minigene repetition improve cell-surface presentation of a transfected, modified melanoma tumour antigen

    DEFF Research Database (Denmark)

    Rasmussen, A B; Zocca, M-B; Bonefeld, C M

    2004-01-01

    on the density of specific major histocompatibility complex-peptide complexes on the surface of the antigen-presenting cell. In this study, we explored the cell-surface presentation of a substituted MART-1 peptide encoded by transfected minigenes. We investigated the potential of proteasomal targeting compared...

  13. Enhanced presentation of MHC class Ia, Ib and class II-restricted peptides encapsulated in biodegradable nanoparticles: a promising strategy for tumor immunotherapy

    Directory of Open Access Journals (Sweden)

    Schroter Stephanie

    2011-03-01

    Full Text Available Abstract Background Many peptide-based cancer vaccines have been tested in clinical trials with a limited success, mostly due to difficulties associated with peptide stability and delivery, resulting in inefficient antigen presentation. Therefore, the development of suitable and efficient vaccine carrier systems remains a major challenge. Methods To address this issue, we have engineered polylactic-co-glycolic acid (PLGA nanoparticles incorporating: (i two MHC class I-restricted clinically-relevant peptides, (ii a MHC class II-binding peptide, and (iii a non-classical MHC class I-binding peptide. We formulated the nanoparticles utilizing a double emulsion-solvent evaporation technique and characterized their surface morphology, size, zeta potential and peptide content. We also loaded human and murine dendritic cells (DC with the peptide-containing nanoparticles and determined their ability to present the encapsulated peptide antigens and to induce tumor-specific cytotoxic T lymphocytes (CTL in vitro. Results We confirmed that the nanoparticles are not toxic to either mouse or human dendritic cells, and do not have any effect on the DC maturation. We also demonstrated a significantly enhanced presentation of the encapsulated peptides upon internalization of the nanoparticles by DC, and confirmed that the improved peptide presentation is actually associated with more efficient generation of peptide-specific CTL and T helper cell responses. Conclusion Encapsulating antigens in PLGA nanoparticles offers unique advantages such as higher efficiency of antigen loading, prolonged presentation of the antigens, prevention of peptide degradation, specific targeting of antigens to antigen presenting cells, improved shelf life of the antigens, and easy scale up for pharmaceutical production. Therefore, these findings are highly significant to the development of synthetic vaccines, and the induction of CTL for adoptive immunotherapy.

  14. Multiple Antigen Peptide Vaccines against Plasmodium falciparum Malaria

    Science.gov (United States)

    2010-01-01

    A2 molecule), and one outbred mouse strain (CD1). Th~.: HLA-A2 transgenic mice were included in these studies to facilitate the determination of...sporozoites were obtained by dissection of the salivary glands of Anopheles stephcnsi mosquitoes as described by Ozaki et al. ( 38). The sporozoites were...immunizations, the strongest anti- MAP-! ELISA IgG responses were observed in mice with the C57BU6 background (in both the HLA-A2 transgene and the wild-type

  15. Poor correspondence between predicted and experimental binding of peptides to class I MHC molecules

    DEFF Research Database (Denmark)

    Andersen, Mads Hald; Tan, L.; Søndergaard, Ib

    2000-01-01

    Naturally processed peptides presented by class I major histocompatibility complex (MHC) molecules display a characteristic allele specific motif of two or more essential amino acid side chains, the so-called peptide anchor residues, in the context of an 8-10 amino acid long peptide. Knowledge...... of the peptide binding motif of individual class I MHC molecules permits the selection of potential peptide antigens from proteins of infectious organisms that could induce protective T-cell-mediated immunity. Several methods have been developed for the prediction of potential class I MHC binding peptides. One...... of peptide binding motifs for individual class I MHC molecules. The actual binding was compared with the results obtained when analyzing the same peptides by two well-known, publicly available computer algorithms. We conclude that there is no strong correlation between actual and predicted binding when using...

  16. Vaccination of High-Risk Breast Cancer Patients with Carbohydrate Mimicking Peptides

    Science.gov (United States)

    2009-05-01

    8.4.1. Gross pathology performed on these organs Mesenteric lymph nodes Ovaries Brain and pituitary gland Pancreas Cecum Rectum Colon...not confirmed via special stain; however, morphology is consistent with fibrin or fibrinogen, either of which is consistent with acute thrombosis ...suggesting that thrombosis is occurring near death. This lesion is temporally removed from vaccination and not significantly different between

  17. Neonatal appendicitis mimicking intestinal duplication: a case report

    Directory of Open Access Journals (Sweden)

    Saeki Isamu

    2012-09-01

    Full Text Available Abstract Introduction Acute appendicitis is a common disease in older children but rare in neonates. Case presentation We report the case of a 2-day-old Asian baby who suffered from neonatal appendicitis mimicking intestinal duplication. Laparoscopic appendectomy was successfully performed after the trans-umbilical division of adhesions, and the postoperative course was uneventful. Conclusion There are few reports describing abdominal masses caused by appendicitis mimicking intestinal duplication. The laparoscopic approach for neonatal appendicitis is considered to be a safe and useful therapeutic modality with good cosmetic results.

  18. Computer analysis of antigenic domains and RGD-like sequences (RGWG) in the E glycoprotein of flaviviruses: an approach to vaccine development.

    Science.gov (United States)

    Becker, Y

    1990-09-01

    Antigenic domains and RGD-like sequences in the E glycoprotein of the flaviviruses Japanese encephalitis virus, yellow fever virus, West Nile virus, dengue type 4 virus, and tick-borne encephalitis virus were analyzed by computer programs that provide information on the physical properties of the polypeptides. The use of computer programs for the development of vaccines based on the synthesis of antigenic peptides is discussed. Synthetic viral peptides are proposed to be used for topical application so as to interfere with the virus-cell interaction. Viral peptides with antigenic epitopes to protect against dengue virus infection without enhancing pathogenesis may also be developed on the basis of the computer analysis.

  19. Selection of peptides for serological detection of equine infectious anemia.

    Science.gov (United States)

    Santos, E M; Cardoso, R; Souza, G R L; Goulart, L R; Heinemann, M B; Leite, R C; Reis, J K P

    2012-08-13

    Equine infectious anemia caused by equine infectious anemia virus is an important disease due to its high severity and incidence in animals. We used a phage display library to isolate peptides that can be considered potential markers for equine infectious anemia diagnosis. We selected peptides using IgG purified from a pool comprised of 20 sera from animals naturally infected with equine infectious anemia virus. The diagnostic potential of these peptides was investigated by ELISA, Western blot and dot blot with purified IgG and serum samples. Based on the results, we chose a peptide mimetic for glycoprotein gp45 epitopes of equine infectious anemia virus, with potential for use as an antigen in indirect diagnostic assays. Synthesis of this peptide has possible applications for the development of new diagnostic tools for this disease.

  20. Low-Cost Peptide Microarrays for Mapping Continuous Antibody Epitopes.

    Science.gov (United States)

    McBride, Ryan; Head, Steven R; Ordoukhanian, Phillip; Law, Mansun

    2016-01-01

    With the increasing need for understanding antibody specificity in antibody and vaccine research, pepscan assays provide a rapid method for mapping and profiling antibody responses to continuous epitopes. We have developed a relatively low-cost method to generate peptide microarray slides for studying antibody binding. Using a setup of an IntavisAG MultiPep RS peptide synthesizer, a Digilab MicroGrid II 600 microarray printer robot, and an InnoScan 1100 AL scanner, the method allows the interrogation of up to 1536 overlapping, alanine-scanning, and mutant peptides derived from the target antigens. Each peptide is tagged with a polyethylene glycol aminooxy terminus to improve peptide solubility, orientation, and conjugation efficiency to the slide surface.

  1. Specificity of rabbit antibodies elicited by related synthetic peptides.

    Science.gov (United States)

    Chersi, A; Houghten, R A; Chillemi, F; Zito, R; Centis, D

    1986-01-01

    Three 17-residue peptides, presenting from 65% to 70% sequence homology, and one endecapeptide, with no apparent homology with the first three, were chemically synthesized and investigated in their ability to elicit rabbit antipeptide antibodies. The complex cross reactivities of the antisera were investigated by testing the binding of the antibodies to the intact peptides, to their enzymatic fragments, and by the use of specific immunoadsorbents. Antipeptide antibodies may or may not crossreact with related "parent" peptides, this depending upon number, distribution, and localization of amino acid differences in low or high antigenicity regions of the immunogen. Related peptides may elicit antibodies that crossreact almost completely, and therefore not specific for one or the other "parent" peptide. Those antibodies may therefore be of little use for the selective recognition of closely related structures.

  2. Immunoreactivity of synthetic peptides derived from proteins of Cryptococcus gattii.

    Science.gov (United States)

    de Serpa Brandão, Rafael Melo Santos; Soares Martins, Liline Maria; de Andrade, Hélida Monteiro; Faria, Angélica Rosa; Soares Leal, Maria José; da Silva, Adalberto Socorro; Wanke, Bodo; dos Santos Lazéra, Márcia; Vainstein, Marilene Henning; Mendes, Rinaldo Poncio; Moris, Daniela Vanessa; de Souza Cavalcante, Ricardo; do Monte, Semiramis Jamil Hadad

    2014-01-01

    To determine the immunoreactivity of synthetic Cryptococcus-derived peptides. A total of 63 B-cell epitopes from previously identified Cryptococcus gattii immunoreactive proteins were synthesized and evaluated as antigens in ELISAs. The peptides were first evaluated for their ability to react against sera from immunocompetent subjects carrying cryptococcal meningitis. Peptides that yielded high sensitivity and specificity in the first test were then retested with sera from individuals with other fungal pathologies for cross-reactivity determination. Six of 63 synthetic peptides were recognized by antibodies in immunoassays, with a specificity of 100%, sensitivity of 78% and low cross-reactivity. We successfully determined the immunoreactivity of selected synthetic peptides of C. gattii derived proteins.

  3. Production and characterization Te-peptide by induced autolysis of Saccharomyces cerevisiae.

    Science.gov (United States)

    Morya, V K; Dong, Shin Jae; Kim, Eun-ki

    2014-04-01

    Recently, the interest in mimicking functions of chalcogen-based catalytic antioxidants like selenoenzymes, has been increased. Various attempts had been done with selenium, but very few attempts were carried out with tellurium. Bio-complex formation and characterization of tellurium was not tried earlier by using any organism. The present study was focused on tellurium peptide production, characterization, and bioactivity assessment especially Mimetic to glutathione peroxidase (GPx). The production was achieved by the autolysis of total proteins obtained from Saccharomyces cerevisiae ATCC 7752 grown with inorganic tellurium. The GPx-like activity of the hydrolyzed tellurium peptide was increased when prepared by autolysis, but decreased when prepared by acid hydrolysis. Tellurium peptide produced by autolysis of the yeast cell showed increased GPx-like activity as well as tellurium content. Tellurium peptide showed little toxicity, compared to highly toxic inorganic tellurium. The results showed the potential of tellurium peptide as an antioxidant that can be produced by simple autolysis of yeast cells.

  4. Pronase E-Based Generation of Fluorescent Peptide Fragments: Tracking Intracellular Peptide Fate in Single Cells.

    Science.gov (United States)

    Mainz, Emilie R; Dobes, Nicholas C; Allbritton, Nancy L

    2015-08-04

    The ability to track intracellular peptide proteolysis at the single cell level is of growing interest, particularly as short peptide sequences continue to play important roles as biosensors, therapeutics, and endogenous participants in antigen processing and intracellular signaling. We describe a rapid and inexpensive methodology to generate fluorescent peptide fragments from a parent sequence with diverse chemical properties, including aliphatic, nonpolar, basic, acidic, and non-native amino acids. Four peptide sequences with existing biochemical applications were fragmented using incubation with Pronase E and/or formic acid, and in each case a complete set of fluorescent fragments was generated for use as proteolysis standards in chemical cytometry. Fragment formation and identity was monitored with capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) and matrix assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-MS) to confirm the presence of all sequences and yield fragmentation profiles across Pronase E concentrations which can readily be used by others. As a pilot study, Pronase E-generated standards from an Abl kinase sensor and an ovalbumin antigenic peptide were then employed to identify proteolysis products arising from the metabolism of these sequences in single cells. The Abl kinase sensor fragmented at 4.2 ± 4.8 zmol μM(-1) s(-1) and the majority of cells possessed similar fragment identities. In contrast, an ovalbumin epitope peptide was degraded at 8.9 ± 0.1 zmol μM(-1) s(-1), but with differential fragment formation between individual cells. Overall, Pronase E-generated peptide standards were a rapid and efficient method to identify proteolysis products from cells.

  5. Regulation of MHC Class II-Peptide Complex Expression by Ubiquitination

    Directory of Open Access Journals (Sweden)

    Kyung Jin eCho

    2013-11-01

    Full Text Available MHC class II (MHC-II molecules are present on antigen presenting cells (APCs and these molecules function by binding antigenic peptides and presenting these peptides to antigen-specific CD4+ T cells. APCs continuously generate and degrade MHC-II molecules, and ubiquitination of MHC-II has recently been shown to be a key regulator of MHC-II expression in dendritic cells (DCs. In this mini-review we will examine the mechanism by which the E3 ubiquitin ligase March-I regulates MHC-II expression on APCs and will discuss the functional consequences of altering MHC-II ubiquitination.

  6. Idala: An unnamed Function Peptide Vaccine for Tuberculosis ...

    African Journals Online (AJOL)

    Purpose: To evaluate Myt272 protein antigenicity and immunogenicity by trial vaccination in mice and its in silico analysis as a potential peptide vaccine for tuberculosis. Methods: Myt272 gene, which has 100 % identity with Mycobacterium tuberculosis H37Rv unknown function gene Rv3424c, was ligated by genomic ...

  7. Nonnecrotizing anterior scleritis mimicking orbital inflammatory disease

    Directory of Open Access Journals (Sweden)

    Lynch MC

    2013-08-01

    Full Text Available Michelle Chen Lynch,1 Andrew B Mick21Optometry Clinic, Ocala West Veterans Affairs Specialty Clinic, Ocala, FL, USA; 2Eye Clinic, San Francisco VA Medical Center, San Francisco, CA, USABackground: Anterior scleritis is an uncommon form of ocular inflammation, often associated with coexisting autoimmune disease. With early recognition and aggressive systemic therapy, prognosis for resolution is good. The diagnosis of underlying autoimmune disease involves a multidisciplinary approach.Case report: A 42-year-old African American female presented to the Eye Clinic at the San Francisco Veteran Affairs Medical Center, with a tremendously painful left eye, worse on eye movement, with marked injection of conjunctiva. There was mild swelling of the upper eyelid. Visual acuity was unaffected, but there was a mild red cap desaturation. The posterior segment was unremarkable. The initial differential diagnoses included anterior scleritis and orbital inflammatory disease. Oral steroid treatment was initiated with rapid resolution over a few days. Orbital imaging was unremarkable, and extensive laboratory work-up was positive only for antinuclear antibodies. The patient was diagnosed with idiopathic diffuse, nonnecrotizing anterior scleritis and has been followed for over 5 years without recurrence. The rheumatology clinic monitors the patient closely, as suspicion remains for potential arthralgias including human leukocyte antigen-B27-associated arthritis, lupus-associated arthritis, seronegative rheumatoid arthritis, recurrent juvenile idiopathic arthritis, and scleroderma, based on her constitutional symptoms and clinical presentation, along with a positive anti-nuclear antibody lab result.Conclusion: Untreated anterior scleritis can progress to formation of cataracts, glaucoma, uveitis, corneal melting, and posterior segment disease with significant risk of vision loss. Patients with anterior scleritis must be aggressively treated with systemic anti

  8. Dynamics of the membrane-cytoskeleton interface in MHC class II-restricted antigen presentation.

    Science.gov (United States)

    Bretou, Marine; Kumari, Anita; Malbec, Odile; Moreau, Hélène D; Obino, Dorian; Pierobon, Paolo; Randrian, Violaine; Sáez, Pablo J; Lennon-Duménil, Ana-Maria

    2016-07-01

    Antigen presentation refers to the ability of cells to show MHC-associated determinants to T lymphocytes, leading to their activation. MHC class II molecules mainly present peptide-derived antigens that are internalized by endocytosis in antigen-presenting cells (APCs). Here, we describe how the interface between cellular membranes and the cytoskeleton regulates the various steps that lead to the presentation of exogenous antigens on MHC class II molecules in the two main types of APCs: dendritic cells (DCs) and B lymphocytes. This includes antigen uptake, processing, APC migration, and APC-T cell interactions. We further discuss how the interaction between APC-specific molecules and cytoskeleton elements allows the coordination of antigen presentation and cell migration in time and space. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Duodenal foreign body mimicking acute pancreatitis

    International Nuclear Information System (INIS)

    Willard, M.D.; Wolf, A.M.; Green, R.

    1993-01-01

    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

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

    DEFF Research Database (Denmark)

    Petersen, E; Høgh, B; Dziegiel, M

    1992-01-01

    The IgG and IgM antibody responses to the C-terminal 783 amino acids of the P. falciparum glutamate-rich protein, GLURP489-1271, expressed as an E. coli fusion protein, the IgG response to a 18-mer synthetic peptide EDKNEKGQHEIVEVEEIL (GLURP899-916) representing the C-terminal repeats of GLURP...... the antigens, the responses were often short-lived. In adults, the antibody responses to the GLURP489-1271 fusion protein and the (EENV)6 peptide peaked after 2 weeks, and not all individuals responded to all antigens. The antibody response, even against large fragments of conserved antigens, is not uniformly...

  11. 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.

  12. 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.)

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

    International Nuclear Information System (INIS)

    Chang, Yun Woo; Yoon, Hye-Kyung; Cho, Jae Min; Sung, Ki Woong

    2003-01-01

    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.)

  14. Large fibroadenoma mimicking malignancy | Smal | SA Journal of ...

    African Journals Online (AJOL)

    SA Journal of Radiology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 8, No 1 (2004) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Large fibroadenoma mimicking malignancy. J Smal. Abstract.

  15. Endometriosis of the meso-appendix mimicking appendicitis: A case ...

    African Journals Online (AJOL)

    Although appendicitis is largely a clinical diagnosis, on occasions diagnostic modalities may be needed to aid with the diagnosis. Despite the use of adjuncts and exploratory surgery, the diagnosis may not be clear until a histological diagnosis is achieved. Endometriosis of the appendix mimicking appendicitis is one of ...

  16. Crystal structure and bio-mimicking of Catecholase activity

    Indian Academy of Sciences (India)

    Unprecedented hetero-geometric discrete copper(II) complexes: Crystal structure and bio-mimicking of Catecholase activity. ABHRANIL DE DHANANJAY DEY HARE RAM YADAV MILAN MAJI VINAYAK RANE R M KADAM ANGSHUMAN ROY CHOUDHURY BHASKAR BISWAS. Regular Article Volume 128 Issue 11 ...

  17. Trichophyton Schoenleinii-induced widespread tinea corporis mimicking parapsoriasis.

    Science.gov (United States)

    Mansouri, P; Farshi, S; Khosravi, A R; Naraghi, Z S; Chalangari, R

    2012-06-01

    We report a case of extensive tinea corporis in an 80-year-old woman on her forearms, thighs, legs, buttocks and trunk, mimicking parapsoriasis due to Trichophyton schoenleinii, without scalp involvement. Diagnosis of Trichophyton schoenleinii was confirmed by microscopy and mycological culture specimens. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  18. Dysplastic bone disease mimicking exostoses of the ear canal ...

    African Journals Online (AJOL)

    We present a case of a 43-year-old man who attended the ENT clinic complaining of bilateral hearing loss. He had multiple bony swellings in both ear canals that mimicked exostoses. An audiogram showed bilateral symmetrical mixed hearing loss. Excision was carried out to facilitate the use of a hearing aid.

  19. African oral histoplasmosis mimicking lip carcinoma: case report ...

    African Journals Online (AJOL)

    A case of Iocalised African histoplasmosis with an unusual presentation in a 56 year old Nigerian farmer is reported. The lesion presented as an ulcer clinically mimicking squamous cell carcinoma of the lower lip. An incisional biopsy and culture studies confirmed African histoplasmosis and the utcer healed spontaneously ...

  20. 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.

  1. T cell response to N-formylated peptides in humans.

    Science.gov (United States)

    Ristori, G; Montesperelli, C; Fiorillo, M T; Battistini, L; Chersi, A; Sorrentino, R; Borsellino, G; Perna, A; Tramonti, D; Cannoni, S; Perrone, M P; Giubilei, F; Riccio, P; Salvetti, M; Buttinelli, C

    2001-09-01

    We present the first evidence of a T lymphocyte response to N-formylated peptides in humans. N-formylated peptide sequences from self (mitochondrial) and foreign (microbial) antigens were used to isolate antigen-specific T cell clones from healthy individuals, including a set of monozygotic twins. The observed response differed from that previously described in mouse (CD4(+) phenotype and MHC class II restriction in humans vs. CD8(+) phenotype and class I restriction in mice). These lymphocytes produce substantial amounts of IFN-gamma. They were isolated in only one of the monozygotic twins, which suggests that their expansion in the healthy immune repertoire is independent of the genetic background. Our result will help in assessing the relevance of N-formylated peptide-specific T cells in protection against infections within the human immune system.

  2. Epstein Barr virus-encoded EBNA1 interference with MHC class I antigen presentation reveals a close correlation between mRNA translation initiation and antigen presentation.

    Directory of Open Access Journals (Sweden)

    Sebastien Apcher

    Full Text Available Viruses are known to employ different strategies to manipulate the major histocompatibility (MHC class I antigen presentation pathway to avoid recognition of the infected host cell by the immune system. However, viral control of antigen presentation via the processes that supply and select antigenic peptide precursors is yet relatively unknown. The Epstein-Barr virus (EBV-encoded EBNA1 is expressed in all EBV-infected cells, but the immune system fails to detect and destroy EBV-carrying host cells. This immune evasion has been attributed to the capacity of a Gly-Ala repeat (GAr within EBNA1 to inhibit MHC class I restricted antigen presentation. Here we demonstrate that suppression of mRNA translation initiation by the GAr in cis is sufficient and necessary to prevent presentation of antigenic peptides from mRNAs to which it is fused. Furthermore, we demonstrate a direct correlation between the rate of translation initiation and MHC class I antigen presentation from a certain mRNA. These results support the idea that mRNAs, and not the encoded full length proteins, are used for MHC class I restricted immune surveillance. This offers an additional view on the role of virus-mediated control of mRNA translation initiation and of the mechanisms that control MHC class I restricted antigen presentation in general.

  3. Synthetic melanin bound to subunit vaccine antigens significantly enhances CD8+ T-cell responses.

    Directory of Open Access Journals (Sweden)

    Antoine F Carpentier

    Full Text Available Cytotoxic T-lymphocytes (CTLs play a key role in immunity against cancer; however, the induction of CTL responses with currently available vaccines remains difficult. Because several reports have suggested that pigmentation and immunity might be functionally linked, we investigated whether melanin can act as an adjuvant in vaccines. Short synthetic peptides (8-35 amino acids long containing T-cell epitopes were mixed with a solution of L-Dopa, a precursor of melanin. The mixture was then oxidized to generate nanoparticles of melanin-bound peptides. Immunization with melanin-bound peptides efficiently triggered CTL responses in mice, even against self-antigens and at a very low dose of peptides (microgram range. Immunization against a tumor antigen inhibited the growth of established tumors in mice, an effect that was abrogated by the depletion of CD8+ lymphocytes. These results demonstrate the efficacy of melanin as a vaccine adjuvant.

  4. A monkey antigen crossreacting with carcinoembryonic antigen, CEA.

    Science.gov (United States)

    Engvall, E.; Vuento, M.; Ruoslahti, E.

    1976-01-01

    Normal monkey tissues were found to contain an antigen which crossreacts immunologically with the carcinoembryonic antigen (CEA) of the human digestive tract. The monkey antigen reacted with complete or partial identity to the normal crossreacting antigen (NCA) in humans when tested in immunodiffusion against anti-CEA or anti-NCA. Extracts of monkey tissues inhibited in radioimmunoassays measuring human NCA. It is possible that monkey foetuses and colonic tumours contain CEA. Images Fig. 1 PMID:823952

  5. 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...

  6. 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.

  7. Pathogen-mimicking vaccine delivery system designed with a bioactive polymer (inulin acetate) for robust humoral and cellular immune responses.

    Science.gov (United States)

    Kumar, Sunny; Kesharwani, Siddharth S; Kuppast, Bhimanna; Bakkari, Mohammed Ali; Tummala, Hemachand

    2017-09-10

    New and improved vaccines are needed against challenging diseases such as malaria, tuberculosis, Ebola, influenza, AIDS, and cancer. The majority of existing vaccine adjuvants lack the ability to significantly stimulate the cellular immune response, which is required to prevent the aforementioned diseases. This study designed a novel particulate based pathogen-mimicking vaccine delivery system (PMVDS) to target antigen-presenting-cells (APCs) such as dendritic cells. The uniqueness of PMVDS is that the polymer used to prepare the delivery system, Inulin Acetate (InAc), activates the innate immune system. InAc was synthesized from the plant polysaccharide, inulin. PMVDS provided improved and persistent antigen delivery to APCs as an efficient vaccine delivery system, and simultaneously, activated Toll-Like Receptor-4 (TLR-4) on APCs to release chemokine's/cytokines as an immune-adjuvant. Through this dual mechanism, PMVDS robustly stimulated both the humoral (>32 times of IgG1 levels vs alum) and the cell-mediated immune responses against the encapsulated antigen (ovalbumin) in mice. More importantly, PMVDS stimulated both cytotoxic T cells and natural killer cells of cell-mediated immunity to provide tumor (B16-ova-Melanoma) protection in around 40% of vaccinated mice and significantly delayed tumor progression in rest of the mice. PMVDS is a unique bio-active vaccine delivery technology with broader applications for vaccines against cancer and several intracellular pathogens, where both humoral and cellular immune responses are desired. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. TCR affinity for p/MHC formed by tumor antigens that are self-proteins: impact on efficacy and toxicity

    Science.gov (United States)

    Stone, Jennifer D.; Harris, Daniel T.; Kranz, David M.

    2016-01-01

    Recent studies have shown that the range of affinities of T cell receptors (TCRs) against non-mutated cancer peptide/class I complexes are lower than TCR affinities for foreign antigens. Raising the affinity of TCRs for optimal activity of CD8 T cells, and for recruitment of CD4 T cell activity against a class I antigen, provides opportunities for more robust adoptive T cell therapies. However, TCRs with enhanced affinities also risk increased reactivity with structurally related self-peptides, and off-target toxicities. Careful selection of tumor peptide antigens, in silico proteome screens, and in vitro peptide specificity assays will be important in the development of the most effective, safe TCR-based adoptive therapies. PMID:25618219

  9. 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. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 58, č. 6 (2001), s. 425-430 ISSN 0001-2815. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 2.864, year: 2001

  11. CD antigens 2002

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2002-01-01

    Roč. 99, č. 10 (2002), s. 3877-3880 ISSN 0006-4971. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 9.631, year: 2002

  12. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2002-01-01

    Roč. 168, č. 5 (2002), s. 2083-2086 ISSN 0022-1767. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 7.014, year: 2002

  13. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 103, č. 4 (2001), s. 401-406 ISSN 0019-2805 R&D Projects: GA ČR GA310/99/0349 Institutional research plan: CEZ:AV0Z5052915 Keywords : antigen * CD * leukocyte Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.656, year: 2001

  14. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 19, č. 6 (2001), s. 556-562 ISSN 1066-5099 R&D Projects: GA AV ČR IAA7052904 Institutional research plan: CEZ:AV0Z5052915 Keywords : CD * leukocyte antigens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.689, year: 2001

  15. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 31, č. 10 (2001), s. 2841-2847 ISSN 0014-2980 R&D Projects: GA AV ČR IAA7052904 Keywords : CD * leukocyte antigens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.990, year: 2001

  16. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 211, č. 2 (2001), s. 81-85 ISSN 0008-8749 R&D Projects: GA ČR GA310/99/0349 Institutional research plan: CEZ:AV0Z5052915 Keywords : antigen * CD * leukocyte Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.604, year: 2001

  17. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2002-01-01

    Roč. 15, č. 1 (2002), s. 71-76 ISSN 0893-3952. [Conference on Human leucocyte differentiation antigens /7./. Harrogate, 20.06.2000-25.06.2000] Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules, HLDA Subject RIV: EC - Immunology Impact factor: 3.821, year: 2002

  18. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 70, č. 5 (2001), s. 685-690 ISSN 0741-5400 R&D Projects: GA AV ČR IAA7052904 Institutional research plan: CEZ:AV0Z5052915 Keywords : CD * leukocyte antigens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.516, year: 2001

  19. CD antigens 2001

    Czech Academy of Sciences Publication Activity Database

    Mason, D.; Andre, P.; Bensussan, A.; Buckley, C.; Civin, C.; Clark, E.; de Haas, M.; Goyert, S.; Hadam, M.; Hart, D.; Hořejší, Václav; Meuer, S.; Morrissey, J.; Schwartz-Albiez, R.; Shaw, S.; Simmons, D.; Uguccioni, M.; van der Schoot, E.; Vivier, E.; Zola, H.

    2001-01-01

    Roč. 13, č. 9 (2001), s. 1095-1098 ISSN 0953-8178 R&D Projects: GA ČR GA310/99/0349 Institutional research plan: CEZ:AV0Z5052915 Keywords : antigen * CD * leukocyte Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.611, year: 2001

  20. β-endorphin antigen

    International Nuclear Information System (INIS)

    1981-01-01

    This invention relates to the production of antigens comprising β-endorphin, βsub(h)-endorphin, or βsub(c)-endorphin, in covalent conjugation with human gammaglobulin as immunogenic carrier material, and an antibody having the property of specifically binding β-endorphin or fragments thereof, containing the (6-15) residue sequence. (U.K.)

  1. Radionuclide therapy with peptides: bench to bedside

    International Nuclear Information System (INIS)

    Das, Tapas

    2016-01-01

    Peptides, which are short chains of amino acids linked by the peptide (amide) bond, play an important role in the management of various types of ailments. Recently, use of radiolabeled peptides has emerged as one of the prime treatment modality for combating against a variety of cancers. At present, 'Peptide Receptor Radionuclide Therapy' (PRRNT) employing 177 Lu-DOTA-TATE (lutetium-177 labeled DOTA coupled Tyr 3 -Octrotate) is considered as the only viable treatment modality for the patients suffering from inoperable and disseminated neuroendocrine cancers over expressing somatostatin receptors. In the last couple of years, clinical evaluations carried outwith 177 Lu-PSMA-617 (PSMA: Prostate Specific Membrane Antigen) have shown encouraging results in targeted radionuclide therapy of patients suffering from prostate cancer. These agents are available from a limited number of foreign suppliers; but are prohibitively expensive, which makes these agents almost unaffordable to most of the Indian patients. Therefore, it was necessary to develop methodologies to formulate these radiotherapeutic agents indigenously in our country. However, the challenges to prepare radiolabeled peptides in clinical-scale are manifold as these agents are required to be prepared with high specific activity using the 177 Lu, produced in our medium flux research reactor, for obtaining the desired therapeutic efficacy. In the past few years, methodologies for the formulation of clinical-scale 177 Lu-labelled peptides, suitable for human administration, have been developed in our facility and successfully translated to nuclear medicine centers of India, where these agents are regularly used for providing the radiotherapeutic treatment to the cancer patients.The presentation will describe our effort in successfully translating these agents from laboratory to nuclear medicine clinics and cover the aspects related to the development, demonstration and deployment of the radiolabeled

  2. Regulation of the Cell Biology of Antigen Cross-Presentation.

    Science.gov (United States)

    Blander, J Magarian

    2018-02-28

    Antigen cross-presentation is an adaptation of the cellular process of loading MHC-I molecules with endogenous peptides during their biosynthesis within the endoplasmic reticulum. Cross-presented peptides derive from internalized proteins, microbial pathogens, and transformed or dying cells. The physical separation of internalized cargo from the endoplasmic reticulum, where the machinery for assembling peptide-MHC-I complexes resides, poses a challenge. To solve this problem, deliberate rewiring of organelle communication within cells is necessary to prepare for cross-presentation, and different endocytic receptors and vesicular traffic patterns customize the emergent cross-presentation compartment to the nature of the peptide source. Three distinct pathways of vesicular traffic converge to form the ideal cross-presentation compartment, each regulated differently to supply a unique component that enables cross-presentation of a diverse repertoire of peptides. Delivery of centerpiece MHC-I molecules is the critical step regulated by microbe-sensitive Toll-like receptors. Defining the subcellular sources of MHC-I and sites of peptide loading during cross-presentation remain key challenges. Expected final online publication date for the Annual Review of Immunology Volume 36 is April 26, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  3. Profile of sequential determinants in tissue polypeptide antigen BrCN:B fragment.

    Science.gov (United States)

    Chersi, A; Camera, M; Trinca, M L; Castelli, M

    1989-02-15

    A synthetic approach has been applied to determine the profile of sequential determinants of one immunodominant region of Tissue Polypeptide Antigen (TPA). Five overlapping peptides, covering 30 of the 32 amino acid residues of this fragment, were chemically synthesized, and their antibody-binding activities for rabbit anti-TPA antibodies determined by enzyme-linked immunoadsorbant assays. Anti-TPA reacted with two overlapping fragments at the COOH-terminal end of the fragment, but not with peptides that include Arg 15 considered as essential for the antigenicity of the whole fragment. This might suggest that this critical residue is involved in the formation of a complex conformational determinant.

  4. Antigenic and structural conservation of herpesvirus DNA-binding proteins.

    Science.gov (United States)

    Littler, E; Yeo, J; Killington, R A; Purifoy, D J; Powell, K L

    1981-10-01

    Previously, we have shown a common antigen of several herpesviruses (pseudorabies virus, equine abortion virus and bovine mammillitis virus) to be antigenically related to the major DNA-binding proteins of herpes simplex virus types 1 and 2. In this study we have purified the cross-reacting polypeptide from cells infected with pseudorabies virus, equine abortion virus and bovine mammillitis virus and shown the cross-reacting protein to be a major DNA-binding protein for each virus. Tryptic peptide analysis of the cross-reacting DNA-binding proteins of all five viruses has shown structural similarities. The proteins thus were shown to share common antigenic sites, to have similar biological properties and to have a highly conserved amino acid sequence. This unexpected similarity between proteins from diverse herpes viruses suggests an essential and fundamental role of the major DNA-binding protein in herpes virus replication.

  5. Immunologic and therapeutic evaluation of a synthetic peptide vaccine for the treatment of patients with metastatic melanoma

    Science.gov (United States)

    Rosenberg, Steven A.; Yang, James C.; Schwartzentruber, Douglas J.; Hwu, Patrick; Marincola, Francesco M.; Topalian, Suzanne L.; Restifo, Nicholas P.; Dudley, Mark E.; Schwarz, Susan L.; Spiess, Paul J.; Wunderlich, John R.; Parkhurst, Maria R.; Kawakami, Yutaka; Seipp, Claudia A.; Einhorn, Jan H.; White, Donald E.

    2007-01-01

    The cloning of the genes encoding cancer antigens has opened new possibilities for the treatment of patients with cancer. In this study, immunodominant peptides from the gp100 melanoma-associated antigen were identified, and a synthetic peptide, designed to increase binding to HLA-A2 molecules, was used as a cancer vaccine to treat patients with metastatic melanoma. On the basis of immunologic assays, 91% of patients could be successfully immunized with this synthetic peptide, and 13 of 31 patients (42%) receiving the peptide vaccine plus IL-2 had objective cancer responses, and four additional patients had mixed or minor responses. Synthetic peptide vaccines based on the genes encoding cancer antigens hold promise for the development of novel cancer immunotherapies. PMID:9500606

  6. Designer Natriuretic Peptides

    Science.gov (United States)

    Lee, Candace Y. W.; Lieu, Hsiao; Burnett, John C.

    2011-01-01

    Designer natriuretic peptides (NPs) are novel hybrid peptides that are engineered from the native NPs through addition, deletion, or substitution of amino acid(s) with a goal toward optimization of pharmacological actions while minimizing undesirable effects. In this article, selected peptides that were designed in our laboratory are reviewed, and future directions for research and development of designer NPs are discussed. PMID:19158603

  7. 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.

  8. 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.

  9. 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....

  10. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    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....

  11. 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....

  12. 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....

  13. 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....

  14. Synthetic Peptide-Based ELISA and ELISpot Assay for Identifying Autoantibody Epitopes.

    Science.gov (United States)

    Pozsgay, Judit; Szarka, Eszter; Huber, Krisztina; Babos, Fruzsina; Magyar, Anna; Hudecz, Ferenc; Sarmay, Gabriella

    2016-01-01

    Enzyme-linked immunosorbent assay (ELISA) is an invaluable diagnostic tool to detect serum autoantibody binding to target antigen. To map the autoantigenic epitope(s), overlapping synthetic peptides covering the total sequence of a protein antigen are used. A large set of peptides synthesized on the crown of pins can be tested by Multipin ELISA for fast screening. Next, to validate the results, the candidate epitope peptides are resynthesized by solid-phase synthesis, coupled to ELISA plate directly, or in a biotinylated form, bound to neutravidin-coated surface and the binding of autoantibodies from patients' sera is tested by indirect ELISA. Further, selected epitope peptides can be applied in enzyme-linked immunospot assay to distinguish individual, citrullinated peptide-specific autoreactive B cells in a pre-stimulated culture of patients' lymphocytes.

  15. Natural micropolymorphism in human leukocyte antigens provides a basis for genetic control of antigen recognition

    Energy Technology Data Exchange (ETDEWEB)

    Archbold, Julia K.; Macdonald, Whitney A.; Gras, Stephanie; Ely, Lauren K.; Miles, John J.; Bell, Melissa J.; Brennan, Rebekah M.; Beddoe, Travis; Wilce, Matthew C.J.; Clements, Craig S.; Purcell, Anthony W.; McCluskey, James; Burrows, Scott R.; Rossjohn, Jamie; (Monash); (Queensland Inst. of Med. Rsrch.); (Melbourne)

    2009-07-10

    Human leukocyte antigen (HLA) gene polymorphism plays a critical role in protective immunity, disease susceptibility, autoimmunity, and drug hypersensitivity, yet the basis of how HLA polymorphism influences T cell receptor (TCR) recognition is unclear. We examined how a natural micropolymorphism in HLA-B44, an important and large HLA allelic family, affected antigen recognition. T cell-mediated immunity to an Epstein-Barr virus determinant (EENLLDFVRF) is enhanced when HLA-B*4405 was the presenting allotype compared with HLA-B*4402 or HLA-B*4403, each of which differ by just one amino acid. The micropolymorphism in these HLA-B44 allotypes altered the mode of binding and dynamics of the bound viral epitope. The structure of the TCR-HLA-B*4405EENLLDFVRF complex revealed that peptide flexibility was a critical parameter in enabling preferential engagement with HLA-B*4405 in comparison to HLA-B*4402/03. Accordingly, major histocompatibility complex (MHC) polymorphism can alter the dynamics of the peptide-MHC landscape, resulting in fine-tuning of T cell responses between closely related allotypes.

  16. pH dependence of MHC class I-restricted peptide presentation

    DEFF Research Database (Denmark)

    Stryhn, A; Pedersen, L O; Romme, T

    1996-01-01

    The function of MHC class I molecules is to bind and present antigenic peptides to cytotoxic T cells. Here, we report that class I-restricted peptide presentation is strongly pH dependent. The presentation of some peptides was enhanced at acidic pH, whereas the presentation of others was inhibited...... of peptide-MHC class I combinations, in some cases leading to considerable peptide exchange. We further speculate that the relative instability of peptide-class I complexes under acidic conditions may affect the outcome of class I-restricted Ag presentation, as less stably associated peptides may dissociate...... from class I during passage of the acidic trans-Golgi network, and therefore may not be presented. Finally, our results may in part explain how endocytosed proteins can be presented by MHC class I molecules to cytotoxic T cells....

  17. Non-HTLV-I associated pleomorphic T-cell lymphoma of the brain mimicking post-vaccinal acute inflammatory demyelination.

    Science.gov (United States)

    Wanschitz, J; Hainfellner, J A; Simonitsch, I; Schnizer, M; Deisenhammer, E; Terunuma, H; Iwasaki, Y; Budka, H

    1997-02-01

    Two weeks after vaccination against tick-borne encephalitis (TBE), a 57-year-old female suddenly developed mental confusion and hemiparesis of the left side. Cranial MRI demonstrated extensive bilateral lesions in the fronto-parietal white matter of both hemispheres, suggesting an acute inflammatory demyelinating disease following vaccination. Despite administration of high-dose corticosteroids, the patient died 3 weeks after onset of neurological symptoms. Autopsy revealed diffuse infiltrates of a primary cerebral pleomorphic T-cell lymphoma of medium and large cell type. PCR on brain tissue for HTLV-I and serology for anti-HTLV-I antibodies in CSF and serum were negative; immunocytochemistry on brain tissue did not detect EBV-related antigen. This is the first recorded observation of a diffusely infiltrating primary central nervous system T-cell lymphoma, clinically and radiologically mimicking a fatal acute inflammatory demyelinating complication after vaccination.

  18. Application of synthetic peptides for detection of anti-citrullinated peptide antibodies.

    Science.gov (United States)

    Trier, Nicole Hartwig; Holm, Bettina Eide; Slot, Ole; Locht, Henning; Lindegaard, Hanne; Svendsen, Anders; Nielsen, Christoffer Tandrup; Jacobsen, Søren; Theander, Elke; Houen, Gunnar

    2016-02-01

    Anti-citrullinated protein antibodies (ACPAs) are a hallmark of rheumatoid arthritis (RA) and represent an important tool for the serological diagnosis of RA. In this study, we describe ACPA reactivity to overlapping citrullinated Epstein-Barr virus nuclear antigen-1 (EBNA-1)-derived peptides and analyze their potential as substrates for ACPA detection by streptavidin capture enzyme-linked immunosorbent assay. Using systematically overlapping peptides, containing a 10 amino acid overlap, labelled with biotin C-terminally or N-terminally, sera from 160 individuals (RA sera (n=60), healthy controls (n=40), systemic lupus erythematosus (n=20), Sjögren's syndrome (n=40)) were screened for antibody reactivity. Antibodies to a panel of five citrullinated EBNA-1 peptides were found in 67% of RA sera, exclusively of the IgG isotype, while 53% of the patient sera reacted with a single peptide, ARGGSRERARGRGRG-Cit-GEKR, accounting for more than half of the ACPA reactivity alone. Moreover, these antibodies were detected in 10% of CCP2-negative RA sera. In addition, 47% of the RA sera reacted with two or three citrullinated EBNA-1 peptides from the selected peptide panel. Furthermore, a negative correlation between the biotin attachment site and the location of citrulline in the peptides was found, i.e. the closer the citrulline was located to biotin, the lower the antibody reactivity. Our data suggest that citrullinated EBNA-1 peptides may be considered a substrate for the detection of ACPAs and that the presence of Epstein-Barr virus may play a role in the induction of these autoantibodies. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. 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.

  20. Neurotropic and neuroprotective activities of the earthworm peptide Lumbricusin

    International Nuclear Information System (INIS)

    Kim, Dae Hong; Lee, Ik Hwan; Nam, Seung Taek; Hong, Ji; Zhang, Peng; Hwang, Jae Sam; Seok, Heon; Choi, Hyemin; Lee, Dong Gun; Kim, Jae Il; Kim, Ho

    2014-01-01

    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 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 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 Kip1 significantly blocked the antiapoptotic effect of Lumbricusin in 6-hydroxy dopamine-treated SH-SY5Y cells. These results suggest that promotion of p27 Kip1 degradation may be the main mechanism underlying the neuroprotective and neurotropic effects of Lumbricusin

  1. Structural requirements and biological significance of interactions between peptides and the major histocompatibility complex

    DEFF Research Database (Denmark)

    Grey, H M; Buus, S; Colon, S

    1989-01-01

    Previous studies indicate that T cells recognize a complex between the major histocompatibility complex (MHC) restriction-element and peptide-antigen fragments. Two aspects of this complex formation are considered in this paper: (1) what is the nature of the specificity of the interactions...... that allows a few MHC molecules to serve as restriction elements for a large universe of antigens; and (2) what is the relative contribution of determinant selection (i.e. antigen-MHC complex formation) and T-cell repertoire in determining the capacity of an individual to respond to an antigen? By analysing...

  2. Acylation of Therapeutic Peptides

    DEFF Research Database (Denmark)

    Trier, Sofie; Henriksen, Jonas Rosager; Jensen, Simon Bjerregaard

    to the harsh and selective gastrointestinal system, and development has lacked far behind injection therapy. Peptide acylation is a powerful tool to alter the pharmacokinetics, biophysical properties and chemical stability of injectable peptide drugs, primarily used to prolong blood circulation....... This work aims to characterize acylated analogues of two therapeutic peptides by systematically increasing acyl chain length in order to elucidate its influence on membrane interaction and intestinal cell translocation in vitro. The studied peptides are the 33 amino acid Glucagon-like peptide-2 (GLP-2...... peptides can increase in vitro intestinal permeability, modestly for GLP-2 and drastically for sCT, and might benefit oral delivery. GLP-2 results provide a well-founded predictive power for future peptide analogues, whereas sCT results hold great promise for future analogues, albeit with a larger...

  3. Computational and Experimental Validation of B and T-Cell Epitopes of the In Vivo Immune Response to a Novel Malarial Antigen

    Science.gov (United States)

    2013-08-16

    only recognize linear peptide fragments of antigens presented by various MHC molecules on antigen-presenting cells (APC). Current methods for...and sequence analysis of a-helical regions displayed distinct amphipathic character suggesting that appropriate helical packing is critical to the...immunoproteasomes. The PfCelTOS protein was subjected to proteasomal cleavage to identify peptides that could potentially bind to MHC molecules and

  4. An MHC-restricted antibody-based chimeric antigen receptor requires TCR-like affinity to maintain antigen specificity

    Directory of Open Access Journals (Sweden)

    Marcela V Maus

    2016-01-01

    Full Text Available Chimeric antigen receptors (CARs are synthetic receptors that usually redirect T cells to surface antigens independent of human leukocyte antigen (HLA. Here, we investigated a T cell receptor-like CAR based on an antibody that recognizes HLA-A*0201 presenting a peptide epitope derived from the cancer-testis antigen NY-ESO-1. We hypothesized that this CAR would efficiently redirect transduced T cells in an HLA-restricted, antigen-specific manner. However, we found that despite the specificity of the soluble Fab, the same antibody in the form of a CAR caused moderate lysis of HLA-A2 expressing targets independent of antigen owing to T cell avidity. We hypothesized that lowering the affinity of the CAR for HLA-A2 would improve its specificity. We undertook a rational approach of mutating residues that, in the crystal structure, were predicted to stabilize binding to HLA-A2. We found that one mutation (DN lowered the affinity of the Fab to T cell receptor-range and restored the epitope specificity of the CAR. DN CAR T cells lysed native tumor targets in vitro, and, in a xenogeneic mouse model implanted with two human melanoma lines (A2+/NYESO+ and A2+/NYESO−, DN CAR T cells specifically migrated to, and delayed progression of, only the HLA-A2+/NY-ESO-1+ melanoma. Thus, although maintaining MHC-restricted antigen specificity required T cell receptor-like affinity that decreased potency, there is exciting potential for CARs to expand their repertoire to include a broad range of intracellular antigens.

  5. 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.

  6. Human platelet antigens - 2013.

    Science.gov (United States)

    Curtis, B R; McFarland, J G

    2014-02-01

    To date, 33 human platelet alloantigens (HPAs) have been identified on six functionally important platelet glycoprotein (GP) complexes and have been implicated in alloimmune platelet disorders including foetal and neonatal alloimmune thrombocytopenia (FNAIT), posttransfusion purpura (PTP) and multitransfusion platelet refractoriness (MPR). The greatest number of recognized HPA (20 of 33) resides on the GPIIb/IIIa complex, which serves as the receptor for ligands important in mediating haemostasis and inflammation. These include HPA-1a, the most commonly implicated HPA in FNAIT and PTP in Caucasian populations. Other platelet GP complexes, GPIb/V/IX, GPIa/IIa and CD109, express the remaining 13 HPAs. Of the recognized HPAs, 12 occur as six serologically and genetically defined biallelic 'systems' where the -a form designates the higher frequency allele and the -b form, the lower. Twenty-one other HPAs are low-frequency or rare antigens for which postulated higher frequency -a alleles have not yet been identified as antibody specificities. In addition to the HPA markers, platelets also express ABO and human leucocyte antigen (HLA) antigens; antibodies directed at the former are occasionally important in FNAIT, and to the latter, in MPR. © 2013 International Society of Blood Transfusion.

  7. 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.

  8. Cell Penetrating Peptides and Cationic Antibacterial Peptides

    Science.gov (United States)

    Rodriguez Plaza, Jonathan G.; Morales-Nava, Rosmarbel; Diener, Christian; Schreiber, Gabriele; Gonzalez, Zyanya D.; Lara Ortiz, Maria Teresa; Ortega Blake, Ivan; Pantoja, Omar; Volkmer, Rudolf; Klipp, Edda; Herrmann, Andreas; Del Rio, Gabriel

    2014-01-01

    Cell penetrating peptides (CPP) and cationic antibacterial peptides (CAP) have similar physicochemical properties and yet it is not understood how such similar peptides display different activities. To address this question, we used Iztli peptide 1 (IP-1) because it has both CPP and CAP activities. Combining experimental and computational modeling of the internalization of IP-1, we show it is not internalized by receptor-mediated endocytosis, yet it permeates into many different cell types, including fungi and human cells. We also show that IP-1 makes pores in the presence of high electrical potential at the membrane, such as those found in bacteria and mitochondria. These results provide the basis to understand the functional redundancy of CPPs and CAPs. PMID:24706763

  9. 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...

  10. 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; Hviid, L

    1996-01-01

    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...

  11. An abdominal tuberculosis case mimicking an abdominal mass

    African Journals Online (AJOL)

    An abdominal tuberculosis case mimicking an abdominal mass. Derya Erdog˘ an a. , Yasemin Ta ¸scı Yıldız b. , Esin Cengiz Bodurog˘lu c and Naciye Go¨nu¨l Tanır d. Abdominal tuberculosis is rare in childhood. It may be difficult to diagnose as it mimics various disorders. We present a 12-year-old child with an unusual ...

  12. Degenerated uterine leiomyomas mimicking malignant bilateral ovarian surface epithelial tumors

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yi Boem Ha; Lee, Hae Kyung; Lee, Min Hee; Choi, Seo Youn; Chung, Soo Ho [Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of)

    2017-07-15

    Uterine leiomyomas are the most common benign uterine neoplasms. Undegenerated uterine leiomyomas are easily recognizable by the typical imaging findings on radiologic studies. However, degenerated fibroids can have unusual and variable appearances. The atypical appearances due to degenerative changes may cause confusion in diagnosis of leiomyomas. In this article, we report a case of a patient with extensive cystic and myxoid degeneration of uterine leiomyoma, mimicking malignant bilateral ovarian surface epithelial tumors.

  13. Localized IgG4-related Cholecystitis Mimicking Gallbladder Cancer.

    Science.gov (United States)

    Inoue, Tadahisa; Okumura, Fumihiro; Mizushima, Takashi; Nishie, Hirotada; Iwasaki, Hiroyasu; Anbe, Kaiki; Ozeki, Takanori; Kachi, Kenta; Fukusada, Shigeki; Suzuki, Yuta; Watanabe, Kazuko; Sano, Hitoshi

    2015-01-01

    We encountered a case of localized IgG4-cholecystitis mimicking gallbladder cancer with focal/segmental type1 autoimmune pancreatitis (AIP). In this case, we were unable to exclude a diagnosis of gallbladder cancer and thus performed radical cholecystectomy. Type1 AIP is often associated with gallbladder lesions, accompanied by generally diffuse, circumferential thickening of the gallbladder wall. Although localized IgG4-related cholecystitis is extremely rare, differentiating this condition from gallbladder cancer is often very difficult.

  14. A case of gallbladder mass: Malakoplakia (The tumor mimicker

    Directory of Open Access Journals (Sweden)

    Kanwaljeet Singh

    2017-01-01

    Full Text Available Diagnosis of malakoplakia presenting as gall bladder mass is a diagnostic dilemma faced by pathologists, radiologists, and surgeons. Malakoplakia is a rare inflammatory disorder and tumor mimicker usually occurring in the urinary tract, may occasionally be found in gall bladder. Here, we present a rare case, presenting as gall bladder mass in a known case of gallstone disease, clinically suspected as carcinoma and later turned out to be malakoplakia in gall bladder.

  15. Glioblastoma mimicking a cerebral contusion: A case report

    OpenAIRE

    LI, XINWEI; WANG, KUN; ZHANG, ANLING; SONG, ZHENGFEI; YANG, SHUXU; QIAN, CONG; WANG, YIRONG

    2013-01-01

    A 61-year-old male presented with a rare case of glioblastoma mimicking a cerebral contusion subsequent to collapsing. The patient had been medicated for hypertension for seven years and diabetes for eight years prior to hospitalization. Brain computed tomography (CT) revealed a cerebral contusion and intracerebral hemorrhage (ICH) in the left temporal region. The patient was initially administered intravenous drugs to reduce the intracranial pressure following the diagnosis of a cerebral con...

  16. A Q fever case mimicking crimean-congo haemorrhagic fever

    Directory of Open Access Journals (Sweden)

    O Karabay

    2011-01-01

    Full Text Available Coxiella burnetii is the bacterium that causes Q fever. Human infection is mainly transmitted from cattle, goats and sheep. The disease is usually self-limited. Pneumonia and hepatitis are the most common clinical manifestations. In this study, we present a case of Q fever from the western part of Turkey mimicking Crimean-Congo haemorrhagic fever (CCHF in terms of clinical and laboratory findings.

  17. Sarcoidosis breaching the fascia and mimicking a sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Hajime; Ikeda, Mitsuaki; Shimofusa, Ryouta [Department of Radiology, Numazu City Hospital, 550 Harunoki-aza, Higashishiiji, Numazu, Shizuoka 410-0302 (Japan); Terauchi, Masami [Department of Plastic Surgery, Numazu City Hospital, 550 Harunoki-aza, Higashishiiji, Numazu, Shizuoka 410-0302 (Japan); Eguchi, Masanobu [Department of Pathology, Numazu City Hospital, 550 Harunoki-aza, Higashishiiji, Numazu, Shizuoka 410-0302 (Japan)

    2002-12-01

    A 55-year-old woman complained of a subcutaneous mass in her left buttock. MR images revealed an ill-defined soft tissue mass that crossed the fascia of the gluteus maximus muscle. Some surrounding edema was noted. The lesion showed some contrast uptake after administration of Gd-DTPA. An excisional biopsy revealed sarcoidosis involving both the muscle and subcutaneous tissue across the fascia, mimicking a sarcoma. (orig.)

  18. Panurgines, novel antimicrobial peptides from the venom of communal bee Panurgus calcaratus (Hymenoptera: Andrenidae).

    Science.gov (United States)

    Čujová, Sabína; Slaninová, Jiřina; Monincová, Lenka; Fučík, Vladimír; Bednárová, Lucie; Štokrová, Jitka; Hovorka, Oldřich; Voburka, Zdeněk; Straka, Jakub; Čeřovský, Václav

    2013-07-01

    Three novel antimicrobial peptides (AMPs), named panurgines (PNGs), were isolated from the venom of the wild bee Panurgus calcaratus. The dodecapeptide of the sequence LNWGAILKHIIK-NH₂ (PNG-1) belongs to the category of α-helical amphipathic AMPs. The other two cyclic peptides containing 25 amino acid residues and two intramolecular disulfide bridges of the pattern Cys8-Cys23 and Cys11-Cys19 have almost identical sequence established as LDVKKIICVACKIXPNPACKKICPK-OH (X=K, PNG-K and X=R, PNG-R). All three peptides exhibited antimicrobial activity against Gram-positive bacteria and Gram-negative bacteria, antifungal activity, and low hemolytic activity against human erythrocytes. We prepared a series of PNG-1 analogs to study the effects of cationicity, amphipathicity, and hydrophobicity on the biological activity. Several of them exhibited improved antimicrobial potency, particularly those with increased net positive charge. The linear analogs of PNG-K and PNG-R having all Cys residues substituted by α-amino butyric acid were inactive, thus indicating the importance of disulfide bridges for the antimicrobial activity. However, the linear PNG-K with all four cysteine residues unpaired, exhibited antimicrobial activity. PNG-1 and its analogs induced a significant leakage of fluorescent dye entrapped in bacterial membrane-mimicking large unilamellar vesicles as well as in vesicles mimicking eukaryotic cell membrane. On the other hand, PNG-K and PNG-R exhibited dye-leakage activity only from vesicles mimicking bacterial cell membrane.

  19. Structural Requirements and Biological Significance of Interactions between Peptides and the Major Histocompatibility Complex

    Science.gov (United States)

    Grey, H. M.; Buus, S.; Colon, S.; Miles, C.; Sette, A.

    1989-06-01

    Previous studies indicate that T cells recognize a complex between the major histocompatibility complex (MHC) restriction-element and peptide-antigen fragments. Two aspects of this complex formation are considered in this paper: (1) what is the nature of the specificity of the interactions that allows a few MHC molecules to serve as restriction elements for a large universe of antigens; and (2) what is the relative contribution of determinant selection (i.e. antigen-MHC complex formation) and Tcell repertoire in determining the capacity of an individual to respond to an antigen? By analysing single amino acid substitution analogues of a peptide antigen (Ova 325-335) as well as by analysing the structural similarities between unrelated peptides capable of binding to the same MHC molecule, we have been able to document the very permissive nature of the antigen--MHC interaction. Despite this permissiveness of binding, it is possible to define certain structural features of peptides that are associated with the capacity to bind to a particular MHC specificity. With respect to the question of the relative role of determinant selection' and 'holes in the T-cell repertoire' in determining immune responsiveness, we present data that suggest both mechanisms operate in concert with one another. Thus only about 30% of a collection of peptides that in sum represent the sequence of a protein molecule were found to bind to Ia. Although immunogenicity was restricted to those peptides that were capable of binding to Ia (i.e. determinant selection was operative), we found that about 40% of Ia-binding peptides were not immunogenic (i.e. there were also 'holes in the T-cell repertoire').

  20. Radiolabeled peptides in the diagnosis and therapy of oncological diseases

    Energy Technology Data Exchange (ETDEWEB)

    Weiner, Ronald E. E-mail: weiner@adp.uchc.edu; Thakur, Mathew L

    2002-11-01

    There has been an exponential growth in the development of radiolabeled peptides for diagnostic and therapeutic applications in oncology. Peptides have fast clearance, rapid tissue penetration, low antigenicity and can be produced easily and inexpensively. However, peptides have problems with in vivo catabolism, unwanted physiological effects, and chelate attachment. The approved {sup 111}In-DTPA-OctreoScan, a somatostatin receptor binder, is well established for diagnosis of neuroendocrine tumors. NeoTect, an approved, {sup 99m}Tc-labeled, somatostatin-receptor-binding analogue has good specificity for lung cancer detection. The receptors for Vasoactive Intestinal Peptide, Cholecystokinin-B/gastrin, Bombesin, Epidermal Growth Factor, and Alpha Melanocyte Stimulating Hormone and the Integrin, {alpha}{sub v}{beta}{sub 3}, are under active investigation as targets. Octreotide and its analogues labeled with {sup 111}In, {sup 90}Y, {sup 64}Cu or {sup 177}Lu are under study for the treatment of patients with promising results.

  1. Dengue fever mimicking acute appendicitis: A case report.

    Science.gov (United States)

    McFarlane, M E C; Plummer, J M; Leake, P A; Powell, L; Chand, V; Chung, S; Tulloch, K

    2013-01-01

    Dengue fever is an acute viral disease, which usually presents as a mild febrile illness. Patients with severe disease present with dengue haemorrhagic fever or dengue toxic shock syndrome. Rarely, it presents with abdominal symptoms mimicking acute appendicitis. We present a case of a male patient presenting with right iliac fossa pain and suspected acute appendicitis that was later diagnosed with dengue fever following a negative appendicectomy. A 13-year old male patient presented with fever, localized right-sided abdominal pain and vomiting. Abdominal ultrasound was not helpful and appendicectomy was performed due to worsening abdominal signs and an elevated temperature. A normal appendix with enlarged mesenteric nodes was found at surgery. Complete blood count showed thrombocytopenia with leucopenia. Dengue fever was now suspected and confirmed by IgM enzyme-linked immunosorbent assay against dengue virus. This unusual presentation of dengue fever mimicking acute appendicitis should be suspected during viral outbreaks and in patients with atypical symptoms and cytopenias on blood evaluation in order to prevent unnecessary surgery. This case highlights the occurrence of abdominal symptoms and complications that may accompany dengue fever. Early recognition of dengue fever mimicking acute appendicitis will avoid non-therapeutic operation and the diagnosis may be aided by blood investigations indicating a leucopenia, which is uncommon in patients with suppurative acute appendicitis. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Plant peptide hormone signalling.

    Science.gov (United States)

    Motomitsu, Ayane; Sawa, Shinichiro; Ishida, Takashi

    2015-01-01

    The ligand-receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone-receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions. © 2015 Authors; published by Portland Press Limited.

  3. Role of autophagy in MHC class I-restricted antigen presentation.

    Science.gov (United States)

    Van Kaer, Luc; Parekh, Vrajesh V; Postoak, J Luke; Wu, Lan

    2017-11-08

    Major histocompatibility complex (MHC) class I molecules present peptide antigens to MHC class I-restricted CD8 + T lymphocytes. The peptides loaded onto MHC class I molecules are typically derived from cytosolic antigens, which includes both self and foreign proteins. In addition to this classical MHC class I antigen presentation pathway, some cell types, especially dendritic cells can present antigens from exogenous sources to MHC class I-restricted CD8 + T cells, in a process called cross-presentation. A variety of cellular processes, including endocytosis, vesicle trafficking, and autophagy, play critical roles in these antigen presentation pathways. In this review article, we discuss the role of autophagy, an intracellular degradation system that delivers cytoplasmic constituents to lysosomes, in MHC class I-restricted antigen presentation. A mechanistic understanding of the role of autophagy-related proteins in MHC class I restricted antigen presentation may guide future efforts in manipulating autophagy to prevent or treat human disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. MHC class I endosomal and lysosomal trafficking coincides with exogenous antigen loading in dendritic cells.

    Directory of Open Access Journals (Sweden)

    Genc Basha

    Full Text Available BACKGROUND: Cross-presentation by dendritic cells (DCs is a crucial prerequisite for effective priming of cytotoxic T-cell responses against bacterial, viral and tumor antigens; however, this antigen presentation pathway remains poorly defined. METHODOLOGY/PRINCIPAL FINDINGS: In order to develop a comprehensive understanding of this process, we tested the hypothesis that the internalization of MHC class I molecules (MHC-I from the cell surface is directly involved in cross-presentation pathway and the loading of antigenic peptides. Here we provide the first examination of the internalization of MHC-I in DCs and we demonstrate that the cytoplasmic domain of MHC-I appears to act as an addressin domain to route MHC-I to both endosomal and lysosomal compartments of DCs, where it is demonstrated that loading of peptides derived from exogenously-derived proteins occurs. Furthermore, by chasing MHC-I from the cell surface of normal and transgenic DCs expressing mutant forms of MHC-I, we observe that a tyrosine-based endocytic trafficking motif is required for the constitutive internalization of MHC-I molecules from the cell surface into early endosomes and subsequently deep into lysosomal peptide-loading compartments. Finally, our data support the concept that multiple pathways of peptide loading of cross-presented antigens may exist depending on the chemical nature and size of the antigen requiring processing. CONCLUSIONS/SIGNIFICANCE: We conclude that DCs have 'hijacked' and adapted a common vacuolar/endocytic intracellular trafficking pathway to facilitate MHC I access to the endosomal and lysosomal compartments where antigen processing and loading and antigen cross-presentation takes place.

  5. MHC class I-presented lung cancer-associated tumor antigens identified by immunoproteomics analysis are targets for cancer-specific T cell response.

    Science.gov (United States)

    Shetty, Vivekananda; Sinnathamby, Gomathinayagam; Nickens, Zacharie; Shah, Punit; Hafner, Julie; Mariello, Lisa; Kamal, Shivali; Vlahović, Gordana; Lyerly, H Kim; Morse, Michael A; Philip, Ramila

    2011-05-01

    The development of potent cancer vaccines for common malignancies such as lung cancer requires identification of suitable target antigens. We hypothesized that peptide epitopes naturally presented by MHC class I molecules on the surface of cancer cells would be the most relevant targets. We used LC/MS/MS analysis and identified 68 MHC class I-presented peptides from lung cancer cells. Using the criteria of strong consensus for HLA-A2 binding and relevance of the source proteins to malignant phenotype, we selected 8 peptides for functional characterization. These peptides, with a range of binding affinities, were confirmed to stabilize HLA-A2 molecules and were used to activate peptide-specific CTLs that efficiently recognized lung tumor cells. No correlation between the transcript levels of the source proteins and the extent of peptide-specific T cell recognition of lung cancer cells was observed. Furthermore, the peptide specific CTLs failed to recognize HLA-A2+ normal lung cells despite expression of the mRNA encoding the source proteins from which the peptides were derived. We conclude that MHC class I associated peptide epitopes are a more relevant source of authentic tumor antigens than over-expressed proteins and the identified peptides may be used as antigens for therapeutic vaccine strategies to treat lung cancer. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. 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.

  7. Lipophilic Muramyl Dipeptide-Antigen Conjugates as Immunostimulating Agents.

    Science.gov (United States)

    Willems, Marian M J H P; Zom, Gijs G; Meeuwenoord, Nico; Khan, Selina; Ossendorp, Ferry; Overkleeft, Herman S; van der Marel, Gijsbert A; Filippov, Dmitri V; Codée, Jeroen D C

    2016-01-19

    Muramyl dipeptide (MDP) is the smallest peptidoglycan fragment capable of triggering the innate immune system through interaction with the intracellular NOD2 receptor. To develop synthetic vaccine modalities composed of an antigenic entity (typically a small peptide) and a molecular adjuvant with well-defined activity, we previously assembled covalent MDP-antigen conjugates. Although these were found to be capable of stimulating the NOD2 receptor and were processed by dendritic cells (DCs) leading to effective antigen presentation, DC maturation--required for an apt immune response--could not be achieved with these conjugates. To improve the efficacy of these vaccine modalities, we equipped the MDP moiety with lipophilic tails, well-known modifications to enhance the immune-stimulatory activity of MDPs. Herein we report the design and synthesis of a lipophilic MDP-antigen conjugate and show that it is a promising vaccine modality capable of stimulating the NOD2 receptor, maturing DCs, and delivering antigen cargo into the MHC-I cross-presentation pathway. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Viral immune evasion: Lessons in MHC class I antigen presentation.

    Science.gov (United States)

    van de Weijer, Michael L; Luteijn, Rutger D; Wiertz, Emmanuel J H J

    2015-03-01

    The MHC class I antigen presentation pathway enables cells infected with intracellular pathogens to signal the presence of the invader to the immune system. Cytotoxic T lymphocytes are able to eliminate the infected cells through recognition of pathogen-derived peptides presented by MHC class I molecules at the cell surface. In the course of evolution, many viruses have acquired inhibitors that target essential stages of the MHC class I antigen presentation pathway. Studies on these immune evasion proteins reveal fascinating strategies used by viruses to elude the immune system. Viral immunoevasins also constitute great research tools that facilitate functional studies on the MHC class I antigen presentation pathway, allowing the investigation of less well understood routes, such as TAP-independent antigen presentation and cross-presentation of exogenous proteins. Viral immunoevasins have also helped to unravel more general cellular processes. For instance, basic principles of ER-associated protein degradation via the ubiquitin-proteasome pathway have been resolved using virus-induced degradation of MHC class I as a model. This review highlights how viral immunoevasins have increased our understanding of MHC class I-restricted antigen presentation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. 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.

  10. Innovative DNA vaccine to break immune tolerance against tumor self-antigen.

    Science.gov (United States)

    Kang, Tae Heung; Mao, Chih-Ping; La, Victor; Chen, Alexander; Hung, Chien-Fu; Wu, T-C

    2013-02-01

    Vaccination is, in theory, a safe and effective approach for controlling disseminated or metastatic cancer due to the specificity of the mammalian immune system, yet its success in the clinic has been hampered thus far by the problem of immune tolerance to tumor self-antigen. Here we describe a DNA vaccination strategy that is able to control cancer by overcoming immune tolerance to tumor self-antigen. We engineered a DNA construct encoding a dimeric form of a secreted single-chain trimer of major histocompatibility complex class I heavy chain, β2-microglobulin, and peptide antigen linked to immunoglobulin G (SCT-Ag/IgG). The chimeric protein was able to bind to antigen-specific CD8(+) T cells with nearly 100% efficiency and strongly induce their activation and proliferation. In addition, the chimeric protein was able to coat professional antigen-presenting cells through the F(c) receptor to activate antigen-specific CD8(+) T cells. Furthermore, intradermal vaccination with DNA-encoding SCT-Ag/IgG could generate significant numbers of cytotoxic effector T cells against tumor self-antigen and leads to successful therapeutic outcomes in a preclinical model of metastatic melanoma. Our data suggest that the DNA vaccine strategy described in the current study is able to break immune tolerance against endogenous antigen from melanoma and result in potent therapeutic antitumor effects. Such strategy may be used in other antigenic systems for the control of infections and/or cancers.

  11. Gallium arsenide exposure impairs processing of particulate antigen by macrophages: modification of the antigen reverses the functional defect.

    Science.gov (United States)

    Hartmann, Constance B; McCoy, Kathleen L

    2004-06-11

    Gallium arsenide (GaAs), a semiconductor used in the electronics industry, causes systemic immunosuppression in animals. The chemical's impact on macrophages to process the particulate antigen, sheep red blood cells (SRBC), for a T cell response in culture was examined after in vivo exposure of mice. GaAs-exposed splenic macrophages were defective in activating SRBC-primed lymph node T cells that could not be attributed to impaired phagocytosis. Modified forms of SRBC were generated to examine the compromised function of GaAs-exposed macrophages. SRBC were fixed to maintain their particulate nature and subsequently delipidated with detergent. Delipidation of intact SRBC was insufficient to restore normal antigen processing in GaAs-exposed macrophages. However, chemically exposed cells efficiently processed soluble sheep proteins. These findings suggest that the problem may lie in the release of sequestered sheep protein antigens, which then could be effectively cleaved to peptides. Furthermore, opsonization of SRBC with IgG compensated for the macrophage processing defect. The influence of signal transduction and phagocytosis via Fcgamma receptors on improved antigen processing could be dissociated. Immobilized anti-Fcgamma receptor antibody activated macrophages to secrete a chemokine, but did not enhance processing of unmodified SRBC by GaAs-exposed macrophages. Restoration of normal processing of particulate SRBC by chemically exposed macrophages involved phagocytosis through Fcgamma receptors. Hence, initial immune responses may be very sensitive to GaAs exposure, and the chemical's immunosuppression may be averted by opsonized particulate antigens.

  12. A Genome-wide multidimensional RNAi screen reveals pathways controlling MHC class II antigen presentation

    NARCIS (Netherlands)

    Paul, Petra; van den Hoorn, Tineke; Jongsma, Marlieke L. M.; Bakker, Mark J.; Hengeveld, Rutger; Janssen, Lennert; Cresswell, Peter; Egan, David A.; van Ham, Marieke; ten Brinke, Anja; Ovaa, Huib; Beijersbergen, Roderick L.; Kuijl, Coenraad; Neefjes, Jacques

    2011-01-01

    MHC class II molecules (MHC-II) present peptides to T helper cells to facilitate immune responses and are strongly linked to autoimmune diseases. To unravel processes controlling MHC-II antigen presentation, we performed a genome-wide flow cytometry-based RNAi screen detecting MHC-II expression and

  13. 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

    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-specif......(+) immune responses during cancer and infectious disease or after immunotherapy. One panel of 28 combinatorially encoded MHC multimers can be prepared in 4 h. Staining and detection takes a further 3 h.......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...

  14. T cell responses affected by aminopeptidase N (CD13)-mediated trimming of major histocompatibility complex class II-bound peptides

    DEFF Research Database (Denmark)

    Larsen, S L; Pedersen, L O; Buus, S

    1996-01-01

    the exopeptidase Aminopeptidase N (APN, CD13) as one of the enzymes involved in the observed cell-surface antigen processing. The NH2-terminal end of the longer peptide could, even while bound to major histocompatibility complex (MHC) class II molecules, be digested by APN with dramatic consequences for T cell......Endocytosed protein antigens are believed to be fragmented in what appears to be a balance between proteolysis and MHC-mediated epitope protection, and the resulting peptide-MHC complexes are transported to the surface of the antigen-presenting cells (APC) and presented to T cells. The events...

  15. Antimicrobial Peptides in Reptiles

    Science.gov (United States)

    van Hoek, Monique L.

    2014-01-01

    Reptiles are among the oldest known amniotes and are highly diverse in their morphology and ecological niches. These animals have an evolutionarily ancient innate-immune system that is of great interest to scientists trying to identify new and useful antimicrobial peptides. Significant work in the last decade in the fields of biochemistry, proteomics and genomics has begun to reveal the complexity of reptilian antimicrobial peptides. Here, the current knowledge about antimicrobial peptides in reptiles is reviewed, with specific examples in each of the four orders: Testudines (turtles and tortosises), Sphenodontia (tuataras), Squamata (snakes and lizards), and Crocodilia (crocodilans). Examples are presented of the major classes of antimicrobial peptides expressed by reptiles including defensins, cathelicidins, liver-expressed peptides (hepcidin and LEAP-2), lysozyme, crotamine, and others. Some of these peptides have been identified and tested for their antibacterial or antiviral activity; others are only predicted as possible genes from genomic sequencing. Bioinformatic analysis of the reptile genomes is presented, revealing many predicted candidate antimicrobial peptides genes across this diverse class. The study of how these ancient creatures use antimicrobial peptides within their innate immune systems may reveal new understandings of our mammalian innate immune system and may also provide new and powerful antimicrobial peptides as scaffolds for potential therapeutic development. PMID:24918867

  16. 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

  17. Structure-based prediction of MHC-peptide association: algorithm comparison and application to cancer vaccine design.

    Science.gov (United States)

    Schiewe, Alexandra J; Haworth, Ian S

    2007-10-01

    Peptide vaccination for cancer immunotherapy requires identification of peptide epitopes derived from antigenic proteins associated with the tumor. Such peptides can bind to MHC proteins (MHC molecules) on the tumor-cell surface, with the potential to initiate a host immune response against the tumor. Computer prediction of peptide epitopes can be based on known motifs for peptide sequences that bind to a certain MHC molecule, on algorithms using experimental data as a training set, or on structure-based approaches. We have developed an algorithm, which we refer to as PePSSI, for flexible structural prediction of peptide binding to MHC molecules. Here, we have applied this algorithm to identify peptide epitopes (of nine amino acids, the common length) from the sequence of the cancer-testis antigen KU-CT-1, based on the potential of these peptides to bind to the human MHC molecule HLA-A2. We compared the PePSSI predictions with those of other algorithms and found that several peptides predicted to be strong HLA-A2 binders by PePSSI were similarly predicted by another structure-based algorithm, PREDEP. The results show how structure-based prediction can identify potential peptide epitopes without known binding motifs and suggest that side chain orientation in binding peptides may be obtained using PePSSI.

  18. The antigenic identity of human class I MHC phosphopeptides is critically dependent upon phosphorylation status.

    Science.gov (United States)

    Mohammed, Fiyaz; Stones, Daniel H; Zarling, Angela L; Willcox, Carrie R; Shabanowitz, Jeffrey; Cummings, Kara L; Hunt, Donald F; Cobbold, Mark; Engelhard, Victor H; Willcox, Benjamin E

    2017-08-15

    Dysregulated post-translational modification provides a source of altered self-antigens that can stimulate immune responses in autoimmunity, inflammation, and cancer. In recent years, phosphorylated peptides have emerged as a group of tumour-associated antigens presented by MHC molecules and recognised by T cells, and represent promising candidates for cancer immunotherapy. However, the impact of phosphorylation on the antigenic identity of phosphopeptide epitopes is unclear. Here we examined this by determining structures of MHC-bound phosphopeptides bearing canonical position 4-phosphorylations in the presence and absence of their phosphate moiety, and examining phosphopeptide recognition by the T cell receptor (TCR). Strikingly, two peptides exhibited major conformational changes upon phosphorylation, involving a similar molecular mechanism, which focussed changes on the central peptide region most critical for T cell recognition. In contrast, a third epitope displayed little conformational alteration upon phosphorylation. In addition, binding studies demonstrated TCR interaction with an MHC-bound phosphopeptide was both epitope-specific and absolutely dependent upon phosphorylation status. These results highlight the critical influence of phosphorylation on the antigenic identity of naturally processed class I MHC epitopes. In doing so they provide a molecular framework for understanding phosphopeptide-specific immune responses, and have implications for the development of phosphopeptide antigen-specific cancer immunotherapy approaches.

  19. T cell antigen receptor activation and actin cytoskeleton remodeling

    Science.gov (United States)

    Kumari, Sudha; Curado, Silvia; Mayya, Viveka

    2013-01-01

    T cells constitute a crucial arm of the adaptive immune system and their optimal function is required for a healthy immune response. After the initial step of T cell-receptor (TCR) triggering by antigenic peptide complexes on antigen presenting cell (APC), the T cell exhibits extensive cytoskeletal remodeling. This cytoskeletal remodeling leads to formation of an “immunological synapse” [1] characterized by regulated clustering, segregation and movement of receptors at the interface. Synapse formation regulates T cell activation and response to antigenic peptides and proceeds via feedback between actin cytoskeleton and TCR signaling. Actin polymerization participates in various events during the synapse formation, maturation, and eventually its disassembly. There is increasing knowledge about the actin effectors that couple TCR activation to actin rearrangements [2, 3], and how defects in these effectors translate into impairment of T cell activation. In this review we aim to summarize and integrate parts of what is currently known about this feedback process. In addition, in light of recent advancements in our understanding of TCR triggering and translocation at the synapse, we speculate on the organizational and functional diversity of microfilament architecture in the T cell. PMID:23680625

  20. 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 the body produces and insulin someone injects ...

  1. Electrophoretic analysis of the "cross-class" interaction between novel inhibitory serpin, squamous cell carcinoma antigen-1 and cysteine proteinases.

    Science.gov (United States)

    Nawata, S; Nakamura, K; Tanaka, T; Numa, F; Suminami, Y; Tsunaga, N; Kakegawa, H; Katunuma, N; Kato, H

    1997-05-01

    We investigated the "cross-class" interaction between cysteine proteinases and a novel inhibitory serpin, recombinant squamous cell carcinoma (rSCC) antigen-1, which inhibits a serine proteinase, chymotrypsin. rSCC antigen-1 inhibited the cysteine proteinases, papain, papaya proteinase IV and cathepsin L. Interestingly, although rSCC antigen-1 formed sodium dodecyl sulfate (SDS)- and heat-stable complexes with chymotrypsin, rSCC antigen-1 gave the 40 kDa fragment and small molecular mass peptide by incubation with papain without forming an SDS- and heat-stable complex. The cleavage was observed between the Gly353-Ser354 bond, indicating that rSCC antigen-1 interacts with cysteine proteinases not at the predicted reactive site P1-P1' portion (Ser354-Ser355), but at the Gly353-Ser354 of the P2-P1 portion. These findings promote understanding of the "suicide inhibition" mechanism of SCC antigen-1 against cysteine proteinases.

  2. Unusual features of Self-Peptide/MHC Binding by Autoimmune T Cell Receptors

    Energy Technology Data Exchange (ETDEWEB)

    Nicholson,M.; Hahn, M.; Wucherpfennig, K.

    2005-01-01

    Structural studies on T cell receptors (TCRs) specific for foreign antigens demonstrated a remarkably similar topology characterized by a central, diagonal TCR binding mode that maximizes interactions with the MHC bound peptide. However, three recent structures involving autoimmune TCRs demonstrated unusual interactions with self-peptide/MHC complexes. Two TCRs from multiple sclerosis patients bind with unconventional topologies, and both TCRs are shifted toward the peptide N terminus and the MHC class II {beta} chain helix. A TCR from the experimental autoimmune encephalomyelitis (EAE) model binds in a conventional orientation, but the structure is unusual because the self-peptide only partially fills the binding site. For all three TCRs, interaction with the MHC bound self-peptide is suboptimal, and only two or three TCR loops contact the peptide. Optimal TCR binding modes confer a competitive advantage for antimicrobial T cells during an infection, whereas altered binding properties may permit survival of a subset of autoreactive T cells during thymic selection.

  3. Cancer associated aberrant protein O-glycosylation can modify antigen processing and immune response.

    Directory of Open Access Journals (Sweden)

    Caroline B Madsen

    Full Text Available Aberrant glycosylation of mucins and other extracellular proteins is an important event in carcinogenesis and the resulting cancer associated glycans have been suggested as targets in cancer immunotherapy. We assessed the role of O-linked GalNAc glycosylation on antigen uptake, processing, and presentation on MHC class I and II molecules. The effect of GalNAc O-glycosylation was monitored with a model system based on ovalbumin (OVA-MUC1 fusion peptides (+/- glycosylation loaded onto dendritic cells co-cultured with IL-2 secreting OVA peptide-specific T cell hybridomas. To evaluate the in vivo response to a cancer related tumor antigen, Balb/c or B6.Cg(CB-Tg(HLA-A/H2-D2Enge/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-γ release, and antibody induction. GalNAc-glycosylation promoted presentation of OVA-MUC1 fusion peptides by MHC class II molecules and the MUC1 antigen elicited specific Ab production and T cell proliferation in both Balb/c and HLA-A2 transgenic mice. In contrast, GalNAc-glycosylation inhibited the presentation of OVA-MUC1 fusion peptides by MHC class I and 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.

  4. Emulsified phosphatidylserine, simple and effective peptide carrier for induction of potent epitope-specific T cell responses.

    Directory of Open Access Journals (Sweden)

    Toru Ichihashi

    Full Text Available BACKGROUND: To induce potent epitope-specific T cell immunity by a peptide-based vaccine, epitope peptides must be delivered efficiently to antigen-presenting cells (APCs in vivo. Therefore, selecting an appropriate peptide carrier is crucial for the development of an effective peptide vaccine. In this study, we explored new peptide carriers which show enhancement in cytotoxic T lymphocyte (CTL induction capability. METHODOLOGY/PRINCIPAL FINDINGS: Data from an epitope-specific in vivo CTL assay revealed that phosphatidylserine (PS has a potent adjuvant effect among candidate materials tested. Further analyses showed that PS-conjugated antigens were preferentially and efficiently captured by professional APCs, in particular, by CD11c(+CD11b(+MHCII(+ conventional dendritic cells (cDCs compared to multilamellar liposome-conjugates or unconjugated antigens. In addition, PS demonstrated the stimulatory capacity of peptide-specific helper T cells in vivo. CONCLUSIONS/SIGNIFICANCE: This work indicates that PS is the easily preparable efficient carrier with a simple structure that delivers antigen to professional APCs effectively and induce both helper and cytotoxic T cell responses in vivo. Therefore, PS is a promising novel adjuvant for T cell-inducing peptide vaccines.

  5. Emulsified phosphatidylserine, simple and effective peptide carrier for induction of potent epitope-specific T cell responses.

    Science.gov (United States)

    Ichihashi, Toru; Satoh, Toshifumi; Sugimoto, Chihiro; Kajino, Kiichi

    2013-01-01

    To induce potent epitope-specific T cell immunity by a peptide-based vaccine, epitope peptides must be delivered efficiently to antigen-presenting cells (APCs) in vivo. Therefore, selecting an appropriate peptide carrier is crucial for the development of an effective peptide vaccine. In this study, we explored new peptide carriers which show enhancement in cytotoxic T lymphocyte (CTL) induction capability. Data from an epitope-specific in vivo CTL assay revealed that phosphatidylserine (PS) has a potent adjuvant effect among candidate materials tested. Further analyses showed that PS-conjugated antigens were preferentially and efficiently captured by professional APCs, in particular, by CD11c(+)CD11b(+)MHCII(+) conventional dendritic cells (cDCs) compared to multilamellar liposome-conjugates or unconjugated antigens. In addition, PS demonstrated the stimulatory capacity of peptide-specific helper T cells in vivo. This work indicates that PS is the easily preparable efficient carrier with a simple structure that delivers antigen to professional APCs effectively and induce both helper and cytotoxic T cell responses in vivo. Therefore, PS is a promising novel adjuvant for T cell-inducing peptide vaccines.

  6. Testicular teratoma, mimicking a simple testicular cyst, in an infant.

    Science.gov (United States)

    Di Renzo, Dacia; Persico, Antonello; Sindici, Giulia; Lelli Chiesa, Pierluigi

    2013-09-01

    Prepubertal testicular tumors are rare, and teratoma is the second most frequent histologic type. Its typical features are those of a hard and painless scrotal mass at clinical examination, and nonhomogeneous, echoic, often with calcifications at ultrasonography. Rare but reported is the atypical presentation as a transilluminating scrotal mass, due to the presence of some internal cystic areas, detectable at ultrasonography. We report the case of an infant with a transilluminating scrotal mass, mimicking at ultrasonography and surgery a simple, fully liquid cyst, which the pathologic examination revealed to be mature cystic testicular teratoma. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Report of ischemic stroke mimicking isolated ulnar nerve paralysis

    Directory of Open Access Journals (Sweden)

    Çetin Kürşad Akpınar

    2016-12-01

    Full Text Available The cortical motor hand area is the precentral gyrus. Small cortical infarcts of this area can caused isolated hand weakness. Weakness can consist of either all fingers or ulnar-sided fingers. A 71-year-old man admitted to the emergency department with sudden weakness of the right fourth and fifth fingers Diffusion-weighted brain imaging of a magnetic resonance imaging scan revealed acute infarction of right precentral gyrus. Cardioembolus is the determined ischemic stroke subtype. This report presented a case of ischemic stroke mimicking isolated ulnar nerve paralysis.

  8. Dual anaplastic large cell lymphoma mimicking meningioma: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Keun Ho; Kim, Ki Hwan; Lee, Ghi Jai; Lee, Hye Kyung; Shim, Jae Chan; Lee, Kyoung Eun; Suh, Jung Ho [Seoul Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of); Lee, Chae Heuck [Dept. of Neurosurgery, Ilsan Paik Hospital, Inje University College of Medicine, Goyang (Korea, Republic of)

    2014-01-01

    Anaplastic large cell lymphoma (ALCL) is a rare T cell lymphoma composed of CD30-positive lymphoid cells. Most ALCLs present as nodal disease, with skin, bone, soft tissue, lung, and liver as common extranodal sites. ALCL rarely occurs in the central nervous system and is even more infrequent in the dura of the brain. We report a case of dural-based ALCL secondary to systemic disease in a 17-year-old male that mimicked meningioma on magnetic resonance imaging and angiography.

  9. Pancreatitis with Electrocardiographic Changes Mimicking Acute Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Paul Khairy

    2001-01-01

    Full Text Available A 64-year-old woman with mild acute pancreatitis presented with epigastric pain, nausea and vomiting while undergoing hemodialysis for chronic renal insufficiency. Serial electrocardiograms revealed new onset ST segment elevations in leads V2 to V4 mimicking an anterior myocardial infarction, followed by diffusely inverted deep T waves. No cardiac pathology was demonstrated by echocardiography or coronary angiography. A review of the literature and possible pathophysiological mechanisms of electrocardiographic changes in acute pancreatitis, such as metabolic abnormalities, hemodynamic instability, vasopressors, pericarditis, myocarditis, a cardiobiliary reflex, exacerbation of underlying cardiac pathology, coagulopathy and coronary vasospasm, are discussed.

  10. Paracoccidioidomycosis Mimicking Sarcoidosis: A Review of 8 Cases.

    Science.gov (United States)

    Coelho, Mariana Guimarães; Severo, Cecília Bittencourt; de Mattos Oliveira, Flávio; Hochhegger, Bruno; Severo, Luiz Carlos

    2016-02-01

    Sarcoidosis is a multisystem disorder that is characterized by noncaseous epithelioid cell granulomas, which may affect almost any organ. Thoracic involvement is common and accounts for most of the morbidity and mortality associated with this disease. The diagnosis is based on exhaustive exclusion of differential diagnoses, particularly granulomatous infections. We report data on eight patients with paracoccidioidomycosis mimicking sarcoidosis. Five patients presented with a chronic pulmonary type infection and three had a disseminated form after immunosuppressive treatment. The mycological diagnosis in noncaseating granulomas is emphasized and reviewed.

  11. Epithelioid sarcoma mimicking abscess: review of the MRI appearances

    International Nuclear Information System (INIS)

    Dion, E.; Forest, M.; Brasseur, J.L.; Grenier, P.; Amoura, Z.

    2001-01-01

    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.)

  12. Cartilage Delamination Flap Mimicking a Torn Medial Meniscus

    Directory of Open Access Journals (Sweden)

    Gan Zhi-Wei Jonathan

    2016-01-01

    Full Text Available We report a case of a chondral delamination lesion due to medial parapatellar plica friction syndrome involving the medial femoral condyle. This mimicked a torn medial meniscus in clinical and radiological presentation. Arthroscopy revealed a chondral delamination flap, which was debrided. Diagnosis of chondral lesions in the knee can be challenging. Clinical examination and MRI have good accuracy for diagnosis and should be used in tandem. Early diagnosis and treatment of chondral lesions are important to prevent progression to early osteoarthritis.

  13. 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.

  14. Subcutaneous phaeohyphomycosis due to Pyrenochaeta romeroi mimicking a synovial cyst

    Directory of Open Access Journals (Sweden)

    Aurelien Dinh

    2016-08-01

    Full Text Available 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.

  15. Cystic fibrous dysplasia mimicking giant cell tumor: MRI appearance

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Kyoji; Yoshida, Sumiko [Department of Orthopaedics, Akita University School of Medicine, Akita (Japan); Okane, Kumiko [Department of Radiology, Akita University School of Medicine, Akita (Japan); Sageshima, Masato [Division of Clinical Pathology, Akita University Hospital, Akita (Japan)

    2000-01-01

    We report the case of a 43-year-old man who presented with an osteolytic and expansive lesion in the left distal femur mimicking a giant cell tumor. Magnetic resonance imaging (MRI) showed that most of the lesion was cystic, and histological examination revealed fibrous dysplasia with marked cystic degeneration. Radiographic findings of cystic fibrous dysplasia in the end of a long bone may be similar to those of a giant cell tumor, and a biopsy is essential for the final diagnosis. (orig.)

  16. Mental foramen mimicking as periapical pathology - A case report

    Directory of Open Access Journals (Sweden)

    Anusha Rangare Lakshman

    2014-09-01

    Full Text Available The radiographic recognition of any disease requires a thorough knowledge of the radiographic appearance of normal structure. Intelligent diagnosis mandates an appreciation of the wide range of variation in the appearance of normal anatomical structures. The mental foramen is usually the anterior limit of the inferior dental canal that is apparent on radiographs. It opens on the facial aspect of the mandible in the region of the premolars. It can pose diagnostic dilemma radiographically because of its anatomical variation which can mimic as a periapical pathosis. Hereby we are reporting a rare case of superimposed mental foramen over the apex of right mandibular second premolar mimicking as periapical pathology.

  17. Femoroacetabular impingement mimicking avascular osteonecrosis on bone scintigraphy

    International Nuclear Information System (INIS)

    Suarez, Juan Pablo; Domínguez, María Luz; Nogareda, Zulema; Gómez, María Asunción; Muñoz, Jose

    2016-01-01

    Femoroacetabular impingement (FAI) is a structural abnormality of proximal femur and/or acetabulum. It has been recently described, and there are limited reports in nuclear medicine literature because bone scintigraphy is not listed in its diagnostic protocol, but it should be included on differential diagnosis when evaluating patients, with hip-related symptoms because it may be misinterpreted as degenerative changes or avascular necrosis, and its early treatment avoid progression to osteoarthritis. We describe the case of a male who suffered from hip pain. Bone planar scintigraphic appearance mimicked avascular necrosis, but single photon emission computed tomography (CT) imaging and CT examination confirmed the diagnosis of FAI

  18. Embolized prostatic brachytherapy seeds mimicking acute chest pain syndromes

    Directory of Open Access Journals (Sweden)

    Nirmal Guragai

    2017-01-01

    Full Text Available A 59-year-old male with a history of nonobstructive coronary artery disease, diabetes mellitus, hypertension, and prostate cancer presented to the hospital with 1-day history of pleuritic chest pain. Initial workup for acute coronary event was unremarkable. Chest X-ray revealed multiple small radial densities which were linear and hyperdense, consistent with embolization of metallic seeds to the pulmonary circulation. The patient was noted to have had radioactive metallic seeds implanted for prostate cancer 6 months ago. Diagnosis of pulmonary embolization of prostatic seeds is challenging as they frequently present with chest pain mimicking acute coronary syndromes.

  19. Mondor Disease Of Penis; A Rare Entity Mimicking Peyronie's Disease

    Directory of Open Access Journals (Sweden)

    Türker Acar

    2015-11-01

    Full Text Available Mondor’s disease of the penis is a rare entity characterized by thrombosis in the dorsal penile vein. Unlike anxiety resulting from this condition which is conservatively treated, recognizing this disease is quite easy with Doppler ultrasonography. Peyronie’s disease and sclerosing lymphangitis are considered in the differential diagnosis of Mondor’s disease. In this present case report we aimed to present ultrasonography findings and briefly review the literature in a male patient diagnosed with Mondor's disease who admitted with rope like stiffness on the dorsal side of penis mimicking Peyronie's disease.

  20. Endometriosis mimicking the perianal fistula tract: Case report

    Directory of Open Access Journals (Sweden)

    Gül Türkcü

    2014-09-01

    Full Text Available Endometriosis is the presence of endometrial glands and stroma outside the uterine cavity. Nowadays, in many cases, although routine use of episiotomy perineal endo metriosis is extremely rare. A 36 year old female patient was referred to our hospital with complaints of pain in the perianal region for five months. On physical examination, stiffness was palpated and then magnetic resonance im aging (MRI was performed. MRI is compatible with fistula tract. The lesion was excised and the histopathological appearance correspond to endometriosis. Perianal endo metriosis is rare in the perianal region and in the clinic mimicking perianal fistulas and malignancy should be kept in mind in the differential diagnosis

  1. Proteomic peptide scan of porphyromonas gingivalis fima type ii for searching potential b-cell epitopes

    Science.gov (United States)

    LUCCHESE, A.; GUIDA, A.; CAPONE, G.; DONNARUMMA, G.; LAINO, L.; PETRUZZI, M.; SERPICO, R.; SILVESTRE, F.; GARGARI, M.

    2016-01-01

    SUMMARY Purpose To identify potential antigenic targets for Porphyromonas gingivalis vaccine development. Materials and methods In the present study, we analyzed the Porphyromonas gingivalis, fimA type II primary amino acid sequence and characterized the similarity to the human proteome at the pentapeptide level. Results We found that exact peptide-peptide profiling of the fimbrial antigen versus the human proteome shows that only 19 out of 344 fimA type II pentapeptides are uniquely owned by the bacterial protein. Conclusions The concept that protein immunogenicity is allocated in rare peptide sequences and the search the Porphyromonas gingivalis fimA type II sequence for peptides unique to the bacterial protein and absent in the human host, might be used in new therapeutical approaches as a significant adjunct to current periodontal therapies. PMID:28042435

  2. 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...

  3. Detection of human spermatozoal peptides after conjugation to 125I-labelled human serum albumin

    International Nuclear Information System (INIS)

    Metler, L.; Skrabei, H.; Czuppon, A.B.

    1981-01-01

    Human spermatozoal peptides, liberated during autolysis of the cells, were fractionated by gel-filtration chromatography and thin-layer chromatography. After conjugation to 125 I-labelled human serum albumin, all fractions were assayed with rabbit antihuman spermatozoa antiserum. In earlier publications, human sperm-immobilizing and sperm-agglutinating sera were used for the detection of solubilized spermatozoal antigen. The low sensitivity of these tests necessitated a more sensitive test. The purpose of this work is to describe a solid-phase radioimmunoassay for the detection of antigenic peptides

  4. Cancer antigen 125 and prognosis

    DEFF Research Database (Denmark)

    Høgdall, Estrid Vilma Solyom

    2008-01-01

    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...

  5. Archaeosome Adjuvant Overcomes Tolerance to Tumor-Associated Melanoma Antigens Inducing Protective CD8+ T Cell Responses

    Directory of Open Access Journals (Sweden)

    Lakshmi Krishnan

    2010-01-01

    Full Text Available Vesicles comprised of the ether glycerolipids of the archaeon Methanobrevibacter smithii (archaeosomes are potent adjuvants for evoking CD8+ T cell responses. We therefore explored the ability of archaeosomes to overcome immunologic tolerance to self-antigens. Priming and boosting of mice with archaeosome-antigen evoked comparable CD8+ T cell response and tumor protection to an alternate boosting strategy utilizing live bacterial vectors for antigen delivery. Vaccination with melanoma antigenic peptides TRP181-189 and Gp10025-33 delivered in archaeosomes resulted in IFN-γ producing antigen-specific CD8+ T cells with strong cytolytic capability and protection against subcutaneous B16 melanoma. Targeting responses against multiple antigens afforded prolonged median survival against melanoma challenge. Entrapment of multiple peptides within the same vesicle or admixed formulations were both effective at evoking CD8+ T cells against each antigen. Melanoma-antigen archaeosome formulations also afforded therapeutic protection against established B16 tumors when combined with depletion of T-regulatory cells. Overall, we demonstrate that archaeosome adjuvants constitute an effective choice for formulating cancer vaccines.

  6. 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

  7. Radioimmunoassays of hidden viral antigens

    International Nuclear Information System (INIS)

    Neurath, A.R.; Strick, N.; Baker, L.; Krugman, S.

    1982-01-01

    Antigens corresponding to infectious agents may be present in biological specimens only in a cryptic form bound to antibodies and, thus, may elude detection. We describe a solid-phase technique for separation of antigens from antibodies. Immune complexes are precipitated from serum by polyethylene glycol, dissociated with NaSCN, and adsorbed onto nitrocellulose or polystyrene supports. Antigens remain topographically separated from antibodies after removal of NaSCN and can be detected with radiolabeled antibodies. Genomes from viruses immobilized on nitrocellulose can be identified by nucleic acid hybridization. Nanogram quantities of sequestered hepatitis B surface and core antigens and picogram amounts of hepatitis B virus DNA were detected. Antibody-bound adenovirus, herpesvirus, and measles virus antigens were discerned by the procedure

  8. A computational method for identification of vaccine targets from protein regions of conserved human leukocyte antigen binding

    DEFF Research Database (Denmark)

    Olsen, Lars Rønn; Simon, Christian; Kudahl, Ulrich J.

    2015-01-01

    Background: Computational methods for T cell-based vaccine target discovery focus on selection of highly conserved peptides identified across pathogen variants, followed by prediction of their binding of human leukocyte antigen molecules. However, experimental studies have shown that T cells ofte...... or proteome using human leukocyte antigen binding predictions and made a web-accessible software implementation freely available at http://met-hilab.cbs.dtu.dk/blockcons/....

  9. Spontaneous motor entrainment to music in multiple vocal mimicking species.

    Science.gov (United States)

    Schachner, Adena; Brady, Timothy F; Pepperberg, Irene M; Hauser, Marc D

    2009-05-26

    The human capacity for music consists of certain core phenomena, including the tendency to entrain, or align movement, to an external auditory pulse [1-3]. This ability, fundamental both for music production and for coordinated dance, has been repeatedly highlighted as uniquely human [4-11]. However, it has recently been hypothesized that entrainment evolved as a by-product of vocal mimicry, generating the strong prediction that only vocal mimicking animals may be able to entrain [12, 13]. Here we provide comparative data demonstrating the existence of two proficient vocal mimicking nonhuman animals (parrots) that entrain to music, spontaneously producing synchronized movements resembling human dance. We also provide an extensive comparative data set from a global video database systematically analyzed for evidence of entrainment in hundreds of species both capable and incapable of vocal mimicry. Despite the higher representation of vocal nonmimics in the database and comparable exposure of mimics and nonmimics to humans and music, only vocal mimics showed evidence of entrainment. We conclude that entrainment is not unique to humans and that the distribution of entrainment across species supports the hypothesis that entrainment evolved as a by-product of selection for vocal mimicry.

  10. Tension pneumocephalus mimicking septic shock: a case report

    Directory of Open Access Journals (Sweden)

    Caroline Miranda, MD

    2018-02-01

    Full Text Available Tension pneumocephalus can lead to rapid neurologic deterioration. We report for the first time its association with aseptic systemic inflammatory response syndrome mimicking septic shock and the efficacy of prompt neurosurgical intervention and critical care support in treating this condition. A 64-year-old man underwent 2-stage olfactory groove meningioma resection. The patient developed altered mental status and gait instability on postoperative day 6. Imaging showed significant pneumocephalus. The patient subsequently developed worsening mental status, respiratory failure, and profound shock requiring multiple vasopressors. Bedside needle decompression, identification and repair of the cranial fossa defect, and critical care support led to improved mental status and reversal of shock and multiorgan dysfunction. Thorough evaluation revealed no evidence of an underlying infection. In this case, tension pneumocephalus incited an aseptic systemic inflammatory response syndrome mimicking septic shock. Prompt neurosurgical correction of pneumocephalus and critical care support not only improved neurologic status, but also reversed shock. Such a complication indicates the importance of close monitoring of patients with progressive pneumocephalus.

  11. Tissue-mimicking phantoms for photoacoustic and ultrasonic imaging

    Science.gov (United States)

    Cook, Jason R.; Bouchard, Richard R.; Emelianov, Stanislav Y.

    2011-01-01

    In both photoacoustic (PA) and ultrasonic (US) imaging, overall image quality is influenced by the optical and acoustical properties of the medium. Consequently, with the increased use of combined PA and US (PAUS) imaging in preclinical and clinical applications, the ability to provide phantoms that are capable of mimicking desired properties of soft tissues is critical. To this end, gelatin-based phantoms were constructed with various additives to provide realistic acoustic and optical properties. Forty-micron, spherical silica particles were used to induce acoustic scattering, Intralipid® 20% IV fat emulsion was employed to enhance optical scattering and ultrasonic attenuation, while India Ink, Direct Red 81, and Evans blue dyes were utilized to achieve optical absorption typical of soft tissues. The following parameters were then measured in each phantom formulation: speed of sound, acoustic attenuation (from 6 to 22 MHz), acoustic backscatter coefficient (from 6 to 22 MHz), optical absorption (from 400 nm to 1300 nm), and optical scattering (from 400 nm to 1300 nm). Results from these measurements were then compared to similar measurements, which are offered by the literature, for various soft tissue types. Based on these comparisons, it was shown that a reasonably accurate tissue-mimicking phantom could be constructed using a gelatin base with the aforementioned additives. Thus, it is possible to construct a phantom that mimics specific tissue acoustical and/or optical properties for the purpose of PAUS imaging studies. PMID:22076278

  12. Accurate pan-specific prediction of peptide-MHC class II binding affinity with improved binding core identification

    DEFF Research Database (Denmark)

    Andreatta, Massimo; Karosiene, Edita; Rasmussen, Michael

    2015-01-01

    A key event in the generation of a cellular response against malicious organisms through the endocytic pathway is binding of peptidic antigens by major histocompatibility complex class II (MHC class II) molecules. The bound peptide is then presented on the cell surface where it can be recognized...... by T helper lymphocytes. NetMHCIIpan is a state-of-the-art method for the quantitative prediction of peptide binding to any human or mouse MHC class II molecule of known sequence. In this paper, we describe an updated version of the method with improved peptide binding register identification. Binding...... register prediction is concerned with determining the minimal core region of nine residues directly in contact with the MHC binding cleft, a crucial piece of information both for the identification and design of CD4+ T cell antigens. When applied to a set of 51 crystal structures of peptide-MHC complexes...

  13. Gene transfer strategies for improving radiolabeled peptide imaging and therapy

    International Nuclear Information System (INIS)

    Rogers, B.E.; Buchsbaum, D.J.; Zinn, K.R.

    2000-01-01

    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 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

  14. Peptide Immunotherapy for Type 1 Diabetes—Clinical Advances

    Science.gov (United States)

    Smith, Emma L.; Peakman, Mark

    2018-01-01

    Autoimmune and allergic diseases occur when an individual mounts an inappropriate immune response to a self-antigen or an innocuous environmental antigen. This triggers a pathogenic T-cell response resulting in damage to specific tissues and organs. In type 1 diabetes (T1D), this manifests as destruction of the insulin-secreting β cells, resulting in a life-long dependency on recombinant insulin. Modulation of the pathogenic T-cell response with antigen-specific peptide immunotherapy offers the potential to restore the immune homeostasis and prevent further tissue destruction. Recent clinical advances with peptide therapy approaches in both T1D and other diseases are beginning to show encouraging results. New technologies targeting the peptides to specific cell types are also moving from pre-clinical development to the clinic. While many challenges remain in clinical development, not least selection of the optimal dose and dosing frequency, this is clearly becoming a very active field of drug development. PMID:29541078

  15. Identification of a Novel UTY‐Encoded Minor Histocompatibility Antigen

    DEFF Research Database (Denmark)

    Mortensen, B. K.; Rasmussen, A. H.; Larsen, Malene Erup

    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...... 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....../HLA tetramers, the specificity of the CD8+ T cell response was successfully validated as being HLA‐A*24:02‐restricted and directed against the male UTY139–147 peptide. Functional analysis of these T cells demonstrated male UTY139–147 peptide‐specific cytokine secretion (IFNγ, TNFα and MIP‐1β) and cytotoxic...

  16. Antigen presentation profiling reveals recognition of lymphoma immunoglobulin neoantigens.

    Science.gov (United States)

    Khodadoust, Michael S; Olsson, Niclas; Wagar, Lisa E; Haabeth, Ole A W; Chen, Binbin; Swaminathan, Kavya; Rawson, Keith; Liu, Chih Long; Steiner, David; Lund, Peder; Rao, Samhita; Zhang, Lichao; Marceau, Caleb; Stehr, Henning; Newman, Aaron M; Czerwinski, Debra K; Carlton, Victoria E H; Moorhead, Martin; Faham, Malek; Kohrt, Holbrook E; Carette, Jan; Green, Michael R; Davis, Mark M; Levy, Ronald; Elias, Joshua E; Alizadeh, Ash A

    2017-03-30

    Cancer somatic mutations can generate neoantigens that distinguish malignant from normal cells. However, the personalized identification and validation of neoantigens remains a major challenge. Here we discover neoantigens in human mantle-cell lymphomas by using an integrated genomic and proteomic strategy that interrogates tumour antigen peptides presented by major histocompatibility complex (MHC) class I and class II molecules. We applied this approach to systematically characterize MHC ligands from 17 patients. Remarkably, all discovered neoantigenic peptides were exclusively derived from the lymphoma immunoglobulin heavy- or light-chain variable regions. Although we identified MHC presentation of private polymorphic germline alleles, no mutated peptides were recovered from non-immunoglobulin somatically mutated genes. Somatic mutations within the immunoglobulin variable region were almost exclusively presented by MHC class II. We isolated circulating CD4 + T cells specific for immunoglobulin-derived neoantigens and found these cells could mediate killing of autologous lymphoma cells. These results demonstrate that an integrative approach combining MHC isolation, peptide identification, and exome sequencing is an effective platform to uncover tumour neoantigens. Application of this strategy to human lymphoma implicates immunoglobulin neoantigens as targets for lymphoma immunotherapy.

  17. Development of Peptide Vaccines in Dengue.

    Science.gov (United States)

    Reginald, Kavita; Chan, Yanqi; Plebanski, Magdalena; Poh, Chit Laa

    2017-09-13

    Dengue is one of the most important arboviral infection worldwide, infecting up to 390 million people and causing 25,000 deaths annually. Although a licensed dengue vaccine is available, it is not efficacious against dengue serotypes that infect people living in South East Asia, where dengue is an endemic disease. Hence, there is an urgent need to develop an efficient dengue vaccine for this region. Data from different clinical trials indicate that a successful dengue vaccine must elicit both neutralizing antibodies and cell mediated immunity. This can be achieved by designing a multi-epitope peptide vaccine comprising B, CD8+ and CD4+ T cell epitopes. As recognition of T cell epitopes are restricted by human leukocyte antigens (HLA), T cell epitopes which are able to recognize several major HLAs will be preferentially included in the vaccine design. While peptide vaccines are safe, biocompatible and cost-effective, it is poorly immunogenic. Strategies to improve its immunogenicity by the use of long peptides, adjuvants and nanoparticle delivery mechanisms are discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. 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...

  19. Cellular vaccines in listeriosis: role of the Listeria antigen GAPDH.

    Science.gov (United States)

    Calderón-González, Ricardo; Frande-Cabanes, Elisabet; Bronchalo-Vicente, Lucía; Lecea-Cuello, M Jesús; Pareja, Eduardo; Bosch-Martínez, Alexandre; Fanarraga, Mónica L; Yañez-Díaz, Sonsoles; Carrasco-Marín, Eugenio; Alvarez-Domínguez, Carmen

    2014-01-01

    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.

  20. 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.

  1. Cellular vaccines in listeriosis: role of the Listeria antigen GAPDH

    Science.gov (United States)

    Calderón-González, Ricardo; Frande-Cabanes, Elisabet; Bronchalo-Vicente, Lucía; Lecea-Cuello, M. Jesús; Pareja, Eduardo; Bosch-Martínez, Alexandre; Fanarraga, Mónica L.; Yañez-Díaz, Sonsoles; Carrasco-Marín, Eugenio; Álvarez-Domínguez, Carmen

    2014-01-01

    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. PMID:24600592

  2. New insights into the bioactivity of peptides from probiotics.

    Science.gov (United States)

    Mandal, Santi M; Pati, Bikas R; Chakraborty, Ranadhir; Franco, Octavio L

    2016-06-01

    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.

  3. [Novel achievements in development and application of GPCR-peptides].

    Science.gov (United States)

    Shpakov, A O; Derkach, K V

    2015-01-01

    One of the approaches to creating the regulators of G-protein-coupled receptors (GPCR) is the development of peptides that structurally correspond to the functionally important regions of the intracellular extracellular loops of the receptors. GPCR-peptides can selectively regulate the functional activity of homologous receptor and affect the hormonal signal transduction via the receptor. Among the peptides corresponding to the intracellular regions of GPCR, their derivatives modified with hydrophobic radicals exhibit the highest activity and selectivity of action in vitro and in vivo. Ample evidence demonstrates that lipophilic GPCR-peptides may be used to treat diseases and various abnormalities that depend on the functional activity of receptors homologous to them. In turn, the peptides corresponding to the extracellular regions of GPCR can be used as functional probes for studying the specific interaction between the receptors and their ligands, as well as for studying the etiology and pathogenesis of autoimmune diseases caused by the production of antibodies to GPCR antigenic determinants that are localized in the receptor extracellular loops. The present review focuses on the recent achievements in development and application of GPCR-peptides and on the prospects for their further use in medicine and fundamental biology.

  4. 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.

  5. 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.

  6. Colonoscopy and carcinoembryonic antigen variations.

    Science.gov (United States)

    Sousa, Rita G; Nunes, Ana; Meira, Tânia; Carreira, Olga; Pires, Ana M; Freitas, João

    2014-01-01

    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. To evaluate the influence of bowel preparation and colonoscopy in carcinoembryonic antigen blood levels. 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. 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). 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. Circulating viral core and E1 antigen levels as supplemental markers for HCV Chronic hepatitis

    Directory of Open Access Journals (Sweden)

    El Awady Mostafa K

    2006-09-01

    Full Text Available Abstract The performance of polyclonal monospecific rabbit anti-sera raised against synthetic peptides derived from conserved HCV sequences of genotype 4 was evaluated for efficient detection of viral core and E1 antigens in circulating immune complexes (ICs precipitated from 65 serum samples of HCV patients. The infection was established in those patients by the presence of HCV RNA in their sera. A novel enzyme-linked immunosorbent assay (ELISA was developed for the detection of HCV core and E1 antigen in serum samples. Western blot analyses were used to demonstrate the presence of the core and E1 target antigen in serum samples. The mean OD readings of both core and E1 antigens were significantly higher (P

  8. Methyldopa blocks MHC class II binding to disease-specific antigens in autoimmune diabetes.

    Science.gov (United States)

    Ostrov, David A; Alkanani, Aimon; McDaniel, Kristen A; Case, Stephanie; Baschal, Erin E; Pyle, Laura; Ellis, Samuel; Pöllinger, Bernadette; Seidl, Katherine J; Shah, Viral N; Garg, Satish K; Atkinson, Mark A; Gottlieb, Peter A; Michels, Aaron W

    2018-02-13

    Major histocompatibility (MHC) class II molecules are strongly associated with many autoimmune disorders. In type 1 diabetes, the DQ8 molecule is common, confers significant disease risk and is involved in disease pathogenesis. We hypothesized blocking DQ8 antigen presentation would provide therapeutic benefit by preventing recognition of self-peptides by pathogenic T cells. We used the crystal structure of DQ8 to select drug-like small molecules predicted to bind structural pockets in the MHC antigen-binding cleft. A limited number of the predicted compounds inhibited DQ8 antigen presentation in vitro with one compound preventing insulin autoantibody production and delaying diabetes onset in an animal model of spontaneous autoimmune diabetes. An existing drug of similar structure, methyldopa, specifically blocked DQ8 in recent-onset patients with type 1 diabetes along with reducing inflammatory T cell responses toward insulin, highlighting the relevance of blocking disease-specific MHC class II antigen presentation to treat autoimmunity.

  9. Tax mimicking and yardstick competition among local governments in the Netherlands

    NARCIS (Netherlands)

    Allers, MA; Elhorst, JP

    This paper provides a spatial-econometric analysis of the setting of property tax rates by Dutch municipalities. We find evidence of tax mimicking: a ten percent higher property tax rate in neighboring municipalities leads to a 3.5 percent higher tax rate. Mimicking is less pronounced in

  10. 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.

  11. Structural analysis of a functional DIAP1 fragment bound to grim and hid peptides.

    Science.gov (United States)

    Wu, J W; Cocina, A E; Chai, J; Hay, B A; Shi, Y

    2001-07-01

    The inhibitor of apoptosis protein DIAP1 suppresses apoptosis in Drosophila, with the second BIR domain (BIR2) playing an important role. Three proteins, Hid, Grim, and Reaper, promote apoptosis, in part by binding to DIAP1 through their conserved N-terminal sequences. The crystal structures of DIAP1-BIR2 by itself and in complex with the N-terminal peptides from Hid and Grim reveal that these peptides bind a surface groove on DIAP1, with the first four amino acids mimicking the binding of the Smac tetrapeptide to XIAP. The next 3 residues also contribute to binding through hydrophobic interactions. Interestingly, peptide binding induces the formation of an additional alpha helix in DIAP1. Our study reveals the structural conservation and diversity necessary for the binding of IAPs by the Drosophila Hid/Grim/Reaper and the mammalian Smac proteins.

  12. Tumor penetrating peptides

    Directory of Open Access Journals (Sweden)

    Tambet eTeesalu

    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

  13. Tumor-Penetrating Peptides

    Science.gov (United States)

    Teesalu, Tambet; Sugahara, Kazuki N.; Ruoslahti, Erkki

    2013-01-01

    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 present in the

  14. Intracellular Transport Routes for MHC I and Their Relevance for Antigen Cross-Presentation

    Science.gov (United States)

    Adiko, Aimé Cézaire; Babdor, Joel; Gutiérrez-Martínez, Enric; Guermonprez, Pierre; Saveanu, Loredana

    2015-01-01

    Cross-presentation, in which exogenous antigens are presented via MHC I complexes, is involved both in the generation of anti-infectious and anti-tumoral cytotoxic CD8+ T cells and in the maintenance of immune tolerance. While cross-presentation was described almost four decades ago and while it is now established that some dendritic cell (DC) subsets are better than others in processing and cross-presenting internalized antigens, the involved molecular mechanisms remain only partially understood. Some of the least explored molecular mechanisms in cross-presentation concern the origin of cross-presenting MHC I molecules and the cellular compartments where antigenic peptide loading occurs. This review focuses on MHC I molecules and their intracellular trafficking. We discuss the source of cross-presenting MHC I in DCs as well as the role of the endocytic pathway in their recycling from the cell surface. Next, we describe the importance of the TAP peptide transporter for delivering peptides to MHC I during cross-presentation. Finally, we highlight the impact of innate immunity mechanisms on specific antigen cross-presentation mechanisms in which TLR activation modulates MHC I trafficking and TAP localization. PMID:26191062

  15. Novel Endogenous Antimicrobial Peptides

    OpenAIRE

    Nordahl, Emma

    2009-01-01

    Antimicrobial peptides serve as a first line of defence against invading microorganisms and are an essential part of our fast innate immune system. They are ancient molecules found in all classes of life. Antimicrobial peptides rapidly kill a broad spectrum of microbes and are immunomodulatory, i.e. having additional actions influencing inflammation and other innate immune responses. Results presented in this thesis demonstrate that proteases of common human pathogens degrade and inactivate t...

  16. From Viral genome to specific peptide epitopes - Methods for identifying porcine T cell epitopes based on in silico predictions, in vitro identification and ex vivo verification

    DEFF Research Database (Denmark)

    Pedersen, Lasse Eggers; Rasmussen, Michael; Harndahl, Mikkel

    The affinity for and stability of peptides bound by major histocompatibility complex (MHC) class I molecules are instrumental factors in presentation of viral epitopes to cytotoxic T lymphocytes (CTLs). In swine, such peptide presentations by swine leukocyte antigens (SLA) are crucial for swine i...

  17. From viral genome to specific peptide epitopes: methods for identifying porcine T cell epitopes based on in silico predictions, in vitro identification and ex vivo verification

    DEFF Research Database (Denmark)

    Pedersen, Lasse Eggers; Rasmussen, Michael; Harndah, Mikkel

    2013-01-01

    The affinity with which major histocompatibility complex (MHC) class I molecules bind peptides is instrumental to presentation of viral epitopes to cytotoxic T lymphocytes (CTLs). We analyzed three swine leukocyte antigen (SLA) molecules for complete nonamer peptide-based binding matrices in orde...

  18. Brute-Force Approach for Mass Spectrometry-Based Variant Peptide Identification in Proteogenomics without Personalized Genomic Data

    Science.gov (United States)

    Ivanov, Mark V.; Lobas, Anna A.; Levitsky, Lev I.; Moshkovskii, Sergei A.; Gorshkov, Mikhail V.

    2018-02-01

    In a proteogenomic approach based on tandem mass spectrometry analysis of proteolytic peptide mixtures, customized exome or RNA-seq databases are employed for identifying protein sequence variants. However, the problem of variant peptide identification without personalized genomic data is important for a variety of applications. Following the recent proposal by Chick et al. (Nat. Biotechnol. 33, 743-749, 2015) on the feasibility of such variant peptide search, we evaluated two available approaches based on the previously suggested "open" search and the "brute-force" strategy. To improve the efficiency of these approaches, we propose an algorithm for exclusion of false variant identifications from the search results involving analysis of modifications mimicking single amino acid substitutions. Also, we propose a de novo based scoring scheme for assessment of identified point mutations. In the scheme, the search engine analyzes y-type fragment ions in MS/MS spectra to confirm the location of the mutation in the variant peptide sequence.

  19. A biochemical approach for detecting interactions between peptides from the HIV gp120 glycoprotein and a CD4 sequence.

    Science.gov (United States)

    Chersi, Alberto; Falasca, Giuliana; Malorni, Walter

    2004-01-01

    Peptides selected from the HIV viral protein gp120 bind to a synthetic peptide mimicking sequence 78-89 of the human lymphocyte CD4 molecule, linked to activated Sepharose. The binding of viral fragments to the CD4 peptide-Sepharose beads was ascertained either by aid of a ninhydrin reagent or by fluorescence microscopy. A suitable alignment of these HIV peptides with the CD4 fragment showed that multiple interactions might occur between hydrophobic or charged groups of the two molecules. Although this experiment does not demonstrate that these two amino acid stretches are involved in the primary binding of gp120 to CD4 receptors, the present data suggest that the two sequences might have some kind of interaction during subsequent steps of viral infection.

  20. Discovery of novel cyclic peptide inhibitors of dengue virus NS2B-NS3 protease with antiviral activity.

    Science.gov (United States)

    Takagi, Youhei; Matsui, Kouhei; Nobori, Haruaki; Maeda, Haruka; Sato, Akihiko; Kurosu, Takeshi; Orba, Yasuko; Sawa, Hirofumi; Hattori, Kazunari; Higashino, Kenichi; Numata, Yoshito; Yoshida, Yutaka

    2017-08-01

    NS2B-NS3 protease is an essential enzyme for the replication of dengue virus (DENV), which continues to be a serious threat to worldwide public health. We designed and synthesized a series of cyclic peptides mimicking the substrates of this enzyme, and assayed their activity against the DENV-2 NS2B-NS3 protease. The introduction of aromatic residues at the appropriate positions and conformational restriction generated the most promising cyclic peptide with an IC 50 of 0.95μM against NS2B-NS3 protease. Cyclic peptides with proper positioning of additional arginines and aromatic residues exhibited antiviral activity against DENV. Furthermore, replacing the C-terminal amide bond of the polybasic amino acid sequence with an amino methylene moiety stabilized the cyclic peptides against hydrolysis by NS2B-NS3 protease, while maintaining their enzyme inhibitory activity and antiviral activity. Copyright © 2017 Elsevier Ltd. All rights reserved.