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Sample records for antigen cd123 mediate

  1. Cysteine protease antigens cleave CD123, the α subunit of murine IL-3 receptor, on basophils and suppress IL-3-mediated basophil expansion

    International Nuclear Information System (INIS)

    Nishikado, Hideto; Fujimura, Tsutomu; Taka, Hikari; Mineki, Reiko; Ogawa, Hideoki; Okumura, Ko; Takai, Toshiro

    2015-01-01

    Th2 type immune responses are essential for protective immunity against parasites and play crucial roles in allergic disorders. Helminth parasites secrete a variety of proteases for their infectious cycles including for host entry, tissue migration, and suppression of host immune effector cell function. Furthermore, a number of pathogen-derived antigens, as well as allergens such as papain, belong to the family of cysteine proteases. Although the link between protease activity and Th2 type immunity is well documented, the mechanisms by which proteases regulate host immune responses are largely unknown. Here, we demonstrate that the cysteine proteases papain and bromelain selectively cleave the α subunit of the IL-3 receptor (IL-3Rα/CD123) on the surface of murine basophils. The decrease in CD123 expression on the cell surface, and the degradation of the extracellular domain of recombinant CD123 were dependent on the protease activity of papain and bromelain. Pre-treatment of murine basophils with papain resulted in inhibition of IL-3-IL-3R signaling and suppressed IL-3- but not thymic stromal lymphopoietin-induced expansion of basophils in vitro. Our unexpected findings illuminate a novel mechanism for the regulation of basophil functions by protease antigens. Because IL-3 plays pivotal roles in the activation and proliferation of basophils and in protective immunity against helminth parasites, pathogen-derived proteases might contribute to the pathogenesis of infections by regulating IL-3-mediated functions in basophils. - Highlights: • We identified the murine IL3R as a novel target of papain-family cysteine proteases. • Papain-family cysteine proteases cleaved IL3Rα/CD123 on murine basophils. • Papain suppressed IL3- but not TSLP-induced expansion of murine basophils. • The inactivation of IL3R might be a strategy for pathogens to suppress host immunity

  2. Cysteine protease antigens cleave CD123, the α subunit of murine IL-3 receptor, on basophils and suppress IL-3-mediated basophil expansion

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    Nishikado, Hideto [Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, Tokyo (Japan); Fujimura, Tsutomu; Taka, Hikari; Mineki, Reiko [Laboratory of Proteomics and Biomolecular Science, BioMedical Research Center, Juntendo University Graduate School of Medicine, Tokyo (Japan); Ogawa, Hideoki; Okumura, Ko [Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, Tokyo (Japan); Takai, Toshiro, E-mail: t-takai@juntendo.ac.jp [Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, Tokyo (Japan)

    2015-05-01

    Th2 type immune responses are essential for protective immunity against parasites and play crucial roles in allergic disorders. Helminth parasites secrete a variety of proteases for their infectious cycles including for host entry, tissue migration, and suppression of host immune effector cell function. Furthermore, a number of pathogen-derived antigens, as well as allergens such as papain, belong to the family of cysteine proteases. Although the link between protease activity and Th2 type immunity is well documented, the mechanisms by which proteases regulate host immune responses are largely unknown. Here, we demonstrate that the cysteine proteases papain and bromelain selectively cleave the α subunit of the IL-3 receptor (IL-3Rα/CD123) on the surface of murine basophils. The decrease in CD123 expression on the cell surface, and the degradation of the extracellular domain of recombinant CD123 were dependent on the protease activity of papain and bromelain. Pre-treatment of murine basophils with papain resulted in inhibition of IL-3-IL-3R signaling and suppressed IL-3- but not thymic stromal lymphopoietin-induced expansion of basophils in vitro. Our unexpected findings illuminate a novel mechanism for the regulation of basophil functions by protease antigens. Because IL-3 plays pivotal roles in the activation and proliferation of basophils and in protective immunity against helminth parasites, pathogen-derived proteases might contribute to the pathogenesis of infections by regulating IL-3-mediated functions in basophils. - Highlights: • We identified the murine IL3R as a novel target of papain-family cysteine proteases. • Papain-family cysteine proteases cleaved IL3Rα/CD123 on murine basophils. • Papain suppressed IL3- but not TSLP-induced expansion of murine basophils. • The inactivation of IL3R might be a strategy for pathogens to suppress host immunity.

  3. Redirecting Specificity of T cells Using the Sleeping Beauty System to Express Chimeric Antigen Receptors by Mix-and-Matching of VL and VH Domains Targeting CD123+ Tumors.

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    Radhika Thokala

    Full Text Available Adoptive immunotherapy infusing T cells with engineered specificity for CD19 expressed on B- cell malignancies is generating enthusiasm to extend this approach to other hematological malignancies, such as acute myelogenous leukemia (AML. CD123, or interleukin 3 receptor alpha, is overexpressed on most AML and some lymphoid malignancies, such as acute lymphocytic leukemia (ALL, and has been an effective target for T cells expressing chimeric antigen receptors (CARs. The prototypical CAR encodes a VH and VL from one monoclonal antibody (mAb, coupled to a transmembrane domain and one or more cytoplasmic signaling domains. Previous studies showed that treatment of an experimental AML model with CD123-specific CAR T cells was therapeutic, but at the cost of impaired myelopoiesis, highlighting the need for systems to define the antigen threshold for CAR recognition. Here, we show that CARs can be engineered using VH and VL chains derived from different CD123-specific mAbs to generate a panel of CAR+ T cells. While all CARs exhibited specificity to CD123, one VH and VL combination had reduced lysis of normal hematopoietic stem cells. This CAR's in vivo anti-tumor activity was similar whether signaling occurred via chimeric CD28 or CD137, prolonging survival in both AML and ALL models. Co-expression of inducible caspase 9 eliminated CAR+ T cells. These data help support the use of CD123-specific CARs for treatment of CD123+ hematologic malignancies.

  4. Characterization of SGN-CD123A, A Potent CD123-Directed Antibody-Drug Conjugate for Acute Myeloid Leukemia.

    Science.gov (United States)

    Li, Fu; Sutherland, May Kung; Yu, Changpu; Walter, Roland B; Westendorf, Lori; Valliere-Douglass, John; Pan, Lucy; Cronkite, Ashley; Sussman, Django; Klussman, Kerry; Ulrich, Michelle; Anderson, Martha E; Stone, Ivan J; Zeng, Weiping; Jonas, Mechthild; Lewis, Timothy S; Goswami, Maitrayee; Wang, Sa A; Senter, Peter D; Law, Che-Leung; Feldman, Eric J; Benjamin, Dennis R

    2018-02-01

    Treatment choices for acute myelogenous leukemia (AML) patients resistant to conventional chemotherapies are limited and novel therapeutic agents are needed. IL3 receptor alpha (IL3Rα, or CD123) is expressed on the majority of AML blasts, and there is evidence that its expression is increased on leukemic relative to normal hematopoietic stem cells, which makes it an attractive target for antibody-based therapy. Here, we report the generation and preclinical characterization of SGN-CD123A, an antibody-drug conjugate using the pyrrolobenzodiazepine dimer (PBD) linker and a humanized CD123 antibody with engineered cysteines for site-specific conjugation. Mechanistically, SGN-CD123A induces activation of DNA damage response pathways, cell-cycle changes, and apoptosis in AML cells. In vitro , SGN-CD123A-mediated potent cytotoxicity of 11/12 CD123 + AML cell lines and 20/23 primary samples from AML patients, including those with unfavorable cytogenetic profiles or FLT3 mutations. In vivo , SGN-CD123A treatment led to AML eradication in a disseminated disease model, remission in a subcutaneous xenograft model, and significant growth delay in a multidrug resistance xenograft model. Moreover, SGN-CD123A also resulted in durable complete remission of a patient-derived xenograft AML model. When combined with a FLT3 inhibitor quizartinib, SGN-CD123A enhanced the activity of quizartinib against two FLT3-mutated xenograft models. Overall, these data demonstrate that SGN-CD123A is a potent antileukemic agent, supporting an ongoing trial to evaluate its safety and efficacy in AML patients (NCT02848248). Mol Cancer Ther; 17(2); 554-64. ©2017 AACR . ©2017 American Association for Cancer Research.

  5. Distribution and levels of cell surface expression of CD33 and CD123 in acute myeloid leukemia

    Science.gov (United States)

    Ehninger, A; Kramer, M; Röllig, C; Thiede, C; Bornhäuser, M; von Bonin, M; Wermke, M; Feldmann, A; Bachmann, M; Ehninger, G; Oelschlägel, U

    2014-01-01

    Owing to the more recent positive results with the anti-CD33 immunotoxin gemtuzumab ozogamicin, therapy against acute myeloid leukemias (AMLs) targeting CD33 holds many promises. Here, CD33 and CD123 expression on AML blasts was studied by flow cytometry in a cohort of 319 patients with detailed information on French–American–British/World Health Organization (FAB/WHO) classification, cytogenetics and molecular aberrations. AMLs of 87.8% express CD33 and would therefore be targetable with anti-CD33 therapies. Additionally, 9.4% of AMLs express CD123 without concomitant CD33 expression. Thus, nearly all AMLs could be either targeted via CD33 or CD123. Simultaneous presence of both antigens was observed in 69.5% of patients. Most importantly, even AMLs with adverse cytogenetics express CD33 and CD123 levels comparable to those with favorable and intermediate subtypes. Some patient groups with unfavorable alterations, such as FMS-related tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutations, high FLT3-ITD mutant/wild-type ratios and monosomy 5 are even characterized by high expression of CD33 and CD123. In addition, blasts of patients with mutant nucleophosmin (NPM1) revealed significantly higher CD33 and CD123 expression pointing toward the possibility of minimal residual disease-guided interventions in mutated NPM1-positive AMLs. These results stimulate the development of novel concepts to redirect immune effector cells toward CD33- and CD123-expressing blasts using bi-specific antibodies or engineered T cells expressing chimeric antigen receptors. PMID:24927407

  6. CD123 immunohistochemistry for plasmacytoid dendritic cells is useful in the diagnosis of scarring alopecia.

    Science.gov (United States)

    Fening, Katherine; Parekh, Vishwas; McKay, Kristopher

    2016-08-01

    Distinguishing types of lymphocytic scarring alopecia is often difficult because of the overlapping features. Recently, the presence of plasmacytoid dendritic cells (PDCs) in cutaneous lupus erythematosus (LE) was demonstrated and further shown to help distinguish lupus from other dermatoses.1-6 This study aims to determine if the presence and distribution of PDCs can aid in the diagnosis of scarring alopecia. Cases of scarring alopecia due to chronic cutaneous lupus erythematosus (CCLE), lichen planopilaris (LPP) and central centrifugal cicatricial alopecia (CCCA) were examined histopathologically. A total of 45 total biopsies were evaluated and CD123 immunohistochemistry was performed on all samples. The relative percentage of PDCs, the presence of clusters and the distribution of CD123+ cells were noted. PDCs comprised a greater percentage of the infiltrate and were arranged in clusters in cases of CCLE vs. LPP or CCCA. In CCLE, the location of PDCs was perivascular, perifollicular, perieccrine and/or at the follicular junction. In LPP and CCCA, PDCs were mainly arranged as single, interstitial cells. Our findings suggest that the presence and arrangement of CD123+ PDCs may assist in the diagnosis of scarring alopecia. We anticipate this will be of value in diagnosing challenging cases of highly inflammatory scarring alopecia. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Protein antigen delivery by gene gun-mediated epidermal antigen incorporation (EAI).

    Science.gov (United States)

    Scheiblhofer, Sandra; Ritter, Uwe; Thalhamer, Josef; Weiss, Richard

    2013-01-01

    The gene gun technology can not only be employed for efficient transfer of gene vaccines into upper layers of the skin, but also for application of protein antigens. As a tissue rich in professional antigen presenting cells, the skin represents an attractive target for immunizations. In this chapter we present a method for delivery of the model antigen ovalbumin into the skin of mice termed epidermal antigen incorporation and describe in detail how antigen-specific proliferation in draining lymph nodes can be followed by flow cytometry.

  8. ONCOLYTIC VIRUS-MEDIATED REVERSAL OF IMPAIRED TUMOR ANTIGEN PRESENTATION

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    Shashi Ashok Gujar

    2014-04-01

    Full Text Available Anti-tumor immunity can eliminate existing cancer cells and also maintain a constant surveillance against possible relapse. Such an antigen-specific adaptive response begins when tumor-specific T cells become activated. T cell activation requires two signals on antigen presenting cells (APCs: antigen presentation through MHC molecules and co-stimulation. In the absence of one or both of these signals, T cells remain inactivated or can even become tolerized. Cancer cells and their associated microenvironment strategically hinder the processing and presentation of tumor antigens and consequently prevent the development of anti-tumor immunity. Many studies, however, demonstrate that interventions that overturn tumor-associated immune evasion mechanisms can establish anti-tumor immune responses of therapeutic potential. One such intervention is oncolytic virus (OV-based anti-cancer therapy. Here we discuss how OV-induced immunological events override tumor-associated antigen presentation impairment and promote appropriate T cell:APC interaction. Detailed understanding of this phenomenon is pivotal for devising the strategies that will enhance the efficacy of OV-based anti-cancer therapy by complementing its inherent oncolytic

  9. Virosome-mediated delivery of protein antigens to dendritic cells

    NARCIS (Netherlands)

    Bungener, L; Serre, K; Bijl, L; Leserman, L; Wilschut, J; Daemen, T; Machy, P

    2002-01-01

    Virosomes are reconstituted viral membranes in which protein can be encapsulated. Fusion-active virosomes, fusion-inactive virosomes and liposomes were used to study the conditions needed for delivery of encapsulated protein antigen ovalbumin (OVA) to dendritic cells (DCs) for MHC class I and 11

  10. Microbial antigenic variation mediated by homologous DNA recombination

    NARCIS (Netherlands)

    C. Vink (Cornelis); L. Rudenko (Larisa); H.S. Seifert (H. Steven)

    2012-01-01

    textabstractPathogenic microorganisms employ numerous molecular strategies in order to delay or circumvent recognition by the immune system of their host. One of the most widely used strategies of immune evasion is antigenic variation, in which immunogenic molecules expressed on the surface of a

  11. A new Kupffer cell receptor mediating plasma clearance of carcinoembryonic antigen by the rat.

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    Toth, C A; Thomas, P; Broitman, S A; Zamcheck, N

    1982-01-01

    Native human carcinoembryonic antigen is rapidly removed from the circulation by the rat liver Kupffer cell after intravenous injection. The molecule is subsequently transferred to the hepatocyte in an immunologically identifiable form. Carcinoembryonic antigen has a circulatory half-life of 3.7 (+/- 0.8) min, and cellular entry is by receptor-mediated endocytosis. Non-specific fluid pinocytosis and phagocytosis can be excluded as possible mechanisms by the kinetics of clearance and failure of colloidal carbon to inhibit uptake. Substances with known affinity for the hepatic receptors for mannose, N-acetylglucosamine, fucose and galactose all fail to inhibit carcinoembryonic antigen clearance. After two cycles of the Smith degradation, carcinoembryonic antigen is still able to inhibit clearance of the native molecule. Receptor specificity is apparently not dependent on those non-reducing terminal sugars of the native molecule. Performic acid-oxidized carcinoembryonic antigen also inhibits clearance of carcinoembryonic antigen in vivo. Receptor binding is not dependent on tertiary protein conformation. Non-specific cross-reacting antigen, a glycoprotein structurally similar to carcinoembryonic antigen, is cleared by the same mechanism. PMID:6896821

  12. Humoral and cell-mediated immune response to crude antigens of Dermatophilus congolensis during experimental infection of rabbits.

    Science.gov (United States)

    Makinde, A A; Wilkie, B N

    1979-01-01

    Rabbits were infected with Dermatophilus congolensis and tested for humoral immune response by indirect haemagglutination and for cell-mediated immune response to crude antigens of D. congolensis. Lymphocyte transformation and macrophage migration inhibition assays were used as in vitro correlates of cell-mediated immune response while cutaneous delayed hypersensitivity was used in vivo. Endo-antigen and whole cell antigen were found to significantly induce cell-mediated immune response. In contrast, humoral responses were found to be more significantly induced by exo-antigen. A biphasic immune response was revealed by the lymphocyte transformation test.

  13. A plasmacytoid dendritic cell (CD123+/CD11c-) based assay system to predict contact allergenicity of chemicals

    International Nuclear Information System (INIS)

    Ayehunie, Seyoum; Snell, Maureen; Child, Matthew; Klausner, Mitchell

    2009-01-01

    A predictive allergenicity test system for assessing the contact allergenicity of chemicals is needed by the cosmetic and pharmaceutical industry to monitor product safety in the marketplace. Development of such non-animal alternative assay systems for skin sensitization and hazard identification has been pursued by policy makers and regulatory agencies. We investigated whether phenotypic and functional changes to a subset of dendritic cells (DC), plasmacytoid DC (pDC), could be used to identify contact allergens. To achieve this goal, normal human DC were generated from CD34+ progenitor cells and cryopreserved. Frozen DC were thawed and the pDC fraction (CD123+/CD11c-) was harvested using FACS sorting. The pDC were cultured, expanded, and exposed to chemical allergens (N = 26) or non-allergens (N = 22). Concentrations of each chemical that resulted in >50% viability was determined using FACS analysis of propidium iodide stained cells using pDC from 2 to 5 donors. Expression of the surface marker, CD86, which has been implicated in dendritic cell maturation, was used as a marker of allergenicity. CD86 expression increased (≥1.5-fold) for 25 of 26 allergens (sensitivity = 96%) but did not increase for 19 of 22 non-allergens (specificity = 86%). In a direct comparison to historical data for the regulatory approved, mouse local lymph node assay (LLNA) for 23 allergens and 22 non-allergens, the pDC method had sensitivity and specificity of 96% and 86%, respectively, while the sensitivity and specificity of the LLNA assay was 83% and 82%, respectively. In conclusion, CD86 expression in pDC appears to be a sensitive and specific indicator to identify contact allergenicity. Such an assay method utilizing normal human cells will be useful for high throughput screening of chemicals for allergenicity.

  14. A plasmacytoid dendritic cell (CD123+/CD11c-) based assay system to predict contact allergenicity of chemicals

    Science.gov (United States)

    Ayehunie, Seyoum; Snell, Maureen; Child, Matthew; Klausner, Mitchell

    2009-01-01

    A predictive allergenicity test system for assessing the contact allergenicity of chemicals is needed by the cosmetic and pharmaceutical industry to monitor product safety in the marketplace. Development of such non-animal alternative assay systems for skin sensitization and hazard identification has been pursued by policy makers and regulatory agencies. We investigated whether phenotypic and functional changes to a subset of dendritic cells (DC), plasmacytoid DC (pDC), could be used to identify contact allergens. To achieve this goal, normal human DC were generated from CD34+ progenitor cells and cryopreserved. Frozen DC were thawed and the pDC fraction (CD123+/CD11c-) was harvested using FACS sorting. The pDC were cultured, expanded, and exposed to chemical allergens (N=26) or non-allergens (N=22). Concentrations of each chemical that resulted in >50% viability was determined using FACS analysis of propidium iodide stained cells using pDC from 2-5 donors. Expression of the surface marker, CD86, which has been implicated in dendritic cell maturation, was used as a marker of allergenicity. CD86 expression increased (≥ 1.5 fold) for 25 of 26 allergens (sensitivity = 96%) but did not increase for 19 of 22 non-allergens (specificity = 86%). In a direct comparison to historical data for the regulatory approved, mouse local lymph node assay (LLNA) for 23 allergens and 22 non-allergens, the pDC method had sensitivity and specificity of 96% and 86%, respectively, while the sensitivity and specificity of the LLNA assay was 83% and 82%, respectively. In conclusion, CD86 expression in pDC appears to be a sensitive and specific indicator to identify contact allergenicity. Such an assay method utilizing normal human cells will be useful for high throughput screening of chemicals for allergenicity. PMID:19665512

  15. Cell-mediated immunity against human retinal extract, S-antigen, and interphotoreceptor retinoid binding protein in onchocercal chorioretinopathy

    NARCIS (Netherlands)

    van der Lelij, A.; Rothova, A.; Stilma, J. S.; Hoekzema, R.; Kijlstra, A.

    1990-01-01

    Autoimmune mechanisms are thought to be involved in the pathogenesis of onchocercal chorioretinopathy. Cell-mediated immune responses to human retinal S-antigen, interphotoreceptor retinoid binding protein (IRBP), and crude retinal extract were investigated in patients with onchocerciasis from

  16. Optimization of Human NK Cell Manufacturing: Fully Automated Separation, Improved Ex Vivo Expansion Using IL-21 with Autologous Feeder Cells, and Generation of Anti-CD123-CAR-Expressing Effector Cells.

    Science.gov (United States)

    Klöß, Stephan; Oberschmidt, Olaf; Morgan, Michael; Dahlke, Julia; Arseniev, Lubomir; Huppert, Volker; Granzin, Markus; Gardlowski, Tanja; Matthies, Nadine; Soltenborn, Stephanie; Schambach, Axel; Koehl, Ulrike

    2017-10-01

    The administration of ex vivo expanded natural killer (NK) cells as potential antitumor effector cells appears to be suitable for effector cell-based immunotherapies in high-risk cancer patients. However, good manufacturing practice (GMP)-compliant manufacturing of clinical-grade NK cells at sufficiently high numbers represents a great challenge. Therefore, previous expansion protocols for those effector cells were improved and optimized by using newly developed culture medium, interleukin (IL)-21, and autologous feeder cells (FCs). Separation of primary human NK cells (CD56 + CD3 - ) was carried out with the CliniMACS Prodigy ® in a single process, starting with approximately 1.2 × 10 9 leukocytes collected by small-scale lymphapheresis or from buffy coats. Enriched NK cells were adjusted to starting cell concentrations within approximately 1 × 10 6 effector cells/mL and cultured in comparative expansion experiments for 14 days with IL-2 (1,000 IU/mL) in different GMP-compliant media (X-VIVO ™ 10, CellGro ® , TexMACS ™ , and NK MACS ® ). After medium optimization, beneficial effects for functionality and phenotype were investigated at the beginning of cell expansion with irradiated (25 Gy) autologous FCs at a ratio of 20:1 (feeder: NK) in the presence or absence of IL-21 (100 ng/mL). Additionally, expanded NK cells were gene modified to express chimeric antigen receptors (CARs) against CD123, a common marker for acute myeloid leukemia (AML). Cytotoxicity, degranulation, and cytokine release of transduced NK cells were determined against KG1a cells in flow cytometric analysis and fluorescent imaging. The Prodigy manufacturing process revealed high target cell viabilities (median 95.4%), adequate NK cell recovery (median 60.4%), and purity of 95.4% in regard to CD56 + CD3 - target cells. The process in its early phase of development led to a median T-cell depletion of log 3.5 after CD3 depletion and log 3.6 after the whole process, including CD3

  17. Role of very late antigen-1 in T-cell-mediated immunity to systemic viral infection

    DEFF Research Database (Denmark)

    Ørding Kauffmann, Susanne; Thomsen, Allan Randrup; Christensen, Jan Pravsgaard

    2006-01-01

    The T-cell response to lymphocytic choriomeningitis virus was studied in mice lacking very late antigen-1 (VLA-1). The generation of virus-specific effector T cells was unimpaired in VLA-1(-/-) mice. In the memory phase, VLA-1 deficiency did not influence the number of memory CD8(+) T cells or th......, the current findings indicate that the expression of VLA-1 is not pivotal for T-cell-mediated antiviral immunity to a systemic infection....... or their distribution between lymphoid and nonlymphoid organs. Regarding a functional role of VLA-1, we found that intracerebral infection of both VLA-1(-/-) and wild-type (wt) mice resulted in lethal T-cell-mediated meningitis, and quantitative and qualitative analyses of the cellular exudate did not reveal any...

  18. T cells targeting a neuronal paraneoplastic antigen mediate tumor rejection and trigger CNS autoimmunity with humoral activation.

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    Blachère, Nathalie E; Orange, Dana E; Santomasso, Bianca D; Doerner, Jessica; Foo, Patricia K; Herre, Margaret; Fak, John; Monette, Sébastien; Gantman, Emily C; Frank, Mayu O; Darnell, Robert B

    2014-11-01

    Paraneoplastic neurologic diseases (PND) involving immune responses directed toward intracellular antigens are poorly understood. Here, we examine immunity to the PND antigen Nova2, which is expressed exclusively in central nervous system (CNS) neurons. We hypothesized that ectopic expression of neuronal antigen in the periphery could incite PND. In our C57BL/6 mouse model, CNS antigen expression limits antigen-specific CD4+ and CD8+ T-cell expansion. Chimera experiments demonstrate that this tolerance is mediated by antigen expression in nonhematopoietic cells. CNS antigen expression does not limit tumor rejection by adoptively transferred transgenic T cells but does limit the generation of a memory population that can be expanded upon secondary challenge in vivo. Despite mediating cancer rejection, adoptively transferred transgenic T cells do not lead to paraneoplastic neuronal targeting. Preliminary experiments suggest an additional requirement for humoral activation to induce CNS autoimmunity. This work provides evidence that the requirements for cancer immunity and neuronal autoimmunity are uncoupled. Since humoral immunity was not required for tumor rejection, B-cell targeting therapy, such as rituximab, may be a rational treatment option for PND that does not hamper tumor immunity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Case Report: A case of hypertrophic lupus erythematosus with negative CD123 staining and absence of transepidermal elimination of elastin [v2; ref status: indexed, http://f1000r.es/3n7

    Directory of Open Access Journals (Sweden)

    Matthew Hughes

    2014-06-01

    Full Text Available We report the case of a 49-year-old male with clinical and histological findings consistent with hypertrophic lupus erythematosus (HLE. HLE must be clinically and histologically differentiated from keratoacanthoma, hypertrophic lichen planus, squamous cell carcinoma and plaque type psoriasis. CD123 positivity and transepidermal elimination of elastin have recently been reported as tools to distinguish HLE. Interestingly, in this case, biopsies of two separate lesions failed to reveal these two features. The etiology of this discrepancy is unknown and further studies are needed to clarify the utility of CD123 positivity and transepidermal elimination of elastin in the diagnosis of hypertrophic lupus erythematosus.

  20. Simultaneous presence of endogenous retrovirus and herpes virus antigens has profound effect on cell-mediated immune responses

    DEFF Research Database (Denmark)

    Brudek, Tomasz; Christensen, Tove; Hansen, Hans Jacob

    2004-01-01

    Retroviruses have been suggested as possible pathogenic factors in multiple sclerosis (MS), supported by the observation that endogenous retroviruses are activated in MS patients. Different members of the herpes family of which several are neurotropic have also been suggested as factors in MS...... pathogenesis. Further, interactions between retroviruses and herpes viruses have been implied in the development of MS. The objective of the study was investigation of cell-mediated immune responses of MS patients to retrovirus and herpes virus antigens, particularly antigen combinations, with analyses...... retrovirus HERV-H and herpes virus antigens resulted in highly increased cellular immune responses among both the MS patients and healthy subjects. The increase was synergistic in character in most samples. Very pronounced effects were obtained using HHV-6A and HSV-1 antigens. Blast transformation assays...

  1. IgE/FcεRI-Mediated Antigen Cross-Presentation by Dendritic Cells Enhances Anti-Tumor Immune Responses

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    Barbara Platzer

    2015-03-01

    Full Text Available Epidemiologic studies discovered an inverse association between immunoglobulin E (IgE-mediated allergies and cancer, implying tumor-protective properties of IgE. However, the underlying immunologic mechanisms remain poorly understood. Antigen cross-presentation by dendritic cells (DCs is of key importance for anti-tumor immunity because it induces the generation of cytotoxic CD8+ T lymphocytes (CTLs with specificity for tumor antigens. We demonstrate that DCs use IgE and FcεRI, the high-affinity IgE receptor, for cross-presentation and priming of CTLs in response to free soluble antigen at low doses. Importantly, IgE/FcεRI-mediated cross-presentation is a distinct receptor-mediated pathway because it does not require MyD88 signals or IL-12 induction in DCs. Using passive immunization with tumor antigen-specific IgE and DC-based vaccination experiments, we demonstrate that IgE-mediated cross-presentation significantly improves anti-tumor immunity and induces memory responses in vivo. Our findings suggest a cellular mechanism for the tumor-protective features of IgE and expand the known physiological functions of this immunoglobulin.

  2. 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

  3. 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

  4. IFNG-mediated immune responses enhance autophagy against Mycobacterium tuberculosis antigens in patients with active tuberculosis

    Science.gov (United States)

    Rovetta, Ana I; Peña, Delfina; Hernández Del Pino, Rodrigo E; Recalde, Gabriela M; Pellegrini, Joaquín; Bigi, Fabiana; Musella, Rosa M; Palmero, Domingo J; Gutierrez, Marisa; Colombo, María I; García, Verónica E

    2015-01-01

    Protective immunity against Mycobacterium tuberculosis (Mtb) requires IFNG. Besides, IFNG-mediated induction of autophagy suppresses survival of virulent Mtb in macrophage cell lines. We investigated the contribution of autophagy to the defense against Mtb antigen (Mtb-Ag) in cells from tuberculosis patients and healthy donors (HD). Patients were classified as high responders (HR) if their T cells produced significant IFNG against Mtb-Ag; and low responders (LR) when patients showed weak or no T cell responses to Mtb-Ag. The highest autophagy levels were detected in HD cells whereas the lowest quantities were observed in LR patients. Interestingly, upon Mtb-Ag stimulation, we detected a positive correlation between IFNG and MAP1LC3B-II/LC3-II levels. Actually, blockage of Mtb-Ag-induced IFNG markedly reduced autophagy in HR patients whereas addition of limited amounts of IFNG significantly increased autophagy in LR patients. Therefore, autophagy collaborates with human immune responses against Mtb in close association with specific IFNG secreted against the pathogen. PMID:25426782

  5. T Cells Targeting Carcinoembryonic Antigen Can Mediate Regression of Metastatic Colorectal Cancer but Induce Severe Transient Colitis

    Science.gov (United States)

    Parkhurst, Maria R; Yang, James C; Langan, Russell C; Dudley, Mark E; Nathan, Debbie-Ann N; Feldman, Steven A; Davis, Jeremy L; Morgan, Richard A; Merino, Maria J; Sherry, Richard M; Hughes, Marybeth S; Kammula, Udai S; Phan, Giao Q; Lim, Ramona M; Wank, Stephen A; Restifo, Nicholas P; Robbins, Paul F; Laurencot, Carolyn M; Rosenberg, Steven A

    2011-01-01

    Autologous T lymphocytes genetically engineered to express a murine T cell receptor (TCR) against human carcinoembryonic antigen (CEA) were administered to three patients with metastatic colorectal cancer refractory to standard treatments. All patients experienced profound decreases in serum CEA levels (74–99%), and one patient had an objective regression of cancer metastatic to the lung and liver. However, a severe transient inflammatory colitis that represented a dose limiting toxicity was induced in all three patients. This report represents the first example of objective regression of metastatic colorectal cancer mediated by adoptive T cell transfer and illustrates the successful use of a TCR, raised in human leukocyte antigen (HLA) transgenic mice, against a human tumor associated antigen. It also emphasizes the destructive power of small numbers of highly avid T cells and the limitations of using CEA as a target for cancer immunotherapy. PMID:21157437

  6. Neurofibromatosis type 2 tumor suppressor protein, NF2, induces proteasome-mediated degradation of JC virus T-antigen in human glioblastoma.

    Directory of Open Access Journals (Sweden)

    Sarah Beltrami

    Full Text Available Neurofibromatosis type 2 protein (NF2 has been shown to act as tumor suppressor primarily through its functions as a cytoskeletal scaffold. However, NF2 can also be found in the nucleus, where its role is less clear. Previously, our group has identified JC virus (JCV tumor antigen (T-antigen as a nuclear binding partner for NF2 in tumors derived from JCV T-antigen transgenic mice. The association of NF2 with T-antigen in neuronal origin tumors suggests a potential role for NF2 in regulating the expression of the JCV T-antigen. Here, we report that NF2 suppresses T-antigen protein expression in U-87 MG human glioblastoma cells, which subsequently reduces T-antigen-mediated regulation of the JCV promoter. When T-antigen mRNA was quantified, it was determined that increasing expression of NF2 correlated with an accumulation of T-antigen mRNA; however, a decrease in T-antigen at the protein level was observed. NF2 was found to promote degradation of ubiquitin bound T-antigen protein via a proteasome dependent pathway concomitant with the accumulation of the JCV early mRNA encoding T-antigen. The interaction between T-antigen and NF2 maps to the FERM domain of NF2, which has been shown previously to be responsible for its tumor suppressor activity. Co-immunoprecipitation assays revealed a ternary complex among NF2, T-antigen, and the tumor suppressor protein, p53 within a glioblastoma cell line. Further, these proteins were detected in various degrees in patient tumor tissue, suggesting that these associations may occur in vivo. Collectively, these results demonstrate that NF2 negatively regulates JCV T-antigen expression by proteasome-mediated degradation, and suggest a novel role for NF2 as a suppressor of JCV T-antigen-induced cell cycle regulation.

  7. Antigenic specificity of antibody-dependent cell-mediated cytotoxicity directed against human immunodeficiency virus in antibody-positive sera.

    OpenAIRE

    Koup, R A; Sullivan, J L; Levine, P H; Brewster, F; Mahr, A; Mazzara, G; McKenzie, S; Panicali, D

    1989-01-01

    Antibody-dependent cell-mediated cytotoxicity (ADCC) specific for human immunodeficiency virus (HIV) has been described for HIV-infected individuals. To determine the antigenic specificity of this immune response and to define its relationship to the disease state, an ADCC assay was developed using Epstein-Barr virus-transformed lymphoblastoid cell line targets infected with vaccinia virus vectors expressing HIV proteins. The vaccinia virus vectors induced appropriate HIV proteins (envelope g...

  8. Bovine lactoferrin counteracts Toll-like receptor mediated activation signals in antigen presenting cells.

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    Patrizia Puddu

    Full Text Available Lactoferrin (LF, a key element in mammalian immune system, plays pivotal roles in host defence against infection and excessive inflammation. Its protective effects range from direct antimicrobial activities against a large panel of microbes, including bacteria, viruses, fungi and parasites, to antinflammatory and anticancer activities. In this study, we show that monocyte-derived dendritic cells (MD-DCs generated in the presence of bovine LF (bLF fail to undergo activation by up-modulating CD83, co-stimulatory and major histocompatibility complex molecules, and cytokine/chemokine secretion. Moreover, these cells are weak activators of T cell proliferation and retain antigen uptake activity. Consistent with an impaired maturation, bLF-MD-DC primed T lymphocytes exhibit a functional unresponsiveness characterized by reduced expression of CD154 and impaired expression of IFN-γ and IL-2. The observed imunosuppressive effects correlate with an increased expression of molecules with negative regulatory functions (i.e. immunoglobulin-like transcript 3 and programmed death ligand 1, indoleamine 2,3-dioxygenase, and suppressor of cytokine signaling-3. Interestingly, bLF-MD-DCs produce IL-6 and exhibit constitutive signal transducer and activator of transcription 3 activation. Conversely, bLF exposure of already differentiated MD-DCs completely fails to induce IL-6, and partially inhibits Toll-like receptor (TLR agonist-induced activation. Cell-specific differences in bLF internalization likely account for the distinct response elicited by bLF in monocytes versus immature DCs, providing a mechanistic base for its multiple effects. These results indicate that bLF exerts a potent anti-inflammatory activity by skewing monocyte differentiation into DCs with impaired capacity to undergo activation and to promote Th1 responses. Overall, these bLF-mediated effects may represent a strategy to block excessive DC activation upon TLR-induced inflammation, adding

  9. Expression of the T cell receptor αβ on a CD123+ BDCA2+ HLA-DR+ subpopulation in head and neck squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Annette Thiel

    Full Text Available Human Plasmacytoid Dendritic Cells (PDCs infiltrating solid tumor tissues and draining lymph nodes of Head and Neck Squamous Cell Carcinoma (HNSCC show an impaired immune response. In addition to an attenuated secretion of IFN-α little is known about other HNSCC-induced functional alterations in PDCs. Particular objectives in this project were to gain new insights regarding tumor-induced phenotypical and functional alterations in the PDC population. We showed by FACS analysis and RT-PCR that HNSCC orchestrates an as yet unknown subpopulation exhibiting functional autonomy in-vitro and in-vivo besides bearing phenotypical resemblance to PDCs and T cells. A subset, positive for the PDC markers CD123, BDCA-2, HLA-DR and the T cell receptor αβ (TCR-αβ was significantly induced subsequent to stimulation with HNSCC in-vitro (p = 0.009 and also present in metastatic lymph nodes in-vivo. This subgroup could be functionally distinguished due to an enhanced production of IL-2 (p = 0.02, IL-6 (p = 0.0007 and TGF-β (not significant. Furthermore, after exposure to HNSCC cells, mRNA levels revealed a D-J-beta rearrangement of the TCR-beta chain besides a strong enhancement of the CD3ε chain in the PDC population. Our data indicate an interface between the PDC and T cell lineage. These findings will improve our understanding of phenotypical and functional intricacies concerning the very heterogeneous PDC population in-vivo.

  10. Receptor-mediated antigen delivery into macrophages. Complexing antigen to alpha 2-macroglobulin enhances presentation to T cells.

    Science.gov (United States)

    Chu, C T; Pizzo, S V

    1993-01-01

    Macrophages secrete alpha 2-macroglobulin (alpha 2M), a protein that may facilitate early Ag handling. alpha 2M is able to entrap and form covalent linkages with diverse proteins during a transient proteinase-activated state. The resulting complexes are rapidly endocytosed after binding to high affinity receptors. Such a system could be capable of efficiently delivering a multitude of proteins to macrophages. We have used T hybridoma clones that respond only to hen egg lysozyme, in a MHC-restricted manner, to probe the effect of complex formation on Ag uptake and processing by murine macrophages. Radiolabeled lysozyme was internalized more rapidly and to a greater extent when bound to alpha 2M than when unbound. Macrophages pulsed with lysozyme-alpha 2M-elastase complexes required 200 to 250 times less Ag than those pulsed with free lysozyme to achieve effective presentation to T cells. Adding equimolar amounts of alpha 2M-elastase complexes, or of alpha 2M-methylamine, to free lysozyme had no effect on basal lysozyme presentation. Receptor-recognized forms of alpha 2M, but not lysozyme or BSA, competed effectively for both uptake and presentation of lysozyme-alpha 2M-elastase complexes. These results indicate that proteinase-activated alpha 2M can enhance Ag processing by carrying Ag into macrophages through a receptor-mediated process.

  11. Tumor-Derived Microvesicles Modulate Antigen Cross-Processing via Reactive Oxygen Species-Mediated Alkalinization of Phagosomal Compartment in Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Federico Battisti

    2017-09-01

    Full Text Available Dendritic cells (DCs are the only antigen-presenting cells able to prime naïve T cells and cross-prime antigen-specific CD8+ T cells. Their functionality is a requirement for the induction and maintenance of long-lasting cancer immunity. Albeit intensively investigated, the in vivo mechanisms underlying efficient antigen cross-processing and presentation are not fully understood. Several pieces of evidence indicate that antigen transfer to DCs mediated by microvesicles (MVs enhances antigen immunogenicity. This mechanism is also relevant for cross-presentation of those tumor-associated glycoproteins such as MUC1 that are blocked in HLA class II compartment when internalized by DCs as soluble molecules. Here, we present pieces of evidence that the internalization of tumor-derived MVs modulates antigen-processing machinery of DCs. Employing MVs derived from ovarian cancer ascites fluid and established tumor cell lines, we show that MV uptake modifies DC phagosomal microenvironment, triggering reactive oxygen species (ROS accumulation and early alkalinization. Indeed, tumor MVs carry radical species and the MV uptake by DCs counteracts the chemically mediated acidification of the phagosomal compartment. Further pieces of evidence suggest that efficacious antigen cross-priming of the MUC1 antigen carried by the tumor MVs results from the early signaling induced by MV internalization and the function of the antigen-processing machinery of DCs. These results strongly support the hypothesis that tumor-derived MVs impact antigen immunogenicity by tuning the antigen-processing machinery of DCs, besides being carrier of tumor antigens. Furthermore, these findings have important implications for the exploitation of MVs as antigenic cell-free immunogen for DC-based therapeutic strategies.

  12. Humoral and cell-mediated immune response against human retinal antigens in relation to ocular onchocerciasis

    NARCIS (Netherlands)

    van der Lelij, A.; Rothova, A.; Stilma, J. S.; Vetter, J. C.; Hoekzema, R.; Kijlstra, A.

    1990-01-01

    Autoimmune mechanisms are thought to be involved in the pathogenesis of the chorioretinal changes in ocular onchocerciasis. The humoral autoimmune response was determined by measuring serum levels of autoantibodies, directed against human S-antigen and interphotoreceptor retinoid binding protein

  13. Lipid motif of a bacterial antigen mediates immune responses via TLR2 signaling.

    Directory of Open Access Journals (Sweden)

    Amit A Lugade

    Full Text Available The cross-talk between the innate and the adaptive immune system is facilitated by the initial interaction of antigen with dendritic cells. As DCs express a large array of TLRs, evidence has accumulated that engagement of these molecules contributes to the activation of adaptive immunity. We have evaluated the immunostimulatory role of the highly-conserved outer membrane lipoprotein P6 from non-typeable Haemophilus influenzae (NTHI to determine whether the presence of the lipid motif plays a critical role on its immunogenicity. We undertook a systematic analysis of the role that the lipid motif plays in the activation of DCs and the subsequent stimulation of antigen-specific T and B cells. To facilitate our studies, recombinant P6 protein that lacked the lipid motif was generated. Mice immunized with non-lipidated rP6 were unable to elicit high titers of anti-P6 Ig. Expression of the lipid motif on P6 was also required for proliferation and cytokine secretion by antigen-specific T cells. Upregulation of T cell costimulatory molecules was abrogated in DCs exposed to non-lipidated rP6 and in TLR2(-/- DCs exposed to native P6, thereby resulting in diminished adaptive immune responses. Absence of either the lipid motif on the antigen or TLR2 expression resulted in diminished cytokine production from stimulated DCs. Collectively, our data suggest that the lipid motif of the lipoprotein antigen is essential for triggering TLR2 signaling and effective stimulation of APCs. Our studies establish the pivotal role of a bacterial lipid motif on activating both innate and adaptive immune responses to an otherwise poorly immunogenic protein antigen.

  14. Suppressor cell mediated regulation of delayed-type hypersensitivity to histocompatibility antigens

    NARCIS (Netherlands)

    A. Molendijk (Arie)

    1987-01-01

    textabstractDTH to allogeneic histocompatibility antigens is a T cell dependent reaction, which can be induced in immunologically competent individuals by subcutaneous (s.c.) or intravenous (i.v.) administration of alloantigens (Vander Kwast and Benner, 1978; Bianchi et al., 1984). After

  15. The Francisella O-antigen mediates survival in the macrophage cytosol via autophagy avoidance

    Science.gov (United States)

    Di Russo Case, Elizabeth; Chong, Audrey; Wehrly, Tara D.; Hansen, Bryan; Child, Robert; Hwang, Seungmin; Virgin, Herbert W.; Celli, Jean

    2014-01-01

    Summary Autophagy is a key innate immune response to intracellular parasites that promotes their delivery to degradative lysosomes following detection in the cytosol or within damaged vacuoles. Like Listeria and Shigella, which use specific mechanisms to avoid autophagic detection and capture, the bacterial pathogen Francisella tularensis proliferates within the cytosol of macrophages without demonstrable control by autophagy. To examine how Francisella evades autophagy, we screened a library of F. tularensis subsp. tularensis Schu S4 HimarFT transposon mutants in GFP-LC3-expressing murine macrophages by microscopy for clones localised within autophagic vacuoles after phagosomal escape. Eleven clones showed autophagic capture at six hours post-infection, whose HimarFT insertions clustered to four genetic loci involved in lipopolysaccharidic and capsular O-antigen biosynthesis. Consistent with the HimarFT mutants, in-frame deletion mutants of two representative loci, FTT1236 and FTT1448c (manC), lacking both LPS and capsular O-antigen, underwent phagosomal escape but were cleared from the host cytosol. Unlike wild type Francisella, the O-antigen deletion mutants were ubiquitinated, and recruited the autophagy adaptor p62/SQSTM1 and LC3 prior to cytosolic clearance. Autophagy-deficient macrophages partially supported replication of both mutants, indicating that O-antigen-lacking Francisella are controlled by autophagy. These data demonstrate the intracellular protective role of this bacterial surface polysaccharide against autophagy. PMID:24286610

  16. Antigen-43-mediated autoaggregation of Escherichia coli is blocked by fimbriation

    DEFF Research Database (Denmark)

    Hasman, Henrik; Chakraborty, Trinad; Klemm, Per

    1999-01-01

    Antigen 43 (Ag43), the product of the flu gene, is a surface-displayed autotransporter protein of Escherichia coli. Ag43 is responsible for the autoaggregation and flocculation of static liquid cultures of many E. coli strains. The expression of Ag43 has been reported to be phase variable...

  17. Phosphatase and tensin homolog (PTEN) in antigen-presenting cells controls Th17-mediated autoimmune arthritis

    NARCIS (Netherlands)

    Bluml, S.; Sahin, E.; Saferding, V.; Goncalves-Alves, E.; Hainzl, E.; Niederreiter, B.; Hladik, A.; Lohmeyer, T.; Brunner, J.S.; Bonelli, M.; Koenders, M.I.; Berg, W.B. van den; Superti-Furga, G.; Smolen, J.S.; Schabbauer, G.; Redlich, K.

    2015-01-01

    INTRODUCTION: Autoreactive T cells are a central element in many systemic autoimmune diseases. The generation of these pathogenic T cells is instructed by antigen-presenting cells (APCs). However, signaling pathways in APCs that drive autoimmune diseases, such as rheumatoid arthritis, are not

  18. Small intestinal motility disorders in preruminant calves chronically fed a diet based on antigenic soya: characterization and possible mediators.

    Science.gov (United States)

    Lallès, J P; Duvaux-Ponter, C; Sissons, J W; Toullec, R

    1998-01-01

    Intestinal motility disorders and some mediators implicated in these disorders were studied in preruminant calves that had been chronically fed a diet containing an antigenic heated soyabean flour (HSF) for 3 months. The calves in the present study had previously been shown to present strong immune reactions against soyabean proteins, as assessed through plasma antibody titres, direct skin tests and in vitro lymphoproliferation. Four of these calves sensitive to soya were fitted with an abomasal catheter and wire electrodes on the jejunum. Myoelectric activity was recorded over 7 h following test meals containing skim milk powder (SMP), HSF or a non-antigenic hydrolysed soya protein isolate (HSPI). The pattern of myoelectric complexes migrating to the jejunum was regular with SMP (mean durations of phases I, II and III: 26, 38 and 5.28 min, respectively). With HSF, diarrhoea appeared, and the total duration of phase I decreased from 149 to 68 min (P feeding HSPI. When promethazine, a H-1 histamine receptor antagonist, was administered i.v. prior to feeding HSF the number of phases I tended to decrease and diarrhoea virtually disappeared. In contrast, indomethacin, a cyclooxygenase inhibitor, had limited effects on motility patterns and diarrhoea. These disorders were partially reproduced by i.p. administration of platelet-activating factor (PAF) prior to feeding with SMP. These findings suggest that calves chronically fed antigenic soya suffer from immune-mediated motility disorders which are linked to histamine action via H-1 receptors, and possibly with PAF. The role of arachidonic acid catabolites of the cyclooxygenase pathway is probably minor.

  19. Glycan elongation beyond the mucin associated Tn antigen protects tumor cells from immune-mediated killing

    DEFF Research Database (Denmark)

    Madsen, Caroline B; Lavrsen, Kirstine; Steentoft, Catharina

    2013-01-01

    and pancreatic cancer cell lines T47D and Capan-1 increases sensitivity to both NK cell mediated antibody-dependent cellular-cytotoxicity (ADCC) and cytotoxic T lymphocyte (CTL)-mediated killing. In addition, we investigated the association between total cell surface expression of MUC1/MUC16 and NK or CTL...

  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. Proliferating cell nuclear antigen binds DNA polymerase-β and mediates 1-methyl-4-phenylpyridinium-induced neuronal death.

    Directory of Open Access Journals (Sweden)

    Zhentao Zhang

    Full Text Available The mechanisms leading to dopaminergic neuronal loss in the substantia nigra of patients with Parkinson disease (PD remain poorly understood. We recently reported that aberrant DNA replication mediated by DNA polymerase-β (DNA pol-β plays a causal role in the death of postmitotic neurons in an in vitro model of PD. In the present study, we show that both proliferating cell nuclear antigen (PCNA and DNA pol-β are required for MPP(+-induced neuronal death. PCNA binds to the catalytic domain of DNA pol-β in MPP(+-treated neurons and in post-mortem brain tissues of PD patients. The PCNA-DNA pol-β complex is loaded into DNA replication forks and mediates DNA replication in postmitotic neurons. The aberrant DNA replication mediated by the PCNA-DNA pol-β complex induces p53-dependent neuronal cell death. Our results indicate that the interaction of PCNA and DNA pol-β contributes to neuronal death in PD.

  2. Duffy antigen receptor for chemokines mediates chemokine endocytosis through a macropinocytosis-like process in endothelial cells.

    Directory of Open Access Journals (Sweden)

    Yani Zhao

    Full Text Available The Duffy antigen receptor for chemokines (DARC shows high affinity binding to multiple inflammatory CC and CXC chemokines and is expressed by erythrocytes and endothelial cells. Recent evidence suggests that endothelial DARC facilitates chemokine transcytosis to promote neutrophil recruitment. However, the mechanism of chemokine endocytosis by DARC remains unclear.We investigated the role of several endocytic pathways in DARC-mediated ligand internalization. Here we report that, although DARC co-localizes with caveolin-1 in endothelial cells, caveolin-1 is dispensable for DARC-mediated (125I-CXCL1 endocytosis as knockdown of caveolin-1 failed to inhibit ligand internalization. (125I-CXCL1 endocytosis by DARC was also independent of clathrin and flotillin-1 but required cholesterol and was, in part, inhibited by silencing Dynamin II expression.(125I-CXCL1 endocytosis was inhibited by amiloride, cytochalasin D, and the PKC inhibitor Gö6976 whereas Platelet Derived Growth Factor (PDGF enhanced ligand internalization through DARC. The majority of DARC-ligand interactions occurred on the endothelial surface, with DARC identified along plasma membrane extensions with the appearance of ruffles, supporting the concept that DARC provides a high affinity scaffolding function for surface retention of chemokines on endothelial cells.These results show DARC-mediated chemokine endocytosis occurs through a macropinocytosis-like process in endothelial cells and caveolin-1 is dispensable for CXCL1 internalization.

  3. IL-2/neuroantigen fusion proteins as antigen-specific tolerogens in experimental autoimmune encephalomyelitis (EAE): correlation of T cell-mediated antigen presentation and tolerance induction.

    Science.gov (United States)

    Mannie, Mark D; Clayson, Barbara A; Buskirk, Elizabeth J; DeVine, Jarret L; Hernandez, Jose J; Abbott, Derek J

    2007-03-01

    The purpose of this study was to assess whether the Ag-targeting activity of cytokine/neuroantigen (NAg) fusion proteins may be associated with mechanisms of tolerance induction. To assess this question, we expressed fusion proteins comprised of a N-terminal cytokine domain and a C-terminal NAg domain. The cytokine domain comprised either rat IL-2 or IL-4, and the NAg domain comprised the dominant encephalitogenic determinant of the guinea pig myelin basic protein. Subcutaneous administration of IL2NAg (IL-2/NAg fusion protein) into Lewis rats either before or after an encephalitogenic challenge resulted in an attenuated course of experimental autoimmune encephalomyelitis. In contrast, parallel treatment of rats with IL4NAg (IL-4/NAg fusion protein) or NAg lacked tolerogenic activity. In the presence of IL-2R(+) MHC class II(+) T cells, IL2NAg fusion proteins were at least 1,000 times more potent as an Ag than NAg alone. The tolerogenic activity of IL2NAg in vivo and the enhanced potency in vitro were both dependent upon covalent linkage of IL-2 and NAg. IL4NAg also exhibited enhanced antigenic potency. IL4NAg was approximately 100-fold more active than NAg alone in the presence of splenic APC. The enhanced potency of IL4NAg also required covalent linkage of cytokine and NAg and was blocked by soluble IL-4 or by a mAb specific for IL-4. Other control cytokine/NAg fusion proteins did not exhibit a similar enhancement of Ag potency compared with NAg alone. Thus, the IL2NAg and IL4NAg fusion proteins targeted NAg for enhanced presentation by particular subsets of APC. The activities of IL2NAg revealed a potential relationship between NAg targeting to activated T cells, T cell-mediated Ag presentation, and tolerance induction.

  4. Nature of the suppressor cells mediating prolonged graft survival after administration of extracted histocompatibility antigen and cyclosporine

    International Nuclear Information System (INIS)

    Yoshimura, N.; Kahan, B.D.

    1985-01-01

    Antigen-specific suppressor T cells are induced by donor histocompatibility antigen extracted from spleen cells with 3M KCl combined with cyclosporine (Ag-CsA). A single i.v. injection of 5 mg 3M-KCl-extracted donor Buffalo (Buf, RT1b) antigen (Ag) combined with a three day course of CsA prolonged renal allograft survival in Wistar-Furth (WFu, RT1u) hosts to a greater extent (MST 26.5 days) than CsA alone (MST 11.8 days). Peripheral blood lymphocytes (PBL) or spleen cells harvested from Ag-CsA-treated recipients ten days after transplantation inhibited the mixed lymphocyte reaction (MLR) between normal responder WFu cells and irradiated Buf cells (55.6% and 64.4% suppression, respectively, P less than 0.025), but not third-party Brown-Norway (BN, RT1n) stimulator cells (13.6% and -18.3% suppression, respectively, NS). The suppressor effect was not mediated by cytolytic cells; there was neither primary nor secondary cytolytic activity against 51 Cr-labeled Con-A blastoid Buf cells. The suppressor cells were neither adherent to plastic dishes nor to nylon-wool columns. PBL irradiated with 800 rads, but not 1500 rads, suppressed the MLR. A single injection of cyclophosphamide (CY, 25 mg/kg) seven days after transplantation abrogated the suppression induced by Ag-CsA treatment. Moreover, PBL from Ag-CsA recipients failed to suppress the MLR, if depleted either of all T cells by treatment with monoclonal antibody (Mab) W3/13 HLK (pan T cells; % suppression -15.8), or of cytotoxic/suppressor cells with Mab OX-8 (-19.3% suppression) together with rabbit antimouse immunoglobulin and complement

  5. [Agrobacterium-mediated transformation of lettuce (Lactuca sativa L.) with vectors bearing genes of bacterial antigenes from Mycobacterium tuberculosis].

    Science.gov (United States)

    Marveeva, N A; Vasilenko, M Iu; Shakhovskiĭ, A M; Kuchuk, N V

    2009-01-01

    Transgenic plants of lettuce Lactuca sativa L. cv. Eralash, Sniezinka, Rubinovoje kruzevo with genes coding synthesis of tuberculosis antigenes have been obtained by Agrobacterium-mediated transformation. Cotyledons of in vitro seedlings were used as the initial material for transformation with plasmids pCB063 (genes ESAT6, nptII) and pCB064 (genes ESAT6:AG85B(-TMD), nptII). PCR-analysis has shown the presence both selective and target genes in all plants analyzed. At the same time, the RT-PCR has shown that both the presence and the absence of a transcription of gene ESAT6 at a stable transcription of a gene nptII is possible.

  6. Recurrent Vulvovaginal Candidiasis: Could It Be Related to Cell-Mediated Immunity Defect in Response to Candida Antigen?

    Directory of Open Access Journals (Sweden)

    Zahra Talaei

    2017-09-01

    Full Text Available Background Recurrent vulvovaginal candidiasis (RVVC is a common cause of morbidity affecting millions of women worldwide. Patients with RVVC are thought to have an underlying immunologic defect. This study has been established to evaluate cell-mediated immunity defect in response to candida antigen in RVVC cases. Materials and Methods Our cross-sectional study was performed in 3 groups of RVVC patients (cases, healthy individuals (control I and known cases of chronic mucocutaneous candidiasis (CMC (control II. Patients who met the inclusion criteria of RVVC were selected consecutively and were allocated in the case group. Peripheral blood mononuclear cells were isolated and labeled with CFSE and proliferation rate was measured in exposure to candida antigen via flow cytometry. Results T lymphocyte proliferation in response to candida was significantly lower in RVVC cases (n=24 and CMC patients (n=7 compared to healthy individuals (n=20, P0.05. Family history of primary immunodeficiency diseases (PID differed significantly among groups (P=0.01, RVVC patients has family history of PID more than control I (29.2 vs. 0%, P=0.008 but not statistically different from CMC patients (29.2 vs. 42.9%, P>0.05. Prevalence of atopy was greater in RVVC cases compared to healthy individuals (41.3 vs. 15%, P=0.054. Lymphoproliferative activity and vaginal symptoms were significantly different among RVVC cases with and without allergy (P=0.01, P=0.02. Conclusion Our findings revealed that T cells do not actively proliferate in response to Candida antigen in some RVVC cases. So it is concluded that patients with cell-mediated immunity defect are more susceptible to recurrent fungal infections of vulva and vagina. Nonetheless, some other cases of RVVC showed normal function of T cells. Further evaluations showed that these patients suffer from atopy. It is hypothesized that higher frequency of VVC in patients with history of atopy might be due to allergic response

  7. Novel Non-Histocompatibility Antigen Mismatched Variants Improve the Ability to Predict Antibody-Mediated Rejection Risk in Kidney Transplant

    Directory of Open Access Journals (Sweden)

    Silvia Pineda

    2017-12-01

    Full Text Available Transplant rejection is the critical clinical end-point limiting indefinite survival after histocompatibility antigen (HLA mismatched organ transplantation. The predominant cause of late graft loss is antibody-mediated rejection (AMR, a process whereby injury to the organ is caused by donor-specific antibodies, which bind to HLA and non-HLA (nHLA antigens. AMR is incompletely diagnosed as donor/recipient (D/R matching is only limited to the HLA locus and critical nHLA immunogenic antigens remain to be identified. We have developed an integrative computational approach leveraging D/R exome sequencing and gene expression to predict clinical post-transplant outcome. We performed a rigorous statistical analysis of 28 highly annotated D/R kidney transplant pairs with biopsy-confirmed clinical outcomes of rejection [either AMR or T-cell-mediated rejection (CMR] and no-rejection (NoRej, identifying a significantly higher number of mismatched nHLA variants in AMR (ANOVA—p-value = 0.02. Using Fisher’s exact test, we identified 123 variants associated mainly with risk of AMR (p-value < 0.001. In addition, we applied a machine-learning technique to circumvent the issue of statistical power and we found a subset of 65 variants using random forest, that are predictive of post-tx AMR showing a very low error rate. These variants are functionally relevant to the rejection process in the kidney and AMR as they relate to genes and/or expression quantitative trait loci (eQTLs that are enriched in genes expressed in kidney and vascular endothelium and underlie the immunobiology of graft rejection. In addition to current D/R HLA mismatch evaluation, additional mismatch nHLA D/R variants will enhance the stratification of post-tx AMR risk even before engraftment of the organ. This innovative study design is applicable in all solid organ transplants, where the impact of mitigating AMR on graft survival may be greater, with considerable benefits on

  8. Identification of chimeric antigen receptors that mediate constitutive or inducible proliferation of T cells

    Science.gov (United States)

    Frigault, Matthew J; Lee, Jihyun; Basil, Maria Ciocca; Carpenito, Carmine; Motohashi, Shinichiro; Scholler, John; Kawalekar, Omkar U.; Guedan, Sonia; McGettigan, Shannon E.; Posey, Avery D.; Ang, Sonny; Cooper, Laurence J. N.; Platt, Jesse M.; Johnson, F. Brad; Paulos, Chrystal M; Zhao, Yangbing; Kalos, Michael; Milone, Michael C.; June, Carl H.

    2015-01-01

    This study compared second generation chimeric antigen receptors encoding signaling domains composed of CD28, ICOS and 4-1BB. Here we report that certain CARs endow T cells with the ability to undergo long-term autonomous proliferation. Transduction of primary human T-cell with lentiviral vectors encoding some of the CARs resulted in sustained proliferation for up to three months following a single stimulation through the TCR. Sustained numeric expansion was independent of cognate antigen and did not require the addition of exogenous cytokines or feeder cells after a single stimulation of the TCR and CD28. Results from gene array and functional assays linked sustained cytokine secretion and expression of T-bet, EOMES and GATA-3 to the effect. Sustained expression of the endogenous IL2 locus has not been reported in primary T cells. Sustained proliferation was dependent on CAR structure and high expression, the latter of which was necessary but not sufficient. The mechanism involves constitutive signaling through NF-kB, Akt, Erk and NFAT. The propagated CAR T cells retained a diverse TCR repertoire and cellular transformation was not observed. The CARs with a constitutive growth phenotype displayed inferior antitumor effects and engraftment in vivo. Therefore the design of CARs that have a non-constitutive growth phenotype may be a strategy to improve efficacy and engraftment of CAR T cells. The identification of CARs that confer constitutive or non-constitutive growth patterns may explain observations that CAR T cells have differential survival patterns in clinical trials. PMID:25600436

  9. Identification of chimeric antigen receptors that mediate constitutive or inducible proliferation of T cells.

    Science.gov (United States)

    Frigault, Matthew J; Lee, Jihyun; Basil, Maria Ciocca; Carpenito, Carmine; Motohashi, Shinichiro; Scholler, John; Kawalekar, Omkar U; Guedan, Sonia; McGettigan, Shannon E; Posey, Avery D; Ang, Sonny; Cooper, Laurence J N; Platt, Jesse M; Johnson, F Brad; Paulos, Chrystal M; Zhao, Yangbing; Kalos, Michael; Milone, Michael C; June, Carl H

    2015-04-01

    This study compared second-generation chimeric antigen receptors (CAR) encoding signaling domains composed of CD28, ICOS, and 4-1BB (TNFRSF9). Here, we report that certain CARs endow T cells with the ability to undergo long-term autonomous proliferation. Transduction of primary human T cells with lentiviral vectors encoding some of the CARs resulted in sustained proliferation for up to 3 months following a single stimulation through the T-cell receptor (TCR). Sustained numeric expansion was independent of cognate antigen and did not require the addition of exogenous cytokines or feeder cells after a single stimulation of the TCR and CD28. Results from gene array and functional assays linked sustained cytokine secretion and expression of T-bet (TBX21), EOMES, and GATA-3 to the effect. Sustained expression of the endogenous IL2 locus has not been reported in primary T cells. Sustained proliferation was dependent on CAR structure and high expression, the latter of which was necessary but not sufficient. The mechanism involves constitutive signaling through NF-κB, AKT, ERK, and NFAT. The propagated CAR T cells retained a diverse TCR repertoire, and cellular transformation was not observed. The CARs with a constitutive growth phenotype displayed inferior antitumor effects and engraftment in vivo. Therefore, the design of CARs that have a nonconstitutive growth phenotype may be a strategy to improve efficacy and engraftment of CAR T cells. The identification of CARs that confer constitutive or nonconstitutive growth patterns may explain observations that CAR T cells have differential survival patterns in clinical trials. ©2015 American Association for Cancer Research.

  10. Deterioration of epithelium mediated mechanisms in diabetic-antigen sensitized airways of guinea pigs.

    Science.gov (United States)

    Bano, Saidullah; Swati, Omanwar; Kambadur, Muralidhar; Mohammad, Fahim

    2016-01-01

    The onset of diabetes causes disruption of respiratory epithelial mediators. The present study investigates whether diabetes modifies the epithelium mediated bronchial responses in hyper-reactive airway smooth muscle (ASM) primarily through nitric oxide (NO), cyclooxygenase (COX), and epithelium derived hyperpolarizing factor (EpDHF) pathways. Experimental model of guinea pigs having hyper-reactive airways with or without diabetes were developed. The responses of tracheal rings to cumulative concentrations of acetylcholine (ACh) and isoproterenol (IP) in the presence and absence of epithelium and before and after incubation with NO, K + ATP and COX inhibitors, N-(ω)-Nitro-L-arginine methyl ester (L-NAME; 100 μM), glybenclamide (10 μM) and indomethacin (100 μM) were assessed. In diabetic guinea pigs with hyper-reactive airways, a decrease in ACh induced bronchoconstriction was observed after epithelium removal and after incubation with L-NAME/indomethacin, suggesting damage to NO/COX pathways. Hyper-reactivity did not alter the response of trachea to ACh but affected the response to IP which was further reduced in hyper-reactive animals with diabetes. The ASM response to IP after glybenclamide treatment did not alter in hyper-reactive guinea pigs and diabetic guinea pigs with hyper-reactive airways, suggesting damage to the EpDHF pathway. Treatment with indomethacin reduced IP response in the hyper-reactive model, and did not produce any change in diabetic model with hyper-reactive airways, indicating further disruption of the COX pathway. EpDHF pathway is damaged in hyper-reactive guinea pigs and in diabetic guinea pigs with hyper-reactive airways. Diabetes further aggravates the NO and COX mediated pathways in diabetic guinea pigs with hyper-reactive airways.

  11. [T cell-mediated immune responses and the recognition of tuberculosis antigens].

    Science.gov (United States)

    Tsujimura, Kunio; Koide, Yukio

    2010-06-01

    T cell-mediated immune responses profoundly contribute to the protection against the re-activation of latently infected Mycobacterium tuberculosis. Th1 cells produce IFN-gamma to activate infected macrophages and promote the formation of granulomas around infected macrophages. CD8+, gamma delta and CD1-restricted T cells also produce IFN-gamma and participate the protective responses against bacterial growth. Th17 cells produce IL-17 to promote the mobilization of immunocompetent cells and contribute to the granuloma formation. On the contrary, Th2 cells and Tregs interfere these protective immune responses.

  12. Low expression of soluble human leukocyte antigen G in early gestation and subsequent placenta-mediated complications of pregnancy.

    Science.gov (United States)

    Marozio, Luca; Garofalo, Anna; Berchialla, Paola; Tavella, Anna Maria; Salton, Loredana; Cavallo, Franco; Benedetto, Chiara

    2017-09-01

    Abnormal placentation is a common pathogenic mechanism of many placenta-mediated complications of late pregnancy, including pre-eclampsia, fetal growth restriction, stillbirth, and placental abruption. During successful placentation, the trophoblast (which is a semi-allograft) is not rejected by decidual immune cells because of maternal immune tolerance, mainly induced by human leukocyte antigen G (HLA-G). Deficient HLA-G expression seems to be associated with the development of complications of pregnancy. The aim of this study was to determine whether low soluble HLA-G (sHLA-G) levels in maternal blood at the beginning of pregnancy may be associated with subsequent placenta-mediated complications. For this retrospective case-control study, 117 cases of placenta-mediated complications of pregnancy and 234 controls with uneventful pregnancy were selected. Plasma sHLA-G levels were measured at 11-13 weeks' gestation by the enzyme-linked immunosorbent assay method in blood samples previously obtained at first-trimester prenatal screening for chromosomal fetal abnormalities. Women who subsequently developed placenta-mediated complications had significantly lower sHLA-G levels at the beginning of pregnancy (median, 43.08 IU/mL) than controls (median, 49.10 IU/mL; P = 0.008). An sHLA-G level lower than 43.50 IU/mL at the end of the first trimester was associated with a twofold increased risk of developing a pregnancy complication (odds ratio, 1.82; 95% confidence interval, 1.22-2.73). The strongest association, although only moderately strong, was observed with severe pre-eclampsia (odds ratio, 2.66; 95% confidence interval, 1.08-6.56). Placenta-mediated complications of pregnancy may be associated with low sHLA-G levels in the first trimester, suggesting a potential role of sHLA-G in the early stages of placentation. © 2017 Japan Society of Obstetrics and Gynecology.

  13. Immunotoxicity of aflatoxin B1: Impairment of the cell-mediated response to vaccine antigen and modulation of cytokine expression

    International Nuclear Information System (INIS)

    Meissonnier, Guylaine M.; Pinton, Philippe; Laffitte, Joelle; Cossalter, Anne-Marie; Gong, Yun Yun; Wild, Christopher P.; Bertin, Gerard; Galtier, Pierre; Oswald, Isabelle P.

    2008-01-01

    Aflatoxin B1 (AFB1), a mycotoxin produced by Aspergillus flavus or A. parasiticus, is a frequent contaminant of food and feed. This toxin is hepatotoxic and immunotoxic. The present study analyzed in pigs the influence of AFB1 on humoral and cellular responses, and investigated whether the immunomodulation observed is produced through interference with cytokine expression. For 28 days, pigs were fed a control diet or a diet contaminated with 385, 867 or 1807 μg pure AFB1/kg feed. At days 4 and 15, pigs were vaccinated with ovalbumin. AFB1 exposure, confirmed by an observed dose-response in blood aflatoxin-albumin adduct, had no major effect on humoral immunity as measured by plasma concentrations of total IgA, IgG and IgM and of anti-ovalbumin IgG. Toxin exposure did not impair the mitogenic response of lymphocytes but delayed and decreased their specific proliferation in response to the vaccine antigen, suggesting impaired lymphocyte activation in pigs exposed to AFB1. The expression level of pro-inflammatory (TNF-α, IL-1β, IL-6, IFN-γ) and regulatory (IL-10) cytokines was assessed by real-time PCR in spleen. A significant up-regulation of all 5 cytokines was observed in spleen from pigs exposed to the highest dose of AFB1. In pigs exposed to the medium dose, IL-6 expression was increased and a trend towards increased IFN-γ and IL-10 was observed. In addition we demonstrate that IL-6 impaired in vitro the antigenic- but not the mitogenic-induced proliferation of lymphocytes from control pigs vaccinated with ovalbumin. These results indicate that AFB1 dietary exposure decreases cell-mediated immunity while inducing an inflammatory response. These impairments in the immune response could participate in failure of vaccination protocols and increased susceptibility to infections described in pigs exposed to AFB1

  14. Genomic Characterization of Variable Surface Antigens Reveals a Telomere Position Effect as a Prerequisite for RNA Interference-Mediated Silencing in Paramecium tetraurelia

    Science.gov (United States)

    Baranasic, Damir; Oppermann, Timo; Cheaib, Miriam; Cullum, John; Schmidt, Helmut

    2014-01-01

    ABSTRACT Antigenic or phenotypic variation is a widespread phenomenon of expression of variable surface protein coats on eukaryotic microbes. To clarify the mechanism behind mutually exclusive gene expression, we characterized the genetic properties of the surface antigen multigene family in the ciliate Paramecium tetraurelia and the epigenetic factors controlling expression and silencing. Genome analysis indicated that the multigene family consists of intrachromosomal and subtelomeric genes; both classes apparently derive from different gene duplication events: whole-genome and intrachromosomal duplication. Expression analysis provides evidence for telomere position effects, because only subtelomeric genes follow mutually exclusive transcription. Microarray analysis of cultures deficient in Rdr3, an RNA-dependent RNA polymerase, in comparison to serotype-pure wild-type cultures, shows cotranscription of a subset of subtelomeric genes, indicating that the telomere position effect is due to a selective occurrence of Rdr3-mediated silencing in subtelomeric regions. We present a model of surface antigen evolution by intrachromosomal gene duplication involving the maintenance of positive selection of structurally relevant regions. Further analysis of chromosome heterogeneity shows that alternative telomere addition regions clearly affect transcription of closely related genes. Consequently, chromosome fragmentation appears to be of crucial importance for surface antigen expression and evolution. Our data suggest that RNAi-mediated control of this genetic network by trans-acting RNAs allows rapid epigenetic adaptation by phenotypic variation in combination with long-term genetic adaptation by Darwinian evolution of antigen genes. PMID:25389173

  15. Streptococcus salivarius-mediated CD8+T cell stimulation required antigen presentation by macrophages in oral squamous cell carcinoma.

    Science.gov (United States)

    Wang, Jie; Yang, Lina; Mao, Xiaohe; Li, Zaiye; Lin, Xiaoyu; Jiang, Canhua

    2018-05-15

    It has been shown that the peripheral blood mononuclear cells (PBMCs) from oral squamous cell carcinoma (OSCC) patients presented cytotoxic CD8 T cell response against Streptococcus salivarius (S. salivarius), of which the frequency was positively associated with recurrence-free survival in OSCC patients. To identify the conditions required for regulating S. salivarius-specific CD8 T cell-mediated cytotoxicity, we selectively depleted individual components of the PBMCs, and observed that the depletion of monocytes/macrophages, but not other immune cell subsets, significantly downregulated the S. salivarius-specific CD8 T cell cytotoxicity. Monocyte/macrophage alone was sufficient to reconstitute optimal granzyme B expression from S. salivarius-specific CD8 T cells. Also, both the memory and the naive CD8 T cells reacted to S. salivarius-stimulation, with the memory CD8 T cells presenting significantly higher S. salivarius-reactivity. Using M1- and M2-polarized macrophages from circulating monocytes, we found that M1-polarized macrophages, with significantly higher IL-12 expression and significantly lower IL-10 and MHC class II molecule expression, was more effective at promoting granzyme B responses in CD8 T cells, and required CD80/CD86 costimulating molecules for optimal responses. Interestingly, the tumor-associated macrophages (TAMs) from resected tumors presented characteristics of M2-polarized macrophages with high MHC class II expression and low IL-12 secretion. The frequency of tumor-infiltrating S. salivarius-specific cytotoxic CD8 T cell was inversely correlated with the level of IL-10 secretion and the MHC class II molecule expression in autologous TAMs. Together, we demonstrated that monocyte/macrophages presented essential antigen-presentation and costimulatory roles in CD8 T cell-mediated S. salivarius-specific granzyme B responses, and the polarization of macrophages could influence the potency of CD8 T cell responses. Copyright © 2018 Elsevier Inc

  16. 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...

  17. A rhamnose-rich O-antigen mediates adhesion, virulence, and host colonization for the xylem-limited phytopathogen Xylella fastidiosa.

    Science.gov (United States)

    Clifford, Jennifer C; Rapicavoli, Jeannette N; Roper, M Caroline

    2013-06-01

    Xylella fastidiosa is a gram-negative, xylem-limited bacterium that causes a lethal disease of grapevine called Pierce's disease. Lipopolysaccharide (LPS) composes approximately 75% of the outer membrane of gram-negative bacteria and, because it is largely displayed on the cell surface, it mediates interactions between the bacterial cell and its surrounding environment. LPS is composed of a conserved lipid A-core oligosaccharide component and a variable O-antigen portion. By targeting a key O-antigen biosynthetic gene, we demonstrate the contribution of the rhamnose-rich O-antigen to surface attachment, cell-cell aggregation, and biofilm maturation: critical steps for successful infection of the host xylem tissue. Moreover, we have demonstrated that a fully formed O-antigen moiety is an important virulence factor for Pierce's disease development in grape and that depletion of the O-antigen compromises its ability to colonize the host. It has long been speculated that cell-surface polysaccharides play a role in X. fastidiosa virulence and this study confirms that LPS is a major virulence factor for this important agricultural pathogen.

  18. Macrophages present pinocytosed exogenous antigen via MHC class I whereas antigen ingested by receptor-mediated endocytosis is presented via MHC class II

    NARCIS (Netherlands)

    Peppelenbosch, M. P.; DeSmedt, M.; Pynaert, G.; van Deventer, S. J.; Grooten, J.

    2000-01-01

    Macrophages present exogenous Ag either via MHC class I or MHC class II molecules. We investigated whether the mode of hemagglutinin (HA) uptake influences the class of MHC molecule by which this Ag is presented. Normally, HA is ingested by receptor-mediated endocytosis, but this may be switched to

  19. Marrow grafts between phenotypically DLA-identical and haploidentical unrelated dogs: additional antigens controlling engraftment are not detected by cell-mediated lympholysis

    Energy Technology Data Exchange (ETDEWEB)

    Deeg, H.J. (Fred Hutchinson Cancer Research Center, Seattle, WA); Storb, R.; Raff, R.F.; Weiden, P.L.; DeRose, S.; Thomas, E.D.

    1982-01-01

    Bone marrow transplants with low marrow cell doses (less than or equal to4 X 10/sup 8/ cells/kg) from unrelated donors were carried out in 16 dogs conditioned with 9 Gy (900 rad) of total body irradiation. No immunosuppression was given after grafting. Eleven donor-recipient pairs were phenotypically identical (group 1) for the known antigens of the canine major histocompatibility complex (DLA) and in five the donor was homozygous and the recipient heterozygous for DLA (group 2), as determined by serological histocompatibility typing and mixed leukocyte cultures including homozygous cell typing. In addition, lymphocytes from donors and recipients in group 1 were mutually nonreactive in cell-mediated lympholysis; lymphocytes from recipients in group 2 were not cytotoxic against donor cells. Eight dogs rejected their grafts and eight showed sustained engraftment; of these, four died from graft-versus-host disease. The incidence of rejection was higher than in DLA-identical littermates but lower than in DLA-nonidentical unrelated or littermate dogs. These results indicate that antigens different from the recognized alleles at DLA are involved in the control of engraftment. These antigens most likely represent the expression of unrecognized differences within DLA or are coded for by a locus different from but linked to DLA-A, B, C or D; they are not recognized in the cell-mediated lympholysis assay.

  20. Multivalent Soluble Antigen Arrays Exhibit High Avidity Binding and Modulation of B Cell Receptor-Mediated Signaling to Drive Efficacy against Experimental Autoimmune Encephalomyelitis.

    Science.gov (United States)

    Hartwell, Brittany L; Pickens, Chad J; Leon, Martin; Berkland, Cory

    2017-06-12

    A pressing need exists for antigen-specific immunotherapies (ASIT) that induce selective tolerance in autoimmune disease while avoiding deleterious global immunosuppression. Multivalent soluble antigen arrays (SAgA PLP:LABL ), consisting of a hyaluronic acid (HA) linear polymer backbone cografted with multiple copies of autoantigen (PLP) and cell adhesion inhibitor (LABL) peptides, are designed to induce tolerance to a specific multiple sclerosis (MS) autoantigen. Previous studies established that hydrolyzable SAgA PLP:LABL , employing a degradable linker to codeliver PLP and LABL, was therapeutic in experimental autoimmune encephalomyelitis (EAE) in vivo and exhibited antigen-specific binding with B cells, targeted the B cell receptor (BCR), and dampened BCR-mediated signaling in vitro. Our results pointed to sustained BCR engagement as the SAgA PLP:LABL therapeutic mechanism, so we developed a new version of the SAgA molecule using nonhydrolyzable conjugation chemistry, hypothesizing it would enhance and maintain the molecule's action at the cell surface to improve efficacy. "Click SAgA" (cSAgA PLP:LABL ) uses hydrolytically stable covalent conjugation chemistry (Copper-catalyzed Azide-Alkyne Cycloaddition (CuAAC)) rather than a hydrolyzable oxime bond to attach PLP and LABL to HA. We explored cSAgA PLP:LABL B cell engagement and modulation of BCR-mediated signaling in vitro through flow cytometry binding and calcium flux signaling assays. Indeed, cSAgA PLP:LABL exhibited higher avidity B cell binding and greater dampening of BCR-mediated signaling than hydrolyzable SAgA PLP:LABL . Furthermore, cSAgA PLP:LABL exhibited significantly enhanced in vivo efficacy compared to hydrolyzable SAgA PLP:LABL , achieving equivalent efficacy at one-quarter of the dose. These results indicate that nonhydrolyzable conjugation increased the avidity of cSAgA PLP:LABL to drive in vivo efficacy through modulated BCR-mediated signaling.

  1. CD1d-mediated presentation of endogenous lipid antigens by adipocytes requires microsomal triglyceride transfer protein (MTP)

    DEFF Research Database (Denmark)

    Rakhshandehroo, Maryam; Gijzel, Sanne M W; Siersbæk, Rasmus

    2014-01-01

    microsomal triglyceride transfer protein (MTP), which we show is also under the transcriptional regulation of C/EBPβ and -δ, as a novel player in the presentation of endogenous lipid antigens by adipocytes. Overall, our findings indicate that adipocytes can function as non-professional lipid antigen...... presenting cells (APCs), which may present an important aspect of adipocyte-immune cell communication in the regulation of whole body energy metabolism and immune homeostasis....

  2. Heterologous expression of carcinoembryonic antigen in Lactococcus lactis via LcsB-mediated surface displaying system for oral vaccine development.

    Science.gov (United States)

    Zhang, Xiaowei; Hu, Shumin; Du, Xue; Li, Tiejun; Han, Lanlan; Kong, Jian

    2016-12-01

    Carcinoembryonic antigen (CEA) is an attractive target for immunotherapy because it is expressed minimally in normal tissue, but is overexpressed in a wide variety of malignant epithelial tissues. Lactic acid bacteria (LABs), widely used in food processes, are attractive candidates for oral vaccination. Thus, we examined whether LABs could be used as a live vaccine vector to deliver CEA antigen. CEA was cloned into an Escherichia coli/Lactococcus lactis shuttle vector pSEC:LEISS under the control of a nisin promoter. For displaying the CEA on the cell surface of the L. lactis strain, the anchor motif LcsB from the S-layer protein of Lactobacillus crispatus was fused with CEA. Intracellular and cell surface expression of the CEA-LcsB fusion was confirmed by western blot analysis. Significantly higher levels of CEA-specific secretory immunoglobulin A in the sera of mice were observed upon oral administration of strain cultures containing the CEA-LcsB fused protein. In addition, the CEA-LcsB antigen group showed a higher spleen index compared to the CEA antigen alone or negative control, demonstrating that surface-displayed CEA antigen could induce a higher immune response. These results provided the first evidence for displaying CEA antigen on the cell surfaces of LABs as oral vaccines against cancer or infectious diseases. Copyright © 2014. Published by Elsevier B.V.

  3. Human mast cell line-1 (HMC-1) cells transfected with FcεRIα are sensitive to IgE/antigen-mediated stimulation demonstrating selectivity towards cytokine production.

    Science.gov (United States)

    Xia, YuXiu C; Sun, ShanShan; Kuek, Li Eon; Lopata, Andreas L; Hulett, Mark D; Mackay, Graham A

    2011-08-01

    Mast cells play important roles in allergic and inflammatory diseases. Efforts to better understand human mast cell activation and develop novel inhibitory agents have been hampered by the lack of suitable human mast cell lines. The HMC-1 mast cell line has been extensively used, but lacks native expression of the human high-affinity IgE receptor FcεRI limiting its applications. We have stably transfected HMC-1 cells with the IgE-binding α-subunit of FcεRI to generate HMCα cells that are antigen-responsive. We have used flow cytometry, cell signaling assays, pharmacological pathway inhibitors and cell functional assays to characterize the properties of HMCα cells. IgE/antigen responses were compared with those of the adenosine receptor agonist NECA. Surface expression of FcεRI in HMCα cells was demonstrated and was enhanced by prior sensitization with IgE. Activation of HMCα cells with IgE/antigen did not produce degranulation, but did lead to release of numerous cytokines. Whilst there was no measurable increase of intracellular Ca(2+) or marked general changes in protein tyrosine phosphorylation, IgE/antigen stimulation of HMCα cells enhanced phosphorylation of p38(MAPK) and Erk. Inhibitors of these pathways, as well as the src kinase inhibitor PP2, attenuated IgE/antigen-induced cytokine release. In summary, we have generated and characterized HMCα cells and show that they are a useful and relevant human mast cell model to examine FcεRI stabilization, signaling and mediator release. We envisage that HMCα cells will have utility in understanding the importance of mast cells in human allergic disease and in assessing the activity of novel anti-allergic compounds. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Cd1b-Mediated T Cell Recognition of a Glycolipid Antigen Generated from Mycobacterial Lipid and Host Carbohydrate during Infection

    Science.gov (United States)

    Moody, D. Branch; Guy, Mark R.; Grant, Ethan; Cheng, Tan-Yun; Brenner, Michael B.; Besra, Gurdyal S.; Porcelli, Steven A.

    2000-01-01

    T cells recognize microbial glycolipids presented by CD1 proteins, but there is no information regarding the generation of natural glycolipid antigens within infected tissues. Therefore, we determined the molecular basis of CD1b-restricted T cell recognition of mycobacterial glycosylated mycolates, including those produced during tissue infection in vivo. Transfection of the T cell receptor (TCR) α and β chains from a glucose monomycolate (GMM)-specific T cell line reconstituted GMM recognition in TCR-deficient T lymphoblastoma cells. This TCR-mediated response was highly specific for natural mycobacterial glucose-6-O-(2R, 3R) monomycolate, including the precise structure of the glucose moiety, the stereochemistry of the mycolate lipid, and the linkage between the carbohydrate and the lipid. Mycobacterial production of antigenic GMM absolutely required a nonmycobacterial source of glucose that could be supplied by adding glucose to media at concentrations found in mammalian tissues or by infecting tissue in vivo. These results indicate that mycobacteria synthesized antigenic GMM by coupling mycobacterial mycolates to host-derived glucose. Specific T cell recognition of an epitope formed by interaction of host and pathogen biosynthetic pathways provides a mechanism for immune response to those pathogenic mycobacteria that have productively infected tissues, as distinguished from ubiquitous, but innocuous, environmental mycobacteria. PMID:11015438

  5. Microneedle-mediated immunization of an adenovirus-based malaria vaccine enhances antigen-specific antibody immunity and reduces anti-vector responses compared to the intradermal route

    Science.gov (United States)

    Carey, John B.; Vrdoljak, Anto; O'Mahony, Conor; Hill, Adrian V. S.; Draper, Simon J.; Moore, Anne C.

    2014-01-01

    Substantial effort has been placed in developing efficacious recombinant attenuated adenovirus-based vaccines. However induction of immunity to the vector is a significant obstacle to its repeated use. Here we demonstrate that skin-based delivery of an adenovirus-based malaria vaccine, HAdV5-PyMSP142, to mice using silicon microneedles induces equivalent or enhanced antibody responses to the encoded antigen, however it results in decreased anti-vector responses, compared to intradermal delivery. Microneedle-mediated vaccine priming and resultant induction of low anti-vector antibody titres permitted repeated use of the same adenovirus vaccine vector. This resulted in significantly increased antigen-specific antibody responses in these mice compared to ID-treated mice. Boosting with a heterologous vaccine; MVA-PyMSP142 also resulted in significantly greater antibody responses in mice primed with HAdV5-PyMSP142 using MN compared to the ID route. The highest protection against blood-stage malaria challenge was observed when a heterologous route of immunization (MN/ID) was used. Therefore, microneedle-mediated immunization has potential to both overcome some of the logistic obstacles surrounding needle-and-syringe-based immunization as well as to facilitate the repeated use of the same adenovirus vaccine thereby potentially reducing manufacturing costs of multiple vaccines. This could have important benefits in the clinical ease of use of adenovirus-based immunization strategies. PMID:25142082

  6. Development of A Chimeric Antigen Receptor Targeting C-Type Lectin-Like Molecule-1 for Human Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Eduardo Laborda

    2017-10-01

    Full Text Available The treatment of patients with acute myeloid leukemia (AML with targeted immunotherapy is challenged by the heterogeneity of the disease and a lack of tumor-exclusive antigens. Conventional immunotherapy targets for AML such as CD33 and CD123 have been proposed as targets for chimeric antigen receptor (CAR-engineered T-cells (CAR-T-cells, a therapy that has been highly successful in the treatment of B-cell leukemia and lymphoma. However, CD33 and CD123 are present on hematopoietic stem cells, and targeting with CAR-T-cells has the potential to elicit long-term myelosuppression. C-type lectin-like molecule-1 (CLL1 or CLEC12A is a myeloid lineage antigen that is expressed by malignant cells in more than 90% of AML patients. CLL1 is not expressed by healthy Hematopoietic Stem Cells (HSCs, and is therefore a promising target for CAR-T-cell therapy. Here, we describe the development and optimization of an anti-CLL1 CAR-T-cell with potent activity on both AML cell lines and primary patient-derived AML blasts in vitro while sparing healthy HSCs. Furthermore, in a disseminated mouse xenograft model using the CLL1-positive HL60 cell line, these CAR-T-cells completely eradicated tumor, thus supporting CLL1 as a promising target for CAR-T-cells to treat AML while limiting myelosuppressive toxicity.

  7. Protective vaccination with promastigote surface antigen 2 from Leishmania major is mediated by a TH1 type of immune response.

    OpenAIRE

    Handman, E; Symons, F M; Baldwin, T M; Curtis, J M; Scheerlinck, J P

    1995-01-01

    Leishmania major promastigote surface antigen-2 complex (PSA-2) comprises a family of three similar but distinct polypeptides. The three PSA-2 polypeptides were purified from cultured promastigotes by a combination of detergent phase separation and monoclonal antibody affinity chromatography. Intraperitoneal vaccination of C3H/He mice with PSA-2 with Corynebacterium parvum as an adjuvant resulted in complete protection from lesion development after challenge infection with virulent L. major. ...

  8. Multi-antigenic human cytomegalovirus mRNA vaccines that elicit potent humoral and cell-mediated immunity.

    Science.gov (United States)

    John, Shinu; Yuzhakov, Olga; Woods, Angela; Deterling, Jessica; Hassett, Kimberly; Shaw, Christine A; Ciaramella, Giuseppe

    2018-03-14

    A cytomegalovirus (CMV) vaccine that is effective at preventing congenital infection and reducing CMV disease in transplant patients remains a high priority as no approved vaccines exist. While the precise correlates of protection are unknown, neutralizing antibodies and antigen-specific T cells have been implicated in controlling infection. We demonstrate that the immunization of mice and nonhuman primates (NHPs) with lipid nanoparticles (LNP) encapsulating modified mRNA encoding CMV glycoproteins gB and pentameric complex (PC) elicit potent and durable neutralizing antibody titers. Since the protective correlates in pregnant women and transplant recipients may differ, we developed an additional mRNA vaccine expressing the immunodominant CMV T cell antigen pp65. Administration of pp65 vaccine with PC and gB elicited robust multi-antigenic T cell responses in mice. Our data demonstrate that mRNA/LNP is a versatile platform that enables the development of vaccination strategies that could prevent CMV infection and consequent disease in different target populations. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  9. Nuclear export signal-interacting protein forms complexes with lamin A/C-Nups to mediate the CRM1-independent nuclear export of large hepatitis delta antigen.

    Science.gov (United States)

    Huang, Cheng; Jiang, Jia-Yin; Chang, Shin C; Tsay, Yeou-Guang; Chen, Mei-Ru; Chang, Ming-Fu

    2013-02-01

    Nuclear export is an important process that not only regulates the functions of cellular factors but also facilitates the assembly of viral nucleoprotein complexes. Chromosome region maintenance 1 (CRM1) that mediates the transport of proteins bearing the classical leucine-rich nuclear export signal (NES) is the best-characterized nuclear export receptor. Recently, several CRM1-independent nuclear export pathways were also identified. The nuclear export of the large form of hepatitis delta antigen (HDAg-L), a nucleocapsid protein of hepatitis delta virus (HDV), which contains a CRM1-independent proline-rich NES, is mediated by the host NES-interacting protein (NESI). The mechanism of the NESI protein in mediating nuclear export is still unknown. In this study, NESI was characterized as a highly glycosylated membrane protein. It interacted and colocalized well in the nuclear envelope with lamin A/C and nucleoporins. Importantly, HDAg-L could be coimmunoprecipitated with lamin A/C and nucleoporins. In addition, binding of the cargo HDAg-L to the C terminus of NESI was detected for the wild-type protein but not for the nuclear export-defective HDAg-L carrying a P205A mutation [HDAg-L(P205A)]. Knockdown of lamin A/C effectively reduced the nuclear export of HDAg-L and the assembly of HDV. These data indicate that by forming complexes with lamin A/C and nucleoporins, NESI facilitates the CRM1-independent nuclear export of HDAg-L.

  10. Seasonal changes in cell mediated immune responses to soluble Plasmodium falciparum antigens in children with haemoglobin AA and haemoglobin AS

    DEFF Research Database (Denmark)

    Abu-Zeid, Y A; Abdulhadi, N H; Theander, T G

    1992-01-01

    In this longitudinal study peripheral blood mononuclear cells (PBMC) were obtained before and during the malaria season from healthy HbAA and HbAS children. Cells were compared for proliferation in response to stimulation by soluble Plasmodium falciparum antigens (SPAg) or purified derivative...... of tuberculin (PPD). The lymphoproliferative responses to SPAg of the paired PBMC samples showed 2 distinct seasonal changes in relation to the haemoglobin phenotype. In HbAA children, the lymphoproliferative responses to SPAg were suppressed during the malaria season. In contrast, they were enhanced in Hb...

  11. Cell-mediated immune responses to Plasmodium falciparum purified soluble antigens in sickle-cell trait subjects.

    Science.gov (United States)

    Bayoumi, R A; Abu-Zeid, Y A; Abdulhadi, N H; Saeed, B O; Theander, T G; Hviid, L; Ghalib, H W; Nugud, A H; Jepsen, S; Jensen, J B

    1990-08-01

    To determine the possible differences in the immune response to Plasmodium falciparum between sickle-cell trait (Hb AS) and normal haemoglobin (Hb AA) individuals, we examined 35 Hb AS and 24 Hb AA subjects matched for age and microenvironment. Their age was 2-55 years and all lived in a malaria endemic area 300 km south of Khartoum. Antibodies to ring-infected erythrocyte surface antigen (Pf155/RESA) and to circumsporozoite (CS) protein (anti-NANP40) indicated equal exposure to falciparum malaria. Peripheral blood mononuclear cells (BMNCs) from 20/35 (57%) Hb AS subjects compared with 10/24 (42%) Hb AA subjects, responded to affinity-purified P. falciparum soluble antigens (SPAg). Of those responding to SPAg, 9 (26%) Hb AS subjects and only two (8%) Hb AA subjects had high responses. The mean proliferative response to SPAg of BMNCs from Hb AS individuals was significantly higher than in Hb AA individuals (P less than 0.025). Responses of BMNCs to PPD and PHA were also higher among Hb AS individuals and correlated positively with responses to SPAg. These findings support the hypotheses that the sickle-cell trait protects individuals from P. falciparum infections, at least in part, by modulating the immune response.

  12. Recent advances in Major Histocompatibility Complex (MHC) class I antigen presentation: Plastic MHC molecules and TAPBPR-mediated quality control.

    Science.gov (United States)

    van Hateren, Andy; Bailey, Alistair; Elliott, Tim

    2017-01-01

    We have known since the late 1980s that the function of classical major histocompatibility complex (MHC) class I molecules is to bind peptides and display them at the cell surface to cytotoxic T cells. Recognition by these sentinels of the immune system can lead to the destruction of the presenting cell, thus protecting the host from pathogens and cancer. Classical MHC class I molecules (MHC I hereafter) are co-dominantly expressed, polygenic, and exceptionally polymorphic and have significant sequence diversity. Thus, in most species, there are many different MHC I allotypes expressed, each with different peptide-binding specificity, which can have a dramatic effect on disease outcome. Although MHC allotypes vary in their primary sequence, they share common tertiary and quaternary structures. Here, we review the evidence that, despite this commonality, polymorphic amino acid differences between allotypes alter the ability of MHC I molecules to change shape (that is, their conformational plasticity). We discuss how the peptide loading co-factor tapasin might modify this plasticity to augment peptide loading. Lastly, we consider recent findings concerning the functions of the non-classical MHC I molecule HLA-E as well as the tapasin-related protein TAPBPR (transporter associated with antigen presentation binding protein-related), which has been shown to act as a second quality-control stage in MHC I antigen presentation.

  13. Archaeosomes varying in lipid composition differ in receptor-mediated endocytosis and differentially adjuvant immune responses to entrapped antigen

    Directory of Open Access Journals (Sweden)

    G. Dennis Sprott

    2003-01-01

    Full Text Available Archaeosomes prepared from total polar lipids extracted from six archaeal species with divergent lipid compositions had the capacity to deliver antigen for presentation via both MHC class I and class II pathways. Lipid extracts from Halobacterium halobium and from Halococcus morrhuae strains 14039 and 16008 contained archaetidylglycerol methylphosphate and sulfated glycolipids rich in mannose residues, and lacked archaetidylserine, whereas the opposite was found in Methanobrevibacter smithii, Methanosarcina mazei and Methanococcus jannaschii. Annexin V labeling revealed a surface orientation of phosphoserine head groups in M. smithii, M. mazei and M. jannaschii archaeosomes. Uptake of rhodamine-labeled M. smithii or M. jannaschii archaeosomes by murine peritoneal macrophages was inhibited by unlabeled liposomes containing phosphatidylserine, by the sulfhydryl inhibitor N-ethylmaleimide, and by ATP depletion using azide plus fluoride, but not by H. halobium archaeosomes. In contrast, N-ethylmaleimide failed to inhibit uptake of the four other rhodamine-labeled archaeosome types, and azide plus fluoride did not inhibit uptake of H. halobium or H. morrhuae archaeosomes. These results suggest endocytosis of archaeosomes rich in surface-exposed phosphoserine head groups via a phosphatidylserine receptor, and energy-independent surface adsorption of certain other archaeosome composition classes. Lipid composition affected not only the endocytic mechanism, but also served to differentially modulate the activation of dendritic cells. The induction of IL-12 secretion from dendritic cells exposed to H. morrhuae 14039 archaeosomes was striking compared with cells exposed to archaeosomes from 16008. Thus, archaeosome types uniquely modulate antigen delivery and dendritic cell activation.

  14. Recent advances in Major Histocompatibility Complex (MHC) class I antigen presentation: Plastic MHC molecules and TAPBPR-mediated quality control

    Science.gov (United States)

    van Hateren, Andy; Bailey, Alistair; Elliott, Tim

    2017-01-01

    We have known since the late 1980s that the function of classical major histocompatibility complex (MHC) class I molecules is to bind peptides and display them at the cell surface to cytotoxic T cells. Recognition by these sentinels of the immune system can lead to the destruction of the presenting cell, thus protecting the host from pathogens and cancer. Classical MHC class I molecules (MHC I hereafter) are co-dominantly expressed, polygenic, and exceptionally polymorphic and have significant sequence diversity. Thus, in most species, there are many different MHC I allotypes expressed, each with different peptide-binding specificity, which can have a dramatic effect on disease outcome. Although MHC allotypes vary in their primary sequence, they share common tertiary and quaternary structures. Here, we review the evidence that, despite this commonality, polymorphic amino acid differences between allotypes alter the ability of MHC I molecules to change shape (that is, their conformational plasticity). We discuss how the peptide loading co-factor tapasin might modify this plasticity to augment peptide loading. Lastly, we consider recent findings concerning the functions of the non-classical MHC I molecule HLA-E as well as the tapasin-related protein TAPBPR (transporter associated with antigen presentation binding protein-related), which has been shown to act as a second quality-control stage in MHC I antigen presentation. PMID:28299193

  15. Antigen delivery by filamentous bacteriophage fd displaying an anti-DEC-205 single-chain variable fragment confers adjuvanticity by triggering a TLR9-mediated immune response.

    Science.gov (United States)

    Sartorius, Rossella; D'Apice, Luciana; Trovato, Maria; Cuccaro, Fausta; Costa, Valerio; De Leo, Maria Giovanna; Marzullo, Vincenzo Manuel; Biondo, Carmelo; D'Auria, Sabato; De Matteis, Maria Antonietta; Ciccodicola, Alfredo; De Berardinis, Piergiuseppe

    2015-07-01

    Filamentous bacteriophage fd particles delivering antigenic determinants via DEC-205 (fdsc-αDEC) represent a powerful delivery system that induces CD8(+) T-cell responses even when administered in the absence of adjuvants or maturation stimuli for dendritic cells. In order to investigate the mechanisms of this activity, RNA-Sequencing of fd-pulsed dendritic cells was performed. A significant differential expression of genes involved in innate immunity, co-stimulation and cytokine production was observed. In agreement with these findings, we demonstrate that induction of proinflammatory cytokines and type I interferon by fdsc-αDEC was MYD88 mediated and TLR9 dependent. We also found that fdsc-αDEC is delivered into LAMP-1-positive compartments and co-localizes with TLR9. Thus, phage particles containing a single-strand DNA genome rich in CpG motifs delivered via DEC-205 are able to intercept and trigger the active TLR9 innate immune receptor into late endosome/lysosomes and to enhance the immunogenicity of the displayed antigenic determinants. These findings make fd bacteriophage a valuable tool for immunization without administering exogenous adjuvants. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.

  16. Augmented acetylcholine-induced, Rho-mediated Ca2+ sensitization of bronchial smooth muscle contraction in antigen-induced airway hyperresponsive rats

    Science.gov (United States)

    Chiba, Yoshihiko; Takada, Yuka; Miyamoto, Shigeki; Mitsui-Saito, Minori; Karaki, Hideaki; Misawa, Miwa

    1999-01-01

    Treatment with acetylcholine (ACh) of a β-escin-permeabilized intrapulmonary bronchial smooth muscle of the rat induced force when the Ca2+ concentration was clamped at 1 μM. The ACh-induced Ca2+ sensitization of myofilaments was significantly greater in antigen-induced airway hyperresponsive rats than in control rats. The ACh-induced Ca2+ sensitization was completely blocked by treatment with Clostridium botulinum C3 exoenzyme, an inactivator of Rho family of proteins. Moreover, the protein level of RhoA in the intrapulmonary bronchi was significantly increased in the airway hyperresponsive rats. Thus, increased airway smooth muscle contractility observed in asthmatics may be related to augmented agonist-induced, Rho-mediated Ca2+ sensitization of myofilaments. PMID:10401547

  17. Acute antibody-mediated rejection after AB0-incomptible kidney transplantation treated successfully with antigen-specific immunoadsorption

    DEFF Research Database (Denmark)

    Just, Søren Andreas; Marcussen, Niels; Sprogøe, Ulrik

    2009-01-01

    ABO-incompatible kidney transplantation is possible after pre-treatment with rituximab, intravenous immunoglobulin and basiliximab combined with tacrolimus, mycophenolate mofetil and prednisolone. We report on the first patient treated with this protocol who developed acute antibody-mediated reje......ABO-incompatible kidney transplantation is possible after pre-treatment with rituximab, intravenous immunoglobulin and basiliximab combined with tacrolimus, mycophenolate mofetil and prednisolone. We report on the first patient treated with this protocol who developed acute antibody......-mediated rejection (Banff grade II with IgG deposits) caused by ABO antibodies (anti-B). Anti-rejection treatment with anti-B-specific immunoadsorption, intravenous immunoglobulin and methylprednisolone efficiently cleared deposited IgG from the kidney allograft and re-established normal kidney function. We suggest...... that ABO-incompatible kidney transplantation complicated by acute antibody-mediated rejection, caused by ABO antibodies, may successfully be treated with this regime....

  18. Acute antibody-mediated rejection after ABO-incompatible kidney transplantation treated successfully with antigen-specific immunoadsorption

    DEFF Research Database (Denmark)

    Just, Søren Andreas; Marcussen, Niels; Sprogøe, Ulrik

    2010-01-01

    ABO-incompatible kidney transplantation is possible after pre-treatment with rituximab, intravenous immunoglobulin and basiliximab combined with tacrolimus, mycophenolate mofetil and prednisolone. We report on the first patient treated with this protocol who developed acute antibody-mediated reje......ABO-incompatible kidney transplantation is possible after pre-treatment with rituximab, intravenous immunoglobulin and basiliximab combined with tacrolimus, mycophenolate mofetil and prednisolone. We report on the first patient treated with this protocol who developed acute antibody......-mediated rejection (Banff grade II with IgG deposits) caused by ABO antibodies (anti-B). Anti-rejection treatment with anti-B-specific immunoadsorption, intravenous immunoglobulin and methylprednisolone efficiently cleared deposited IgG from the kidney allograft and re-established normal kidney function. We suggest...... that ABO-incompatible kidney transplantation complicated by acute antibody-mediated rejection, caused by ABO antibodies, may successfully be treated with this regime....

  19. Trastuzumab mediated T-cell response against HER-2/neu overexpressing esophageal adenocarcinoma depends on intact antigen processing machinery.

    Directory of Open Access Journals (Sweden)

    Francesca Milano

    2010-08-01

    Full Text Available Esophageal adenocarcinoma (EAC is a highly aggressive disease with poor prognosis, which frequently exhibits HER-2 gene amplification. Trastuzumab, the humanized antibody against HER-2, has potent growth inhibitory effects on HER-2 overexpressing cancers. One effect of trastuzumab is that it causes HER-2 receptor internalization and degradation, enhancing presentation of HER-2 epitopes on MHC-Class I molecules. This enhances the ability of HER-2 specific cytotoxic T lymphocytes (CTLs to recognize and kill cancer cells. Novel strategies targeting the HER-2 receptor either directly by trastuzumab and/or indirectly by inducing a CTL response against HER-2 epitopes with, for instance, DC immunotherapy and consequently combining these strategies might prove to be very effective.In this study we report that trastuzumab has potent growth inhibitory effects on two HER-2 overexpressing EAC cell lines OE33 and OE19. However, we found that trastuzumab and HER-2 specific CTLs act synergistically in inducing tumor lysis in OE33 but not in OE19. We discovered that in OE19 this deficient response is due to a down-regulation of the Transporter Associated with Antigen Processing-2 (TAP-2. TAP-2 is an important member of the Antigen Processing Machinery (APM, and is one of the essential elements for loading antigens on MHC class I molecules. Importantly, we demonstrated that by inducing re-expression of TAP-2 in OE19 with INF-γ treatment or by incubating the cells with INF-γ producing CTLs, the specific anti HER-2 CTL tumor lysis response and synergistic effect with trastuzumab can be restored.An inefficient response of HER-2 overexpressing EAC to trastuzumab and/or DC immunotherapy can be due to a down-regulated TAP-2 expression and thus a deficient APM. Future studies combining trastuzumab with IFN-γ and/or immune-therapies inducing potent anti HER-2 CTL responses could lead to an effective combinatorial strategy for successful treatment of HER-2

  20. Third-stage Gnathostoma spinigerum larva excretory secretory antigens modulate function of Fc gamma receptor I-mediated monocytes in peripheral blood mononuclear cell culture.

    Science.gov (United States)

    Benjathummarak, Surachet; Kumsiri, Ratchanok; Nuamtanong, Supaporn; Kalambaheti, Thareerat; Waikagul, Jitra; Viseshakul, Nareerat; Maneerat, Yaowapa

    2016-01-01

    Third (infective)-stage Gnathostoma spinigerum larvae (L3) mainly cause human gnathostomiasis. G. spinigerum L3 migrate throughout the subcutaneous tissues, vital organs, and central nervous system and can cause various pathogenesis including sudden death. Interestingly, G. spinigerum L3 can survive and evade host cellular immunity for months or years. The effects of G. spinigerum excretory-secretory (ES) products involved in larval migration and immune-evasive strategies are unknown. Monocytes are innate immune cells that act as phagocytic and antigen-presenting cells and also play roles against helminthic infections via a complex interplay between other immune cells. Fc gamma receptor I (FcγRI) is a high-affinity receptor that is particularly expressed on monocytes, macrophages, and dendritic cells. The cross-linking of FcγRI and antigen-antibody complex initiates signal transduction cascades in phagocytosis, cytokine production, and antibody-dependent cell-mediated cytotoxicity (ADCC). This study investigated whether ES antigen (ESA) from G. spinigerum L3 affects monocyte functions. Cultures of normal peripheral blood mononuclear cells (PBMC) separated from healthy buffy coats were used as a human immune cell model. ESA was prepared from G. spinigerum L3 culture. Using Real-Time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), the effect of ESA to down-regulate FcγRI mRNA expression in monocytes during 90 min of observation was not well delineated. Flow cytometry analysis revealed a significant phenotypic-decreased FcγRI expression on the monocyte surface at 12 hours (h) of cultivation with the ESA (p = 0.033). Significantly reduced monocyte-mediated phagocytosis capacity was consistently observed after 12 h of ESA pretreatment (p = 0.001). Our results suggest that G. spinigerum ESA modulates monocyte function via depletion of FcγRI expression. This study provides preliminary information for future in-depth studies to

  1. Cell-mediated immune responses to Plasmodium falciparum purified soluble antigens in sickle-cell trait subjects

    DEFF Research Database (Denmark)

    Bayoumi, R A; Abu-Zeid, Y A; Abdulhadi, N H

    1990-01-01

    To determine the possible differences in the immune response to Plasmodium falciparum between sickle-cell trait (Hb AS) and normal haemoglobin (Hb AA) individuals, we examined 35 Hb AS and 24 Hb AA subjects matched for age and microenvironment. Their age was 2-55 years and all lived in a malaria...... individuals (P less than 0.025). Responses of BMNCs to PPD and PHA were also higher among Hb AS individuals and correlated positively with responses to SPAg. These findings support the hypotheses that the sickle-cell trait protects individuals from P. falciparum infections, at least in part, by modulating...... endemic area 300 km south of Khartoum. Antibodies to ring-infected erythrocyte surface antigen (Pf155/RESA) and to circumsporozoite (CS) protein (anti-NANP40) indicated equal exposure to falciparum malaria. Peripheral blood mononuclear cells (BMNCs) from 20/35 (57%) Hb AS subjects compared with 10/24 (42...

  2. Complement component C1r mediated cleavage of the heavy chain of the major histocompatibility class I antigens

    DEFF Research Database (Denmark)

    Eriksson, H; Nissen, Mogens Holst

    1992-01-01

    Apart from cleaving C1s, we demonstrate for the first time that: 1) at concentrations found in serum, the activated forms of the complement components C1r in addition to C1s can cleave the heavy chain of MHC class I antigens, 2) the cleavage by C1r and C1s is seemingly dependent upon a native con......-chain of MHC class I was shown to take place between the alpha 2- and alpha 3- domains as estimated by the Con A-Sepharose precipitation pattern on SDS-PAGE. The alpha 1/alpha 2 fragment was still shown to interact with beta 2-microglobulin as shown by immunoprecipitation....

  3. Protective vaccination with promastigote surface antigen 2 from Leishmania major is mediated by a TH1 type of immune response.

    Science.gov (United States)

    Handman, E; Symons, F M; Baldwin, T M; Curtis, J M; Scheerlinck, J P

    1995-11-01

    Leishmania major promastigote surface antigen-2 complex (PSA-2) comprises a family of three similar but distinct polypeptides. The three PSA-2 polypeptides were purified from cultured promastigotes by a combination of detergent phase separation and monoclonal antibody affinity chromatography. Intraperitoneal vaccination of C3H/He mice with PSA-2 with Corynebacterium parvum as an adjuvant resulted in complete protection from lesion development after challenge infection with virulent L. major. Significant protection was also obtained in the genetically susceptible BALB/cH-2k and BALB/c mice. One of the PSA-2 genes was cloned and expressed in both Escherichia coli and Leishmania mexicana promastigotes. Vaccination with the recombinant PSA-2 purified from E. coli did not confer protection, in contrast to the L. mexicana-derived recombinant PSA-2, which provided excellent protection. CD4+ T cells isolated from the spleens of vaccinated mice produced large amounts of gamma interferon but no detectable interleukin 4 upon stimulation with PSA-2 in vitro. Limiting dilution analysis showed a marked increase in the precursor frequency of PSA-2-specific gamma interferon-secreting CD4+ T cells. No substantial change in precursor frequency was observed for interleukin 4-secreting T cells in the vaccinated mice. A CD4+ PSA-2 specific T-cell line generated from splenocytes of a vaccinated mouse produces a cytokine pattern consistent with a TH1 phenotype. Intravenous injection of this line into naive mice reduced significantly the parasite burden upon challenge infection. Taken together, the data suggest that vaccination with PSA-2 induces a TH1 type of immune response which protects mice from L. major infection. Moreover, a single recombinant PSA-2 polypeptide derived from a genomic clone can also vaccinate, provided that the structural form of the antigen is near native.

  4. OSBP-related protein 8 (ORP8) interacts with Homo sapiens sperm associated antigen 5 (SPAG5) and mediates oxysterol interference of HepG2 cell cycle

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Wenbin [Department of Biotechnology, Jinan University, Guangzhou 510632 (China); Zhou, You [Minerva Foundation Institute for Medical Research, Helsinki (Finland); Li, Jiwei [Department of Biotechnology, Jinan University, Guangzhou 510632 (China); Mysore, Raghavendra [Minerva Foundation Institute for Medical Research, Helsinki (Finland); Luo, Wei; Li, Shiqian [Department of Biotechnology, Jinan University, Guangzhou 510632 (China); Chang, Mau-Sun [Institute of Biochemical Sciences, National Taiwan University, No. 1, Taipei, Taiwan (China); Olkkonen, Vesa M. [Minerva Foundation Institute for Medical Research, Helsinki (Finland); Yan, Daoguang, E-mail: tydg@jnu.edu.cn [Department of Biotechnology, Jinan University, Guangzhou 510632 (China)

    2014-04-01

    We earlier identified OSBP-related protein 8 (ORP8) as an endoplasmic reticulum/nuclear envelope oxysterol-binding protein implicated in cellular lipid homeostasis, migration, and organization of the microtubule cytoskeleton. Here, a yeast two-hybrid screen identified Homo sapiens sperm associated antigen 5 (SPAG5)/Astrin as interaction partner of ORP8. The putative interaction was further confirmed by pull-down and co-immunoprecipitation assays. ORP8 did not colocalize with kinetochore-associated SPAG5 in mitotic HepG2 or HuH7 cells, but overexpressed ORP8 was capable of recruiting SPAG5 onto endoplasmic reticulum membranes in interphase cells. In our experiments, 25-hydroxycholesterol (25OHC) retarded the HepG2 cell cycle, causing accumulation in G2/M phase; ORP8 overexpression resulted in the same phenotype. Importantly, ORP8 knock-down dramatically inhibited the oxysterol effect on HepG2 cell cycle, suggesting a mediating role of ORP8. Furthermore, knock-down of SPAG5 significantly reduced the effects of both ORP8 overexpression and 25OHC on the cell cycle, placing SPAG5 downstream of the two cell-cycle interfering factors. Taken together, the present results suggest that ORP8 may via SPAG5 mediate oxysterol interference of the HepG2 cell cycle. - Highlights: • The oxysterol-binding protein ORP8 was found to interact with the mitotic regulator SPAG5/Astrin. • Treatment of HepG2 cells with 25-hydroxycholesterol caused cell cycle retardation in G2/M. • ORP8 overexpression caused a similar G2/M accumulation, and ORP8 knock-down reversed the 25-hydroxycholesterol effect. • Reduction of cellular of SPAG5/Astrin reversed the cell cycle effects of both 25-hydroxycholesterol and ORP8 overexpression. • Our results suggest that ORP8 mediates via SPAG5/Astrin the oxysterol interference of HepG2 cell cycle.

  5. OSBP-related protein 8 (ORP8) interacts with Homo sapiens sperm associated antigen 5 (SPAG5) and mediates oxysterol interference of HepG2 cell cycle

    International Nuclear Information System (INIS)

    Zhong, Wenbin; Zhou, You; Li, Jiwei; Mysore, Raghavendra; Luo, Wei; Li, Shiqian; Chang, Mau-Sun; Olkkonen, Vesa M.; Yan, Daoguang

    2014-01-01

    We earlier identified OSBP-related protein 8 (ORP8) as an endoplasmic reticulum/nuclear envelope oxysterol-binding protein implicated in cellular lipid homeostasis, migration, and organization of the microtubule cytoskeleton. Here, a yeast two-hybrid screen identified Homo sapiens sperm associated antigen 5 (SPAG5)/Astrin as interaction partner of ORP8. The putative interaction was further confirmed by pull-down and co-immunoprecipitation assays. ORP8 did not colocalize with kinetochore-associated SPAG5 in mitotic HepG2 or HuH7 cells, but overexpressed ORP8 was capable of recruiting SPAG5 onto endoplasmic reticulum membranes in interphase cells. In our experiments, 25-hydroxycholesterol (25OHC) retarded the HepG2 cell cycle, causing accumulation in G2/M phase; ORP8 overexpression resulted in the same phenotype. Importantly, ORP8 knock-down dramatically inhibited the oxysterol effect on HepG2 cell cycle, suggesting a mediating role of ORP8. Furthermore, knock-down of SPAG5 significantly reduced the effects of both ORP8 overexpression and 25OHC on the cell cycle, placing SPAG5 downstream of the two cell-cycle interfering factors. Taken together, the present results suggest that ORP8 may via SPAG5 mediate oxysterol interference of the HepG2 cell cycle. - Highlights: • The oxysterol-binding protein ORP8 was found to interact with the mitotic regulator SPAG5/Astrin. • Treatment of HepG2 cells with 25-hydroxycholesterol caused cell cycle retardation in G2/M. • ORP8 overexpression caused a similar G2/M accumulation, and ORP8 knock-down reversed the 25-hydroxycholesterol effect. • Reduction of cellular of SPAG5/Astrin reversed the cell cycle effects of both 25-hydroxycholesterol and ORP8 overexpression. • Our results suggest that ORP8 mediates via SPAG5/Astrin the oxysterol interference of HepG2 cell cycle

  6. H-2g, a glucose analog of blood group H antigen, mediates monocyte recruitment in vitro and in vivo via IL-8/CXCL8

    Directory of Open Access Journals (Sweden)

    Rabquer BJ

    2012-09-01

    Full Text Available Bradley J Rabquer,1,2 Yong Hou,1 Jeffrey H Ruth,1 Wei Luo,1 Daniel T Eitzman,1 Alisa E Koch,3,1 Mohammad A Amin11University of Michigan Medical School, Department of Internal Medicine, Ann Arbor, MI, USA; 2Albion College, Biology Department, Albion, MI, USA; 3VA Medical Service, Department of Veterans Affairs, Ann Arbor, MI, USAObjective: Monocyte (MN recruitment is an essential inflammatory component of many autoimmune diseases, including rheumatoid arthritis (RA. In this study we investigated the ability of 2-fucosyllactose (H-2g, a glucose analog of blood group H antigen to induce MN migration in vivo and determined if H-2g-induced interleukin-8 (IL-8/CXCL8 plays a role in MN ingress in RA.Methods: Sponge granuloma and intravital microscopy assays were performed to examine H-2g-induced in vivo MN migration and rolling, respectively. MNs were stimulated with H-2g, and the production of IL-8/CXCL8 was assessed by enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. Lastly, in vitro MN migration assays and an in vivo RA synovial tissue severe combined immunodeficiency mouse model were used to determine the role of IL-8/CXCL8 in H-2g-induced MN migration.Results: In vivo, H-2g induced significantly greater MN migration compared to phosphate buffered saline. Intravital microscopy revealed that H-2g mediates MN migration in vivo by inducing MN rolling. In addition, H-2g induced MN production of IL-8/CXCL8, a process that was dependent on Src kinase. Moreover, we found that H-2g mediated MN migration in vitro, and in vivo migration was inhibited by a neutralizing anti-IL-8/CXCL8 antibody.Conclusion: These findings suggest that H-2g mediates MN recruitment in vitro and in vivo (in part via IL-8/CXCL8.Keywords: inflammation, rheumatoid arthritis, chemokine, migration

  7. Cathepsin B in antigen-presenting cells controls mediators of the Th1 immune response during Leishmania major infection.

    Directory of Open Access Journals (Sweden)

    Iris J Gonzalez-Leal

    2014-09-01

    Full Text Available Resistance and susceptibility to Leishmania major infection in the murine model is determined by the capacity of the host to mount either a protective Th1 response or a Th2 response associated with disease progression. Previous reports involving the use of cysteine cathepsin inhibitors indicated that cathepsins B (Ctsb and L (Ctsl play important roles in Th1/Th2 polarization during L. major infection in both susceptible and resistant mouse strains. Although it was hypothesized that these effects are a consequence of differential patterns of antigen processing, the mechanisms underlying these differences were not further investigated. Given the pivotal roles that dendritic cells and macrophages play during Leishmania infection, we generated bone-marrow derived dendritic cells (BMDC and macrophages (BMM from Ctsb-/- and Ctsl-/- mice, and studied the effects of Ctsb and Ctsl deficiency on the survival of L. major in infected cells. Furthermore, the signals used by dendritic cells to instruct Th cell polarization were addressed: the expression of MHC class II and co-stimulatory molecules, and cytokine production. We found that Ctsb-/- BMDC express higher levels of MHC class II molecules than wild-type (WT and Ctsl-/- BMDC, while there were no significant differences in the expression of co-stimulatory molecules between cathepsin-deficient and WT cells. Moreover, both BMDC and BMM from Ctsb-/- mice significantly up-regulated the levels of interleukin 12 (IL-12 expression, a key Th1-inducing cytokine. These findings indicate that Ctsb-/- BMDC display more pro-Th1 properties than their WT and Ctsl-/- counterparts, and therefore suggest that Ctsb down-regulates the Th1 response to L. major. Moreover, they propose a novel role for Ctsb as a regulator of cytokine expression.

  8. Co-delivery of PLGA encapsulated invariant NKT cell agonist with antigenic protein induce strong T cell-mediated antitumor immune responses

    NARCIS (Netherlands)

    Dolen, Y.; Kreutz, M.; Gileadi, U.; Tel, J.; Vasaturo, A.; Dinther, E.A.W. van; Hout-Kuijer, M.A. van; Cerundolo, V.; Figdor, C.G.

    2016-01-01

    Antitumor immunity can be enhanced by the coordinated release and delivery of antigens and immune-stimulating agents to antigen-presenting cells via biodegradable vaccine carriers. So far, encapsulation of TLR ligands and tumor-associated antigens augmented cytotoxic T cell (CTLs) responses. Here,

  9. Antibody-mediated allotype suppression in adult mice: the role of antigen, effector isotype and regulatory T cells.

    Science.gov (United States)

    Curling, E M; Dresser, D W

    1984-10-01

    It has been reported (Contemp. Top. Immunobiol. 1974. 3:41) that allotype-specific T suppressor cells can be induced after monoclonal anti-allotype treatment of neonatal (BALB/c X SJL)F1 (Igha/b) mice. Here we show that (BALB/c X CB20)F1 adult-derived spleen cells (SC) are, by contrast, potently suppressed by monoclonal allotype-specific reagents, (when transferred into irradiated BALB/c recipients) in the absence of primary T suppressor cell induction. Such suppression is only induced in activated B cells [exposed to lipopolysaccharide or sheep red blood cells (SRBC)], and is probably dependent on the isotype of the anti-allotype sera administered. For example, two independently produced IgG1 monoclonal reagents raised against the Igh-1b allotype were poorly suppressive or nonsuppressive, whereas an IgG3 and an IgG2a monoclonal antibody induced a 90% suppression of the target allotype in transferred adult SC. It was found that suppression was not due to a depletion of antigen-specific T cell help since: (a) the addition of SRBC-educated T cells did not break suppression and (b) suppressed SC were as good a source of T cell help as normal SC, in the response of virgin or memory B cell (Thy-1-depleted) responses to SRBC in vivo. Suppression was maintained in suppressed cells which had been rechallenged with SRBC after transfer into a second irradiated recipient, but was not induced in normal SC when these were admixed with an equal number from this suppressed SC population. These findings point to a possible mechanism for the regulation of B cell expression, through the formation of an antibody-Ig receptor complex at the surface of the B lymphocyte. After complexing the target cell is either deleted or inactivated. The response to SRBC was reduced or ablated for at least 70 days after treatment with a single dose of anti-allotype serum.

  10. Antigen-Specificity of T Cell Infiltrates in Biopsies With T Cell-Mediated Rejection and BK Polyomavirus Viremia: Analysis by Next Generation Sequencing.

    Science.gov (United States)

    Zeng, G; Huang, Y; Huang, Y; Lyu, Z; Lesniak, D; Randhawa, P

    2016-11-01

    This study interrogates the antigen-specificity of inflammatory infiltrates in renal biopsies with BK polyomavirus (BKPyV) viremia (BKPyVM) with or without allograft nephropathy (BKPyVN). Peripheral blood mononuclear cells (PBMC) from five healthy HLA-A0101 subjects were stimulated by peptides derived from the BKPYV proteome or polymorphic regions of HLA. Next generation sequencing of the T cell-receptor complementary DNA was performed on peptide-stimulated PBMC and 23 biopsies with T cell-mediated rejection (TCMR) or BKPyVN. Biopsies from patients with BKPyVM or BKVPyVN contained 7.7732 times more alloreactive than virus-reactive clones. Biopsies with TCMR also contained BKPyV-specific clones, presumably a manifestation of heterologous immunity. The mean cumulative T cell clonal frequency was 0.1378 for alloreactive clones and 0.0375 for BKPyV-reactive clones. Samples with BKPyVN and TCMR clustered separately in dendrograms of V-family and J-gene utilization patterns. Dendrograms also revealed that V-gene, J-gene, and D-gene usage patterns were a function of HLA type. In conclusion, biopsies with BKPyVN contain abundant allospecific clones that exceed the number of virus-reactive clones. The T cell component of tissue injury in viral nephropathy appears to be mediated primarily by an "innocent bystander" mechanism in which the principal element is secondary T cell influx triggered by both antiviral and anti-HLA immunity. © Copyright 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

  11. The Tol2 transposon system mediates the genetic engineering of T-cells with CD19-specific chimeric antigen receptors for B-cell malignancies.

    Science.gov (United States)

    Tsukahara, T; Iwase, N; Kawakami, K; Iwasaki, M; Yamamoto, C; Ohmine, K; Uchibori, R; Teruya, T; Ido, H; Saga, Y; Urabe, M; Mizukami, H; Kume, A; Nakamura, M; Brentjens, R; Ozawa, K

    2015-02-01

    Engineered T-cell therapy using a CD19-specific chimeric antigen receptor (CD19-CAR) is a promising strategy for the treatment of advanced B-cell malignancies. Gene transfer of CARs to T-cells has widely relied on retroviral vectors, but transposon-based gene transfer has recently emerged as a suitable nonviral method to mediate stable transgene expression. The advantages of transposon vectors compared with viral vectors include their simplicity and cost-effectiveness. We used the Tol2 transposon system to stably transfer CD19-CAR into human T-cells. Normal human peripheral blood lymphocytes were co-nucleofected with the Tol2 transposon donor plasmid carrying CD19-CAR and the transposase expression plasmid and were selectively propagated on NIH3T3 cells expressing human CD19. Expanded CD3(+) T-cells with stable and high-level transgene expression (~95%) produced interferon-γ upon stimulation with CD19 and specifically lysed Raji cells, a CD19(+) human B-cell lymphoma cell line. Adoptive transfer of these T-cells suppressed tumor progression in Raji tumor-bearing Rag2(-/-)γc(-/-) immunodeficient mice compared with control mice. These results demonstrate that the Tol2 transposon system could be used to express CD19-CAR in genetically engineered T-cells for the treatment of refractory B-cell malignancies.

  12. A multimeric carcinoembryonic antigen signal inhibits the activation of human T cells by a SHP-independent mechanism: a potential mechanism for tumor-mediated suppression of T-cell immunity.

    Science.gov (United States)

    Lee, Kyoo-A; Bae, Eun-Ah; Song, You Chan; Kim, Eun-Kyung; Lee, Yoon-Sook; Kim, Tai-Gyu; Kang, Chang-Yuil

    2015-06-01

    Carcinoembryonic antigen (CEA) is a well-known tumor antigen that is found in the serum of patients with various cancers and is correlated with an increased risk of cancer recurrence and metastasis. To understand the tumor environment and to develop antitumor therapies, CEA has been studied as an antigen to activate/tolerate specific T cells. In this study, we show that CEA can function as a coinhibitory molecule and can inhibit the activation of human peripheral blood mononucleated cell-derived T cells. The addition of CEA-overexpressing tumor cells or immobilized CEA dampened both cell proliferation and the expression of IL-2 and CD69 expression in T cells after TCR stimulation. The phosphorylation of ERK and translocation of NFAT were hampered in these cells, whereas the phosphorylation of proximal TCR signaling molecules such as ZAP70 and phospholipase Cγ was not affected by immobilized CEA. To determine the relevance of carcinoembryonic antigen-related cell adhesion molecule-1 and Src homology region 2 domain-containing phosphatase (SHP) molecules to CEA-mediated suppression, we tested the effect of the SHP inhibitor, NSC-87877, on CEA-mediated suppression of T cells; however, it did not reverse the effect of CEA. Collectively, these results indicate that CEA can function as a modulator of T-cell responses suggesting a novel mechanism of tumor evasion. © 2014 UICC.

  13. Immunotherapy of acute leukemia by chimeric antigen receptor-modified lymphocytes using an improved Sleeping Beauty transposon platform.

    Science.gov (United States)

    Magnani, Chiara F; Turazzi, Nice; Benedicenti, Fabrizio; Calabria, Andrea; Tenderini, Erika; Tettamanti, Sarah; Giordano Attianese, Greta M P; Cooper, Laurence J N; Aiuti, Alessandro; Montini, Eugenio; Biondi, Andrea; Biagi, Ettore

    2016-08-09

    Chimeric antigen receptor (CAR)-modified T-cell adoptive immunotherapy is a remarkable therapeutic option proven effective in the treatment of hematological malignancies. In order to optimize cell manufacturing, we sought to develop a novel clinical-grade protocol to obtain CAR-modified cytokine-induced killer cells (CIKs) using the Sleeping Beauty (SB) transposon system. Administration of irradiated PBMCs overcame cell death of stimulating cells induced by non-viral transfection, enabling robust gene transfer together with efficient T-cell expansion. Upon single stimulation, we reached an average of 60% expression of CD123- and CD19- specific 3rd generation CARs (CD28/OX40/TCRzeta). Furthermore, modified cells displayed persistence of cell subsets with memory phenotype, specific and effective lytic activity against leukemic cell lines and primary blasts, cytokine secretion, and proliferation. Adoptive transfer of CD123.CAR or CD19.CAR lymphocytes led to a significant anti-tumor response against acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL) disseminated diseases in NSG mice. Notably, we found no evidence of integration enrichment near cancer genes and transposase expression at the end of the differentiation. Taken all together, our findings describe a novel donor-derived non-viral CAR approach that may widen the repertoire of available methods for T cell-based immunotherapy.

  14. The use of reference strand-mediated conformational analysis for the study of cheetah (Acinonyx jubatus) feline leucocyte antigen class II DRB polymorphisms.

    Science.gov (United States)

    Drake, G J C; Kennedy, L J; Auty, H K; Ryvar, R; Ollier, W E R; Kitchener, A C; Freeman, A R; Radford, A D

    2004-01-01

    There is now considerable evidence to suggest the cheetah (Acinonyx jubatus) has limited genetic diversity. However, the extent of this and its significance to the fitness of the cheetah population, both in the wild and captivity, is the subject of some debate. This reflects the difficulty associated with establishing a direct link between low variability at biologically significant loci and deleterious aspects of phenotype in this, and other, species. Attempts to study one such region, the feline leucocyte antigen (FLA), are hampered by a general reliance on cloning and sequencing which is expensive, labour-intensive, subject to PCR artefact and always likely to underestimate true variability. In this study we have applied reference strand-mediated conformational analysis (RSCA) to determine the FLA-DRB phenotypes of 25 cheetahs. This technique was rapid, repeatable and less prone to polymerase chain reaction (PCR)-induced sequence artefacts associated with cloning. Individual cheetahs were shown to have up to three FLA-DRB genes. A total of five alleles were identified (DRB*ha14-17 and DRB*gd01) distributed among four genotypes. Fifteen cheetahs were DRB*ha14/ha15/ha16/ha17, three were DRB*ha15/ha16/ha17, six were DRB*ha14/ha16/ha17 and one was DRB*ha14/ha15/ha16/ha17/gd01. Sequence analysis of DRB*gd01 suggested it was a recombinant of DRB*ha16 and DRB*ha17. Generation of new alleles is difficult to document, and the clear demonstration of such an event is unusual. This study confirms further the limited genetic variability of the cheetah at a biologically significant region. RSCA will facilitate large-scale studies that will be needed to correlate genetic diversity at such loci with population fitness in the cheetah and other species.

  15. Mediatization

    DEFF Research Database (Denmark)

    Hjarvard, Stig

    2017-01-01

    Mediatization research shares media effects studies' ambition of answering the difficult questions with regard to whether and how media matter and influence contemporary culture and society. The two approaches nevertheless differ fundamentally in that mediatization research seeks answers...... research is concerned with long-term structural changes involving media, culture, and society, i.e. the influences of the media are understood in relation to how media are implicated in social and cultural changes and how these processes come to create new conditions for human communication and interaction....... From the perspective of mediatization research, the most important effect of the media stems from their embeddedness in culture and society....

  16. In vitro and in vivo evidence of a potential A(H1N1)pdm09 antigenic drift mediated by escape mutations in the haemagglutinin Sa antigenic site.

    Science.gov (United States)

    Retamal, Miguel; Abed, Yacine; Rhéaume, Chantal; Baz, Mariana; Boivin, Guy

    2017-06-01

    Influenza A(H1N1)pdm09 virus continues to circulate worldwide without evidence of significant antigenic drift between 2009 and 2016. By using escape mutants, we previously identified six haemagglutinin (HA) changes (T80R, G143E, G158E, N159D, K166E and A198E) that were located within antigenic sites. Combinations of these mutations were introduced into the A(H1N1)pdm09 HA plasmid by mutagenesis. Reassortant 6 : 2 viruses containing both the HA and NA genes of the A(H1N1)pdm09 and the six internal gene segments of A/PR/8/34 were rescued by reverse genetics. In vitro, HA inhibition and microneutralization assays showed that the HA hexa-mutant reassortant virus (RG1) escaped A(H1N1)pdm09 hyper-immune ferret antiserum recognition. C57Black/6 mice that received the vaccine formulated with A/California/07/09 were challenged with 2×104 p.f.u. of either the 6 : 2 wild-type (WT) or RG1 viruses. Reductions in body weight loss, mortality rate and lung viral titre were observed in immunized animals challenged with the 6 : 2 WT virus compared to non-immunized mice. However, immunization did not protect mice challenged with RG1 virus. To further characterize the mutations causing this antigenic change, 11 additional RG viruses whose HA gene contained single or combinations of mutations were evaluated in vitro. Although the RG1 virus was still the least reactive against hyper-immune serum by HAI testing, mutations G158E and N159D within the Sa antigenic site appeared to play the major role in the altered antigenicity of the A(H1N1)pdm09 virus. These results show that the Sa antigenic site contains the most prominent epitopes susceptible to cause an antigenic drift, escaping actual vaccine protection.

  17. Subclinical antibody-mediated rejection due to anti-human-leukocyte-antigen-DR53 antibody accompanied by plasma cell-rich acute rejection in a patient with cadaveric kidney transplantation.

    Science.gov (United States)

    Katsuma, Ai; Yamamoto, Izumi; Komatsuzaki, Yo; Niikura, Takahito; Kawabe, Mayuko; Okabayashi, Yusuke; Yamakawa, Takafumi; Katsumata, Haruki; Nakada, Yasuyuki; Kobayashi, Akimitsu; Tanno, Yudo; Miki, Jun; Yamada, Hiroki; Ohkido, Ichiro; Tsuboi, Nobuo; Yamamoto, Hiroyasu; Yokoo, Takashi

    2016-07-01

    A 56-year-old man who had undergone cadaveric kidney transplantation 21 months earlier was admitted to our hospital for a protocol biopsy; he had a serum creatinine level of 1.2 mg/dL and no proteinuria. Histological features showed two distinct entities: (i) inflammatory cell infiltration, in the glomerular and peritubular capillaries and (ii) focal, aggressive tubulointerstitial inflammatory cell infiltration, predominantly plasma cells, with mild tubulitis (Banff 13 classification: i2, t1, g2, ptc2, v0, ci1, ct1, cg0, cv0). Immunohistological studies showed mildly positive C4d immunoreactivity in the peritubular capillaries. The patient had donor specific antibody to human-leucocyte-antigen-DR53. We diagnosed him with subclinical antibody-mediated rejection accompanied by plasma cell-rich acute rejection. Both antibody-mediated rejection due to anti- human-leucocyte-antigen -DR53 antibodies and plasma cell-rich acute rejection are known to be refractory and have a poor prognosis. Thus, we started plasma exchange with intravenous immunoglobulin and rituximab for the former and 3 days of consecutive steroid pulse therapy for the latter. Three months after treatment, a follow-up allograft biopsy showed excellent responses to treatment for both histological features. This case report considers the importance of an early diagnosis and appropriate intervention for subclinical antibody-mediated rejection due to donor specific antibody to human-leucocyte-antigen-DR53 and plasma cell-rich acute rejection. © 2016 Asian Pacific Society of Nephrology.

  18. Improving the malaria transmission-blocking activity of a Plasmodium falciparum 48/45 based vaccine antigen by SpyTag/SpyCatcher mediated virus-like display

    DEFF Research Database (Denmark)

    Singh, Susheel K; Thrane, Susan; Janitzek, Christoph M

    2017-01-01

    Malaria is a devastating disease caused by Plasmodium parasites, resulting in almost 0.5 million deaths per year. The Pfs48/45 protein exposed on the P. falciparum sexual stages is one of the most advanced antigen candidates for a transmission-blocking (TB) vaccine in the clinical pipeline. However...

  19. Macropinocytosis in phagocytes: regulation of MHC class-II-restricted antigen presentation in dendritic cells

    OpenAIRE

    Liu, Zhenzhen; Roche, Paul A.

    2015-01-01

    AbstractDendritic cells (DCs) are outstanding antigen presenting cells (APCs) due to their robust ability to internalize extracellular antigens using endocytic processes such as receptor-mediated endocytosis, phagocytosis, and macropinocytosis. Macropinocytosis mediates the non-specific uptake of soluble antigens and occurs in DCs constitutively. Macropinocytosis plays a key role in DC-mediated antigen presentation to T cells against pathogens and the efficiency of macropinocytosis in antigen...

  20. Mycobacterium tuberculosis Latent Antigen Rv2029c from the Multistage DNA Vaccine A39 Drives TH1 Responses via TLR-mediated Macrophage Activation

    Directory of Open Access Journals (Sweden)

    Haibo Su

    2017-11-01

    Full Text Available Targeting of Mycobacterium tuberculosis (MTB latent antigens comprises a crucial strategy for the development of alternative tuberculosis (TB vaccine(s that protects against TB reactivation. Here, we generated a multistage DNA vaccine, A39, containing the early antigens Ag85A and Rv3425 as well as the latency-associated protein Rv2029c, which conferred protective immunity in a pre-exposure mouse model. Moreover, administration of the A39 vaccination after MTB exposure inhibited reactivation and resulted in significantly lower bacterial loads in the lungs and spleen of mice, compared to those in the control population. Subsequently, we investigated the effect of Rv2029c on innate immunity and characterized the molecular details of the interaction of this protein with the host via iTRAQ proteomic and biochemical assay analyses. Rv2029c activated macrophages, triggered the production of pro-inflammatory cytokines, and promoted toll-like receptor/mitogen-activated protein kinase (TLR/MAPK-dependent macrophage apoptosis. Furthermore, Rv2029c treatment enhanced the ability of Mycobacterium bovis Bacillus Calmette-Guérin (BCG-infected macrophages to present antigens to CD4+ T cells in vitro, which correlated with an increase in MHC-II expression. Lastly, Rv2029c-treated macrophages activated T cells, effectively polarized CD4+ and CD8+ T cells to secrete IFN-γ and IL-2, and specifically expanded a population of CD44highCD62LlowCD4+/CD8+ effector/memory cells, indicating that Rv2029c, as a specific recall antigen, contributes to Th1 polarization in T cell immunity. These results suggest that Rv2029c and A39 comprise promising targets for the development of next-generation clinical TB therapeutic vaccines.

  1. Virosomes for antigen and DNA delivery

    NARCIS (Netherlands)

    Daemen, T; de Mare, A; Bungener, L; de Jonge, J; Huckriede, A; Wilschut, J

    2005-01-01

    Specific targeting and delivery as well as the display of antigens on the surface of professional antigen-presenting cells (APCs) are key issues in the design and development of new-generation vaccines aimed at the induction of both humoral and cell-mediated immunity. Prophylactic vaccination

  2. PiggyBac-mediated cancer immunotherapy using EBV-specific cytotoxic T-cells expressing HER2-specific chimeric antigen receptor.

    Science.gov (United States)

    Nakazawa, Yozo; Huye, Leslie E; Salsman, Vita S; Leen, Ann M; Ahmed, Nabil; Rollins, Lisa; Dotti, Gianpietro; Gottschalk, Stephen M; Wilson, Matthew H; Rooney, Cliona M

    2011-12-01

    Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes (CTLs) can be modified to function as heterologous tumor directed effector cells that survive longer in vivo than tumor directed T cells without virus specificity, due to chronic stimulation by viral antigens expressed during persistent infection in seropositive individuals. We evaluated the nonviral piggyBac (PB) transposon system as a platform for modifying EBV-CTLs to express a functional human epidermal growth factor receptor 2-specific chimeric antigen receptor (HER2-CAR) thereby directing virus-specific, gene modified CTLs towards HER2-positive cancer cells. Peripheral blood mononuclear cells (PBMCs) were nucleofected with transposons encoding a HER2-CAR and a truncated CD19 molecule for selection followed by specific activation and expansion of EBV-CTLs. HER2-CAR was expressed in ~40% of T cells after CD19 selection with retention of immunophenotype, polyclonality, and function. HER2-CAR-modified EBV-CTLs (HER2-CTLs) killed HER2-positive brain tumor cell lines in vitro, exhibited transient and reversible increases in HER2-CAR expression following antigen-specific stimulation, and stably expressed HER2-CAR beyond 120 days. Adoptive transfer of PB-modified HER2-CTLs resulted in tumor regression in a murine xenograft model. Our results demonstrate that PB can be used to redirect virus-specific CTLs to tumor targets, which should prolong tumor-specific T cell survival in vivo producing more efficacious immunotherapy.

  3. Tissue-specific transplantation antigen P35B (TSTA3) immune response-mediated metabolism coupling cell cycle to postreplication repair network in no-tumor hepatitis/cirrhotic tissues (HBV or HCV infection) by biocomputation.

    Science.gov (United States)

    Wang, Lin; Huang, Juxiang; Jiang, Minghu; Lin, Hong

    2012-06-01

    We constructed the low-expression tissue-specific transplantation antigen P35B (TSTA3) immune response-mediated metabolism coupling cell cycle to postreplication repair network in no-tumor hepatitis/cirrhotic tissues (HBV or HCV infection) compared with high-expression (fold change ≥ 2) human hepatocellular carcinoma in GEO data set, by using integration of gene regulatory network inference method with gene ontology analysis of TSTA3-activated up- and downstream networks. Our results showed TSTA3 upstream-activated CCNB2, CKS1B, ELAVL3, GAS7, NQO1, NTN1, OCRL, PLA2G1B, REG3A, SSTR5, etc. and TSTA3 downstream-activated BAP1, BRCA1, CCL20, MCM2, MS4A2, NTN1, REG1A, TP53I11, VCAN, SLC16A3, etc. in no-tumor hepatitis/cirrhotic tissues. TSTA3-activated network enhanced the regulation of apoptosis, cyclin-dependent protein kinase activity, cell migration, insulin secretion, transcription, cell division, cell proliferation, DNA replication, postreplication repair, cell differentiation, T-cell homeostasis, neutrophil-mediated immunity, neutrophil chemotaxis, interleukin-8 production, inflammatory response, immune response, B-cell activation, humoral immune response, actin filament organization, xenobiotic metabolism, lipid metabolism, phospholipid metabolism, leukotriene biosynthesis, organismal lipid catabolism, phosphatidylcholine metabolism, arachidonic acid secretion, activation of phospholipase A2, deoxyribonucleotide biosynthesis, heterophilic cell adhesion, activation of MAPK activity, signal transduction by p53 class mediator resulting in transcription of p21 class mediator, G-protein-coupled receptor protein signaling pathway, response to toxin, acute-phase response, DNA damage response, intercellular junction assembly, cell communication, and cell recognition, as a result of inducing immune response-mediated metabolism coupling cell cycle to postreplication repair in no-tumor hepatitis/cirrhotic tissues.

  4. 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.

  5. Recent advances in Major Histocompatibility Complex (MHC class I antigen presentation: Plastic MHC molecules and TAPBPR-mediated quality control [version 1; referees: 4 approved

    Directory of Open Access Journals (Sweden)

    Andy van Hateren

    2017-02-01

    Full Text Available We have known since the late 1980s that the function of classical major histocompatibility complex (MHC class I molecules is to bind peptides and display them at the cell surface to cytotoxic T cells. Recognition by these sentinels of the immune system can lead to the destruction of the presenting cell, thus protecting the host from pathogens and cancer. Classical MHC class I molecules (MHC I hereafter are co-dominantly expressed, polygenic, and exceptionally polymorphic and have significant sequence diversity. Thus, in most species, there are many different MHC I allotypes expressed, each with different peptide-binding specificity, which can have a dramatic effect on disease outcome. Although MHC allotypes vary in their primary sequence, they share common tertiary and quaternary structures. Here, we review the evidence that, despite this commonality, polymorphic amino acid differences between allotypes alter the ability of MHC I molecules to change shape (that is, their conformational plasticity. We discuss how the peptide loading co-factor tapasin might modify this plasticity to augment peptide loading. Lastly, we consider recent findings concerning the functions of the non-classical MHC I molecule HLA-E as well as the tapasin-related protein TAPBPR (transporter associated with antigen presentation binding protein-related, which has been shown to act as a second quality-control stage in MHC I antigen presentation.

  6. Supraphysiologic control over HIV-1 replication mediated by CD8 T cells expressing a re-engineered CD4-based chimeric antigen receptor.

    Directory of Open Access Journals (Sweden)

    Rachel S Leibman

    2017-10-01

    Full Text Available HIV is adept at avoiding naturally generated T cell responses; therefore, there is a need to develop HIV-specific T cells with greater potency for use in HIV cure strategies. Starting with a CD4-based chimeric antigen receptor (CAR that was previously used without toxicity in clinical trials, we optimized the vector backbone, promoter, HIV targeting moiety, and transmembrane and signaling domains to determine which components augmented the ability of T cells to control HIV replication. This re-engineered CAR was at least 50-fold more potent in vitro at controlling HIV replication than the original CD4 CAR, or a TCR-based approach, and substantially better than broadly neutralizing antibody-based CARs. A humanized mouse model of HIV infection demonstrated that T cells expressing optimized CARs were superior at expanding in response to antigen, protecting CD4 T cells from infection, and reducing viral loads compared to T cells expressing the original, clinical trial CAR. Moreover, in a humanized mouse model of HIV treatment, CD4 CAR T cells containing the 4-1BB costimulatory domain controlled HIV spread after ART removal better than analogous CAR T cells containing the CD28 costimulatory domain. Together, these data indicate that potent HIV-specific T cells can be generated using improved CAR design and that CAR T cells could be important components of an HIV cure strategy.

  7. Drug-associated dermatomyositis following ipilimumab therapy: a novel immune-mediated adverse event associated with cytotoxic T-lymphocyte antigen 4 blockade.

    Science.gov (United States)

    Sheik Ali, Shirwa; Goddard, Allison L; Luke, Jason J; Donahue, Hilary; Todd, Derrick J; Werchniak, Andrew; Vleugels, Ruth Ann

    2015-02-01

    Ipilimumab, a human monoclonal antibody targeted against cytotoxic T-lymphocyte antigen 4, has shown promise in the treatment of metastatic melanoma. However, given its mechanism of action, immune-related adverse effects have been reported with this therapy. Despite increasing reports of immune-related adverse effects related to ipilimumab therapy, dermatomyositis associated with this agent has not previously been reported. We describe a woman undergoing treatment with ipilimumab for metastatic melanoma who developed classic cutaneous findings of dermatomyositis along with proximal muscle weakness and elevated muscle enzymes. This case adds to the expanding literature regarding immune-related adverse events associated with ipilimumab. To our knowledge, drug-induced dermatomyositis from ipilimumab has not previously been reported. Physicians should be aware of these potential immune-related adverse events and consider drug-associated dermatomyositis in the differential diagnosis in patients receiving ipilimumab who present with a cutaneous eruption or muscle weakness.

  8. Influenza human monoclonal antibody 1F1 interacts with three major antigenic sites and residues mediating human receptor specificity in H1N1 viruses.

    Directory of Open Access Journals (Sweden)

    Tshidi Tsibane

    Full Text Available Most monoclonal antibodies (mAbs to the influenza A virus hemagglutinin (HA head domain exhibit very limited breadth of inhibitory activity due to antigenic drift in field strains. However, mAb 1F1, isolated from a 1918 influenza pandemic survivor, inhibits select human H1 viruses (1918, 1943, 1947, and 1977 isolates. The crystal structure of 1F1 in complex with the 1918 HA shows that 1F1 contacts residues that are classically defined as belonging to three distinct antigenic sites, Sa, Sb and Ca(2. The 1F1 heavy chain also reaches into the receptor binding site (RBS and interacts with residues that contact sialoglycan receptors and determine HA receptor specificity. The 1F1 epitope is remarkably similar to the previously described murine HC63 H3 epitope, despite significant sequence differences between H1 and H3 HAs. Both antibodies potently inhibit receptor binding, but only HC63 can block the pH-induced conformational changes in HA that drive membrane fusion. Contacts within the RBS suggested that 1F1 may be sensitive to changes that alter HA receptor binding activity. Affinity assays confirmed that sequence changes that switch the HA to avian receptor specificity affect binding of 1F1 and a mAb possessing a closely related heavy chain, 1I20. To characterize 1F1 cross-reactivity, additional escape mutant selection and site-directed mutagenesis were performed. Residues 190 and 227 in the 1F1 epitope were found to be critical for 1F1 reactivity towards 1918, 1943 and 1977 HAs, as well as for 1I20 reactivity towards the 1918 HA. Therefore, 1F1 heavy-chain interactions with conserved RBS residues likely contribute to its ability to inhibit divergent HAs.

  9. ST2 Requires Th2-, but Not Th17-, Type Airway Inflammation in Epicutaneously Antigen-Sensitized Mice

    Directory of Open Access Journals (Sweden)

    Hideaki Morita

    2012-01-01

    Conclusions: The IL-33/ST2 pathway is crucial for Th2-cytokine-mediated eosinophilic, rather than Th17-cytokine-mediated neutrophilic, airway inflammation in mice that had been epicutaneously sensitized with antigens and then challenged with antigen.

  10. 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)

  11. Small interference RNA-mediated knockdown of sperm associated antigen 9 having structural homology with c-Jun N-terminal kinase-interacting protein

    International Nuclear Information System (INIS)

    Rana, Ritu; Jagadish, Nirmala; Garg, Manoj; Mishra, Deepshikha; Dahiya, Neetu; Chaurasiya, Dipak; Suri, Anil

    2006-01-01

    Recently, we reported a novel testis-specific sperm associated antigen 9 (SPAG9) protein, a new member of the JNK-interacting protein family, having a functional role in sperm-egg fusion [N. Jagadish, R. Rana, R. Selvi, D. Mishra, M. Garg, S. Yadav, J.C. Herr, K. Okumura, A. Hasegawa, K. Koyama, A. Suri, Biochem. J. 389 (2005) 73-82]. NCBI Blast searches revealed SPAG9 nucleotide sequence similarities with ESTs of various cancerous tissues. In the present study, we compared the efficiency of two independent SPAG9 specific small interfering RNA (siRNA) constructs, BS/U6/spag9 and BS/U6/spag9-I, to ablate the SPAG9 expression in mammalian cells. A positive correlation between the ratio of target gene versus siRNA and the suppression of SPAG9 expression was observed. Further, the cotransfection of BS/U6/spag9 with pcDNA-SPAG9 and pFlag-CMV2-JNK-3 resulted in specific suppression of SPAG9 without affecting JNK-3 expression. The present investigation will eventually extend the application of SPAG9 siRNA in in vivo targeting experiments that aim to define the SPAG9 functional genomics in tumor and reproductive biology

  12. Suppression of Ongoing Experimental Arthritis by a Chinese Herbal Formula (Huo-Luo-Xiao-Ling Dan Involves Changes in Antigen-Induced Immunological and Biochemical Mediators of Inflammation

    Directory of Open Access Journals (Sweden)

    Ying-Hua Yang

    2011-01-01

    Full Text Available Rheumatoid arthritis (RA is one of the major autoimmune diseases of global prevalence. The use of the anti-inflammatory drugs for the treatment of RA is associated with severe adverse reactions and toxicity. This limitation has necessitated the search for novel therapeutic products. We report here a traditional Chinese medicine-based herbal formula, Huo luo xiao ling dan (HLXL, which has potent antiarthritic activity as validated in the rat adjuvant-induced arthritis (AA model. HLXL (2.3 g/Kg was fed to Lewis (RT.11 rats daily by gavage beginning at the onset of arthritis and then continued through the observation period. HLXL inhibited the severity of ongoing AA. This suppression of arthritis was associated with significant alterations in the T cell proliferative and cytokine responses as well as the antibody response against the disease-related antigen, mycobacterial heat-shock protein 65 (Bhsp65. There was a reduction in the level of the proinflammatory cytokines IL-17 and IL-1β but enhancement of the anti-inflammatory cytokine IL-10 level. In addition, there was inhibition of both the anti-Bhsp65 antibody response and the serum level of nitric oxide. Thus, HLXL is a promising CAM modality for further testing in RA patients.

  13. Bcl-xL regulates CD1d-mediated antigen presentation to NKT cells by altering CD1d trafficking through the endocytic pathway.

    Science.gov (United States)

    Subrahmanyam, Priyanka B; Carey, Gregory B; Webb, Tonya J

    2014-09-01

    NKT cells are a unique subset of T cells that recognize glycolipid Ags presented in the context of CD1d molecules. NKT cells mount strong antitumor responses and are a major focus in developing effective cancer immunotherapy. It is known that CD1d molecules are constantly internalized from the cell surface, recycled through the endocytic compartments, and re-expressed on the cell surface. However, little is known about the regulation of CD1d-mediated Ag processing and presentation in B cell lymphoma. Prosurvival factors of the Bcl-2 family, such as Bcl-xL, are often upregulated in B cell lymphomas and are intimately linked to sphingolipid metabolism, as well as the endocytic compartments. We hypothesized that Bcl-xL can regulate CD1d-mediated Ag presentation to NKT cells. We found that overexpression or induction of Bcl-xL led to increased Ag presentation to NKT cells. Conversely, the inhibition or knockdown of Bcl-xL led to decreased NKT cell activation. Furthermore, knockdown of Bcl-xL resulted in the loss of CD1d trafficking to lysosome-associated membrane protein 1(+) compartments. Rab7, a late endosomal protein, was upregulated and CD1d molecules accumulated in the Rab7(+) late endosomal compartment. These results demonstrate that Bcl-xL regulates CD1d-mediated Ag processing and presentation to NKT cells by altering the late endosomal compartment and changing the intracellular localization of CD1d. Copyright © 2014 by The American Association of Immunologists, Inc.

  14. Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) mediates periarticular bone loss, but not joint destruction, in murine antigen-induced arthritis.

    Science.gov (United States)

    Shimizu, Tomohiro; Takahata, Masahiko; Kameda, Yusuke; Endo, Tsutomu; Hamano, Hiroki; Hiratsuka, Shigeto; Ota, Masahiro; Iwasaki, Norimasa

    2015-10-01

    Osteoclastogenesis requires immunoreceptor tyrosine-based activation motif signaling. Multiple immunoreceptors associated with immunoreceptor tyrosine-based activation motif adaptor proteins, including DNAX-activating protein 12 kDa (DAP12) and Fc receptor common γ (FcRγ), have been identified in osteoclast lineage cells, and some are involved in arthritis-induced bone destruction. Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) is an immunoreceptor that regulates osteoclast development and bone resorption in association with DAP12. Whether Siglec-15 is involved in arthritis-induced bone lesions, however, remains unknown. Here we used a murine antigen-induced arthritis model to examine the role of Siglec-15 in the development of bone lesions induced by joint inflammation. Arthritis was unilaterally induced in the knee joints of 8-week-old female wild-type (WT) and Siglec-15(-/-) mice, and the contralateral knees were used as a control. The degree of joint inflammation, and cartilage and subchondral bone destruction in Siglec-15(-/-) mice was comparable to that in WT mice, indicating that Siglec-15 is not involved in the development of arthritis and concomitant cartilage and subchondral bone destruction. On the other hand, the degree of periarticular bone loss in the proximal tibia of the arthritic knee was significantly lower in Siglec-15(-/-) mice compared to WT mice. Although osteoclast formation in the metaphysis was enhanced in both WT and Siglec-15(-/-) mice after arthritis induction, mature multinucleated osteoclast formation was impaired in Siglec-15(-/-) mice, indicating impaired osteoclast bone resorptive function in the periarticular regions of the arthritic joint in Siglec-15(-/-) mice. Confirming this result, Siglec-15(-/-) primary unfractionated bone marrow cells harvested from arthritic femurs and tibiae failed to develop into mature multinuclear osteoclasts. Our findings suggest that Siglec-15 is a therapeutic target for periarticular

  15. Use of retroviral-mediated gene transfer to deliver and test function of chimeric antigen receptors in human T-cells

    Directory of Open Access Journals (Sweden)

    Ana C. Parente-Pereira

    2014-07-01

    Full Text Available Chimeric antigen receptors (CARs are genetically delivered fusion molecules that elicit T-cell activation upon binding of a native cell surface molecule. These molecules can be used to generate a large number of memory and effector T-cells that are capable of recognizing and attacking tumor cells. Most commonly, stable CAR expression is achieved in T-cells using retroviral vectors. In the method described here, retroviral vectors are packaged in a two-step procedure. First, H29D human retroviral packaging cells (a derivative of 293 cells are transfected with the vector of interest, which is packaged transiently in vesicular stomatitis virus (VSV G pseudotyped particles. These particles are used to deliver the vector to PG13 cells, which achieve stable packaging of gibbon ape leukaemia virus (GALV-pseudotyped particles that are suitable for infection of human T-cells. The key advantage of the method reported here is that it robustly generates polyclonal PG13 cells that are 100% positive for the vector of interest. This means that efficient gene transfer may be repeatedly achieved without the need to clone individual PG13 cells for experimental pre-clinical testing. To achieve T-cell transduction, cells must first be activated using a non-specific mitogen. Phytohemagglutinin (PHA provides an economic and robust stimulus to achieve this. After 48-72 h, activated T-cells and virus-conditioned medium are mixed in RetroNectin-coated plasticware, which enhances transduction efficiency. Transduced cells are analyzed for gene transfer efficiency by flow cytometry 48 h following transduction and may then be tested in several assays to evaluate CAR function, including target-dependent cytotoxicity, cytokine production and proliferation.

  16. Antibody-mediated targeting of antigen to C-type lectin-like receptors Clec9A and Clec12A elicits different vaccination outcomes.

    Science.gov (United States)

    Macri, Christophe; Dumont, Claire; Panozza, Scott; Lahoud, Mireille H; Caminschi, Irina; Villadangos, Jose A; Johnston, Angus P R; Mintern, Justine D

    2017-01-01

    Targeting antigen (Ag) to dendritic cell (DC) surface receptors is a potential new mode of vaccination. C-type lectin-like receptors Clec9A and Clec12A are attractive receptor targets however their targeting in vivo elicits significantly different outcomes for unknown reasons. To gain insight into the mechanisms responsible, we have examined the intrinsic capacity of Clec9A and Clec12A to elicit MHC I and MHC II Ag presentation following ex vivo targeting with primary murine DC. Both receptors exhibited high rates of internalization by CD8 + DCs, while Clec12A delivered a significantly higher Ag owing to its higher expression level. Targeting Ag to immature CD8 + DCs via both Clec9A and Clec12A failed to elicit MHC I cross-presentation above that of controls, while Clec12A was the superior receptor to target following CD8 + DC maturation. CD8 - DCs were unable to elicit MHC I cross-presentation regardless of the receptor targeted. For MHC II presentation, targeting Ag to Clec12A enabled significant responses by both immature CD8 + and CD8 - DCs, whereas Clec9A did not elicit significant MHC II Ag presentation by either DC subset, resting or mature. Therefore, Clec9A and Clec12A exhibit different intrinsic capacities to elicit MHC I and MHC II presentation following direct Ag targeting, though they can only elicit MHC I responses if the DC expressing the receptor is equipped with the capacity to cross-present. Our conclusions have consequences for the exploitation of these receptors for vaccination purposes, in addition to providing insight into their roles as Ag targets in vivo. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. 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

  18. Helicobacter pylori antigen HP0986 (TieA) interacts with cultured gastric epithelial cells and induces IL8 secretion via NF-κB mediated pathway.

    Science.gov (United States)

    Devi, Savita; Ansari, Suhail A; Vadivelu, Jamuna; Mégraud, Francis; Tenguria, Shivendra; Ahmed, Niyaz

    2014-02-01

    The envisaged roles and partly understood functional properties of Helicobacter pylori protein HP0986 are significant in the context of proinflammatory and or proapoptotic activities, the two important facilitators of pathogen survival and persistence. In addition, sequence analysis of this gene predicts a restriction endonuclease function which remained unknown thus far. To evaluate the role of HP0986 in gastric inflammation, we studied its expression profile using a large number of clinical isolates but a limited number of biopsies and patient sera. Also, we studied antigenic role of HP0986 in altering cytokine responses of human gastric epithelial (AGS) cells including its interaction with and localization within the AGS cells. For in vitro expression study of HP0986, 110 H. pylori clinical isolates were cultured from patients with functional dyspepsia. For expression analysis by qRT PCR of HP0986, 10 gastric biopsy specimens were studied. HP0986 was also used to detect antibodies in patient sera. AGS cells were incubated with recombinant HP0986 to determine cytokine response and NF-κB activation. Transient transfection with HP0986 cloned in pEGFPN1 was used to study its subcellular localization or homing in AGS cells. Out of 110 cultured H. pylori strains, 34 (31%) were positive for HP0986 and this observation was correlated with in vitro expression profiles. HP0986 mRNA was detected in 7 of the 10 biopsy specimens. Further, HP0986 induced IL-8 secretion in gastric epithelial cells in a dose and time-dependent manner via NF-κB pathway. Serum antibodies against HP0986 were positively associated with H. pylori positive patients. Transient transfection of AGS cells revealed both cytoplasmic and nuclear localization of HP0986. HP0986 was moderately prevalent in clinical isolates and its expression profile in cultures and gastric biopsies points to its being naturally expressed. Collective observations including the induction of IL-8 via TNFR1 and NF

  19. Stable interaction between the human proliferating cell nuclear antigen loader complex Ctf18-replication factor C (RFC) and DNA polymerase {epsilon} is mediated by the cohesion-specific subunits, Ctf18, Dcc1, and Ctf8.

    Science.gov (United States)

    Murakami, Takeshi; Takano, Ryuji; Takeo, Satoshi; Taniguchi, Rina; Ogawa, Kaori; Ohashi, Eiji; Tsurimoto, Toshiki

    2010-11-05

    One of the proliferating cell nuclear antigen loader complexes, Ctf18-replication factor C (RFC), is involved in sister chromatid cohesion. To examine its relationship with factors involved in DNA replication, we performed a proteomics analysis of Ctf18-interacting proteins. We found that Ctf18 interacts with a replicative DNA polymerase, DNA polymerase ε (pol ε). Co-immunoprecipitation with recombinant Ctf18-RFC and pol ε demonstrated that their binding is direct and mediated by two distinct interactions, one weak and one stable. Three subunits that are specifically required for cohesion in yeast, Ctf18, Dcc1, and Ctf8, formed a trimeric complex (18-1-8) and together enabled stable binding with pol ε. The C-terminal 23-amino acid stretch of Ctf18 was necessary for the trimeric association of 18-1-8 and was required for the stable interaction. The weak interaction was observed with alternative loader complexes including Ctf18-RFC(5), which lacks Dcc1 and Ctf8, suggesting that the common loader structures, including the RFC small subunits (RFC2-5), are responsible for the weak interaction. The two interaction modes, mediated through distinguishable structures of Ctf18-RFC, both occurred through the N-terminal half of pol ε, which includes the catalytic domain. The addition of Ctf18-RFC or Ctf18-RFC(5) to the DNA synthesis reaction caused partial inhibition and stimulation, respectively. Thus, Ctf18-RFC has multiple interactions with pol ε that promote polymorphic modulation of DNA synthesis. We propose that their interaction alters the DNA synthesis mode to enable the replication fork to cooperate with the establishment of cohesion.

  20. Neutrophil transmigration mediated by the neutrophil-specific antigen CD177 is influenced by the endothelial S536N dimorphism of platelet endothelial cell adhesion molecule-1.

    Science.gov (United States)

    Bayat, Behnaz; Werth, Silke; Sachs, Ulrich J H; Newman, Debra K; Newman, Peter J; Santoso, Sentot

    2010-04-01

    The human neutrophil-specific adhesion molecule CD177 (also known as the NB1 alloantigen) becomes upregulated on the cell surface in a number of inflammatory settings. We recently showed that CD177 functions as a novel heterophilic counterreceptor for the endothelial junctional protein PECAM-1 (CD31), an interaction that is mediated by membrane-proximal PECAM-1 IgD 6, which is known to harbor an S(536)N single nucleotide polymorphism of two major isoforms V(98)N(536)G(643) and L(98)S(536)R(643) and a yet-to-be-determined region on CD177. In vitro transendothelial migration experiments revealed that CD177(+) neutrophils migrated significantly faster through HUVECs expressing the LSR, compared with the VNG, allelic variant of PECAM-1 and that this correlated with the decreased ability of anti-PECAM-1 Ab of ITIM tyrosine phosphorylation in HUVECs expressing the LSR allelic variant relative to the VNG allelic variant. Moreover, engagement of PECAM-1 with rCD177-Fc (to mimic heterophilic CD177 binding) suppressed Ab-induced tyrosine phosphorylation to a greater extent in cells expressing the LSR isoform compared with the VNG isoform, with a corresponding increased higher level of beta-catenin phosphorylation. These data suggest that heterophilic PECAM-1/CD177 interactions affect the phosphorylation state of PECAM-1 and endothelial cell junctional integrity in such a way as to facilitate neutrophil transmigration in a previously unrecognized allele-specific manner.

  1. Strong interferon-gamma mediated cellular immunity to scrub typhus demonstrated using a novel whole cell antigen ELISpot assay in rhesus macaques and humans.

    Directory of Open Access Journals (Sweden)

    Manutsanun Sumonwiriya

    2017-09-01

    Full Text Available Scrub typhus is a febrile infection caused by the obligate intracellular bacterium Orientia tsutsugamushi, which causes significant morbidity and mortality across the Asia-Pacific region. The control of this vector-borne disease is challenging due to humans being dead-end hosts, vertical maintenance of the pathogen in the vector itself, and a potentially large rodent reservoir of unclear significance, coupled with a lack of accurate diagnostic tests. Development of an effective vaccine is highly desirable. This however requires better characterization of the natural immune response of this neglected but important disease. Here we implement a novel IFN-γ ELISpot assay as a tool for studying O. tsutsugamushi induced cellular immune responses in an experimental scrub typhus rhesus macaque model and human populations. Whole cell antigen for O. tsutsugamushi (OT-WCA was prepared by heat inactivation of Karp-strain bacteria. Rhesus macaques were infected intradermally with O. tsutsugamushi. Freshly isolated peripheral blood mononuclear cells (PBMC from infected (n = 10 and uninfected animals (n = 5 were stimulated with OT-WCA, and IFN-γ secreting cells quantitated by ELISpot assay at five time points over 28 days. PBMC were then assayed from people in a scrub typhus-endemic region of Thailand (n = 105 and responses compared to those from a partially exposed population in a non-endemic region (n = 14, and to a naïve population in UK (n = 12. Mean results at Day 0 prior to O. tsutsugamushi infection were 12 (95% CI 0-25 and 15 (2-27 spot-forming cells (SFC/106 PBMC for infected and control macaques respectively. Strong O. tsutsugamushi-specific IFN-γ responses were seen post infection, with ELISpot responses 20-fold higher than baseline at Day 7 (mean 235, 95% CI 200-270 SFC/106 PBMC, 105-fold higher at Day 14 (mean 1261, 95% CI 1,097-1,425 SFC/106 PBMC, 125-fold higher at Day 21 (mean 1,498, 95% CI 1,496-1,500 SFC/106 PBMC and 118-fold higher at

  2. Myosins 1 and 6, myosin light chain kinase, actin and microtubules cooperate during antibody-mediated internalisation and trafficking of membrane-expressed viral antigens in feline infectious peritonitis virus infected monocytes.

    Science.gov (United States)

    Dewerchin, Hannah L; Desmarets, Lowiese M; Noppe, Ytse; Nauwynck, Hans J

    2014-02-12

    Monocytes infected with feline infectious peritonitis virus, a coronavirus, express viral proteins in their plasma membranes. Upon binding of antibodies, these proteins are quickly internalised through a new clathrin- and caveolae-independent internalisation pathway. By doing so, the infected monocytes can escape antibody-dependent cell lysis. In the present study, we investigated which kinases and cytoskeletal proteins are of importance during internalisation and subsequent intracellular transport. The experiments showed that myosin light chain kinase (MLCK) and myosin 1 are crucial for the initiation of the internalisation. With co-localisation stainings, it was found that MLCK and myosin 1 co-localise with antigens even before internalisation started. Myosin 6 co-localised with the internalising complexes during passage through the cortical actin, were it might play a role in moving or disintegrating actin filaments, to overcome the actin barrier. One minute after internalisation started, vesicles had passed the cortical actin, co-localised with microtubules and association with myosin 6 was lost. The vesicles were further transported over the microtubules and accumulated at the microtubule organising centre after 10 to 30 min. Intracellular trafficking over microtubules was mediated by MLCK, myosin 1 and a small actin tail. Since inhibiting MLCK with ML-7 was so efficient in blocking the internalisation pathway, this target can be used for the development of a new treatment for FIPV.

  3. DNA fragmentation and cell death mediated by T cell antigen receptor/CD3 complex on a leukemia T cell line.

    Science.gov (United States)

    Takahashi, S; Maecker, H T; Levy, R

    1989-10-01

    An anti-T cell receptor (TcR) monoclonal antibody (mAb), LC4, directed against a human leukemic T cell line, SUP-T13, caused DNA fragmentation ("apoptosis") and cell death upon binding to this cell line. Cross-linking of receptor molecules was necessary for this effect since F(ab')2, but not Fab', fragments of LC4 could induce cell death. Five anti-CD3 mAb tested also caused apoptosis, but only when they were presented on a solid phase. Interestingly, soluble anti-CD3 mAb induced calcium flux and had an additive effect on the calcium flux and interleukin 2 receptor expression induced by LC4, but these anti-CD3 mAb reversed the growth inhibition and apoptosis caused by LC4. The calcium ionophore A23187, but not the protein kinase C activator phorbol 12-myristate 13-acetate (PMA), also induced apoptosis, suggesting that protein kinase C activation alone does not cause apoptosis, although PMA is growth inhibitory. These results suggest that two distinct biological phenomena can accompany stimulation of the TcR/CD3 complex. In both cases, calcium flux and interleukin 2 receptor expression is induced, but only in one case is apoptosis and cell death seen. The signal initiating apoptosis can be selectively prevented by binding CD3 portion of the receptor in this cell line. This difference in signals mediated by the TcR/CD3 complex may be important in explaining the process of thymic selection, as well as in choosing anti-TcR mAb for therapeutic use.

  4. Nude mice produce a T cell-derived antigen-binding factor that mediates the early component of delayed-type hypersensitivity.

    Science.gov (United States)

    Herzog, W R; Meade, R; Pettinicchi, A; Ptak, W; Askenase, P W

    1989-03-15

    The elicitation of delayed-type hypersensitivity (DTH) reactions in mice is caused by the sequential action of two different T cells. An early-acting, DTH-initiating T cell produces an Ag-specific T cell factor, that is analogous to IgE antibody and initiates DTH by sensitizing the local tissues for release of the vasoactive amine serotonin. In picryl chloride or oxazolone contact sensitivity, this T cell factor is Ag-specific, but MHC unrestricted. We, therefore, hypothesized that DTH-initiating T cells are primitive T cells with Ag receptors that can bind Ag without MHC restriction. In order to characterize the origin of this DTH-initiating T cell and the conditions that are necessary for its development, we contact-sensitized various strains of immunodeficient mice. Surprisingly, we found that the early phase of DTH was present in athymic nude mice. In contrast, the early component of DTH was absent in mice with severe combined immunodeficiency. These mice lack T and B cells, but have NK cells. These findings suggested that the early component of DTH was not caused by NK cells, and was caused by cells belonging to a lineage from a rearranging gene family. The early component of DTH in nude mice was Ag specific, was caused by MHC unrestricted Thy-1+ T cells, and was mediated by Ag-binding, Ag-specific T cell factors. We found that DTH-initiating, T cell-derived, Ag-binding molecules from nude mice and normal CBA/J mice had the same functional properties. The early component of DTH was elicited in two different systems (contact sensitivity and SRBC-specific DTH) in two strains of nude mice (BALB/c athymic nudes and CByB6F1/J-nu) from two different suppliers, but not in BALB/c and athymic nudes from a third supplier. From these findings we concluded that DTH-initiating T cells, which produce IgE-like Ag-specific T cell factors, are present in some strains of athymic nude mice and thus are relatively thymic independent T cells.

  5. 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.

  6. An immobilization antigen gene of the fish-parasitic protozoan Ichthyophthirius multifiliis strain ARS-6

    Science.gov (United States)

    Ichthyophthirius multifiliis (Ich) is a severe fish parasite that causes ‘white spot’ disease in many freshwater fish and leads to high mortality. The antigens on the parasite surface are involved in the antibody-mediated immobilization and hence designated as immobilization antigens (i-antigens). ...

  7. 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

  8. 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

  9. Macropinocytosis in phagocytes: regulation of MHC class-II-restricted antigen presentation in dendritic cells.

    Science.gov (United States)

    Liu, Zhenzhen; Roche, Paul A

    2015-01-01

    Dendritic cells (DCs) are outstanding antigen presenting cells (APCs) due to their robust ability to internalize extracellular antigens using endocytic processes such as receptor-mediated endocytosis, phagocytosis, and macropinocytosis. Macropinocytosis mediates the non-specific uptake of soluble antigens and occurs in DCs constitutively. Macropinocytosis plays a key role in DC-mediated antigen presentation to T cells against pathogens and the efficiency of macropinocytosis in antigen capture is regulated during the process of DC maturation. Here, we review the methods to study macropinocytosis, describe our current knowledge of the regulatory mechanisms of antigen uptake via macropinocytosis and the intracellular trafficking route followed by macropinocytosed antigens, and discuss the significance of macropinocytosis for DC function.

  10. Macropinocytosis in Phagocytes: Regulation of MHC Class-II-Restricted Antigen Presentation in Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Zhenzhen eLiu

    2015-01-01

    Full Text Available AbstractDendritic cells (DCs are outstanding antigen presenting cells (APCs due to their robust ability to internalize extracellular antigens using endocytic processes such as receptor-mediated endocytosis, phagocytosis, and macropinocytosis. Macropinocytosis mediates the non-specific uptake of soluble antigens and occurs in DCs constitutively. Macropinocytosis plays a key role in DC-mediated antigen presentation to T cells against pathogens and the efficiency of macropinocytosis in antigen capture is regulated during the process of DC maturation. Here, we review the methods to study macropinocytosis, describe our current knowledge of the regulatory mechanisms of antigen uptake via macropinocytosis and the intracellular trafficking route followed by macropinocytosed antigens, and discuss the significance of macropinocytosis for DC function.

  11. 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

  12. Presensitization to Ascaris antigens promotes induction of mite-specific IgE upon mite antigen inhalation in mice.

    Science.gov (United States)

    Suzuki, Mayu; Hara, Mutsuko; Ichikawa, Saori; Kamijo, Seiji; Nakazawa, Takuya; Hatanaka, Hideki; Akiyama, Kazuo; Ogawa, Hideoki; Okumura, Ko; Takai, Toshiro

    2016-01-01

    Patients with house dust mite (HDM) allergy or Ascariasis produce serum IgE specific to the antigens of HDM or nematode Ascaris, respectively. Although human IgE cross-reactivity has been reported between HDM and Ascaris antigens, it remains unclear whether it contributes to the pathogenesis of allergic diseases. We herein investigated the induction of cross-reactive antibodies and T cells in mice and effects of airway exposure to HDM antigens after preimmunization with Ascaris antigens. Mice were intraperitoneally immunized with HDM or Ascaris antigens with Alum, followed by the intranasal administration of HDM antigens. Serum antigen-specific IgE and IgG were measured by ELISA. Cytokine release in splenocytes from Ascaris-immunized mice upon in vitro restimulation with HDM antigens were measured by ELISA. Immunization with Ascaris or HDM antigens induced cross-reactive IgG1. Splenocytes from Ascaris-immunized mice released IL-5 and IL-13 in response to the restimulation with HDM antigens. Subsequent airway exposure to HDM antigens promoted the induction of HDM-specific IgE and upregulation of HDM-specific IgG1 in Ascaris-immunized mice, whereas these responses were not detected or smaller without the Ascaris presensitization. We demonstrated that the immunization of naïve mice with Ascaris antigens induced production of antibodies and differentiation of Th2 cells, which were cross-reactive to HDM antigens, and accelerated induction of serum HDM-specific IgE upon subsequent airway exposure to HDM antigens in mice. These results suggest that sensitization to HDM towards IgE-mediated allergic diseases is faster in individuals with a previous history of Ascaris infection than in those without presensitization to Ascaris. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  13. 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

  14. Montanide™ ISA 71 VG adjuvant enhances antibody and cell-mediated immune responses to profilin subunit antigen vaccination and promotes protection against Eimeria acervulina and Eimeria tenella. Experimental Parasitology

    Science.gov (United States)

    The present study was conducted to investigate the immunoenhancing effects of MontanideTM ISA 71 VG adjuvant on profilin subunit antigen vaccination. Broiler chickens were immunized subcutaneously with a purified Eimeria acervulina recombinant profilin protein, either alone or mixed with ISA 71 VG, ...

  15. Addendum to “Novel antigens for detection of cell mediated immune responses to Mycobacterium avium subsp. paratuberculosis infection in cattle” [Vet. Immunol. Immunopathol. 143 (2011) 46–54

    DEFF Research Database (Denmark)

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

    2012-01-01

    In the original published paper, the identities of the 14 novel antigens used were not revealed. Their identities are now available to supplement Table 1 in the original paper, as listed in Table S1, which also includes the names of the corresponding M. tuberculosis and M. bovis orthologs. In Table...

  16. Methods for examination of antigenicity of heterogeneous polymerized hemoglobin

    International Nuclear Information System (INIS)

    Chen Lin; Zhang Yadong; Bu Fengrong; Zhang Jingang

    2004-01-01

    Objective: To choose and establish the methods for examination of heterogeneous polymerized hemoglobin in order to offer the reference for evaluating the antigenicity of heterogeneous polymerized hemoglobin against human. Methods: Antigenicity of heterogeneous polymerized hemoglobin was examined for hypersensitivity, cell-mediated immunity reaction, humoral immunity reaction and cross-reaction of antigen. Results: The rabbit and guinea pig did not give rise to hypersensitivity. In immunized rabbits, the level of serum total IgG was normal, but the level of serum specific IgG was high. The examination of B lymphocytes showed that there was no significant difference (P>0.05) in comparison with control. Cross-reaction of antigen proved that bovine hemoglobin had cross-reaction with human hemoglobin. Suggesting that they may be homologous, the level of the serum specific antibody is high in the immunized animal. According to the immunology theories, the polymerized hemoglobin has antigenicity. (authors)

  17. 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.

  18. Antigen binding characteristics of immunoglobulin free light chains: crosslinking by antigen is essential to induce allergic inflammation.

    Directory of Open Access Journals (Sweden)

    Marco Thio

    Full Text Available Beside the production of complete immunoglobulins IgG, IgE, IgA, IgM and IgD, consisting of tetrameric heterodimers of immunoglobulin heavy and light chains, B cells also secrete immunoglobulin free light chains (Ig-fLC. Previous studies showed that Ig-fLCs are able to induce immediate hypersensitivity reactions. It is apparent that recognition and binding of antigen are crucial steps in the onset of these inflammatory responses. In this study, the binding characteristics of Ig-fLC to antigen were further investigated using various biochemical approaches. In addition, we investigated whether antigen-mediated crosslinking of Ig-fLC is required to initiate allergic skin inflammation in vivo. Our study shows that binding of Ig-fLCs to antigen can be measured with different experimental setups. Surface plasmon resonance analysis showed real-time antigen binding characteristics. Specific antigen binding by Ig-fLCs was further detected using immunoblotting and ELISA. Using the ELISA-based assay, a binding affinity of 76.9±3.8 nM was determined for TNP-specific Ig-fLC. Antigen-induced ear swelling in mice passively sensitized with trinitrophenol-specific Ig-fLC was inhibited when multivalent antigen was combined with excess of monovalent antigen during challenge. We conclude that Ig-fLCs are able to interact with antigen, a prerequisite for antigen-specific cellular activation. In analogy to antigen-specific Fc receptor-induced mast cell activation, crosslinking of Ig-fLCs is necessary to initiate a local allergic response.

  19. 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

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  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. 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

  11. 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.)

  12. Association of Pneumococcal Protein Antigen Serology With Age and Antigenic Profile of Colonizing Isolates.

    Science.gov (United States)

    Azarian, Taj; Grant, Lindsay R; Georgieva, Maria; Hammitt, Laura L; Reid, Raymond; Bentley, Stephen D; Goldblatt, David; Santosham, Mathuran; Weatherholtz, Robert; Burbidge, Paula; Goklish, Novalene; Thompson, Claudette M; Hanage, William P; O'Brien, Kate L; Lipsitch, Marc

    2017-03-01

    Several Streptococcus pneumoniae proteins play a role in pathogenesis and are being investigated as vaccine targets. It is largely unknown whether naturally acquired antibodies reduce the risk of colonization with strains expressing a particular antigenic variant. Serum immunoglobulin G (IgG) titers to 28 pneumococcal protein antigens were measured among 242 individuals aged - 30 days after serum collection, and the antigen variant in each pneumococcal isolate was determined using genomic data. We assessed the association between preexisting variant-specific antibody titers and subsequent carriage of pneumococcus expressing a particular antigen variant. Antibody titers often increased across pediatric groups before decreasing among adults. Individuals with low titers against group 3 pneumococcal surface protein C (PspC) variants were more likely to be colonized with pneumococci expressing those variants. For other antigens, variant-specific IgG titers do not predict colonization. We observed an inverse association between variant-specific antibody concentration and homologous pneumococcal colonization for only 1 protein. Further assessment of antibody repertoires may elucidate the nature of antipneumococcal antibody-mediated mucosal immunity while informing vaccine development. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  13. Methamphetamine inhibits antigen processing, presentation, and phagocytosis.

    Directory of Open Access Journals (Sweden)

    Zsolt Tallóczy

    2008-02-01

    Full Text Available Methamphetamine (Meth is abused by over 35 million people worldwide. Chronic Meth abuse may be particularly devastating in individuals who engage in unprotected sex with multiple partners because it is associated with a 2-fold higher risk for obtaining HIV and associated secondary infections. We report the first specific evidence that Meth at pharmacological concentrations exerts a direct immunosuppressive effect on dendritic cells and macrophages. As a weak base, Meth collapses the pH gradient across acidic organelles, including lysosomes and associated autophagic organelles. This in turn inhibits receptor-mediated phagocytosis of antibody-coated particles, MHC class II antigen processing by the endosomal-lysosomal pathway, and antigen presentation to splenic T cells by dendritic cells. More importantly Meth facilitates intracellular replication and inhibits intracellular killing of Candida albicans and Cryptococcus neoformans, two major AIDS-related pathogens. Meth exerts previously unreported direct immunosuppressive effects that contribute to increased risk of infection and exacerbate AIDS pathology.

  14. Co-incubation with IL-18 potentiates antigen-specific IFN-γ response in a whole-blood stimulation assay for measurement of cell-mediated immune responses in pigs experimentally infected with Lawsonia intracellularis

    DEFF Research Database (Denmark)

    Riber, Ulla; Boesen, Henriette Toft; Jakobsen, Jeanne Toft

    2011-01-01

    The whole-blood interferon-gamma (IFN-γ) assay is a quantitative in-vitro assay for a direct read out of Ag-specific cell-mediated immune (CMI) responses to infectious diseases. The IFN-γ assay is robust in severe intracellular infections like Brucella or mycobacteria, but more difficult to evalu......The whole-blood interferon-gamma (IFN-γ) assay is a quantitative in-vitro assay for a direct read out of Ag-specific cell-mediated immune (CMI) responses to infectious diseases. The IFN-γ assay is robust in severe intracellular infections like Brucella or mycobacteria, but more difficult...

  15. Vaccination with an adenoviral vector encoding the tumor antigen directly linked to invariant chain induces potent CD4(+) T-cell-independent CD8(+) T-cell-mediated tumor control

    DEFF Research Database (Denmark)

    Sorensen, Maria R; Holst, Peter J; Pircher, Hanspeter

    2009-01-01

    of the vaccine antigen to invariant chain (Ii). To evaluate this strategy we used a mouse model, in which an immunodominant epitope (GP33) of the LCMV glycoprotein (GP) represents the tumor-associated neoantigen. Prophylactic vaccination of C57BL/6 mice with a replication-deficient human adenovirus 5 vector...... vaccination with adenovirus expressing GP alone (Ad-GP), or GP and Ii unlinked (Ad-GP+Ii). Ad-Ii-GP- induced tumor control depended on an improved generation of the tumor-associated neoantigen-specific CD8(+) T-cell response and was independent of CD4(+) T cells. IFN-gamma was shown to be a key player during...

  16. The Antigen Presenting Cells Instruct Plasma Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Wei eXu

    2014-01-01

    Full Text Available The professional antigen presenting cells (APCs, including many subsets of dendritic cells and macrophages, not only mediate prompt but nonspecific response against microbes, but also bridge the antigen-specific adaptive immune response through antigen presentation. In the latter, typically activated B cells acquire cognate signals from T helper cells in the germinal center of lymphoid follicles to differentiate into plasma cells, which generate protective antibodies. Recent advances have revealed that many APC subsets provide not only signal 1 (the antigen, but also signal 2 to directly instruct the differentiation process of plasma cells in a T cell-independent manner. Herein, the different signals provided by these APC subsets to direct B cell proliferation, survival, class switching and terminal differentiation are discussed. We furthermore propose that the next generation of vaccines for boosting antibody response could be designed by targeting APCs.

  17. The antigen presenting cells instruct plasma cell differentiation.

    Science.gov (United States)

    Xu, Wei; Banchereau, Jacques

    2014-01-06

    The professional antigen presenting cells (APCs), including many subsets of dendritic cells and macrophages, not only mediate prompt but non-specific response against microbes, but also bridge the antigen-specific adaptive immune response through antigen presentation. In the latter, typically activated B cells acquire cognate signals from T helper cells in the germinal center of lymphoid follicles to differentiate into plasma cells (PCs), which generate protective antibodies. Recent advances have revealed that many APC subsets provide not only "signal 1" (the antigen), but also "signal 2" to directly instruct the differentiation process of PCs in a T-cell-independent manner. Herein, the different signals provided by these APC subsets to direct B cell proliferation, survival, class switching, and terminal differentiation are discussed. We furthermore propose that the next generation of vaccines for boosting antibody response could be designed by targeting APCs.

  18. 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.

  19. Evasion and subversion of antigen presentation by Mycobacterium tuberculosis.

    Science.gov (United States)

    Baena, A; Porcelli, S A

    2009-09-01

    Mycobacterium tuberculosis is one of the most successful of human pathogens and has acquired the ability to establish latent or progressive infection and persist even in the presence of a fully functioning immune system. The ability of M. tuberculosis to avoid immune-mediated clearance is likely to reflect a highly evolved and coordinated program of immune evasion strategies, including some that interfere with antigen presentation to prevent or alter the quality of T-cell responses. Here, we review an extensive array of published studies supporting the view that antigen presentation pathways are targeted at many points by pathogenic mycobacteria. These studies show the multiple potential mechanisms by which M. tuberculosis may actively inhibit, subvert or otherwise modulate antigen presentation by major histocompatibility complex class I, class II and CD1 molecules. Unraveling the mechanisms by which M. tuberculosis evades or modulates antigen presentation is of critical importance for the development of more effective new vaccines based on live attenuated mycobacterial strains.

  20. Antigen processing influences HIV-specific cytotoxic T lymphocyte immunodominance

    DEFF Research Database (Denmark)

    Tenzer, Stefan; Wee, Edmund; Burgevin, Anne

    2009-01-01

    -associated antigen proteins p17 and p24 correlated with epitope abundance, which was strongly influenced by proteasomal digestion profiles, affinity for the transporter protein TAP, and trimming mediated by the endoplasmatic reticulum aminopeptidase ERAAP, and was moderately influenced by HLA affinity. Structural...

  1. Defect internalization and tyrosine kinase activation in Aire deficient antigen presenting cells exposed to Candida albicans antigens.

    Science.gov (United States)

    Brännström, Johan; Hässler, Signe; Peltonen, Leena; Herrmann, Björn; Winqvist, Ola

    2006-12-01

    Patients with Autoimmune polyendocrine syndrome type I (APS I) present with multiple endocrine failures due to organ-specific autoimmune disease, thought to be T-cell-mediated. Paradoxically, APS I patients suffer from chronic mucocutaneous candidiasis. The mutated gene has been identified as the Autoimmune regulator (AIRE). Aire is expressed in medullary epithelial cells of the thymus and in antigen presenting cells in the periphery. T cells from Aire deficient mice and men displayed an enhanced proliferative response against Candida antigen in vitro, suggesting that Aire deficient T cells are competent in recognizing Candida albicans. In contrast, monocytes from APS I patients displayed a decreased and delayed internalization of zymosan. Furthermore, Candida antigen activated monocytes from APS I patients show decreased and altered phoshotyrosine kinase activation. In conclusion, Aire deficient APCs have a defect receptor mediated internalization of Candida which affects kinase activation, likely altering the innate Candida immune response.

  2. High-affinity memory B cells induced by conjugate vaccines against weak tumor antigens are vulnerable to nonconjugated antigen.

    Science.gov (United States)

    Savelyeva, Natalia; Shipton, Michael; Suchacki, Amy; Babbage, Gavin; Stevenson, Freda K

    2011-07-21

    Induction of antibody-mediated immunity against hematologic malignancies requires CD4(+) T-cell help, but weak tumor antigens generally fail to induce adequate T-cell responses, or to overcome tolerance. Conjugate vaccines can harness alternative help to activate responses, but memory B cells may then be exposed to leaking tumor-derived antigen without CD4(+) T-cell support. We showed previously using lymphoma-derived idiotypic antigen that exposure to "helpless" antigen silences the majority of memory IgG(+) B cells. Transfer experiments now indicate that silencing is permanent. In marked contrast to IgG, most coexisting IgM(+) memory B cells exposed to "helpless" antigen survive. Confirmation in a hapten (NP) model allowed measurement of affinity, revealing this, rather than isotype, as the determinant of survival. IgM(+) B cells had Ig variable region gene usage similar to IgG but with fewer somatic mutations. Survival of memory B cells appears variably controlled by affinity for antigen, allowing a minority of low affinity IgG(+), but most IgM(+), memory B cells to escape deletion in the absence of T-cell help. The latter remain, but the majority fail to undergo isotype switch. These findings could apply to other tumor antigens and are relevant for vaccination strategies aimed to induce long-term antibody.

  3. Impaired IFN-α-mediated signal in dendritic cells differentiates active from latent tuberculosis.

    Directory of Open Access Journals (Sweden)

    Stefania Parlato

    Full Text Available Individuals exposed to Mycobacterium tuberculosis (Mtb may be infected and remain for the entire life in this condition defined as latent tuberculosis infection (LTBI or develop active tuberculosis (TB. Among the multiple factors governing the outcome of the infection, dendritic cells (DCs play a major role in dictating antibacterial immunity. However, current knowledge on the role of the diverse components of human DCs in shaping specific T-cell response during Mtb infection is limited. In this study, we performed a comparative evaluation of peripheral blood circulating DC subsets as well as of monocyte-derived Interferon-α DCs (IFN-DCs from patients with active TB, subjects with LTBI and healthy donors (HD. The proportion of circulating myeloid BDCA3+ DCs (mDC2 and plasmacytoid CD123+ DCs (pDCs declined significantly in active TB patients compared to HD, whereas the same subsets displayed a remarkable activation in LTBI subjects. Simultaneously, the differentiation of IFN-DCs from active TB patients resulted profoundly impaired compared to those from LTBI and HD individuals. Importantly, the altered developmental trait of IFN-DCs from active TB patients was associated with down-modulation of IFN-linked genes, marked changes in molecular signaling conveying antigen (Ag presentation and full inability to induce Ag-specific T cell response. Thus, these data reveal an important role of IFN-α in determining the induction of Mtb-specific immunity.

  4. 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

  5. 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.

  6. Role of the Antigen Capture Pathway in the Induction of a Neutralizing Antibody Response to Anthrax Protective Antigen

    Directory of Open Access Journals (Sweden)

    Anita Verma

    2018-02-01

    Full Text Available Toxin neutralizing antibodies represent the major mode of protective immunity against a number of toxin-mediated bacterial diseases, including anthrax; however, the cellular mechanisms that lead to optimal neutralizing antibody responses remain ill defined. Here we show that the cellular binding pathway of anthrax protective antigen (PA, the binding component of anthrax toxin, determines the toxin neutralizing antibody response to this antigen. PA, which binds cellular receptors and efficiently enters antigen-presenting cells by receptor-mediated endocytosis, was found to elicit robust anti-PA IgG and toxin neutralizing antibody responses. In contrast, a receptor binding-deficient mutant of PA, which does not bind receptors and only inefficiently enters antigen-presenting cells by macropinocytosis, elicited very poor antibody responses. A chimeric protein consisting of the receptor binding-deficient PA mutant tethered to the binding subunit of cholera toxin, which efficiently enters cells using the cholera toxin receptor rather than the PA receptor, elicited an anti-PA IgG antibody response similar to that elicited by wild-type PA; however, the chimeric protein elicited a poor toxin neutralizing antibody response. Taken together, our results demonstrate that the antigen capture pathway can dictate the magnitudes of the total IgG and toxin neutralizing antibody responses to PA as well as the ratio of the two responses.

  7. Pharmacokinetics and dosimetry studies for optimization of anti-carcinoembryonic antigen x anti-hapten bispecific antibody-mediated pretargeting of Iodine-131-labeled hapten in a phase I radioimmunotherapy trial.

    Science.gov (United States)

    Kraeber-Bodéré, Françoise; Faivre-Chauvet, Alain; Ferrer, Ludovic; Vuillez, Jean-Philippe; Brard, Pierre-Yves; Rousseau, Caroline; Resche, Isabelle; Devillers, Anne; Laffont, Sophie; Bardiès, Manuel; Chang, Ken; Sharkey, Robert M; Goldenberg, David M; Chatal, Jean-François; Barbet, Jacques

    2003-09-01

    Pharmacokinetics and dosimetry of hMN-14 x m734 bispecific monoclonal antibody (BsMAb) and (131)I-labeled di-diethylenetriaminepentaacetic acid-indium ((131)I-hapten) were studied to optimize pretargeted radioimmunotherapy. Thirty-five patients with carcinoembryonic antigen-expressing tumors were included. In a first group of 12 patients, (131)I-trace-labeled BsMAb doses were escalated from 10 to 100 mg/m(2), and 3.7 GBq of (131)I-hapten were administered 7 days later. In a second group, 12 patients received 75 mg/m(2) BsMAb and 2.6-4.2 GBq of (131)I-hapten 5 days later. The BsMAb dose was then reduced to 40 mg/m(2), and 10 patients received 1.9-5.5 GBq of (131)I-hapten. Blood samples were collected. Biodistribution was monitored by quantitative scintigraphy. Directly labeled BsMAb pharmacokinetics was described by two exponentials: half-lives were 8.1 h (2.0-18.1 h) and 48.2 h (22.8-79.4 h); blood clearance was 123 ml/h (64-195 ml/h). With a 7-day interval, 10 or 30 mg/m(2) BsMAb resulted in fast elimination and very low tumor uptake of hapten, whereas 50 or 100 mg/m(2) resulted in favorable tumor accretion. With 75 mg/m(2) BsMAb and a 5-day interval, hapten clearance was 152 ml/h (81-298 ml/h). Calculated radiation dose to tumor was 3.9 Gy/GBq (0.4-22.4 Gy/GBq) for the hapten, compared with 2.0 Gy/GBq (0.3-3.8 Gy/GBq) for the BsMAb, but hematological toxicity prevented dose escalation. Reduction of the BsMAb dose to 40 mg/m(2) accelerated hapten clearance to 492 ml/h (113-2544 ml/h) and reduced hematological toxicity without compromising tumor uptake [5.2 Gy/GBq (0.5-12.6 Gy/GBq)]. Optimized BsMAb doses and time interval will allow for the administration of higher, tumoricidal, activity doses.

  8. Antigen receptor-mediated regulation of sustained polyphosphoinositide turnover in a human T cell line. Evidence for a receptor-regulated pathway for production of phosphatidylinositol 4,5-bisphosphate

    International Nuclear Information System (INIS)

    Inokuchi, S.; Imboden, J.B.

    1990-01-01

    Stimulation of the human T cell line, Jurkat, by the addition of monoclonal antibodies reactive with the T cell antigen receptor complex (CD3/Ti) leads to sustained increases in levels of inositol 1,4,5-trisphosphate. To investigate the possibility that the production of polyphosphoinositides is regulated during CD3/Ti stimulation, we studied Jurkat cells whose inositol phospholipids had been labeled to steady state with [3H]inositol, as well as Jurkat cells during nonequilibrium labeling with [32P]orthophosphate. The addition of CD3 monoclonal antibodies led to a 4-5-fold increase in [3H]inositol trisphosphate that was sustained for greater than 20 min. Within 60 s of CD3/Ti stimulation, [3H] phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) and [3H]phosphatidylinositol 4-phosphate (PtdIns4P) decreased by 65 and 35%, respectively. This change in [3H]PtdIns(4,5)P2 persisted for greater than 20 min. The decrease in [3H]PtdIns4P, however, was transient, and, after 5 min, the levels of [3H]PtdIns4P were comparable in stimulated and unstimulated cells. To examine the rate of flux through inositol phospholipids, we measured the CD3/Ti-stimulated changes in the ratio, 32P cpm/3H cpm, in each inositol phospholipid. CD3/Ti stimulation led to accelerated fluxes through PtdIns(4,5)P2 and phosphatidylinositol (PtdIns) that were maintained for greater than 20 min. After the initial 30 s, however, there was no detectable effect of anti-CD3 on flux through Ptsins4p. This observation suggested that, during CD3/Ti stimulation, production of PtdIns(4,5)P2 from PtdIns might occur via a small pool of PtdIns4P with a very high turnover. The existence of such a pool was established by determining that, in stimulated cells, the 32P-specific activity of the 1-position phosphate of PtdIns(4,5)P2 was 8-10-fold that of PtdIns4P

  9. Immunogenicity is unrelated to protective immunity when induced by soluble and particulate antigens from Nocardia brasiliensis in BALB/c mice.

    Science.gov (United States)

    Salinas-Carmona, Mario C; Ramos, Alma I; Pérez-Rivera, Isabel

    2006-08-01

    Cell-mediated immunity plays a major role in protection against intracellular microbes. Nocardia brasiliensis is a facultative intracellular pathogen that causes chronic actinomycetoma. In this work, we injected BALB/c mice with soluble P24 and particulate antigens from N. brasiliensis. A higher antibody titer and lymphocyte proliferation was induced by the particulate antigen than by the soluble antigen. However, five months after antigen injection, antibody concentration and lymphocyte proliferation were similar. An increase in CD45R and CD4 T cells was unrelated to protective immunity. Active immunization with soluble or particulate antigens induced complete protection during the primary immune response. This protective response was IgM mediated. The higher immunogenicity was not related to protective immunity since the particulate antigen induced protection similar to the soluble antigen. Using particulate antigens for vaccination guarantees a stronger immune response, local and systemic side effects, but not necessarily protection.

  10. Polymer blend particles with defined compositions for targeting antigen to both class I and II antigen presentation pathways.

    Science.gov (United States)

    Tran, Kenny K; Zhan, Xi; Shen, Hong

    2014-05-01

    Defense against many persistent and difficult-to-treat diseases requires a combination of humoral, CD4(+) , and CD8(+) T-cell responses, which necessitates targeting antigens to both class I and II antigen presentation pathways. In this study, polymer blend particles are developed by mixing two functionally unique polymers, poly(lactide-co-glycolide) (PLGA) and a pH-responsive polymer, poly(dimethylaminoethyl methacrylate-co-propylacrylic acid-co-butyl methacrylate) (DMAEMA-co-PAA-co-BMA). Polymer blend particles are shown to enable the delivery of antigens into both class I and II antigen presentation pathways in vitro. Increasing the ratio of the pH-responsive polymer in blend particles increases the degree of class I antigen presentation, while maintaining high levels of class II antigen presentation. In a mouse model, it is demonstrated that a significantly higher and sustained level of CD4(+) and CD8(+) T-cell responses, and comparable antibody responses, are elicited with polymer blend particles than PLGA particles and a conventional vaccine, Alum. The polymer blend particles offer a potential vaccine delivery platform to generate a combination of humoral and cell-mediated immune responses that insure robust and long-lasting immunity against many infectious diseases and cancers. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Rapid profiling of the antigen regions recognized by serum antibodies using massively parallel sequencing of antigen-specific libraries.

    KAUST Repository

    Domina, Maria

    2014-12-04

    There is a need for techniques capable of identifying the antigenic epitopes targeted by polyclonal antibody responses during deliberate or natural immunization. Although successful, traditional phage library screening is laborious and can map only some of the epitopes. To accelerate and improve epitope identification, we have employed massive sequencing of phage-displayed antigen-specific libraries using the Illumina MiSeq platform. This enabled us to precisely identify the regions of a model antigen, the meningococcal NadA virulence factor, targeted by serum antibodies in vaccinated individuals and to rank hundreds of antigenic fragments according to their immunoreactivity. We found that next generation sequencing can significantly empower the analysis of antigen-specific libraries by allowing simultaneous processing of dozens of library/serum combinations in less than two days, including the time required for antibody-mediated library selection. Moreover, compared with traditional plaque picking, the new technology (named Phage-based Representation OF Immuno-Ligand Epitope Repertoire or PROFILER) provides superior resolution in epitope identification. PROFILER seems ideally suited to streamline and guide rational antigen design, adjuvant selection, and quality control of newly produced vaccines. Furthermore, this method is also susceptible to find important applications in other fields covered by traditional quantitative serology.

  12. 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...

  13. Antigen-specific immune reactions to ischemic stroke

    Directory of Open Access Journals (Sweden)

    Xabier eUrra

    2014-09-01

    Full Text Available Brain proteins are detected in the CSF and blood of stroke patients and their concentration is related to the extent of brain damage. Antibodies against brain antigens develop after stroke, suggesting a humoral immune response to the brain injury. Furthermore, induced immune tolerance is beneficial in animal models of cerebral ischemia. The presence of circulating T cells sensitized against brain antigens, and antigen presenting cells (APCs carrying brain antigens in draining lymphoid tissue of stroke patients support the notion that stroke might induce antigen-specific immune responses. After stroke, brain proteins that are normally hidden from the periphery, inflammatory mediators, and danger signals can exit the brain through several efflux routes. They can reach the blood after leaking out of the damaged blood-brain barrier or following the drainage of interstitial fluid to the dural venous sinus, or reach the cervical lymph nodes through the nasal lymphatics following CSF drainage along the arachnoid sheaths of nerves across the nasal submucosa. The route and mode of access of brain antigens to lymphoid tissue could influence the type of response. Central and peripheral tolerance prevents autoimmunity, but the actual mechanisms of tolerance to brain antigens released into the periphery in the presence of inflammation, danger signals, and APCs, are not fully characterized. Stroke does not systematically trigger autoimmunity, but under certain circumstances, such as pronounced systemic inflammation or infection, autoreactive T cells could escape the tolerance controls. Further investigation is needed to elucidate whether antigen-specific immune events could underlie neurological complications impairing stroke outcome.

  14. 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...

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. Localization of functional memory B cells at sites of antigen localization and its relationship to local aspects of immunological memory

    International Nuclear Information System (INIS)

    Ponzio, N.M.; Baine, Y.; Thorbecke, G.J.

    1980-01-01

    Experiments are described which have been designed to test whether antigen in a draining lymph node can mediate local accumulation of passively transferred antigen-specific memory B cells, using recipients whose own immune response is inhibited via γ-irradiation or by injection of cyclophosphamide. (Auth.)

  20. Antigen Availability Shapes T Cell Differentiation and Function during Tuberculosis.

    Science.gov (United States)

    Moguche, Albanus O; Musvosvi, Munyaradzi; Penn-Nicholson, Adam; Plumlee, Courtney R; Mearns, Helen; Geldenhuys, Hennie; Smit, Erica; Abrahams, Deborah; Rozot, Virginie; Dintwe, One; Hoff, Søren T; Kromann, Ingrid; Ruhwald, Morten; Bang, Peter; Larson, Ryan P; Shafiani, Shahin; Ma, Shuyi; Sherman, David R; Sette, Alessandro; Lindestam Arlehamn, Cecilia S; McKinney, Denise M; Maecker, Holden; Hanekom, Willem A; Hatherill, Mark; Andersen, Peter; Scriba, Thomas J; Urdahl, Kevin B

    2017-06-14

    CD4 T cells are critical for protective immunity against Mycobacterium tuberculosis (Mtb), the cause of tuberculosis (TB). Yet to date, TB vaccine candidates that boost antigen-specific CD4 T cells have conferred little or no protection. Here we examined CD4 T cell responses to two leading TB vaccine antigens, ESAT-6 and Ag85B, in Mtb-infected mice and in vaccinated humans with and without underlying Mtb infection. In both species, Mtb infection drove ESAT-6-specific T cells to be more differentiated than Ag85B-specific T cells. The ability of each T cell population to control Mtb in the lungs of mice was restricted for opposite reasons: Ag85B-specific T cells were limited by reduced antigen expression during persistent infection, whereas ESAT-6-specific T cells became functionally exhausted due to chronic antigenic stimulation. Our findings suggest that different vaccination strategies will be required to optimize protection mediated by T cells recognizing antigens expressed at distinct stages of Mtb infection. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Antigenic relationships among four herpesviruses.

    Science.gov (United States)

    Blue, W T; Plummer, G

    1973-06-01

    Common viral antigens were detected, by fluorescent-antibody studies, in cells infected with herpes simplex virus 1, squirrel monkey herpesvirus 1, bovine rhinotracheitis, and equine abortion viruses. The two primate viruses showed slight cross-neutralization.

  2. HLA-B27 antigen

    Science.gov (United States)

    Human leukocyte antigen B27; Ankylosing spondylitis-HLA; Psoriatic arthritis-HLA; Reactive arthritis-HLA ... Erythrocyte sedimentation rate ( ESR ) Rheumatoid factor X-rays HLA testing is also used to match donated tissue ...

  3. Differential expression of the Escherichia coli autoaggregation factor antigen 43

    DEFF Research Database (Denmark)

    Schembri, Mark; Hjerrild, Louise; Gjermansen, Morten

    2003-01-01

    Antigen 43 (Ag43) is a self-recognizing surface adhesin found in most Escherichia coli strains. Due to its excellent cell-to-cell aggregation characteristics, Ag43 expression confers clumping and fluffing of cells and promotes biofilm formation. Ag43 expression is repressed by the cellular redox......-forming potential of E. coli. Finally, we demonstrated that Ag43-mediated cell aggregation confers significant protection against hydrogen peroxide killing....

  4. Natural selection promotes antigenic evolvability.

    Science.gov (United States)

    Graves, Christopher J; Ros, Vera I D; Stevenson, Brian; Sniegowski, Paul D; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections.

  5. Epicutaneous sensitization with protein antigen

    Directory of Open Access Journals (Sweden)

    I-Lin Liu

    2012-12-01

    Full Text Available In the past few decades there has been a progressive understanding that epicutaneous sensitization with protein antigen is an important sensitization route in patients with atopic dermatitis. A murine protein-patch model has been established, and an abundance of data has been obtained from experiments using this model. This review discusses the characteristics of epicutaneous sensitization with protein antigen, the induced immune responses, the underlying mechanisms, and the therapeutic potential.

  6. T cell recognition of breast cancer antigens

    DEFF Research Database (Denmark)

    Petersen, Nadia Viborg; Andersen, Sofie Ramskov; Andersen, Rikke Sick

    Recent studies are encouraging research of breast cancer immunogenicity to evaluate the applicability ofimmunotherapy as a treatment strategy. The epitope landscape in breast cancer is minimally described, thus it is necessary to identify T cell targets to develop immune mediated therapies.......This project investigates four proteins commonly upregulated in breast cancer and thus probable tumor associated antigens (TAAs). Aromatase, prolactin, NEK3, and PIAS3 contribute to increase growth, survival, and motility of malignant cells. Aspiring to uncover novel epitopes for cytotoxic T cells, a reverse...... recognition utilizing DNA barcode labeled MHC multimers to screen peripheral blood lymphocytes from breast cancer patients and healthy donor samples. Signif-icantly more TAA specific T cell responses were detected in breast cancer patients than healthy donors for both HLA-A*0201 (P

  7. Licensing of γδT cells for professional antigen presentation

    Science.gov (United States)

    Anderson, John; Gustafsson, Kenth; Himoudi, Nourredine; Yan, Mengyong; Heuijerjans, Jennifer

    2012-01-01

    Following activation, γδ T cells display many properties of lymphocytes from the innate immune system, yet how they mediate antigen presentation remains an open conundrum. In humans, circulating γδ T cells that express the Vγ9Vδ2 T-cell receptor become reversibly licensed for professional antigen presentation only upon interaction with a target cell opsonized with IgGs. PMID:23264926

  8. 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

  9. Antigen entrapped in the escheriosomes leads to the generation of CD4(+) helper and CD8(+) cytotoxic T cell response.

    Science.gov (United States)

    Syed, Faisal M; Khan, Masood A; Nasti, Tahseen H; Ahmad, Nadeem; Mohammad, Owais

    2003-06-02

    In previous study, we demonstrated the potential of Escherichia coli (E. coli) lipid liposomes (escheriosomes) to undergo membrane-membrane fusion with cytoplasmic membrane of the target cells including professional antigen presenting cells. Our present study demonstrates that antigen encapsulated in escheriosomes could be successfully delivered simultaneously to the cytosolic as well as endosomal processing pathways of antigen presenting cells, leading to the generation of both CD4(+) T-helper and CD8(+) cytotoxic T cell response. In contrast, encapsulation of same antigen in egg phosphatidyl-choline (egg PC) liposomes, just like antigen-incomplete Freund's adjuvant (IFA) complex, has inefficient access to the cytosolic pathway of MHC I-dependent antigen presentation and failed to generate antigen-specific CD8(+) cytotoxic T cell response. However, both egg PC liposomes as well as escheriosomes-encapsulated antigen elicited strong humoral immune response in immunized animals but antibody titre was significantly higher in the group of animals immunized with escheriosomes-encapsulated antigen. These results imply usage of liposome-based adjuvant as potential candidate vaccine capable of eliciting both cell-mediated as well as humoral immune responses. Furthermore, antigen entrapped in escheriosomes stimulates antigen-specific CD4(+) T cell proliferation and also enhances the level of IL-2, IFN-gamma and IL-4 in the immunized animals.

  10. Human sensitization to Ganoderma antigen.

    Science.gov (United States)

    Tarlo, S M; Bell, B; Srinivasan, J; Dolovich, J; Hargreave, F E

    1979-07-01

    Continuous air sampling with a Hirst volumetric spore trap over 3 yr has identified basidiospores of Ganoderma applanatum, a bracket fungus, as the most numerous fungal spores in two southern Ontario locations. The particle size is small and the calculated total spore mass approximates that of the spores of Cladosporium and Alternaria. Extracts of Ganoderma applanatum bracket fungus and spores in w/v, 1:10 concentration were prepared after collection of samples of the fungus from local woods. Skin prick tests with the extracts were performed in 294 consecutive children and adults attending two chest/allergy clinics. Of these patients, 182 (61.9%) reacted to 1 or more of the common inhalant allergen extracts and 24 (8.2%) reacted to Ganoderma antigen. There was no consistent relationship between reactivity to Ganoderma antigen and any of the common inhaled allergens. IgE-dependent sensitization to Ganoderma was confirmed by the radioallergosorbent test (RAST). Rabbit antisera to Ganoderma antigen preparations did not appear to cross-react with preparations of the various clinically important allergens. The findings indicate that Ganoderma antigen is commonly encountered, can induce human sensitization, and has unique antigenicity among common allergens of clinical importance.

  11. 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.

  12. Analysis of Microtubule Mediated Functions of Prostate Specific Membrane Antigen

    Science.gov (United States)

    2006-04-01

    supplemented with 10% fetal bovine serum, MEM nonessential amino acid solution (Invitrogen, Grand Island, NY), and penicillin/streptomycin. A7 and M2 cells were...results were obtained using immunoconjugates of other vaso - active agents, including recombinant interleukin-1h (IL-1h), physalaemin, histamine

  13. Microbial antigens mediate HLA-B27 diseases via TLRs.

    Science.gov (United States)

    Pöllänen, Raimo; Sillat, Tarvo; Pajarinen, Jukka; Levón, Jaakko; Kaivosoja, Emilia; Konttinen, Yrjö T

    2009-01-01

    HLA-B27 positive individuals are predisposed to reactive arthritis developing 1-3 weeks after urogenital and gastrointestinal infections. Also ankylosing spondylitis (AS) associates strongly to HLA-B27, but no specific infection, Klebsiella pneumoniae excluded, has been linked to it. Before the discovery of its HLA-B27 association there were many reports suggesting a link between chronic prostatitis in men or pelvic inflammatory disease in women and AS. They have since been forgotten although HLA-B27 did not help to understand, why this disease has an axial and ascending nature. It is proposed that the urogenital organs form a source of damage (or danger)-associated molecular patterns (DAMPs), either exogenous pathogen-associated molecular patterns (PAMPs) from microbes or endogenous alarmins, such as uric acid, released from necrotic cells or urate deposits. DAMPs are slowly seeded from low-down upwards via the pelvic and spinal lymphatic pathways. They reach Toll-like receptors (TLRs) in their target mesenchymal stem cells, which are stimulated to ectopic enchondral bone formation leading to syndesmophytes and bamboo spine. At the same time inflammatory cytokines induce secondary osteoporosis of the spine. This new paradigm places microbes, HLA-B27 and TLRs in the pathogenic centre stage, but without pinpointing any (one) specific pathogen; instead, shared microbial patterns are indicated.

  14. Characterisation of Sarcoptes scabiei antigens.

    Science.gov (United States)

    Hejduk, Gloria; Hofstätter, Katja; Löwenstein, Michael; Peschke, Roman; Miller, Ingrid; Joachim, Anja

    2011-02-01

    In pig herds, the status of Sarcoptes scabiei infections is routinely monitored by serodiagnosis. Crude antigen for ELISA is usually prepared from S. scabiei var. canis or other variations and may lead to variations in the outcome of different tests, making assay standardisation difficult. This study was performed to investigate the antigen profiles of S. scabiei, including differences between hydrophilic and more hydrophobic protein fractions, by Western blotting with sera from pigs with defined infection status. Potential cross-reactivity among S. scabiei (var. canis, suis and bovis), Dermatophagoides farinae and Tyrophagus putrescentiae was also analysed. Hydrophobic S. scabiei antigens were detectable in the range of 40-50 kDa, whilst the hydrophilic fraction showed no specific antigenicity. In the hydrophobic fractions of D. farinae and T. putrescentiae, two major protein fractions in a similar size range could be identified, but no cross-reactivity with Sarcoptes-positive sera was detectable. However, examination of the hydrophilic fractions revealed cross-reactivity between Sarcoptes-positive sera and both the house dust mite and the storage mite in the range of 115 and 28/38 kDa. Specific bands in the same range (42 and 48 kDa) could be detected in blots from hydrophobic fractions of all three tested variations of S. scabiei (var. canis, bovis and suis). These results show that there are considerable differences in mange antibody reactivity, including reactions with proteins from free-living mites, which may interfere with tests based on hydrophilic antigens. Further refinement of antigen and the use of specific hydrophobic proteins could improve ELISA performance and standardisation.

  15. 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.

  16. [Farmer's lung antigens in Germany].

    Science.gov (United States)

    Sennekamp, J; Joest, M; Sander, I; Engelhart, S; Raulf-Heimsoth, M

    2012-05-01

    Recent studies suggest that besides the long-known farmer's lung antigen sources Saccharopolyspora rectivirgula (Micropolyspora faeni), Thermoactinomyces vulgaris, and Aspergillus fumigatus, additionally the mold Absidia (Lichtheimia) corymbifera as well as the bacteria Erwinia herbicola (Pantoea agglomerans) and Streptomyces albus may cause farmer's lung in Germany. In this study the sera of 64 farmers with a suspicion of farmer's lung were examined for the following further antigens: Wallemia sebi, Cladosporium herbarum, Aspergillus versicolor, and Eurotium amstelodami. Our results indicate that these molds are not frequent causes of farmer's lung in Germany. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Natural selection promotes antigenic evolvability

    NARCIS (Netherlands)

    Graves, C.J.; Ros, V.I.D.; Stevenson, B.; Sniegowski, P.D.; Brisson, D.

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide

  18. Concepts and applications for influenza antigenic cartography

    Science.gov (United States)

    Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2011-01-01

    Influenza antigenic cartography projects influenza antigens into a two or three dimensional map based on immunological datasets, such as hemagglutination inhibition and microneutralization assays. A robust antigenic cartography can facilitate influenza vaccine strain selection since the antigenic map can simplify data interpretation through intuitive antigenic map. However, antigenic cartography construction is not trivial due to the challenging features embedded in the immunological data, such as data incompleteness, high noises, and low reactors. To overcome these challenges, we developed a computational method, temporal Matrix Completion-Multidimensional Scaling (MC-MDS), by adapting the low rank MC concept from the movie recommendation system in Netflix and the MDS method from geographic cartography construction. The application on H3N2 and 2009 pandemic H1N1 influenza A viruses demonstrates that temporal MC-MDS is effective and efficient in constructing influenza antigenic cartography. The web sever is available at http://sysbio.cvm.msstate.edu/AntigenMap. PMID:21761589

  19. 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.

  20. Endosome-mediated autophagy

    Science.gov (United States)

    Kondylis, Vangelis; van Nispen tot Pannerden, Hezder E.; van Dijk, Suzanne; ten Broeke, Toine; Wubbolts, Richard; Geerts, Willie J.; Seinen, Cor; Mutis, Tuna; Heijnen, Harry F.G.

    2013-01-01

    Activation of TLR signaling has been shown to induce autophagy in antigen-presenting cells (APCs). Using high-resolution microscopy approaches, we show that in LPS-stimulated dendritic cells (DCs), autophagosomes emerge from MHC class II compartments (MIICs) and harbor both the molecular machinery for antigen processing and the autophagosome markers LC3 and ATG16L1. This ENdosome-Mediated Autophagy (ENMA) appears to be the major type of autophagy in DCs, as similar structures were observed upon established autophagy-inducing conditions (nutrient deprivation, rapamycin) and under basal conditions in the presence of bafilomycin A1. Autophagosome formation was not significantly affected in DCs expressing ATG4BC74A mutant and atg4b−/− bone marrow DCs, but the degradation of the autophagy substrate SQSTM1/p62 was largely impaired. Furthermore, we demonstrate that the previously described DC aggresome-like LPS-induced structures (DALIS) contain vesicular membranes, and in addition to SQSTM1 and ubiquitin, they are positive for LC3. LC3 localization on DALIS is independent of its lipidation. MIIC-driven autophagosomes preferentially engulf the LPS-induced SQSTM1-positive DALIS, which become later degraded in autolysosomes. DALIS-associated membranes also contain ATG16L1, ATG9 and the Q-SNARE VTI1B, suggesting that they may represent (at least in part) a membrane reservoir for autophagosome expansion. We propose that ENMA constitutes an unconventional, APC-specific type of autophagy, which mediates the processing and presentation of cytosolic antigens by MHC class II machinery, and/or the selective clearance of toxic by-products of elevated ROS/RNS production in activated DCs, thereby promoting their survival. PMID:23481895

  1. Screening Donors for Rare Antigen Constellations.

    Science.gov (United States)

    Wagner, Franz F

    2009-01-01

    SCREENING BLOOD DONORS FOR RARE ANTIGEN CONSTELLATIONS HAS BEEN IMPLEMENTED USING SIMPLE PCR METHODS: PCR with enzyme digestion has been used to type donor cohorts for Dombrock antigens, and PCR with sequence-specific priming to identify donors negative for antigens of high frequency. The advantages and disadvantages of the methods as well as their current state is discussed.

  2. The Effect of Superparamagnetic Iron Oxide Nanoparticle Surface Charge on Antigen Cross-Presentation.

    Science.gov (United States)

    Mou, Yongbin; Xing, Yun; Ren, Hongyan; Cui, Zhihua; Zhang, Yu; Yu, Guangjie; Urba, Walter J; Hu, Qingang; Hu, Hongming

    2017-12-01

    Magnetic nanoparticles (NPs) of superparamagnetic iron oxide (SPIO) have been explored for different kinds of applications in biomedicine, mechanics, and information. Here, we explored the synthetic SPIO NPs as an adjuvant on antigen cross-presentation ability by enhancing the intracellular delivery of antigens into antigen presenting cells (APCs). Particles with different chemical modifications and surface charges were used to study the mechanism of action of antigen delivery. Specifically, two types of magnetic NPs, γFe 2 O 3 /APTS (3-aminopropyltrimethoxysilane) NPs and γFe 2 O 3 /DMSA (meso-2, 3-Dimercaptosuccinic acid) NPs, with the same crystal structure, magnetic properties, and size distribution were prepared. Then, the promotion of T-cell activation via dendritic cells (DCs) was compared among different charged antigen coated NPs. Moreover, the activation of the autophagy, cytosolic delivery of the antigens, and antigen degradation mediated by the proteasome and lysosome were measured. Our results indicated that positive charged γFe 2 O 3 /APTS NPs, but not negative charged γFe 2 O 3 /DMSA NPs, enhanced the cross-presentation ability of DCs. Increased cross-presentation ability induced by γFe 2 O 3 /APTS NPs was associated with increased cytosolic antigen delivery. On the contrary, γFe 2 O 3 /DMSA NPs was associated with rapid autophagy. Overall, our results suggest that antigen delivered in cytoplasm induced by positive charged particles is beneficial for antigen cross-presentation and T-cell activation. NPs modified with different chemistries exhibit diverse biological properties and differ greatly in their adjuvant potentials. Thus, it should be carefully considered many different effects of NPs to design effective and safe adjuvants.

  3. The Effect of Superparamagnetic Iron Oxide Nanoparticle Surface Charge on Antigen Cross-Presentation

    Science.gov (United States)

    Mou, Yongbin; Xing, Yun; Ren, Hongyan; Cui, Zhihua; Zhang, Yu; Yu, Guangjie; Urba, Walter J.; Hu, Qingang; Hu, Hongming

    2017-01-01

    Magnetic nanoparticles (NPs) of superparamagnetic iron oxide (SPIO) have been explored for different kinds of applications in biomedicine, mechanics, and information. Here, we explored the synthetic SPIO NPs as an adjuvant on antigen cross-presentation ability by enhancing the intracellular delivery of antigens into antigen presenting cells (APCs). Particles with different chemical modifications and surface charges were used to study the mechanism of action of antigen delivery. Specifically, two types of magnetic NPs, γFe2O3/APTS (3-aminopropyltrimethoxysilane) NPs and γFe2O3/DMSA (meso-2, 3-Dimercaptosuccinic acid) NPs, with the same crystal structure, magnetic properties, and size distribution were prepared. Then, the promotion of T-cell activation via dendritic cells (DCs) was compared among different charged antigen coated NPs. Moreover, the activation of the autophagy, cytosolic delivery of the antigens, and antigen degradation mediated by the proteasome and lysosome were measured. Our results indicated that positive charged γFe2O3/APTS NPs, but not negative charged γFe2O3/DMSA NPs, enhanced the cross-presentation ability of DCs. Increased cross-presentation ability induced by γFe2O3/APTS NPs was associated with increased cytosolic antigen delivery. On the contrary, γFe2O3/DMSA NPs was associated with rapid autophagy. Overall, our results suggest that antigen delivered in cytoplasm induced by positive charged particles is beneficial for antigen cross-presentation and T-cell activation. NPs modified with different chemistries exhibit diverse biological properties and differ greatly in their adjuvant potentials. Thus, it should be carefully considered many different effects of NPs to design effective and safe adjuvants.

  4. Identification of an Antigen from Normal Human Tissue That Crossreacts with the Carcinoembryonic Antigen

    Science.gov (United States)

    Kleist, S. Von; Chavanel, G.; Burtin, P.

    1972-01-01

    A glycoprotein present in normal human tissue is characterized that is neither organ- nor tumor-specific (nonspecific crossreacting antigen) and that crossreacts (by the Ouchterlony double-diffusion technique) with the carcinoembryonic antigen. This immunological relationship indicates common determinants on the molecules of both antigens. We demonstrate that the nonspecific crossreacting antigen is not a fragment of the carcinoembryonic antigen molecule. Images PMID:4115954

  5. 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

  6. JC virus T-antigen regulates glucose metabolic pathways in brain tumor cells.

    Science.gov (United States)

    Noch, Evan; Sariyer, Ilker Kudret; Gordon, Jennifer; Khalili, Kamel

    2012-01-01

    Recent studies have reported the detection of the human neurotropic virus, JCV, in a significant population of brain tumors, including medulloblastomas. Accordingly, expression of the JCV early protein, T-antigen, which has transforming activity in cell culture and in transgenic mice, results in the development of a broad range of tumors of neural crest and glial origin. Evidently, the association of T-antigen with a range of tumor-suppressor proteins, including p53 and pRb, and signaling molecules, such as β-catenin and IRS-1, plays a role in the oncogenic function of JCV T-antigen. We demonstrate that T-antigen expression is suppressed by glucose deprivation in medulloblastoma cells and in glioblastoma xenografts that both endogenously express T-antigen. Mechanistic studies indicate that glucose deprivation-mediated suppression of T-antigen is partly influenced by 5'-activated AMP kinase (AMPK), an important sensor of the AMP/ATP ratio in cells. In addition, glucose deprivation-induced cell cycle arrest in the G1 phase is blocked with AMPK inhibition, which also prevents T-antigen downregulation. Furthermore, T-antigen prevents G1 arrest and sustains cells in the G2 phase during glucose deprivation. On a functional level, T-antigen downregulation is partially dependent on reactive oxygen species (ROS) production during glucose deprivation, and T-antigen prevents ROS induction, loss of ATP production, and cytotoxicity induced by glucose deprivation. Additionally, we have found that T-antigen is downregulated by the glycolytic inhibitor, 2-deoxy-D-glucose (2-DG), and the pentose phosphate inhibitors, 6-aminonicotinamide and oxythiamine, and that T-antigen modulates expression of the glycolytic enzyme, hexokinase 2 (HK2), and the pentose phosphate enzyme, transaldolase-1 (TALDO1), indicating a potential link between T-antigen and metabolic regulation. These studies point to the possible involvement of JCV T-antigen in medulloblastoma proliferation and the metabolic

  7. Relationship between systemic inflammation and delayed-type hypersensitivity response to Candida antigen in older adults.

    Directory of Open Access Journals (Sweden)

    Brandt D Pence

    Full Text Available Research has shown that aging is associated with increased systemic inflammation as well as a reduction in the strength of immune responses. However, little evidence exists linking the decrease in cell-mediated immunity in older adults with other health parameters. We sought to examine the relationship between cell-mediated immunity as measured in vivo by the delayed-type hypersensitivity (DTH response to candida antigen and demographic and physiological variables in older (65-80 y.o. adults. Candida antigen response was not related to gender or obesity, or to a number of other physiological variables including fitness and body composition. However, positive responders had significantly lower serum C-reactive protein levels (CRP, p4.75 mg•L(-1. Therefore, positive responses to candida antigen in older adults appears to be related to lower levels of systemic inflammation.

  8. Classing it up to get noticed : MHC class 1 antigen display in dendritic cells and neuroblastoma

    NARCIS (Netherlands)

    Spel, Lotte

    2018-01-01

    In this thesis I have explored the process of MHC-1-mediated antigen presentation in two distinctive cell types: dendritic cells and neuroblastoma tumor cells. Dendritic cells (DCs) are pivotal players that bridge innate and adaptive immunity. DCs are able to engulf tumor-derived material and

  9. Individual cathepsins degrade immune complexes internalized by antigen-presenting cells via Fcgamma receptors.

    NARCIS (Netherlands)

    Driessen, C.A.G.G.; Lennon-Dumenil, A.M.; Ploegh, H.L.

    2001-01-01

    We have analyzed the intracellular degradation of an immune complex after its FcgammaR-mediated uptake in antigen-presenting cells (APC). Mice that lack the cathepsins (Cat) S, L, B and D allowed us to assess the direct contribution of these individual proteases to the processing events observed.

  10. Approach to discover T- and B-cell antigens of intracellular pathogens applied to the design of Chlamydia trachomatis vaccines

    Science.gov (United States)

    Finco, Oretta; Frigimelica, Elisabetta; Buricchi, Francesca; Petracca, Roberto; Galli, Giuliano; Faenzi, Elisa; Meoni, Eva; Bonci, Alessandra; Agnusdei, Mauro; Nardelli, Filomena; Bartolini, Erika; Scarselli, Maria; Caproni, Elena; Laera, Donatello; Zedda, Luisanna; Skibinski, David; Giovinazzi, Serena; Bastone, Riccardo; Ianni, Elvira; Cevenini, Roberto; Grandi, Guido; Grifantini, Renata

    2011-01-01

    Natural immunity against obligate and/or facultative intracellular pathogens is usually mediated by both humoral and cellular immunity. The identification of those antigens stimulating both arms of the immune system is instrumental for vaccine discovery. Although high-throughput technologies have been applied for the discovery of antibody-inducing antigens, few examples of their application for T-cell antigens have been reported. We describe how the compilation of the immunome, here defined as the pool of immunogenic antigens inducing T- and B-cell responses in vivo, can lead to vaccine candidates against Chlamydia trachomatis. We selected 120 C. trachomatis proteins and assessed their immunogenicity using two parallel high-throughput approaches. Protein arrays were generated and screened with sera from C. trachomatis-infected patients to identify antibody-inducing antigens. Splenocytes from C. trachomatis-infected mice were stimulated with 79 proteins, and the frequency of antigen-specific CD4+/IFN-γ+ T cells was analyzed by flow cytometry. We identified 21 antibody-inducing antigens, 16 CD4+/IFN-γ+–inducing antigens, and five antigens eliciting both types of responses. Assessment of their protective activity in a mouse model of Chlamydia muridarum lung infection led to the identification of seven antigens conferring partial protection when administered with LTK63/CpG adjuvant. Protection was largely the result of cellular immunity as assessed by CD4+ T-cell depletion. The seven antigens provided robust additive protection when combined in four-antigen combinations. This study paves the way for the development of an effective anti-Chlamydia vaccine and provides a general approach for the discovery of vaccines against other intracellular pathogens. PMID:21628568

  11. Sec61 blockade by mycolactone inhibits antigen cross-presentation independently of endosome-to-cytosol export.

    Science.gov (United States)

    Grotzke, Jeff E; Kozik, Patrycja; Morel, Jean-David; Impens, Francis; Pietrosemoli, Natalia; Cresswell, Peter; Amigorena, Sebastian; Demangel, Caroline

    2017-07-18

    Although antigen cross-presentation in dendritic cells (DCs) is critical to the initiation of most cytotoxic immune responses, the intracellular mechanisms and traffic pathways involved are still unclear. One of the most critical steps in this process, the export of internalized antigen to the cytosol, has been suggested to be mediated by Sec61. Sec61 is the channel that translocates signal peptide-bearing nascent polypeptides into the endoplasmic reticulum (ER), and it was also proposed to mediate protein retrotranslocation during ER-associated degradation (a process called ERAD). Here, we used a newly identified Sec61 blocker, mycolactone, to analyze Sec61's contribution to antigen cross-presentation, ERAD, and transport of internalized antigens into the cytosol. As shown previously in other cell types, mycolactone prevented protein import into the ER of DCs. Mycolactone-mediated Sec61 blockade also potently suppressed both antigen cross-presentation and direct presentation of synthetic peptides to CD8 + T cells. In contrast, it did not affect protein export from the ER lumen or from endosomes into the cytosol, suggesting that the inhibition of cross-presentation was not related to either of these trafficking pathways. Proteomic profiling of mycolactone-exposed DCs showed that expression of mediators of antigen presentation, including MHC class I and β2 microglobulin, were highly susceptible to mycolactone treatment, indicating that Sec61 blockade affects antigen cross-presentation indirectly. Together, our data suggest that the defective translocation and subsequent degradation of Sec61 substrates is the cause of altered antigen cross-presentation in Sec61-blocked DCs.

  12. Recombinant Salivary Proteins of Phlebotomus orientalis are Suitable Antigens to Measure Exposure of Domestic Animals to Sand Fly Bites.

    OpenAIRE

    Michal Sima; Blanka Ferencova; Alon Warburg; Iva Rohousova; Petr Volf

    2016-01-01

    Background Certain salivary proteins of phlebotomine sand flies injected into the host skin during blood-feeding are highly antigenic and elicit strong antibody-mediated immune responses in repeatedly-exposed hosts. These antibodies can be measured by enzyme-linked immuno sorbent assays (ELISAs) using salivary gland homogenates (SGHs) as the source of antigens and serve as a markers for exposure to biting sand flies. Large-scale screening for anti-sand fly saliva antibodies requires replaceme...

  13. Targeting lentiviral vectors to antigen-specific immunoglobulins.

    Science.gov (United States)

    Ziegler, Leslie; Yang, Lili; Joo, Kye il; Yang, Haiguang; Baltimore, David; Wang, Pin

    2008-09-01

    Gene transfer into B cells by lentivectors can provide an alternative approach to managing B lymphocyte malignancies and autoreactive B cell-mediated autoimmune diseases. These pathogenic B cell populations can be distinguished by their surface expression of monospecific immunoglobulin. Development of a novel vector system to deliver genes to these specific B cells could improve the safety and efficacy of gene therapy. We have developed an efficient method to target lentivectors to monospecific immunoglobulin-expressing cells in vitro and in vivo. We were able to incorporate a model antigen CD20 and a fusogenic protein derived from the Sindbis virus as two distinct molecules into the lentiviral surface. This engineered vector could specifically bind to cells expressing surface immunoglobulin recognizing CD20 (alphaCD20), resulting in efficient transduction of target cells in a cognate antigen-dependent manner in vitro, and in vivo in a xenografted tumor model. Tumor suppression was observed in vivo, using the engineered lentivector to deliver a suicide gene to a xenografted tumor expressing alphaCD20. These results show the feasibility of engineering lentivectors to target immunoglobulin- specific cells to deliver a therapeutic effect. Such targeting lentivectors also could potentially be used to genetically mark antigen-specific B cells in vivo to study their B cell biology.

  14. Inherent and antigen-induced airway hyperreactivity in NC mice

    Directory of Open Access Journals (Sweden)

    Tetsuto Kobayashi

    1999-01-01

    Full Text Available In order to clarify the airway physiology of NC mice, the following experiments were carried out. To investigate inherent airway reactivity, we compared tracheal reactivity to various chemical mediators in NC, BALB/c, C57BL/6 and A/J mice in vitro. NC mice showed significantly greater reactivity to acetylcholine than BALB/c and C57BL/6 mice and a reactivity comparable to that of A/J mice, which are known as high responders. Then, airway reactivity to acetylcholine was investigated in those strains in vivo. NC mice again showed comparable airway reactivity to that seen in A/J mice and a significantly greater reactivity than that seen in BALB/c and C57BL/6 mice. To investigate the effects of airway inflammation on airway reactivity to acetylcholine in vivo, NC and BALB/c mice were sensitized to and challenged with antigen. Sensitization to and challenge with antigen induced accumulation of inflammatory cells, especially eosinophils, in lung and increased airway reactivity in NC and BALB/c mice. These results indicate that NC mice exhibit inherent and antigen-induced airway hyperreactivity. Therefore, NC mice are a suitable strain to use in investigating the mechanisms underlying airway hyperreactivity and such studies will provide beneficial information for understanding the pathophysiology of asthma.

  15. Antigenicity of Dermatophilus congolensis hemolysin.

    Science.gov (United States)

    Skalka, B; Pospísil, L

    1993-05-01

    The separated cell-free form of hemolytic exosubstance was obtained from five strains of Dermatophilus congolensis. Three strains produced exosubstance with high activity, two strains produced exosubstance with lower intensity of activity. The separated forms exhibited the same hemolytic interactions as the native forms produced by growing strains, namely the antagonism with staphylococcal beta hemolysin and the synergism with staphylococcal delta hemolysin, streptococcal CAMP factor and rhodococcal equi factor. Rabbit sera obtained after intravenous or intraperitoneal application of the separated forms contained precipitation and neutralization antibodies. Cross tests of precipitation and neutralization proved antigen identity of hemolysins of different D. congolensis, strains which makes the serodiagnostics of this species possible.

  16. Killer artificial antigen-presenting cells: the synthetic embodiment of a 'guided missile'.

    Science.gov (United States)

    Schütz, Christian; Oelke, Mathias; Schneck, Jonathan P; Mackensen, Andreas; Fleck, Martin

    2010-07-01

    At present, the treatment of T-cell-dependent autoimmune diseases relies exclusively on strategies leading to nonspecific suppression of the immune systems causing a substantial reduced ability to control concomitant infections or malignancies. Furthermore, long-term treatment with most drugs is accompanied by several serious adverse effects and does not consequently result in cure of the primary immunological malfunction. By contrast, antigen-specific immunotherapy offers the potential to achieve the highest therapeutic efficiency in accordance with minimal adverse effects. Therefore, several studies have been performed utilizing antigen-presenting cells specifically engineered to deplete allo- or antigen-specific T cells ('guided missiles'). Many of these strategies take advantage of the Fas/Fas ligand signaling pathway to efficiently induce antigen-presenting cell-mediated apoptosis in targeted T cells. In this article, we discuss the advantages and shortcomings of a novel non-cell-based 'killer artificial antigen-presenting cell' strategy, developed to overcome obstacles related to current cell-based approaches for the treatment of T-cell-mediated autoimmunity.

  17. Killer artificial antigen-presenting cells: the synthetic embodiment of a ‘guided missile’

    Science.gov (United States)

    Schütz, Christian; Oelke, Mathias; Schneck, Jonathan P; Mackensen, Andreas; Fleck, Martin

    2010-01-01

    At present, the treatment of T-cell-dependent autoimmune diseases relies exclusively on strategies leading to nonspecific suppression of the immune systems causing a substantial reduced ability to control concomitant infections or malignancies. Furthermore, long-term treatment with most drugs is accompanied by several serious adverse effects and does not consequently result in cure of the primary immunological malfunction. By contrast, antigen-specific immunotherapy offers the potential to achieve the highest therapeutic efficiency in accordance with minimal adverse effects. Therefore, several studies have been performed utilizing antigen-presenting cells specifically engineered to deplete allo- or antigen-specific T cells (‘guided missiles’). Many of these strategies take advantage of the Fas/Fas ligand signaling pathway to efficiently induce antigen-presenting cell-mediated apoptosis in targeted T cells. In this article, we discuss the advantages and shortcomings of a novel non-cell-based ‘killer artificial antigen-presenting cell’ strategy, developed to overcome obstacles related to current cell-based approaches for the treatment of T-cell-mediated autoimmunity. PMID:20636007

  18. Antigen-specific T cell activation independently of the MHC: chimeric antigen receptor (CAR-redirected T cells.

    Directory of Open Access Journals (Sweden)

    Hinrich eAbken

    2013-11-01

    Full Text Available Adoptive T cell therapy has recently shown powerful in initiating a lasting anti-tumor response with spectacular therapeutic success in some cases. Specific T cell therapy, however, is limited since a number of cancer cells are not recognized by T cells due to various mechanisms including the limited availability of tumor-specific T cells and deficiencies in antigen processing or major histocompatibility complex (MHC expression of cancer cells. To make adoptive cell therapy applicable for the broad variety of cancer entities, patient's T cells are engineered ex vivo with pre-defined specificity by a recombinant chimeric antigen receptor (CAR which consists in the extracellular part of an antibody-derived domain for binding with a tumor-associated antigen and in the intracellular part of a TCR-derived signaling moiety for T cell activation. The specificity of CAR mediated T cell recognition is defined by the antibody domain, is independent of MHC presentation and can be extended to any target for which an antibody is available. We discuss the advantages and limitations of MHC-independent T cell targeting by an engineered CAR and review most significant progress recently made in early stage clinical trials to treat cancer.

  19. Isolation of Fasciola hepatica tegument antigens.

    OpenAIRE

    Hillyer, G V

    1980-01-01

    Fasciola hepatica tegument antigens were isolated from intact worms in the cold by using Nonidet P-40. Proof of the tegumental nature of the antigens was shown by the peroxidase-antiperoxidase immunocytochemical technique at the light microscope level. The potential of F. hepatica tegument antigens for the immunodiagnosis of rabbit and human fascioliasis was shown by Ouchterlony immunodiffusion, although cross-reactivity was evident in one of six serum samples from patients infected with Schi...

  20. Mediatized Humanitarianism

    DEFF Research Database (Denmark)

    Vestergaard, Anne

    2014-01-01

    The article investigates the implications of mediatization for the legitimation strategies of humanitarian organizations. Based on a (full population) corpus of ~400 pages of brochure material from 1970 to 2007, the micro-textual processes involved in humanitarian organizations' efforts to legiti......The article investigates the implications of mediatization for the legitimation strategies of humanitarian organizations. Based on a (full population) corpus of ~400 pages of brochure material from 1970 to 2007, the micro-textual processes involved in humanitarian organizations' efforts...... legitimation by accountancy, legitimation by institutionalization, and legitimation by compensation. The analysis relates these changes to a problem of trust associated with mediatization through processes of mediation....

  1. Blastogenic response of human lymphocytes to early antigen(s) of human cytomegalovirus.

    OpenAIRE

    Waner, J L; Kong, N; Biano, S

    1983-01-01

    The lymphocytes of asymptomatic, seropositive donors demonstrated blastogenic responses to early antigens of human cytomegalovirus whether or not antibodies to early antigens were detectable. The lymphocytes of six of nine patients with active cytomegalovirus infections gave stimulation indexes of greater than or equal to 2.00 with antigens of productively infected cells, whereas only two patients demonstrated comparable stimulation indexes with early antigens. Four patients with stimulation ...

  2. Antigenic cartography of H1N1 influenza viruses using sequence-based antigenic distance calculation.

    Science.gov (United States)

    Anderson, Christopher S; McCall, Patrick R; Stern, Harry A; Yang, Hongmei; Topham, David J

    2018-02-12

    The ease at which influenza virus sequence data can be used to estimate antigenic relationships between strains and the existence of databases containing sequence data for hundreds of thousands influenza strains make sequence-based antigenic distance estimates an attractive approach to researchers. Antigenic mismatch between circulating strains and vaccine strains results in significantly decreased vaccine effectiveness. Furthermore, antigenic relatedness between the vaccine strain and the strains an individual was originally primed with can affect the cross-reactivity of the antibody response. Thus, understanding the antigenic relationships between influenza viruses that have circulated is important to both vaccinologists and immunologists. Here we develop a method of mapping antigenic relationships between influenza virus stains using a sequence-based antigenic distance approach (SBM). We used a modified version of the p-all-epitope sequence-based antigenic distance calculation, which determines the antigenic relatedness between strains using influenza hemagglutinin (HA) genetic coding sequence data and provide experimental validation of the p-all-epitope calculation. We calculated the antigenic distance between 4838 H1N1 viruses isolated from infected humans between 1918 and 2016. We demonstrate, for the first time, that sequence-based antigenic distances of H1N1 Influenza viruses can be accurately represented in 2-dimenstional antigenic cartography using classic multidimensional scaling. Additionally, the model correctly predicted decreases in cross-reactive antibody levels with 87% accuracy and was highly reproducible with even when small numbers of sequences were used. This work provides a highly accurate and precise bioinformatics tool that can be used to assess immune risk as well as design optimized vaccination strategies. SBM accurately estimated the antigenic relationship between strains using HA sequence data. Antigenic maps of H1N1 virus strains reveal

  3. Purification of nonlipopolysaccharide antigen from Brucella abortus during preparation of antigen used for indirect hemolysis test.

    OpenAIRE

    Hoffmann, E M; Houle, J J

    1986-01-01

    The indirect hemolysis test (IHLT) for the diagnosis of brucellosis uses a lipopolysaccharide (LPS) antigen obtained by dimethyl sulfoxide extraction of Brucella abortus. We showed that a non-LPS antigen can be obtained as a by-product of the IHLT antigen preparation. The antigen was purified to homogeneity by a combination of gel-filtration chromatography and ion-exchange chromatography. The substance contained 8% protein and about 65% carbohydrate. The molecular weight of the primary unit w...

  4. Combination of cancer antigen 125 and carcinoembryonic antigen can improve ovarian cancer diagnosis

    DEFF Research Database (Denmark)

    Sørensen, Sofie Sølvsten; Mosgaard, Berit Jul

    2011-01-01

    The purpose of the present study was to evaluate the ability of the tumour marker carcinoembryonic antigen (CEA) in combination with cancer antigen 125 (CA-125) to differentiate between malignant ovarian and malignant non-ovarian disease.......The purpose of the present study was to evaluate the ability of the tumour marker carcinoembryonic antigen (CEA) in combination with cancer antigen 125 (CA-125) to differentiate between malignant ovarian and malignant non-ovarian disease....

  5. Human peripheral blood monocytes display surface antigens recognized by monoclonal antinuclear antibodies

    International Nuclear Information System (INIS)

    Holers, V.M.; Kotzin, B.L.

    1985-01-01

    The authors used monoclonal anti-nuclear autoantibodies and indirect immunofluorescence to examine normal human peripheral blood mononuclear leukocytes for the presence of cell surface nuclear antigens. Only one monoclonal anti-histone antibody (MH-2) was found to bind to freshly isolated PBL, staining approximately 10% of large cells. However, after cells were placed into culture for 16-24 h, a high percentage (up to 60%) of large-sized cells were recognized by an anti-DNA (BWD-1) and several different antihistone monoclonal antibodies (BWH-1, MH-1, and MH-2). These antibodies recognize separate antigenic determinants on chromatin and histones extracted from chromatin. The histone antigen-positive cells were viable, and the monoclonal antibodies could be shown to be binding to the cell surface and not to the nucleus. Using monoclonal antibodies specific for monocytes and T cells, and complement-mediated cytotoxicity, the cells bearing histone antigens were shown to be primarily monocytes. The appearance of histone and DNA antigen-positive cells was nearly completely inhibited by the addition of low concentrations of cycloheximide at initiation of the cultures. In contrast, little effect on the percentage of positive cells was detected if cells were exposed to high doses of gamma irradiation before culture. These data further support the existence of cell surface nuclear antigens on selected cell subsets, which may provide insight into the immunopathogenesis of systemic lupus erythematosus and related autoimmune diseases

  6. Isolation and partial characterization of an immunogenic antigen of Giardia lamblia.

    Science.gov (United States)

    Quintero, Jael; Valdez, Alejandra; Samaniego, Brenda; Lopez-Romero, Gloria; Astiazaran-Garcia, Humberto; Rascon, Lucila; Breci, Linda; Garibay-Escobar, Adriana; Robles-Zepeda, Ramón; Velazquez, Carlos

    2017-06-01

    Humoral and cellular immune responses play an important role during Giardia lamblia infection. Several Giardia proteins have been identified as immunogenic antigens based on their elicited humoral immune response. Poorly is known about Giardia antigens that stimulate a cellular immune response. The main purpose of this study was to isolate and partial characterize an immunogenic antigen (5G8) of G. lamblia. The 5G8 protein was isolated from G. lamblia trophozoite lysates by affinity chromatography using moAb 5G8-coupled CNBr-Sepharose. The isolated protein was analysed by electrospray tandem mass spectrometry (ESI-MS/MS), and by diverse bioinformatics tools (GiardiaDB, BLASTn, BLASTp and ExPASy). Additionally, several biochemical and immunological characteristics of the isolated protein were analysed. By ESI-MS/MS the amino acidic 5G8 sequence was deduced. The 5G8 antigen belongs to the VSP family proteins of G. lamblia. This protein is composed by one polypeptide chain (±71kDa). Using the algorithm SYFPHEITI, we identified candidate CD4 + T-cell epitopes from the 5G8 antigen, which can elicit cell-mediated immune responses. In this study, we have identified a G. lamblia protein that induces a strong immune response in infected mice. The biochemical and immunological characterization of the immunogenic 5G8 antigen may contribute to the rational design of a Giardia vaccine. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  7. Flow cytometric assay detecting cytotoxicity against human endogenous retrovirus antigens expressed on cultured multiple sclerosis cells

    DEFF Research Database (Denmark)

    Møller-Larsen, A; Brudek, T; Petersen, T

    2013-01-01

    expressing increased amounts of human endogenous retrovirus antigens. MS patients also have increased antibody levels to these antigens. The target cells are spontaneously growing peripheral blood mononuclear cells (PBMCs) of B cell lineage, expressing human endogenous retrovirus HERV epitopes...... on their surface. Polyclonal antibodies against defined peptides in the Env- and Gag-regions of the HERVs were raised in rabbits and used in antibody-dependent cell-mediated cytotoxicity (ADCC) -assays. Rituximab® (Roche), a chimeric monoclonal antibody against CD20 expressed primarily on B cells, was used...

  8. A computational framework for influenza antigenic cartography.

    Science.gov (United States)

    Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2010-10-07

    Influenza viruses have been responsible for large losses of lives around the world and continue to present a great public health challenge. Antigenic characterization based on hemagglutination inhibition (HI) assay is one of the routine procedures for influenza vaccine strain selection. However, HI assay is only a crude experiment reflecting the antigenic correlations among testing antigens (viruses) and reference antisera (antibodies). Moreover, antigenic characterization is usually based on more than one HI dataset. The combination of multiple datasets results in an incomplete HI matrix with many unobserved entries. This paper proposes a new computational framework for constructing an influenza antigenic cartography from this incomplete matrix, which we refer to as Matrix Completion-Multidimensional Scaling (MC-MDS). In this approach, we first reconstruct the HI matrices with viruses and antibodies using low-rank matrix completion, and then generate the two-dimensional antigenic cartography using multidimensional scaling. Moreover, for influenza HI tables with herd immunity effect (such as those from Human influenza viruses), we propose a temporal model to reduce the inherent temporal bias of HI tables caused by herd immunity. By applying our method in HI datasets containing H3N2 influenza A viruses isolated from 1968 to 2003, we identified eleven clusters of antigenic variants, representing all major antigenic drift events in these 36 years. Our results showed that both the completed HI matrix and the antigenic cartography obtained via MC-MDS are useful in identifying influenza antigenic variants and thus can be used to facilitate influenza vaccine strain selection. The webserver is available at http://sysbio.cvm.msstate.edu/AntigenMap.

  9. Cooperative Serum Bactericidal Activity Between Human Antibodies to Meningococcal Factor H Binding Protein and Neisserial Heparin Binding Antigen

    Science.gov (United States)

    Vu, David M.; Wong, Tracy T.; Granoff, Dan M.

    2011-01-01

    A meningococcal group B vaccine containing multiple protein antigens including factor H binding protein (fHbp) and Neisserial heparin binding antigen (NHba) is in clinical development. The ability of antibodies against individual antigens to interact and augment protective immunity is unknown. We assayed human complement-mediated bactericidal activity (SBA) in stored sera from six immunized adults before and after depletion of antibodies to fHbp and/or NHba. All six subjects developed ≥4-fold increases in SBA titer against a test strain with fHbp in the variant 1 group with an amino acid sequence that matched the vaccine antigen (GMT 95 percent of the SBA was directed against fHbp. Four subjects developed ≥4-fold increases in SBA titer against a test strain with a heterologous fHbp variant 2 antigen and a homologous NHba amino acid sequence that matched the vaccine antigen (GMT bactericidal anti-fHbp variant 1 antiserum with a mouse anti-NHba antiserum also augmented the anti-NHba SBA titer against this test strain. For meningococcal vaccines that target relatively sparsely-exposed antigens such fHbp or NHba, non-bactericidal antibodies against individual antigens can cooperate and elicit SBA. PMID:21241734

  10. Diagnostic Values of Carcinoembryonic Antigen, Cancer Antigen 15-3 and Cancer Antigen 125 Levels in Nipple Discharge.

    Science.gov (United States)

    Zhao, Song; Gai, Xiaodong; Wang, Yongmei; Liang, Weili; Gao, Haidong; Zhang, Kai; Wang, Huimin; Liu, Yanhong; Wang, Jianli; Ma, Rong

    2015-12-31

    An expedient and cost-effective diagnostic tool is needed to complement galactography and exfoliative cytology for detection of benign or malignant breast diseases with nipple discharge. The aim of this prospective study is to explore the utility of carcinoembryonic antigen, cancer antigen 15-3 and cancer antigen 125 levels in nipple discharge for the diagnosis of various breast diseases. We evaluated the pre-operative tumor marker levels in 153 nipple discharge samples collected from one or both breasts of 142 women undergoing surgery. Patients with nipple discharge underwent auxiliary examination (ultrasonography, exfoliative cytology, ductoscopy and galactography). Statistically higher levels of carcinoembryonic antigen and cancer antigen 15-3 were found in patients in the malignant group as compared to those in the benign group. No statistically significant difference in the level of cancer antigen 125 (P = 0.895). Sensitivities of carcinoembryonic antigen and cancer antigen 15-3 for diagnosing breast cancer were 74.42% and 58.14%, and specificities were 87.27% and 80.00% where as the cutoff values with max-sum of sensitivity and specificity were 224.3 ng/ml and 1368.2 U/ml, respectively. The following sensitivities for telling malignant from benign could be determined: exfoliative cytology 46.67%, ultrasonography 76.74%, galactography 75.00%, and ductoscopy 0%. Exfoliative cytology was found to be a valuable alternative method for differentiating benign from malignancy. Thus, tumor marker analysis of nipple discharge fluid for carcinoembryonic antigen and cancer antigen 15-3 would enhance the accurate assessment and treatment planning for patients with nipple discharge.

  11. HSP: bystander antigen in atopic diseases?

    Directory of Open Access Journals (Sweden)

    Joost A Aalberse

    2012-05-01

    Full Text Available Over the last years insight in the complex interactions between innate and adaptive immunity in the regulation of an inflammatory response has increased enormously. This has revived the interest in stress proteins; proteins that are expressed during cell stress. As these proteins can attract and trigger an immunological response they can act as important mediators in this interaction. In this respect, of special interest are proteins that may act as modulators of both innate and adaptive immunity. Heat shock proteins (HSPs are stress proteins that have these, and more, characteristics. More than two decades of studies on HSPs has revealed that they are part of intrinsic, natural mechanisms that steer inflammation. This has provoked comprehensive explorations of the role of HSPs in various human inflammatory diseases.Most studies have focused on classical autoimmune diseases. This has led to the development of clinical studies with HSPs that have shown promise in Phase II/III clinical trials. Remarkably, only very little is yet known of the role of HSPs in atopic diseases. In allergic disease a number of studies have investigated the possibility that allergen-specific regulatory T cell (Treg function is defective in individuals with allergic diseases. This raises the question whether methods can be identified to improve the Treg repertoire. Studies from other inflammatory diseases have suggested HSPs may have such a beneficial effect on the T cell repertoire. Based on the immune mechanisms of atopic diseases, in this review we will argue that, as in other human inflammatory conditions, understanding immunity to HSPs is likely also relevant for atopic diseases. Specifically, we will discuss why certain HSPs such as HSP60 connect the immune response to environmental antigens with regulation of the inflammatory response.Thus they provide a molecular link that may eventually even help to better understand the immune pathological basis of the hygiene

  12. Liposome-Based Adjuvants for Subunit Vaccines: Formulation Strategies for Subunit Antigens and Immunostimulators

    Directory of Open Access Journals (Sweden)

    Signe Tandrup Schmidt

    2016-03-01

    Full Text Available The development of subunit vaccines has become very attractive in recent years due to their superior safety profiles as compared to traditional vaccines based on live attenuated or whole inactivated pathogens, and there is an unmet medical need for improved vaccines and vaccines against pathogens for which no effective vaccines exist. The subunit vaccine technology exploits pathogen subunits as antigens, e.g., recombinant proteins or synthetic peptides, allowing for highly specific immune responses against the pathogens. However, such antigens are usually not sufficiently immunogenic to induce protective immunity, and they are often combined with adjuvants to ensure robust immune responses. Adjuvants are capable of enhancing and/or modulating immune responses by exposing antigens to antigen-presenting cells (APCs concomitantly with conferring immune activation signals. Few adjuvant systems have been licensed for use in human vaccines, and they mainly stimulate humoral immunity. Thus, there is an unmet demand for the development of safe and efficient adjuvant systems that can also stimulate cell-mediated immunity (CMI. Adjuvants constitute a heterogeneous group of compounds, which can broadly be classified into delivery systems or immunostimulators. Liposomes are versatile delivery systems for antigens, and they can carefully be customized towards desired immune profiles by combining them with immunostimulators and optimizing their composition, physicochemical properties and antigen-loading mode. Immunostimulators represent highly diverse classes of molecules, e.g., lipids, nucleic acids, proteins and peptides, and they are ligands for pattern-recognition receptors (PRRs, which are differentially expressed on APC subsets. Different formulation strategies might thus be required for incorporation of immunostimulators and antigens, respectively, into liposomes, and the choice of immunostimulator should ideally be based on knowledge regarding the

  13. Complex Mediation

    DEFF Research Database (Denmark)

    Bødker, Susanne; Andersen, Peter Bøgh

    2005-01-01

    This article has its starting point in a large number of empirical findings regarding computer-mediated work. These empirical findings have challenged our understanding of the role of mediation in such work; on the one hand as an aspect of communication and cooperation at work and on the other hand...... as an aspect of human engagement with instruments of work. On the basis of previous work in activity-theoretical and semiotic human—computer interaction, we propose a model to encompass both of these aspects. In a dialogue with our empirical findings we move on to propose a number of types of mediation...... that have helped to enrich our understanding of mediated work and the design of computer mediation for such work....

  14. Monoclonal antibodies against rat leukocyte surface antigens

    NARCIS (Netherlands)

    van den Berg, T. K.; Puklavec, M. J.; Barclay, A. N.; Dijkstra, C. D.

    2001-01-01

    Monoclonal antibodies have proven to be powerful tools for studying the properties of leukocyte surface antigens and the cells that express them. In the past decades many monoclonal antibodies (mAb) for identifying the different rat leukocyte surface antigens have been described. A list of mAb is

  15. Prostate-Specific Antigen (PSA) Test

    Science.gov (United States)

    ... antigen level New England Journal of Medicine 2004;350(22):2239-2246. [PubMed Abstract] Barry ... antigen testing for early diagnosis of prostate cancer. New England Journal of Medicine 2001;344(18):1373-1377. [PubMed Abstract] Pinsky ...

  16. Evaluation of an Antigen-Antibody

    African Journals Online (AJOL)

    GB

    1. ABSTRACT. BACKGROUND: Development of “combination” assays detecting in parallel, within a single test,. Hepatitis C Virus (HCV) antigens and antibodies, not ... considered above threshold of detection for antigen proteins suggested a lack of sensitivity by this assay ..... Hepatic veno-occlusive disease (sinusoidal.

  17. Vaccination and antigenic drift in influenza.

    Science.gov (United States)

    Boni, Maciej F

    2008-07-18

    The relationship between influenza antigenic drift and vaccination lies at the intersection of evolutionary biology and public health, and it must be viewed and analyzed in both contexts simultaneously. In this paper, 1 review what is known about the effects of antigenic drift on vaccination and the effects of vaccination on antigenic drift, and I suggest some simple ways to detect the presence of antigenic drift in seasonal influenza data. If antigenic drift occurs on the time scale of a single influenza season, it may be associated with the presence of herd immunity at the beginning of the season and may indicate a need to monitor for vaccine updates at the end of the season. The relationship between antigenic drift and vaccination must also be viewed in the context of the global circulation of influenza strains and the seeding of local and regional epidemics. In the data sets I consider--from New Zealand, New York, and France--antigenic drift can be statistically detected during some seasons, and seeding of epidemics appears to be endogenous sometimes and exogenous at other times. Improved detection of short-term antigenic drift and epidemic seeding would significantly benefit influenza monitoring efforts and vaccine selection.

  18. Complex Mediation

    DEFF Research Database (Denmark)

    Bødker, Susanne; Andersen, Peter Bøgh

    2005-01-01

    This article has its starting point in a large number of empirical findings regarding computer-mediated work. These empirical findings have challenged our understanding of the role of mediation in such work; on the one hand as an aspect of communication and cooperation at work and on the other hand...... as an aspect of human engagement with instruments of work. On the basis of previous work in activity-theoretical and semiotic human—computer interaction, we propose a model to encompass both of these aspects. In a dialogue with our empirical findings we move on to propose a number of types of mediation...

  19. 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

  20. Effect of praziquantel treatment during pregnancy on cytokine responses to schistosome antigens

    DEFF Research Database (Denmark)

    Tweyongyere, Robert; Mawa, Patrice A.; Ngom-Wegi, Sophy

    2008-01-01

    Praziquantel treatment of schistosomiasis boosts antischistosome responses, with type 2 helper T cell bias that may contribute to immunologically mediated killing and to protection against reinfection. Praziquantel treatment during pregnancy was recommended in 2002, but the immunological effects....... Cytokine responses to S. mansoni worm and egg antigens were measured in whole blood culture before and 6 weeks after each treatment. RESULTS: Schistosome-specific cytokine responses were suppressed during pregnancy. Praziquantel treatment during pregnancy caused significant boosts in interferon-gamma (IFN......-gamma), interleukin (IL)-2, IL-4, IL-5, IL-13, and IL-10 responses to schistosome worm antigen and in IFN-gamma, IL-5, and IL-13 responses to schistosome egg antigen, but these boosts were not as substantial as those seen for women treated after delivery. CONCLUSION: Pregnancy suppresses a potentially beneficial...

  1. Antigenic variation: Molecular and genetic mechanisms of relapsing disease

    Energy Technology Data Exchange (ETDEWEB)

    Cruse, J.M.; Lewis, R.E.

    1987-01-01

    This book contains 10 chapters. They are: Contemporary Concepts of Antigenic Variation; Antigenic Variation in the Influenza Viruses; Mechanisms of Escape of Visna Lentiviruses from Immunological Control; A Review of Antigenic Variation by the Equine Infectious Anemia Virus; Biologic and Molecular Variations in AIDS Retrovirus Isolates; Rabies Virus Infection: Genetic Mutations and the Impact on Viral Pathogenicity and Immunity; Immunobiology of Relapsing Fever; Antigenic Variation in African Trypanosomes; Antigenic Variation and Antigenic Diversity in Malaria; and Mechanisms of Immune Evasion in Schistosomiasis.

  2. EpsinR, a target for pyrenocine B, role in endogenous MHC-II-restricted antigen presentation.

    Science.gov (United States)

    Shishido, Tatsuya; Hachisuka, Masami; Ryuzaki, Kai; Miura, Yuko; Tanabe, Atsushi; Tamura, Yasuaki; Kusayanagi, Tomoe; Takeuchi, Toshifumi; Kamisuki, Shinji; Sugawara, Fumio; Sahara, Hiroeki

    2014-11-01

    While the presentation mechanism of antigenic peptides derived from exogenous proteins by MHC class II molecules is well understood, relatively little is known about the presentation mechanism of endogenous MHC class II-restricted antigens. We therefore screened a chemical library of 200 compounds derived from natural products to identify inhibitors of the presentation of endogenous MHC class II-restricted antigens. We found that pyrenocine B, a compound derived from the fungus Pyrenochaeta terrestris, inhibits presentation of endogenous MHC class II-restricted minor histocompatibility antigen IL-4 inducible gene 1 (IL4I1) by primary dendritic cells (DCs). Phage display screening and surface plasmon resonance (SPR) analysis were used to investigate the mechanism of suppressive action by pyrenocine B. EpsinR, a target molecule for pyrenocine B, mediates endosomal trafficking through binding of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs). Lentiviral-mediated short hairpin (sh) RNA downregulation of EpsinR expression in DCs resulted in a decrease in the responsiveness of CD4+ T cells. Our data thus suggest that EpsinR plays a role in antigen presentation, which provides insight into the mechanism of presentation pathway of endogenous MHC class II-restricted antigen. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Posttransplant chimeric antigen receptor therapy.

    Science.gov (United States)

    Smith, Melody; Zakrzewski, Johannes; James, Scott; Sadelain, Michel

    2018-03-08

    Therapeutic T-cell engineering is emerging as a powerful approach to treat refractory hematological malignancies. Its most successful embodiment to date is based on the use of second-generation chimeric antigen receptors (CARs) targeting CD19, a cell surface molecule found in most B-cell leukemias and lymphomas. Remarkable complete remissions have been obtained with autologous T cells expressing CD19 CARs in patients with relapsed, chemo-refractory B-cell acute lymphoblastic leukemia, chronic lymphocytic leukemia, and non-Hodgkin lymphoma. Allogeneic CAR T cells may also be harnessed to treat relapse after allogeneic hematopoietic stem cell transplantation. However, the use of donor T cells poses unique challenges owing to potential alloreactivity. We review different approaches to mitigate the risk of causing or aggravating graft-versus-host disease (GVHD), including CAR therapies based on donor leukocyte infusion, virus-specific T cells, T-cell receptor-deficient T cells, lymphoid progenitor cells, and regulatory T cells. Advances in CAR design, T-cell selection and gene editing are poised to enable the safe use of allogeneic CAR T cells without incurring GVHD. © 2018 by The American Society of Hematology.

  4. Demonstration of Antigenic Identity Between Purified Equine Infectious Anemia Virus and an Antigen Extracted from Infected Horse Spleen

    Science.gov (United States)

    Nakajima, Hideo; Norcross, Neil L.; Coggins, Leroy

    1972-01-01

    Antigenic relationship between purified equine infectious anemia (EIA) virus and spleen-derived antigen from EIA-infected horses was examined by immunodiffusion. Identical antigenicity of these two antigens has been proven because precipitation lines formed between the two antigens and EIA antiserum connected with each other. The results indicate that the antigenic substance derived from infected spleen is a component of EIA virus. Images PMID:4629262

  5. Indirect haemagglutination reaction with Sarcocystis dispersa antigen.

    Science.gov (United States)

    Cerva, L; Cerná, Z

    1982-01-01

    A description is given of the preparation of antigen from Sarcocystis dispersa cystozoites and the procedure of the indirect haemagglutination test (IHA). The antibodies against this antigen were detected in experimentally infected mice from day 20 p.i. (1: 640). In the following weeks the antibody titres reached the value of 1: 40,960. The sera of pigs, sheep and horses spontaneously infected with other Sarcocystis species reacted with this antigen in low titres only. The bovine sera gave negative reactions even in cases when Sarcocystis cysts were present in the muscles of the examined animals. A possible application of IHA for the research and diagnostic purposes is discussed.

  6. Sublingual Administration of an Adenovirus Serotype 5 (Ad5)-Based Vaccine Confirms Toll-Like Receptor Agonist Activity in the Oral Cavity and Elicits Improved Mucosal and Systemic Cell-Mediated Responses against HIV Antigens despite Preexisting Ad5 Immunity ▿

    Science.gov (United States)

    Appledorn, Daniel M.; Aldhamen, Yasser A.; Godbehere, Sarah; Seregin, Sergey S.; Amalfitano, Andrea

    2011-01-01

    HIV/AIDS continue to devastate populations worldwide. Recent studies suggest that vaccines that induce beneficial immune responses in the mucosal compartment may improve the efficacy of HIV vaccines. Adenovirus serotype 5 (Ad5)-based vectors remain a promising platform for the development of effective vaccines. In an effort to improve the efficacy of Ad5-based vaccines, even in the presence of preexisting Ad5 immunity, we evaluated the potential for an Ad5-based HIV vaccine to induce antigen-specific immune responses following sublingual (s.l.) administration, a route not previously tested in regard to Ad-based vaccines. s.l. vaccination with an Ad5-based HIV-Gag vaccine resulted in a significant induction of Gag-specific cytotoxic T-lymphocyte (CTL) responses in both the systemic and the mucosal compartment. We also show that s.l. immunization not only avoided preexisting Ad5 immunity but also elicited a broad repertoire of antigen-specific CTL clones. Additionally, we confirm for the first time that oral delivery of a vaccine expressing a potent Toll-like receptor (TLR) agonist can stimulate innate immune responses through induction of cytokines and chemokines and activation of NK cells, NKT cells, and macrophages in vivo. These results positively correlated with improved antigen-specific CTL responses. These results could be achieved both in Ad5-naïve mice and in mice with preexisting immunity to Ad5. The simplicity of the s.l. vaccination regimen coupled with augmentation of TLR-dependent pathways active in the oral cavity makes s.l. delivery a promising method for HIV vaccine development specifically, as well as for many other vaccine applications in general. PMID:21084461

  7. Enhancement of DNA vaccine potency through linkage of antigen to filamentous bacteriophage coat protein III domain I

    DEFF Research Database (Denmark)

    Cuesta, Àngel M; Suárez, Eduardo; Larsen, Martin

    2006-01-01

    Although DNA-based cancer vaccines have been successfully tested in mouse models, a major drawback of cancer vaccination still remains, namely that tumour antigens are weak and fail to generate a vigorous immune response in tumour-bearing patients. Genetic technology offers strategies for promoting...... immune pathways by adding immune-activating genes to the tumour antigen sequence. In this work, we converted a model non-immunogenic antigen into a vaccine by fusing it to domain I of the filamentous bacteriophage coat protein III gene. Vaccination with a DNA construct encoding the domain I fusion...... generated antigen-specific T helper 1-type cellular immune responses. These results demonstrate that the incorporation of protein III into a DNA vaccine formulation can modulate the gene-mediated immune response and may thus provide a strategy for improving its therapeutic effect....

  8. Transgenic Carrot Expressing Fusion Protein Comprising M. tuberculosis Antigens Induces Immune Response in Mice

    Directory of Open Access Journals (Sweden)

    Natalia V. Permyakova

    2015-01-01

    Full Text Available Tuberculosis remains one of the major infectious diseases, which continues to pose a major global health problem. Transgenic plants may serve as bioreactors to produce heterologous proteins including antibodies, antigens, and hormones. In the present study, a genetic construct has been designed that comprises the Mycobacterium tuberculosis genes cfp10, esat6 and dIFN gene, which encode deltaferon, a recombinant analog of the human γ-interferon designed for expression in plant tissues. This construct was transferred to the carrot (Daucus carota L. genome by Agrobacterium-mediated transformation. This study demonstrates that the fusion protein CFP10-ESAT6-dIFN is synthesized in the transgenic carrot storage roots. The protein is able to induce both humoral and cell-mediated immune responses in laboratory animals (mice when administered either orally or by injection. It should be emphasized that M. tuberculosis antigens contained in the fusion protein have no cytotoxic effect on peripheral blood mononuclear cells.

  9. The Molecular Determinants of Antibody Recognition and Antigenic Drift in the H3 Hemagglutinin of Swine Influenza A Virus

    Science.gov (United States)

    Abente, Eugenio J.; Santos, Jefferson; Lewis, Nicola S.; Gauger, Phillip C.; Stratton, Jered; Skepner, Eugene; Rajao, Daniela S.

    2016-01-01

    ABSTRACT Influenza A virus (IAV) of the H3 subtype is an important respiratory pathogen that affects both humans and swine. Vaccination to induce neutralizing antibodies against the surface glycoprotein hemagglutinin (HA) is the primary method used to control disease. However, due to antigenic drift, vaccine strains must be periodically updated. Six of the 7 positions previously identified in human seasonal H3 (positions 145, 155, 156, 158, 159, 189, and 193) were also indicated in swine H3 antigenic evolution. To experimentally test the effect on virus antigenicity of these 7 positions, substitutions were introduced into the HA of an isogenic swine lineage virus. We tested the antigenic effect of these introduced substitutions by using hemagglutination inhibition (HI) data with monovalent swine antisera and antigenic cartography to evaluate the antigenic phenotype of the mutant viruses. Combinations of substitutions within the antigenic motif caused significant changes in antigenicity. One virus mutant that varied at only two positions relative to the wild type had a >4-fold reduction in HI titers compared to homologous antisera. Potential changes in pathogenesis and transmission of the double mutant were evaluated in pigs. Although the double mutant had virus shedding titers and transmissibility comparable to those of the wild type, it caused a significantly lower percentage of lung lesions. Elucidating the antigenic effects of specific amino acid substitutions at these sites in swine H3 IAV has important implications for understanding IAV evolution within pigs as well as for improved vaccine development and control strategies in swine. IMPORTANCE A key component of influenza virus evolution is antigenic drift mediated by the accumulation of amino acid substitutions in the hemagglutinin (HA) protein, resulting in escape from prior immunity generated by natural infection or vaccination. Understanding which amino acid positions of the HA contribute to the ability

  10. Differing patterns of selection and geospatial genetic diversity within two leading Plasmodium vivax candidate vaccine antigens.

    Directory of Open Access Journals (Sweden)

    Christian M Parobek

    2014-04-01

    Full Text Available Although Plasmodium vivax is a leading cause of malaria around the world, only a handful of vivax antigens are being studied for vaccine development. Here, we investigated genetic signatures of selection and geospatial genetic diversity of two leading vivax vaccine antigens--Plasmodium vivax merozoite surface protein 1 (pvmsp-1 and Plasmodium vivax circumsporozoite protein (pvcsp. Using scalable next-generation sequencing, we deep-sequenced amplicons of the 42 kDa region of pvmsp-1 (n = 44 and the complete gene of pvcsp (n = 47 from Cambodian isolates. These sequences were then compared with global parasite populations obtained from GenBank. Using a combination of statistical and phylogenetic methods to assess for selection and population structure, we found strong evidence of balancing selection in the 42 kDa region of pvmsp-1, which varied significantly over the length of the gene, consistent with immune-mediated selection. In pvcsp, the highly variable central repeat region also showed patterns consistent with immune selection, which were lacking outside the repeat. The patterns of selection seen in both genes differed from their P. falciparum orthologs. In addition, we found that, similar to merozoite antigens from P. falciparum malaria, genetic diversity of pvmsp-1 sequences showed no geographic clustering, while the non-merozoite antigen, pvcsp, showed strong geographic clustering. These findings suggest that while immune selection may act on both vivax vaccine candidate antigens, the geographic distribution of genetic variability differs greatly between these two genes. The selective forces driving this diversification could lead to antigen escape and vaccine failure. Better understanding the geographic distribution of genetic variability in vaccine candidate antigens will be key to designing and implementing efficacious vaccines.

  11. Leukemia Associated Antigens: Their Dual Role as Biomarkers and Immunotherapeutic Targets for Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Michael Schmitt

    2007-01-01

    Full Text Available Leukemia associated antigens (LAAs are being increasingly identified by methods such as cytotoxic T-lymphocyte (CTL cloning, serological analysis of recombinant cDNA expression libraries (SEREX and mass spectrometry (MS. In additional, large scale screening techniques such as microarray, single nucleotide polymorphisms (SNPs, serial analysis of gene expression (SAGE and 2-dimensional gel electrophoresis (2-DE have expanded our understanding of the role that tumor antigens play in the biological processes which are perturbed in acute myeloid leukemia (AML. It has become increasingly apparent that these antigens play a dual role, not only as targets for immunotherapy, but also as biomarkers of disease state, stage, response to treatment and survival. We need biomarkers to enable the identification of the patients who are most likely to benefit from specific treatments (conventional and/or novel and to help clinicians and scientists improve clinical end points and treatment design. Here we describe the LAAs identified in AML, to date, which have already been shown to play a dual role as biomarkers of AML disease.Abbreviations: AML: acute myeloid leukemia; APL: acute promyelocytic leukemia; ATRA: all-trans-retinoic acid; B-CLL: B-cell chronic lymphocytic leukemia; CT: cancer-testis; CTL: cytotoxic T-lymphocyte; FAB: French-American-British; HI: hypusination inhibitors; HSP: heat shock protein; ITD: internal tandem duplication; LAA: leukemia associated antigen; MDS: myelodysplastic syndrome; MGEA6: meningioma antigen 6; MPD: myeloproliferative disease; MS: mass spectrometry; NK: natural killer; PRAME: preferentially expressed antigen of melanoma; PRTN3: proteinase 3; RAGE-1: renal antigen 1; RHAMM: receptor for hyaluronic acid-mediated motility; RQ-PCR: real-time PCR; SAGE: serial analysis of gene expression; SCT: stem cell transplant; SEREX: serological analysis of recombinant cDNA expression libraries; SNPs: single nucleotide polymorphisms; UPD

  12. Antigen delivery to macrophages using liposomal nanoparticles targeting sialoadhesin/CD169.

    Directory of Open Access Journals (Sweden)

    Weihsu C Chen

    Full Text Available Sialoadhesin (Sn, Siglec-1, CD169 is a member of the sialic acid binding Ig-like lectin (siglec family expressed on macrophages. Its macrophage specific expression makes it an attractive target for delivering antigens to tissue macrophages via Sn-mediated endocytosis. Here we describe a novel approach for delivering antigens to macrophages using liposomal nanoparticles displaying high affinity glycan ligands of Sn. The Sn-targeted liposomes selectively bind to and are internalized by Sn-expressing cells, and accumulate intracellularly over time. Our results show that ligand decorated liposomes are specific for Sn, since they are taken up by bone marrow derived macrophages that are derived from wild type but not Sn(-/- mice. Importantly, the Sn-targeted liposomes dramatically enhance the delivery of antigens to macrophages for presentation to and proliferation of antigen-specific T cells. Together, these data provide insights into the potential of cell-specific targeting and delivery of antigens to intracellular organelles of macrophages using Sn-ligand decorated liposomal nanoparticles.

  13. Augmentation of antigen-specific immune responses using DNA-fusogenic liposome vaccine

    International Nuclear Information System (INIS)

    Yoshikawa, Tomoaki; Imazu, Susumu; Gao Jianqing; Hayashi, Kazuyuki; Tsuda, Yasuhiro; Shimokawa, Mariko; Sugita, Toshiki; Niwa, Takako; Oda, Atushi; Akashi, Mitsuru; Tsutsumi, Yasuo; Mayumi, Tadanori; Nakagawa, Shinsaku

    2004-01-01

    In an attempt to enhance the immunological efficacy of genetic immunization, we investigated a new biological means for delivering antigen gene directly to the cytoplasm via membrane fusion. In this context, we investigated fusogenic liposome (FL) encapsulating DNA as a possible genetic immunization vehicle. RT-PCR analysis indicated that a FL could introduce and express encapsulating OVA gene efficiently and rapidly in vitro. Consistent with this observation, an in vitro assay showed that FL-mediated antigen-gene delivery can induce potent presentation of antigen via the MHC class I-dependent pathway. Accordingly, immunization with FL containing the OVA-gene induced potent OVA-specific Th1 and Th2 cytokine production. Additionally, OVA-specific CTL responses and antibody production were also observed in systemic compartments including the spleen, upon immunization with the OVA-gene encapsulating FL. These findings suggest that FL is an effective genetic immunization carrier system for the stimulation of antigen-specific immune responses against its encoding antigen

  14. Immune responses induced by diclofenac or carbamazepine in an oral exposure model using TNP-Ficoll as reporter antigen

    NARCIS (Netherlands)

    Kwast, Lydia; Aida, Tetsuo; Fiechter, Daniëlle; Kruijssen, Laura; Bleumink, Rob; Boon, Louis; Ludwig, Irene; Pieters, Raymond

    2016-01-01

    Immune-mediated drug hypersensitivity reactions (IDHR) may result from immuno-sensitization to a drug-induced neo-antigen. They rarely occur in patients and are usually not predicted preclinically using standard toxicity studies. To assess the potential of a drug to induce T-cell sensitization,

  15. Tissue polypeptide antigen activity in cerebrospinal fluid

    DEFF Research Database (Denmark)

    Bach, F; Söletormos, Georg; Dombernowsky, P

    1991-01-01

    Tissue polypeptide antigen (TPpA) in the cerebrospinal fluid (CSF) was measured in 59 consecutive breast cancer patients with suspected central nervous system (CNS) metastases. Subsequently, we determined that 13 patients had parenchymal brain metastases, 10 had leptomeningeal carcinomatosis...

  16. HLA antigens in three populations of India.

    Science.gov (United States)

    Papiha, S S; Wentzel, J; Shah, K C; Roberts, D F

    1989-01-01

    In blood samples from a Hindu population of Uttar Pradesh (North India) and from two Muslim groups, one from Andhra Pradesh (South India) and the other from Gujurat (West India), frequencies of 38 HLA-A, -B and -C antigens were investigated. Eight antigens - A23, A25, A29, A32, Bw45, B21, Bw22 and Bw53 - were absent in the Hindu population, four different antigens - A29, Bw52, B14 and Bw42 - were absent in Hyderabad Muslims, two antigens - A31 and Bw45 - were lacking in Surat Muslims. The three populations showed considerable genetic heterogeneity. The genetic difference between the two Muslim groups was small, but the Hindu population showed pronounced differences from each of the Muslim groups.

  17. 9 CFR 113.407 - Pullorum antigen.

    Science.gov (United States)

    2010-01-01

    ... determined by a colorimetric method. (2) The phenol content for Pullorum Tube Antigen shall be 0.55 ±0.05 percent as determined by direct titration with a standardized bromide-bromate solution. (d) Sensitivity...

  18. Tumor-Associated Antigens for Specific Immunotherapy of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Marc Schmitz

    2012-02-01

    Full Text Available Prostate cancer (PCa is the most common noncutaneous cancer diagnosis and the second leading cause of cancer-related deaths among men in the United States. Effective treatment modalities for advanced metastatic PCa are limited. Immunotherapeutic strategies based on T cells and antibodies represent interesting approaches to prevent progression from localized to advanced PCa and to improve survival outcomes for patients with advanced disease. CD8+ cytotoxic T lymphocytes (CTLs efficiently recognize and destroy tumor cells. CD4+ T cells augment the antigen-presenting capacity of dendritic cells and promote the expansion of tumor-reactive CTLs. Antibodies mediate their antitumor effects via antibody-dependent cellular cytotoxicity, activation of the complement system, improving the uptake of coated tumor cells by phagocytes, and the functional interference of biological pathways essential for tumor growth. Consequently, several tumor-associated antigens (TAAs have been identified that represent promising targets for T cell- or antibody-based immunotherapy. These TAAs comprise proteins preferentially expressed in normal and malignant prostate tissues and molecules which are not predominantly restricted to the prostate, but are overexpressed in various tumor entities including PCa. Clinical trials provide evidence that specific immunotherapeutic strategies using such TAAs represent safe and feasible concepts for the induction of immunological and clinical responses in PCa patients. However, further improvement of the current approaches is required which may be achieved by combining T cell- and/or antibody-based strategies with radio-, hormone-, chemo- or antiangiogenic therapy.

  19. Tumor-Associated Antigens for Specific Immunotherapy of Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kiessling, Andrea [Biologics Safety and Disposition, Preclinical Safety, Translational Sciences, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Werk Klybeck, Klybeckstraße 141, Basel CH-4057 (Switzerland); Wehner, Rebekka [Institute of Immunology, Medical Faculty, University of Technology Dresden, Fetscherstraße 74, Dresden 01307 (Germany); Füssel, Susanne [Department of Urology, Medical Faculty, University of Technology Dresden, Fetscherstraße 74, Dresden 01307 (Germany); Bachmann, Michael [Institute of Immunology, Medical Faculty, University of Technology Dresden, Fetscherstraße 74, Dresden 01307 (Germany); Wirth, Manfred P. [Department of Urology, Medical Faculty, University of Technology Dresden, Fetscherstraße 74, Dresden 01307 (Germany); Schmitz, Marc, E-mail: marc.schmitz@tu-dresden.de [Institute of Immunology, Medical Faculty, University of Technology Dresden, Fetscherstraße 74, Dresden 01307 (Germany)

    2012-02-22

    Prostate cancer (PCa) is the most common noncutaneous cancer diagnosis and the second leading cause of cancer-related deaths among men in the United States. Effective treatment modalities for advanced metastatic PCa are limited. Immunotherapeutic strategies based on T cells and antibodies represent interesting approaches to prevent progression from localized to advanced PCa and to improve survival outcomes for patients with advanced disease. CD8{sup +} cytotoxic T lymphocytes (CTLs) efficiently recognize and destroy tumor cells. CD4{sup +} T cells augment the antigen-presenting capacity of dendritic cells and promote the expansion of tumor-reactive CTLs. Antibodies mediate their antitumor effects via antibody-dependent cellular cytotoxicity, activation of the complement system, improving the uptake of coated tumor cells by phagocytes, and the functional interference of biological pathways essential for tumor growth. Consequently, several tumor-associated antigens (TAAs) have been identified that represent promising targets for T cell- or antibody-based immunotherapy. These TAAs comprise proteins preferentially expressed in normal and malignant prostate tissues and molecules which are not predominantly restricted to the prostate, but are overexpressed in various tumor entities including PCa. Clinical trials provide evidence that specific immunotherapeutic strategies using such TAAs represent safe and feasible concepts for the induction of immunological and clinical responses in PCa patients. However, further improvement of the current approaches is required which may be achieved by combining T cell- and/or antibody-based strategies with radio-, hormone-, chemo- or antiangiogenic therapy.

  20. Formation of potential antigens from radiographic contrast media

    International Nuclear Information System (INIS)

    Nilsson, R.; Ehrenberg, L.; Fedorcsak, I.

    1987-01-01

    The use of radiographic contrast media is occasionally accompanied by more or less serious adverse effects, evidently of complex etiology, following intravascular administration. Some of these reactions are suspected of having an allergic basis. The in vitro and in vivo formation of iodinated serum proteins following gamma irradiation in the presence of two commonly used radiographic contrast media is demonstrated. Non-toxic concentrations of ascorbate present during the irradiation is shown to prevent the formation of such iodo-proteins in vitro as well as in vivo. The amounts of potentially antigenic iodoprotein formed during radiographic procedures will certainly be very small, but this quantity may be sufficient to elicit a hypersensitivity reaction in cases when an individual has been previously sensitized to immunologically similar iodo-proteins, a mechanism that could account for certain rare and unpredictable reations. The radiation induced formation of iodo-proteins may also serve as a model for the formation of iodine containing antigens mediated by a free radical mechanism, i.e. in the metabolism of iodinated compounds like erythrosine, a widely used colouring agent for certain foods. (orig.)

  1. Carcinoembryonic antigen in thyroid cancer

    International Nuclear Information System (INIS)

    Weissel, M.; Hoefer, R.

    1982-01-01

    In order to investigate the usefulness of determining the serum concentrations of carcinoembryonic antigen (CEA) as a specific tumor marker in thyroid cancer, CEA serum levels were measured (enzymeimmunoassay, Abbott-Kit) repeatedly at the routine followup checks performed at various intervals after total thyroidectomy, in 65 patients with papillary, 82 with follicular, 25 with mixed type (papillary/follicular), 8 with anaplastic, and in 18 patients with medullary thyroid cancer. The postoperative observation period of these patients ranged from 2 to 36 months. Calcitonin serum levels were additionally determined in patients with medullary carcinoma (radioimmunoassay kit of Immuno-Nuclear Corp.). In the family of one patient with medullary carcinoma we also had an opportunity to investigate, within the framework of family screening (pentagastrin tests, etc.), the value of preoperative CEA determination. In the patients with ''non-medullary'' histological types of thyroid cancer, the maximum CEA serum concentration was 9.8 ng/ml. 6% of the patients with papillary, 9% of the patients with follicular, and 8% of those with mixed type thyroid cancer had serum levels above the upper limit of our normal range (5 ng/ml). All patients with anaplastic carcinoma had values below 3 ng/ml. The values quoted represent maximal values and were confirmed at various follow-up checks. However, 1 year after thyroidectomy, a female patient with follicular thyroid carcinoma developed an adenocarcinoma of the rectum: The CEA levels measured in this patient were: 4.2 ng/ml 3 weeks after thyroidectomy, 8.4 ng/ml 6 months later, and 37 ng/ml 1 week before operation on the rectum. In none of the other patients with elevated CEA levels were metastases of thyroid cancer, or any other malignancy, detected. (orig.) [de

  2. The redefinition of Helicobacter pylori lipopolysaccharide O-antigen and core-oligosaccharide domains

    Science.gov (United States)

    Debowski, Aleksandra W.; Nilsson, Hans-Olof; Fulurija, Alma; Dell, Anne; Stubbs, Keith A.; Marshall, Barry J.

    2017-01-01

    Helicobacter pylori lipopolysaccharide promotes chronic gastric colonisation through O-antigen host mimicry and resistance to mucosal antimicrobial peptides mediated primarily by modifications of the lipid A. The structural organisation of the core and O-antigen domains of H. pylori lipopolysaccharide remains unclear, as the O-antigen attachment site has still to be identified experimentally. Here, structural investigations of lipopolysaccharides purified from two wild-type strains and the O-antigen ligase mutant revealed that the H. pylori core-oligosaccharide domain is a short conserved hexasaccharide (Glc-Gal-DD-Hep-LD-Hep-LD-Hep-KDO) decorated with the O-antigen domain encompassing a conserved trisaccharide (-DD-Hep-Fuc-GlcNAc-) and variable glucan, heptan and Lewis antigens. Furthermore, the putative heptosyltransferase HP1284 was found to be required for the transfer of the third heptose residue to the core-oligosaccharide. Interestingly, mutation of HP1284 did not affect the ligation of the O-antigen and resulted in the attachment of the O-antigen onto an incomplete core-oligosaccharide missing the third heptose and the adjoining Glc-Gal residues. Mutants deficient in either HP1284 or O-antigen ligase displayed a moderate increase in susceptibility to polymyxin B but were unable to colonise the mouse gastric mucosa. Finally, mapping mutagenesis and colonisation data of previous studies onto the redefined organisation of H. pylori lipopolysaccharide revealed that only the conserved motifs were essential for colonisation. In conclusion, H. pylori lipopolysaccharide is missing the canonical inner and outer core organisation. Instead it displays a short core and a longer O-antigen encompassing residues previously assigned as the outer core domain. The redefinition of H. pylori lipopolysaccharide domains warrants future studies to dissect the role of each domain in host-pathogen interactions. Also enzymes involved in the assembly of the conserved core structure

  3. Antigenic variation in vector-borne pathogens.

    OpenAIRE

    Barbour, A. G.; Restrepo, B. I.

    2000-01-01

    Several pathogens of humans and domestic animals depend on hematophagous arthropods to transmit them from one vertebrate reservoir host to another and maintain them in an environment. These pathogens use antigenic variation to prolong their circulation in the blood and thus increase the likelihood of transmission. By convergent evolution, bacterial and protozoal vector-borne pathogens have acquired similar genetic mechanisms for successful antigenic variation. Borrelia spp. and Anaplasma marg...

  4. Allosensibilisation to erythrocyte antigens (literature review

    Directory of Open Access Journals (Sweden)

    N. V. Mineeva

    2015-01-01

    Full Text Available In this article literature review of the causes of allosensibilisation to erythrocyte antigens are presented. It is shown that the ability to produce antierythrocyte antibodies is affected by many factors, principal of whom it is difficult to identify. For the allosensibilisation development requires genetically determined differences in erythrocyte antigens phenotypes of donor and recipient, mother and fetus, which can lead to immune response and antibodies production. The biochemical nature of erythrocyte antigens, antigen dose (the amount of transfused doses, the number of antigens determinants on donor and fetus erythrocytes, the number of pregnancies are important. Individual patient characteristics: age, gender, diseases, the use of immunosuppressive therapy and the presence of inflammatory processes, are also relevant. Note that antibody to one erythrocyte antigens have clinical value, and to the other – have no. The actual data about frequency of clinically significant antibodies contribute to the development of post-transfusion hemolytic complications prophylaxis as well as the improvement of laboratory diagnosis of hemolytic disease of the newborn in the presence of maternal antierythrocyte antibodies.

  5. [Antigenic relations of several strains of Naegleria].

    Science.gov (United States)

    Zubiaur, E; Alonso, P

    1987-02-01

    In previous papers different aspects of one strain of Naegleria lovaniensis (Aq/9/1/45D) and two strains of N. gruberi (1518/le and 1518/lf) have been studied. From the results obtained it can be concluded that each strain behaves differently; no more similarities have been found between both N. gruberi strains, than between each of these and N. lovaniensis. Such an event has prompted us to characterize their antigenic relationships by means of an immunoprecipitation assay (double diffusion in plate). Each antiserum was tested against the different antigenic extracts. For N. lovaniensis, besides the whole extract, two fractions (particulate and soluble) and their respective antisera were assayed separately. No reaction occurred between any of the anti-N. lovaniensis sera and either of the two N. gruberi extracts. The antiserum to N. gruberi 1518/lf reacted only with its homologue and with N. lovaniensis antigens. Both N. lovaniensis fractions share some antigenic components being more complex the antigenic structure of the soluble fraction. Therefore no more similarities occur between both N. gruberi strains than between each one and N. lovaniensis, rather N. gruberi 1518/le exhibits more antigenic relationships with N. lovaniensis than with 1518/lf strains. In view of such results the species N. gruberi should be taxonomically reconsidered, criterium shared by other authors.

  6. MHC class I is functionally associated with antigen receptors in human T and B lymphomas

    DEFF Research Database (Denmark)

    Pedersen, Anders Elm; Jacoby, B F; Skov, S

    1996-01-01

    lines the increase in [Ca2+]i after MHC-I cross-linking caused upregulation of CD69, an early marker of activation. When studying the effect of MHC-I cross-linking on the TCR- and B cell antigen receptor (BCR)- mediated increase in [Ca2+]i, respectively, we observed that MHC-I had a costimulatory effect...... on the TCR-mediated increase in [Ca2+]i in Jurkat cells but not on the anti-IgM-mediated activity of Solubo cells. Studies of subpopulations of Jurkat and Solubo cells expressing different levels of MHC-I on their cell surfaces revealed that the TCR- and BCR-mediated increases in [Ca2+]i, respectively, were...

  7. Mediatized play

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    Children’s play must nowadays be understood as a mediatized field in society and culture. Media – understood in a very broad sense - holds severe explanatory power in describing and understanding the practice of play, since play happens both with, through and inspired by media of different sorts....... In this presentation the case of ‘playing soccer’ will be outlined through its different mediated manifestations, including soccer games and programs on TV, computer games, magazines, books, YouTube videos and soccer trading cards....

  8. Mediating Business

    DEFF Research Database (Denmark)

    "Mediating Business" is a study of the expansion of business journalism. Building on evidence from Denmark, Finland, Norway and Sweden, "Mediating Business" is a comparative and multidisciplinary study of one of the major transformations of the mass media and the realm of business - nationally...... and globally. The book explores the history of key innovations and innovators in the business press. It analyzes changes in the discourse of business journalism associated with the growth in business news and the development of new ways of framing business issues and events. Finally, it examines...... the organizational implications of the increased media visibility of business and, in particular, the development of corporate governance and media relations....

  9. Recognition of melanoma-derived antigens by CTL: possible mechanisms involved in down-regulating anti-tumor T-cell reactivity

    DEFF Research Database (Denmark)

    Rivoltini, L; Loftus, D J; Squarcina, P

    1998-01-01

    Several T cell-recognized epitopes presented by melanoma cells have been identified recently. Despite the large array of epitopes potentially available for clinical use, it is still unclear which of these antigens could be effective in mediating anti-tumor responses when used as a vaccine...... (detected as increased antigen-specific CTL activity in peripheral blood) was obtained by vaccinating HLA-A2.1+ melanoma patients with the immunodominant epitope (residues 27-35) of the differentiation antigen MART-1, but this immunization was not accompanied by a significant clinical response. To implement...... immunotherapeuties capable of significantly impacting disease outcome, it is necessary to identify the potential mechanisms responsible for the failure of some antigens to mediate significant anti-tumor responses in vivo. In the case of the MART-1(27-35) epitope, we hypothesize that one of these mechanisms may...

  10. VaxiJen: a server for prediction of protective antigens, tumour antigens and subunit vaccines

    Directory of Open Access Journals (Sweden)

    Flower Darren R

    2007-01-01

    Full Text Available Abstract Background Vaccine development in the post-genomic era often begins with the in silico screening of genome information, with the most probable protective antigens being predicted rather than requiring causative microorganisms to be grown. Despite the obvious advantages of this approach – such as speed and cost efficiency – its success remains dependent on the accuracy of antigen prediction. Most approaches use sequence alignment to identify antigens. This is problematic for several reasons. Some proteins lack obvious sequence similarity, although they may share similar structures and biological properties. The antigenicity of a sequence may be encoded in a subtle and recondite manner not amendable to direct identification by sequence alignment. The discovery of truly novel antigens will be frustrated by their lack of similarity to antigens of known provenance. To overcome the limitations of alignment-dependent methods, we propose a new alignment-free approach for antigen prediction, which is based on auto cross covariance (ACC transformation of protein sequences into uniform vectors of principal amino acid properties. Results Bacterial, viral and tumour protein datasets were used to derive models for prediction of whole protein antigenicity. Every set consisted of 100 known antigens and 100 non-antigens. The derived models were tested by internal leave-one-out cross-validation and external validation using test sets. An additional five training sets for each class of antigens were used to test the stability of the discrimination between antigens and non-antigens. The models performed well in both validations showing prediction accuracy of 70% to 89%. The models were implemented in a server, which we call VaxiJen. Conclusion VaxiJen is the first server for alignment-independent prediction of protective antigens. It was developed to allow antigen classification solely based on the physicochemical properties of proteins without

  11. Expression and Antigenic Evaluation of VacA Antigenic Fragment of Helicobacter Pylori

    Science.gov (United States)

    Hasanzadeh, Leila; Ghaznavi-Rad, Ehsanollah; Soufian, Safieh; Farjadi, Vahideh; Abtahi, Hamid

    2013-01-01

    Objective(s) : Helicobacter pylori, a human specific gastric pathogen is a causative agent of chronic active gastritis. The vacuolating cytotoxin (VacA) is an effective virulence factor involved in gastric injury. The aim of this study was to construct a recombinant protein containing antigenic region of VacA gene and determine its antigenicity. Materials and Methods: The antigenic region of VacA gene was detected by bioinformatics methods. The polymerase chain reaction method was used to amplify a highly antigenic region of VacA gene from chromosomal DNA of H. pylori. The eluted product was cloned into the prokaryotic expression vector pET32a. The target protein was expressed in the Escherichia coli BL21 (DE3) pLysS. The bacteria including pET32a-VacA plasmids were induced by IPTG. The antigenicity was finally studied by western blotting using sera of 15 H. pylori infected patients after purification. Results: Enzyme digestion analysis, PCR and DNA sequencing results showed that the target gene was inserted correctly into the recombinant vector. The expressed protein was purified successfully via affinity chromatography. Data indicated that antigenic region of VacA protein from Helicobacter pylori was recognized by all 15 patient’s sera. Conclusion : Our data showed that antigenic region of VacA protein can be expressed by in E. co.li. This protein was recognized by sera patients suffering from H. pylori infection. the recombinant protein has similar epitopes and close antigenic properties to the natural form of this antigen. Recombinant antigenic region of VacA protein also seems to be a promising antigen for protective and serologic diagnosis . PMID:23997913

  12. Expression and Antigenic Evaluation of VacA Antigenic Fragment of Helicobacter Pylori

    Directory of Open Access Journals (Sweden)

    Leila Hasanzadeh

    2013-07-01

    Full Text Available Objective(s: Helicobacter pylori, a human specific gastric pathogen is a causative agent of chronic active gastritis. The vacuolating cytotoxin (VacA is an effective virulence factor involved in gastric injury. The aim of this study was to construct a recombinant protein containing antigenic region of VacA gene and determine its antigenicity.   Materials and Methods: The antigenic region of VacA gene was detected by bioinformatics methods. The polymerase chain reaction method was used to amplify a highly antigenic region of VacA gene from chromosomal DNA of H. pylori. The eluted product was cloned into the prokaryotic expression vector pET32a. The target protein was expressed in the Escherichia coli BL21 (DE3 pLysS. The bacteria including pET32a-VacA plasmids were induced by IPTG. The antigenicity was finally studied by western blotting using sera of 15 H. pylori infected patients after purification. Results: Enzyme digestion analysis, PCR and DNA sequencing results showed that the target gene was inserted correctly into the recombinant vector. The expressed protein was purified successfully via affinity chromatography. Data indicated that antigenic region of VacA protein from Helicobacter pylori was recognized by all 15 patient’s sera. Conclusion : Our data showed that antigenic region of VacA protein can be expressed by in E. co.li. This protein was recognized by sera patients suffering from H. pylori infection. the recombinant protein has similar epitopes and close antigenic properties to the natural form of this antigen. Recombinant antigenic region of VacA protein also seems to be a promising antigen for protective and serologic diagnosis .

  13. Functional role of BK virus tumor antigens in transformation.

    OpenAIRE

    Nakshatri, H; Pater, M M; Pater, A

    1988-01-01

    We have examined the role of the human papovavirus BK virus (BKV) tumor (T) antigen(s) in the maintenance of transformation and have identified the domain of T antigen essential for transformation. BKV-transformed BHK 21 and NIH 3T3 cells expressing antisense T-antigen RNA lose their ability to grow in soft agar, indicating the need for the continued expression of T antigen for the maintenance of the transformed phenotype. Experiments using translation termination linker insertion and deletio...

  14. Antigenic determinant of the Lancefield group H antigen of Streptococcus sanguis.

    Science.gov (United States)

    Rosan, B; Argenbright, L

    1982-01-01

    Previous studies indicated that the teichoic acid isolated from strains of Streptococcus sanguis was group specific and defined the Lancefield group H streptococci. To determine the specific antigenic determinants, the antigen was extracted from a group H streptococcus (ATCC 903) by the phenol-water method and purified by column chromatography. The isolated antigen had a glycerol/phosphate/glucose molar ratio of 1:0.9:0.3; the lipid concentration was 7.6% of its dry weight. No nucleic acids were detected, and amino acids constituted approximately 2% of the dry weight. The minimum concentration of antigen required to sensitize erythrocytes for hemagglutination with a 1:1,000 dilution of either group H antiserum or antiteichoic acid serum was 0.02 microgram/ml. Hemagglutination inhibition studies suggested that the major antigenic determinant consisted of an alpha-glucose linked to the glycerol phosphate backbone. Images PMID:6185428

  15. [Enterobacterial antigen in human peripheral blood lymphocytes].

    Science.gov (United States)

    Faure-Fontenla, M A; García-Tamayo, F

    1989-11-01

    The following study has as prior history the research reports which have shown the existence of an antigenic tissue deposit in gram-negative enterobacteria. The antigens of the enterobacteria have also been found in the lymphocytic membranes and cytoplasm. Since intestinal lymphoid tissue cells can recirculate by means of the thoracic duct to the peripheral venous system, it was proposed that the circulating lymphocytes in healthy people could also contain small amounts of a common enterobacterial antigen. The study was carried out in 15 human venous blood samples, of which the lymphocytic population was separated to later be used in the preparation of 15 alcohol soluble extracts. This material was used for inhibiting the immuno-hemolysis assay in three occasions in order to show the presence of antigens shared by different enterobacterias, using as reference a fraction separated from the LPS of Escherichia coli 08. The results showed that the human lymphocytes also had antigenic determinants common to gram-negative bacteria.

  16. Antigen-specific acquired immunity in human brucellosis: implications for diagnosis, prognosis, and vaccine development

    Directory of Open Access Journals (Sweden)

    Anthony P Cannella

    2012-02-01

    Full Text Available Brucella spp. are facultative intracellular Gram negative bacteria with specific tropism for monocytes/macrophages. Clinical manifestations of brucellosis are primarily immune-mediated and not thought to be due to bacterial virulence factors. Acquired immunity to brucellosis has been studied through observations of naturally infected hosts (cattle, goats, laboratory mouse models, and human infection. Cell-mediated immunity drives the clinical manifestations of human disease after exposure to Brucella species but high antibody responses are not associated with protective immunity. The precise mechanisms by which cell-mediated immune responses confer protection or lead to disease manifestations remain poorly understood. Descriptive studies of immune responses in human brucellosis show that TH1 (interferon-gamma are associated with dominant immune responses, findings consistent with animal studies. Whether these T cell responses are protective, or determine the different clinical responses associated with brucellosis is unknown, especially with regard to undulant fever manifestations, relapsing disease, or are associated with responses to distinct sets of Brucella spp. antigens are unknown. Few data regarding T cell responses in terms of specific recognition of Brucella spp. protein antigens and peptidic epitopes, either by CD4+ or CD8+ T cells, have been identified in human brucellosis patients. Additionally because current attenuated Brucella vaccines used in animals cause human disease, there is a true need for a recombinant protein subunit vaccine for human brucellosis, as well as for improved diagnostics in terms of prognosis and identification of unusual forms of brucellosis. This review will focus on current understandings of antigen-specific immune responses induced by Brucella protein antigens that has promise for yielding new insights into vaccine and diagnostics development, and for understanding pathogenetic mechanisms of human

  17. Opsonic and protective properties of antibodies raised to conjugate vaccines targeting six Staphylococcus aureus antigens.

    Directory of Open Access Journals (Sweden)

    Clarissa Pozzi

    Full Text Available Staphylococcus aureus is a major cause of nosocomial and community-acquired infections for which a vaccine is greatly desired. Antigens found on the S. aureus outer surface include the capsular polysaccharides (CP of serotype 5 (CP5 or 8 (CP8 and/or a second antigen, a β-(1→6-polymer of N-acetyl-D-glucosamine (PNAG. Antibodies specific for either CP or PNAG antigens have excellent in vitro opsonic killing activity (OPKA, but when mixed together have potent interference in OPKA and murine protection. To ascertain if this interference could be abrogated by using a synthetic non-acetylated oligosaccharide fragment of PNAG, 9GlcNH(2, in place of chemically partially deacetylated PNAG, three conjugate vaccines consisting of 9GlcNH(2 conjugated to a non-toxic mutant of alpha-hemolysin (Hla H35L, CP5 conjugated to clumping factor B (ClfB, or CP8 conjugated to iron-surface determinant B (IsdB were used separately to immunize rabbits. Opsonic antibodies mediating killing of multiple S. aureus strains were elicited for all three vaccines and showed carbohydrate antigen-specific reductions in the tissue bacterial burdens in animal models of S. aureus skin abscesses, pneumonia, and nasal colonization. Carrier-protein specific immunity was also shown to be effective in reducing bacterial levels in infected lungs and in nasal colonization. However, use of synthetic 9GlcNH(2 to induce antibody to PNAG did not overcome the interference in OPKA engendered when these were combined with antibody to either CP5 or CP8. Whereas each individual vaccine showed efficacy, combining antisera to CP antigens and PNAG still abrogated individual OPKA activities, indicating difficulty in achieving a multi-valent vaccine targeting both the CP and PNAG antigens.

  18. HLA antigens, epilepsy and cytomegalovirus infection.

    Science.gov (United States)

    Iannetti, P; Morellini, M; Raucci, U; Cappellacci, S

    1988-01-01

    Thirty-one epileptic patients, selected from among 900 children with previous febrile convulsions and subsequent epilepsy, were typed for HLA antigens. In 16 of the 31 patients CMV was isolated from the urine shortly after the appearance of spontaneous fits; in the remaining 15 patients the virus was never detected. All the examined children were typed for 14 HLA-A, 23 HLA-B, 7 HLA-C and 9 HLA-DR specificities, and compared with a group of healthy subjects. The HLA-A11 antigen was present in 25% of the children with chronic CMV infection and epilepsy, and absent in patients with epilepsy but without CMV infection (p less than 0.02). The possibility that the A11 antigen is a marker of the predisposing genes for CMV infection in children with epilepsy following FC is proposed.

  19. Antigenic typing Polish isolates of canine parvovirus

    Energy Technology Data Exchange (ETDEWEB)

    Mizak, B. [National Veterinary Research Institute, Pulawy (Poland); Plucienniczak, A. [Polish Academy ofd Sciences. Microbiology and Virology Center, Lodz (Poland)

    1995-12-31

    Polish strains of canine parvovirus isolated between 1982 and 1993 were examined to determine the extent to which the virus has evolved antigenically and genetically over eleven years. Two CPV isolates obtained in Warsaw in 1982 and Pulawy in 1993, were examined using monoclonal antibody typing, restriction analysis and sequencing VP-2 protein gene. Five other isolates from Warsaw and Pulawy were tested with the panel of monoclonal antibodies specific to CPV-2, CPV-2a and common for canine parvovirus, feline panleukopenia virus and milk enteritis virus. Results of the studies demonstrated that all isolates tested represented CPV-2a antigenic type. Rapid antigenic strain replacement recorded by Parrish and Senda in the U.S.A and Japan was not confirmed in Poland. (author). 30 refs, 2 tabs.

  20. Idiopathic focal segmental glomerulosclerosis and HLA antigens

    Directory of Open Access Journals (Sweden)

    M. Gerbase-DeLima

    1998-03-01

    Full Text Available The objective of the present study was to investigate a possible association between HLA class II antigens and idiopathic focal segmental glomerulosclerosis (FSGS. HLA-A, -B, -DR and -DQ antigens were determined in 19 Brazilian patients (16 white subjects and three subjects of Japanese origin with biopsy-proven FSGS. Comparison of the HLA antigen frequencies between white patients and white local controls showed a significant increase in HLA-DR4 frequency among FSGS patients (37.7 vs 17.2%, P<0.05. In addition, the three patients of Japanese extraction, not included in the statistical analysis, also presented HLA-DR4. In conclusion, our data confirm the association of FSGS with HLA-DR4 previously reported by others, thus providing further evidence for a role of genes of the HLA complex in the susceptibility to this disease

  1. Harnessing Dendritic Cells for Tumor Antigen Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Nierkens, Stefan [Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Geert Grooteplein 28, Nijmegen 6525 GA (Netherlands); Janssen, Edith M., E-mail: edith.janssen@cchmc.org [Division of Molecular Immunology, Cincinnati Children' s Hospital Research Foundation, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229 (United States)

    2011-04-26

    Dendritic cells (DC) are professional antigen presenting cells that are crucial for the induction of anti-tumor T cell responses. As a consequence, research has focused on the harnessing of DCs for therapeutic interventions. Although current strategies employing ex vivo-generated and tumor-antigen loaded DCs have been proven feasible, there are still many obstacles to overcome in order to improve clinical trial successes and offset the cost and complexity of customized cell therapy. This review focuses on one of these obstacles and a pivotal step for the priming of tumor-specific CD8{sup +} and CD4{sup +} T cells; the in vitro loading of DCs with tumor antigens.

  2. Original antigenic sin: A comprehensive review.

    Science.gov (United States)

    Vatti, Anup; Monsalve, Diana M; Pacheco, Yovana; Chang, Christopher; Anaya, Juan-Manuel; Gershwin, M Eric

    2017-09-01

    The concept of "original antigenic sin" was first proposed by Thomas Francis, Jr. in 1960. This phenomenon has the potential to rewrite what we understand about how the immune system responds to infections and its mechanistic implications on how vaccines should be designed. Antigenic sin has been demonstrated to occur in several infectious diseases in both animals and humans, including human influenza infection and dengue fever. The basis of "original antigenic sin" requires immunological memory, and our immune system ability to autocorrect. In the context of viral infections, it is expected that if we are exposed to a native strain of a pathogen, we should be able to mount a secondary immune response on subsequent exposure to the same pathogen. "Original antigenic sin" will not contradict this well-established immunological process, as long as the subsequent infectious antigen is identical to the original one. But "original antigenic sin" implies that when the epitope varies slightly, then the immune system relies on memory of the earlier infection, rather than mount another primary or secondary response to the new epitope which would allow faster and stronger responses. The result is that the immunological response may be inadequate against the new strain, because the immune system does not adapt and instead relies on its memory to mount a response. In the case of vaccines, if we only immunize to a single strain or epitope, and if that strain/epitope changes over time, then the immune system is unable to mount an accurate secondary response. In addition, depending of the first viral exposure the secondary immune response can result in an antibody-dependent enhancement of the disease or at the opposite, it could induce anergy. Both of them triggering loss of pathogen control and inducing aberrant clinical consequences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Tumor-derived exosomes confer antigen-specific immunosuppression in a murine delayed-type hypersensitivity model.

    Directory of Open Access Journals (Sweden)

    Chenjie Yang

    Full Text Available Exosomes are endosome-derived small membrane vesicles that are secreted by most cell types including tumor cells. Tumor-derived exosomes usually contain tumor antigens and have been used as a source of tumor antigens to stimulate anti-tumor immune responses. However, many reports also suggest that tumor-derived exosomes can facilitate tumor immune evasion through different mechanisms, most of which are antigen-independent. In the present study we used a mouse model of delayed-type hypersensitivity (DTH and demonstrated that local administration of tumor-derived exosomes carrying the model antigen chicken ovalbumin (OVA resulted in the suppression of DTH response in an antigen-specific manner. Analysis of exosome trafficking demonstrated that following local injection, tumor-derived exosomes were internalized by CD11c+ cells and transported to the draining LN. Exosome-mediated DTH suppression is associated with increased mRNA levels of TGF-β1 and IL-4 in the draining LN. The tumor-derived exosomes examined were also found to inhibit DC maturation. Taken together, our results suggest a role for tumor-derived exosomes in inducing tumor antigen-specific immunosuppression, possibly by modulating the function of APCs.

  4. Langerhans Cells Prevent Autoimmunity via Expansion of Keratinocyte Antigen-Specific Regulatory T Cells

    Directory of Open Access Journals (Sweden)

    Daniela Y. Kitashima

    2018-01-01

    Full Text Available Langerhans cells (LCs are antigen-presenting cells in the epidermis whose roles in antigen-specific immune regulation remain incompletely understood. Desmoglein 3 (Dsg3 is a keratinocyte cell-cell adhesion molecule critical for epidermal integrity and an autoantigen in the autoimmune blistering disease pemphigus. Although antibody-mediated disease mechanisms in pemphigus are extensively characterized, the T cell aspect of this autoimmune disease still remains poorly understood. Herein, we utilized a mouse model of CD4+ T cell-mediated autoimmunity against Dsg3 to show that acquisition of Dsg3 and subsequent presentation to T cells by LCs depended on the C-type lectin langerin. The lack of LCs led to enhanced autoimmunity with impaired Dsg3-specific regulatory T cell expansion. LCs expressed the IL-2 receptor complex and the disruption of IL-2 signaling in LCs attenuated LC-mediated regulatory T cell expansion in vitro, demonstrating that direct IL-2 signaling shapes LC function. These data establish that LCs mediate peripheral tolerance against an epidermal autoantigen and point to langerin and IL-2 signaling pathways as attractive targets for achieving tolerogenic responses particularly in autoimmune blistering diseases such as pemphigus.

  5. Outer membrane protein antigens of Moraxella bovis.

    Science.gov (United States)

    Ostle, A G; Rosenbusch, R F

    1986-07-01

    Outer membranes were isolated from bovine isolates and type strains of Moraxella bovis, M phenylpyruvica, M lacunata, and M ovis by sodium N lauroyl sarcosinate extraction and differential centrifugation. Analysis of outer membranes from these organisms by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis revealed that all M bovis isolates shared a common polypeptide pattern that was readily distinguishable from other Moraxella spp. Nine major outer membrane protein bands were identified by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis analysis of M bovis. Immunoblotting of protein antigens of M bovis revealed several outer membrane proteins that seemed to be common antigens of all M bovis isolates.

  6. 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

  7. Cell-free antigens of Sporothrix brasiliensis: antigenic diversity and application in an immunoblot assay.

    Science.gov (United States)

    Almeida-Paes, Rodrigo; Bailão, Alexandre Melo; Pizzini, Cláudia Vera; Reis, Rosani Santos; Soares, Célia Maria de Almeida; Peralta, José Mauro; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria

    2012-11-01

    Sporotrichosis is a subcutaneous mycosis diagnosed by isolation of the fungus in culture. Serological tests for help in diagnosis in general do not use purified or recombinant antigens, because there is a paucity of described immunoreactive proteins, especially for the new described Sporothrix species, such as Sporothrix brasiliensis. This study aims to characterise antigens from S. brasiliensis and verify their application in serodiagnosis of sporotrichosis. An immunoblot assay allied with computer-based analysis was used to identify putative antigenic molecules in a cell-free extracts of both morphological phases of this fungus, and to delineate antigenic polymorphism among seven S. brasiliensis isolates and one S. schenckii Brazilian strain. The mycelial and yeast phase of the fungus originated 14 and 23 reactive bands, respectively, which were variable in intensity. An 85 kDa antigen, verified in the yeast phase of the fungus, was observed in all strains used and the immunodominant protein was identified. This protein, however, cross-react with serum samples from patients infected with other pathogens. The results show that the S. brasiliensis cell-free antigen extract is a single and inexpensive source of antigens, and can be applied on the sporotrichosis serodiagnosis. © 2012 Blackwell Verlag GmbH.

  8. 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...

  9. The SSX Family of Cancer-Testis Antigens as Target Proteins for Tumor Therapy

    Directory of Open Access Journals (Sweden)

    Heath A. Smith

    2010-01-01

    Full Text Available Cancer-testis antigens (CTAs represent an expanding class of tumor-associated proteins defined on the basis of their tissue-restricted expression to testis or ovary germline cells and frequent ectopic expression in tumor tissue. The expression of CTA in MHC class I-deficient germline cells makes these proteins particularly attractive as immunotherapeutic targets because they serve as essentially tumor-specific antigens for MHC class I-restricted CD8+ T cells. Moreover, because CTAs are expressed in many types of cancer, any therapeutic developed to target these antigens might have efficacy for multiple cancer types. Of particular interest among CTAs is the synovial sarcoma X chromosome breakpoint (SSX family of proteins, which includes ten highly homologous family members. Expression of SSX proteins in tumor tissues has been associated with advanced stages of disease and worse patient prognosis. Additionally, both humoral and cell-mediated immune responses to SSX proteins have been demonstrated in patients with tumors of varying histological origin, which indicates that natural immune responses can be spontaneously generated to these antigens in cancer patients. The current review will describe the history and identification of this family of proteins, as well as what is known of their function, expression in normal and malignant tissues, and immunogenicity.

  10. Blood Group Antigens C, Lub and P1 May Have a Role in HIV Infection in Africans.

    Science.gov (United States)

    Motswaledi, Modisa Sekhamo; Kasvosve, Ishmael; Oguntibeju, Oluwafemi Omoniyi

    2016-01-01

    Botswana is among the world's countries with the highest rates of HIV infection. It is not known whether or not this susceptibility to infection is due to genetic factors in the population. Accumulating evidence, however, points to the role of erythrocytes as potential mediators of infection. We therefore sought to establish the role, if any, of some erythrocyte antigens in HIV infection in a cross-section of the population. 348 (346 HIV-negative and 2 HIV-positive) samples were obtained from the National Blood Transfusion Service as residual samples, while 194 HIV-positive samples were obtained from the Botswana-Harvard HIV Reference Laboratory. Samples were grouped for twenty three antigens. Chi-square or Fischer Exact analyses were used to compare the frequencies of the antigens in the two groups. A stepwise, binary logistic regression was used to study the interaction of the various antigens in the light of HIV-status. The Rh antigens C and E were associated with HIV-negative status, while blood group Jka, P1 and Lub were associated with HIV-positive status. A stepwise binary logistic regression analysis yielded group C as the most significant protective blood group while Lub and P1 were associated with significantly higher odds ratio in favor of HIV-infection. The lower-risk-associated group C was significantly lower in Africans compared to published data for Caucasians and might partially explain the difference in susceptibility to HIV-1. The most influential antigen C, which also appears to be protective, is significantly lower in Africans than published data for Caucasians or Asians. On the other hand, there appear to be multiple antigens associated with increased risk that may override the protective role of C. A study of the distribution of these antigens in other populations may shed light on their roles in the HIV pandemic.

  11. The B cell antigen receptor and overexpression of MYC can cooperate in the genesis of B cell lymphomas.

    Directory of Open Access Journals (Sweden)

    Yosef Refaeli

    2008-06-01

    Full Text Available A variety of circumstantial evidence from humans has implicated the B cell antigen receptor (BCR in the genesis of B cell lymphomas. We generated mouse models designed to test this possibility directly, and we found that both the constitutive and antigen-stimulated state of a clonal BCR affected the rate and outcome of lymphomagenesis initiated by the proto-oncogene MYC. The tumors that arose in the presence of constitutive BCR differed from those initiated by MYC alone and resembled chronic B cell lymphocytic leukemia/lymphoma (B-CLL, whereas those that arose in response to antigen stimulation resembled large B-cell lymphomas, particularly Burkitt lymphoma (BL. We linked the genesis of the BL-like tumors to antigen stimulus in three ways. First, in reconstruction experiments, stimulation of B cells by an autoantigen in the presence of overexpressed MYC gave rise to BL-like tumors that were, in turn, dependent on both MYC and the antigen for survival and proliferation. Second, genetic disruption of the pathway that mediates signaling from the BCR promptly killed cells of the BL-like tumors as well as the tumors resembling B-CLL. And third, growth of the murine BL could be inhibited by any of three distinctive immunosuppressants, in accord with the dependence of the tumors on antigen-induced signaling. Together, our results provide direct evidence that antigenic stimulation can participate in lymphomagenesis, point to a potential role for the constitutive BCR as well, and sustain the view that the constitutive BCR gives rise to signals different from those elicited by antigen. The mouse models described here should be useful in exploring further the pathogenesis of lymphomas, and in preclinical testing of new therapeutics.

  12. Gene Therapy Induces Antigen-Specific Tolerance in Experimental Collagen-Induced Arthritis.

    Directory of Open Access Journals (Sweden)

    Sara Tengvall

    Full Text Available Here, we investigate induction of immunological tolerance by lentiviral based gene therapy in a mouse model of rheumatoid arthritis, collagen II-induced arthritis (CIA. Targeting the expression of the collagen type II (CII to antigen presenting cells (APCs induced antigen-specific tolerance, where only 5% of the mice developed arthritis as compared with 95% of the control mice. In the CII-tolerized mice, the proportion of Tregs as well as mRNA expression of SOCS1 (suppressors of cytokine signaling 1 increased at day 3 after CII immunization. Transfer of B cells or non-B cell APC, as well as T cells, from tolerized to naïve mice all mediated a certain degree of tolerance. Thus, sustainable tolerance is established very early during the course of arthritis and is mediated by both B and non-B cells as APCs. This novel approach for inducing tolerance to disease specific antigens can be used for studying tolerance mechanisms, not only in CIA but also in other autoimmune diseases.

  13. A negative feedback modulator of antigen processing evolved from a frameshift in the cowpox virus genome.

    Directory of Open Access Journals (Sweden)

    Jiacheng Lin

    2014-12-01

    Full Text Available Coevolution of viruses and their hosts represents a dynamic molecular battle between the immune system and viral factors that mediate immune evasion. After the abandonment of smallpox vaccination, cowpox virus infections are an emerging zoonotic health threat, especially for immunocompromised patients. Here we delineate the mechanistic basis of how cowpox viral CPXV012 interferes with MHC class I antigen processing. This type II membrane protein inhibits the coreTAP complex at the step after peptide binding and peptide-induced conformational change, in blocking ATP binding and hydrolysis. Distinct from other immune evasion mechanisms, TAP inhibition is mediated by a short ER-lumenal fragment of CPXV012, which results from a frameshift in the cowpox virus genome. Tethered to the ER membrane, this fragment mimics a high ER-lumenal peptide concentration, thus provoking a trans-inhibition of antigen translocation as supply for MHC I loading. These findings illuminate the evolution of viral immune modulators and the basis of a fine-balanced regulation of antigen processing.

  14. Lectin binding patterns and immunohistochemical antigen detection ...

    African Journals Online (AJOL)

    Ibrahim Eldaghayes

    2018-02-09

    Feb 9, 2018 ... examined by histological, lectin-histochemical, immunohistochemical and cultural techniques. B. abortus antigens were immunohistochemically detected in fetal lungs and placenta. An increase in the labeling with UEA-1, DBA,. PNA, RCA-1 and SBA was found in the lungs and an increase in the labeling ...

  15. Lea blood group antigen on human platelets

    Energy Technology Data Exchange (ETDEWEB)

    Dunstan, R.A.; Simpson, M.B.; Rosse, W.F.

    1985-01-01

    One- and two-stage radioligand assays were used to determine if human platelets possess the Lea antigen. Goat IgG anti-Lea antibody was purified by multiple adsorptions with Le(a-b-) human red blood cells, followed by affinity chromatography with synthetic Lea substance and labeling with /sup 125/I. Human IgG anti-Lea antibody was used either in a two stage radioassay with /sup 125/I-labeled mouse monoclonal IgG anti-human IgG as the second antibody or, alternatively, purified by Staph protein A chromatography, labeled with /sup 125/I, and used in a one-stage radioassay. Platelets from donors of appropriate red blood cell phenotypes were incubated with the antisera, centrifuged through phthalate esters, and assayed in a gamma scintillation counter. Dose response and saturation curve analysis demonstrate the presence of Lewis a antigen on platelets from Lea+ donors. Furthermore, platelets from an Le(a-b-) donor incubated in Le (a+b-) plasma adsorb Lea antigen in a similar manner to red blood cells. The clinical significance of these antigens in platelet transfusion remains undefined.

  16. A NEW SYNTHETIC FUNCTIONALIZED ANTIGEN CARRIER

    NARCIS (Netherlands)

    DRIJFHOUT, JW; BLOEMHOFF, W

    A new synthetic functionalized antigen carrier is described. It consists of a core of seven branched lysine residues, of which each of the four N-terminal lysine residues contains two N-(S-acetylmercaptoacetyl)-glutamyl residues. After removal of the protecting S-acetyl groups affording eight thiol

  17. Non-lineage antigens: section report

    Czech Academy of Sciences Publication Activity Database

    Horváth, Ondřej; Drbal, Karel; Angelisová, Pavla; Hilgert, Ivan; Hořejší, Václav

    2005-01-01

    Roč. 236, 1-2 (2005), s. 42-47 ISSN 0008-8749 R&D Projects: GA MŠk(CZ) 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : non-lineage antigens * cytofluorometry * CD molecules Subject RIV: EC - Immunology Impact factor: 1.558, year: 2005

  18. Carcinoembryonic antigen and head and neck cancer

    NARCIS (Netherlands)

    Laarman, D. A.; van Kamp, G. J.; Balm, A. J.; Braakhuis, B. J.; Snow, G. B.

    1991-01-01

    Carcinoembryonic antigen (CEA) concentrations were determined in the sera of 45 patients with a head and neck squamous cell carcinoma and of 13 controls. In 13 patients serial CEA measurements were made during the follow-up period. In 38% of the patients the serum CEA level was slightly elevated

  19. Antigen dynamics of follicular dendritic cells

    NARCIS (Netherlands)

    Heesters, B.A.

    2015-01-01

    Stromal-derived follicular dendritic cells (FDCs) are a major depot for antigen that are essential for formation of germinal centers, the site where memory and effector B cells differentiate and high-affinity antibody production takes place. Historically, FDCs have been characterized as ‘accessory’

  20. Cloning, expression, purification and antigenic evaluation of ...

    African Journals Online (AJOL)

    Streptococcus pyogenes produce an extracellular hyaluronidase which is associated with the spread of the organism during infection. Enzyme hyaluronidase is capable of degrading hyaluronic acid. The aim of the present study was to clone and express antigenic regions of the hylA of S.pyogenes in Escherichia coli.

  1. Antigenic and genetic variability of human metapneumoviruses

    NARCIS (Netherlands)

    S. Herfst (Sander); L. Sprong; P.A. Cane; E. Forleo-Neto; A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); R.L. de Swart (Rik); B.G. van den Hoogen (Bernadette)

    2004-01-01

    textabstractHuman metapneumovirus (HMPV) is a member of the subfamily Pneumovirinae within the family Paramyxo- viridae. Other members of this subfamily, respiratory syncytial virus and avian pneumovirus, can be divided into subgroups on the basis of genetic or antigenic differences or both. For

  2. 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

  3. Antigenic characterisation of lyssaviruses in South Africa

    Directory of Open Access Journals (Sweden)

    Ernest Ngoepe

    2014-09-01

    Full Text Available There are at least six Lyssavirus species that have been isolated in Africa, which include classical rabies virus, Lagos bat virus, Mokola virus, Duvenhage virus, Shimoni bat virus and Ikoma lyssavirus. In this retrospective study, an analysis of the antigenic reactivity patterns of lyssaviruses in South Africa against a panel of 15 anti-nucleoprotein monoclonal antibodies was undertaken. A total of 624 brain specimens, collected between 2005 and 2009, confirmed as containing lyssavirus antigen by direct fluorescent antibody test, were subjected to antigenic differentiation. The lyssaviruses were differentiated into two species, namely rabies virus (99.5% and Mokola virus (0.5%. Furthermore, rabies virus was further delineated into two common rabies biotypes in South Africa: canid and mongoose. Initially, it was found that the canid rabies biotype had two reactivity patterns; differential staining was observed with just one monoclonal antibody. This difference was likely to have been an artefact related to sample quality, as passage in cell culture restored staining. Mongoose rabies viruses were more heterogeneous, with seven antigenic reactivity patterns detected. Although Mokola viruses were identified in this study, prevalence and reservoir host species are yet to be established. These data demonstrate the usefulness of monoclonal antibody typing panels in lyssavirus surveillance with reference to emergence of new species or spread of rabies biotypes to new geographic zones.

  4. Evaluation of an Antigen-Antibody

    African Journals Online (AJOL)

    GB

    replication would lead to the production of various antigens. Today with BMT history of over 30 years, infection ... Study design: The study involved both retrospective and prospective laboratory-based analysis of ..... core protein of a molecular mass 19 x 103 Da, one picogram (pg) of virus core corresponds to 1.3 x. 105 HCV ...

  5. Lysine acetylation of major Chlamydia trachomatis antigens

    Directory of Open Access Journals (Sweden)

    Jelena Mihailovic

    2016-03-01

    Our data show that important Ct antigens could be post-translationally modified by acetylation of lysine residues at multiple sites. Further studies are needed to investigate total acetylome of Ct and the impact PTMs might have on Ct biology and pathogenicity.

  6. 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.

  7. 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.

  8. 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

  9. Increasing vaccine potency through exosome antigen targeting.

    Science.gov (United States)

    Hartman, Zachary C; Wei, Junping; Glass, Oliver K; Guo, Hongtao; Lei, Gangjun; Yang, Xiao-Yi; Osada, Takuya; Hobeika, Amy; Delcayre, Alain; Le Pecq, Jean-Bernard; Morse, Michael A; Clay, Timothy M; Lyerly, Herbert K

    2011-11-21

    While many tumor associated antigens (TAAs) have been identified in human cancers, efforts to develop efficient TAA "cancer vaccines" using classical vaccine approaches have been largely ineffective. Recently, a process to specifically target proteins to exosomes has been established which takes advantage of the ability of the factor V like C1C2 domain of lactadherin to specifically address proteins to exosomes. Using this approach, we hypothesized that TAAs could be targeted to exosomes to potentially increase their immunogenicity, as exosomes have been demonstrated to traffic to antigen presenting cells (APC). To investigate this possibility, we created adenoviral vectors expressing the extracellular domain (ECD) of two non-mutated TAAs often found in tumors of cancer patients, carcinoembryonic antigen (CEA) and HER2, and coupled them to the C1C2 domain of lactadherin. We found that these C1C2 fusion proteins had enhanced expression in exosomes in vitro. We saw significant improvement in antigen specific immune responses to each of these antigens in naïve and tolerant transgenic animal models and could further demonstrate significantly enhanced therapeutic anti-tumor effects in a human HER2+ transgenic animal model. These findings demonstrate that the mode of secretion and trafficking can influence the immunogenicity of different human TAAs, and may explain the lack of immunogenicity of non-mutated TAAs found in cancer patients. They suggest that exosomal targeting could enhance future anti-tumor vaccination protocols. This targeting exosome process could also be adapted for the development of more potent vaccines in some viral and parasitic diseases where the classical vaccine approach has demonstrated limitations. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Identification of Novel Breast Cancer Antigens Using Phage Antibody Libraries

    National Research Council Canada - National Science Library

    Marks, James

    2002-01-01

    The purpose of this project is to use phage antibody libraries to identify novel breast tumor antigens The antibodies could be used for breast cancer immunotherapy and the antigens could be used as cancer vaccines...

  11. Cysteine proteases as potential antigens in antiparasitic DNA vaccines

    DEFF Research Database (Denmark)

    Jørgensen, Louise von Gersdorff; Buchmann, Kurt

    2011-01-01

    En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner.......En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner....

  12. Dengue viruses cluster antigenically but not as discrete serotypes

    NARCIS (Netherlands)

    L. Katzelnick (Leah); J.M. Fonville (Judith); G.D. Gromowski (Gregory D.); J.B. Arriaga (Jose Bustos); A. Green (Angela); S.L. James (Sarah ); L. Lau (Louis); M. Montoya (Magelda); C. Wang (Chunling); L.A. Van Blargan (Laura A.); C.A. Russell (Colin); H.M. Thu (Hlaing Myat); T.C. Pierson (Theodore C.); P. Buchy (Philippe); J.G. Aaskov (John G.); J.L. Muñoz-Jordán (Jorge L.); N. Vasilakis (Nikos); R.V. Gibbons (Robert V.); R.B. Tesh (Robert B.); A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); A. Durbin (Anna); C.P. Simmons (Cameron P.); E.C. Holmes (Edward C.); E. Harris (Eva); S.S. Whitehead (Stephen S.); D.J. Smith (Derek James)

    2015-01-01

    textabstractThe four genetically divergent dengue virus (DENV) types are traditionally classified as serotypes. Antigenic and genetic differences among the DENV types influence disease outcome, vaccine-induced protection, epidemic magnitude, and viral evolution.We scharacterized antigenic diversity

  13. Cancer Patient T Cells Genetically Targeted to Prostate-Specific Membrane Antigen Specifically Lyse Prostate Cancer Cells and Release Cytokines in Response to Prostate-Specific Membrane Antigen

    Directory of Open Access Journals (Sweden)

    Michael C. Gong

    1999-06-01

    Full Text Available The expression of immunoglobulin-based artificial receptors in normal T lymphocytes provides a means to target lymphocytes to cell surface antigens independently of major histocompatibility complex restriction. Such artificial receptors have been previously shown to confer antigen-specific tumoricidal properties in murine T cells. We constructed a novel ζ chain fusion receptor specific for prostate-specific membrane antigen (PSMA termed Pz-1. PSMA is a cell-surface glycoprotein expressed on prostate cancer cells and the neovascular endothelium of multiple carcinomas. We show that primary T cells harvested from five of five patients with different stages of prostate cancer and transduced with the Pz-1 receptor readily lyse prostate cancer cells. Having established a culture system using fibroblasts that express PSMA, we next show that T cells expressing the Pz-1 receptor release cytokines in response to cell-bound PSMA. Furthermore, we show that the cytokine release is greatly augmented by B7.1-mediated costimulation. Thus, our findings support the feasibility of adoptive cell therapy by using genetically engineered T cells in prostate cancer patients and suggest that both CD4+ and CD8+ T lymphocyte functions can be synergistically targeted against tumor cells.

  14. Adoptive T Cell Therapies: A Comparison of T Cell Receptors and Chimeric Antigen Receptors

    Science.gov (United States)

    Harris, Daniel T.; Kranz, David M.

    2016-01-01

    The tumor-killing properties of T cells provide tremendous opportunities to treat cancer. Adoptive T cell therapies have begun to harness this potential by endowing a functionally diverse repertoire of T cells with genetically modified, tumor-specific recognition receptors. Normally, this antigen recognition function is mediated by an αβ T cell receptor (TCR), but the dominant therapeutic forms currently in development are synthetic constructs called chimeric antigen receptors (CARs). While CAR-based adoptive cell therapies are already showing great promise, their basic mechanistic properties have been studied in less detail compared with those of αβ TCRs. In this review, we compare and contrast various features of TCRs versus CARs, with a goal of highlighting issues that need to be addressed to fully exploit the therapeutic potential of both. PMID:26705086

  15. Liposome-Based Adjuvants for Subunit Vaccines: Formulation Strategies for Subunit Antigens and Immunostimulators

    DEFF Research Database (Denmark)

    Schmidt, Signe Tandrup; Foged, Camilla; Korsholm, Karen Smith

    2016-01-01

    for which no effective vaccines exist. The subunit vaccine technology exploits pathogen subunits as antigens, e.g., recombinant proteins or synthetic peptides, allowing for highly specific immune responses against the pathogens. However, such antigens are usually not sufficiently immunogenic to induce......The development of subunit vaccines has become very attractive in recent years due to their superior safety profiles as compared to traditional vaccines based on live attenuated or whole inactivated pathogens, and there is an unmet medical need for improved vaccines and vaccines against pathogens...... been licensed for use in human vaccines, and they mainly stimulate humoral immunity. Thus, there is an unmet demand for the development of safe and efficient adjuvant systems that can also stimulate cell-mediated immunity (CMI). Adjuvants constitute a heterogeneous group of compounds, which can broadly...

  16. A putative, novel coli surface antigen 8B (CS8B) of enterotoxigenic Escherichia coli.

    Science.gov (United States)

    Njoroge, Samuel M; Boinett, Christine J; Madé, Laure F; Ouko, Tom T; Fèvre, Eric M; Thomson, Nicholas R; Kariuki, Samuel

    2015-10-01

    Enterotoxigenic Escherichia coli (ETEC) strains harbor multiple fimbriae and pili to mediate host colonization, including the type IVb pilus, colonization factor antigen III (CFA/III). Not all colonization factors are well characterized or known in toxin positive ETEC isolates, which may have an impact identifying ETEC isolates based on molecular screening of these biomarkers. We describe a novel coli surface antigen (CS) 8 subtype B (CS8B), a family of CFA/III pilus, in a toxin producing ETEC isolate from a Kenyan collection. In highlighting the existence of this putative CS, we provide the sequence and specific primers, which can be used alongside other ETEC primers previously described. © FEMS 2015.

  17. Chimeric Antigen Receptor-Engineered T Cells for Immunotherapy of Cancer

    Directory of Open Access Journals (Sweden)

    Marc Cartellieri

    2010-01-01

    Full Text Available CD4+ and CD8+ T lymphocytes are powerful components of adaptive immunity, which essentially contribute to the elimination of tumors. Due to their cytotoxic capacity, T cells emerged as attractive candidates for specific immunotherapy of cancer. A promising approach is the genetic modification of T cells with chimeric antigen receptors (CARs. First generation CARs consist of a binding moiety specifically recognizing a tumor cell surface antigen and a lymphocyte activating signaling chain. The CAR-mediated recognition induces cytokine production and tumor-directed cytotoxicity of T cells. Second and third generation CARs include signal sequences from various costimulatory molecules resulting in enhanced T-cell persistence and sustained antitumor reaction. Clinical trials revealed that the adoptive transfer of T cells engineered with first generation CARs represents a feasible concept for the induction of clinical responses in some tumor patients. However, further improvement is required, which may be achieved by second or third generation CAR-engrafted T cells.

  18. Formaldehyde scavengers function as novel antigen retrieval agents

    Science.gov (United States)

    Vollert, Craig T.; Moree, Wilna J.; Gregory, Steven; Bark, Steven J.; Eriksen, Jason L.

    2015-01-01

    Antigen retrieval agents improve the detection of formaldehyde-fixed proteins, but how they work is not well understood. We demonstrate that formaldehyde scavenging represents a key characteristic associated with effective antigen retrieval; under controlled temperature and pH conditions, scavenging improves the typical antigen retrieval process through reversal of formaldehyde-protein adduct formation. This approach provides a rational framework for the identification and development of more effective antigen retrieval agents. PMID:26612041

  19. Defining the immunogenicity and antigenicity of HLA epitopes is crucial for optimal epitope matching in clinical renal transplantation.

    Science.gov (United States)

    Kramer, C S M; Roelen, D L; Heidt, S; Claas, F H J

    2017-07-01

    Transplantation of an human leukocyte antigen (HLA) mismatched graft can lead to the development of donor-specific antibodies (DSA), which can result in antibody mediated rejection and graft loss as well as complicate repeat transplantation. These DSA are induced by foreign epitopes present on the mismatched HLA antigens of the donor. However, not all epitopes appear to be equally effective in their ability to induce DSA. Understanding the characteristics of HLA epitopes is crucial for optimal epitope matching in clinical transplantation. In this review, the latest insights on HLA epitopes are described with a special focus on the definition of immunogenicity and antigenicity of HLA epitopes. Furthermore, the use of this knowledge to prevent HLA antibody formation and to select the optimal donor for sensitised transplant candidates will be discussed. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Advances in alloimmune thrombocytopenia: perspectives on current concepts of human platelet antigens, antibody detection strategies, and genotyping.

    Science.gov (United States)

    Hayashi, Tomoya; Hirayama, Fumiya

    2015-07-01

    Alloimmunisation to platelets leads to the production of antibodies against platelet antigens and consequently to thrombocytopenia. Numerous molecules located on the platelet surface are antigenic and induce immune-mediated platelet destruction with symptoms that can be serious. Human platelet antigens (HPA) cause thrombocytopenias, such as neonatal alloimmune thrombocytopenia, post-transfusion purpura, and platelet transfusion refractoriness. Thirty-four HPA are classified into 28 systems. Assays to identify HPA and anti-HPA antibodies are critically important for preventing and treating thrombocytopenia caused by anti-HPA antibodies. Significant progress in furthering our understanding of HPA has been made in the last decade: new HPA have been discovered, antibody-detection methods have improved, and new genotyping methods have been developed. We review these advances and discuss issues that remain to be resolved as well as future prospects for preventing and treating immune thrombocytopenia.

  1. 21 CFR 660.40 - Hepatitis B Surface Antigen.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product...

  2. Antigen-specific active immunotherapy for ovarian cancer

    NARCIS (Netherlands)

    Leffers, Ninke; Daemen, Toos; Helfrich, Wijnand; Boezen, H. Marike; Cohlen, Ben J.; Melief, Cornelis J. M.; Nijman, Hans W.

    2014-01-01

    BACKGROUND: Despite advances in chemotherapy, prognosis of ovarian cancer remains poor. Antigen-specific active immunotherapy aims to induce tumour-antigen-specific anti-tumour immune responses as an alternative treatment for ovarian cancer. OBJECTIVES: To assess the feasibility of antigen-specific

  3. Antigen-specific active immunotherapy for ovarian cancer

    NARCIS (Netherlands)

    Leffers, N.; Daemen, T.; Helfrich, W.; Boezen, H. M.; Cohlen, B. J.; Melief, Cornelis; Nijman, H. W.

    2010-01-01

    BACKGROUND: Despite advances in chemotherapy, prognosis of ovarian cancer remains poor. Antigen-specific active immunotherapy aims to induce a tumour-antigen-specific anti-tumour immune responses as an alternative treatment for ovarian cancer. OBJECTIVES: To assess feasibility of antigen-specific

  4. Role of HLA antigens in Rh (D) alloimmunized pregnant women ...

    Indian Academy of Sciences (India)

    Immunogenetic studies in various diseases provide potential genetic markers. We have studied the incidence of HLA A, B, C, DR and DQ loci antigen in Rh (D) antigen isoimmunized mothers compared to those nonimmunized isoimmunized Rh negative mothers. Seventy six mothers who were immunized to Rh (D) antigen ...

  5. Use of magnetic nanobeads to study intracellular antigen processing

    Energy Technology Data Exchange (ETDEWEB)

    Perrin-Cocon, Laure A.; Chesne, Serge; Pignot-Paintrand, Isabelle; Marche, Patrice N.; Villiers, Christian L. E-mail: christian.villiers@cea.fr

    2001-07-01

    Magnetic nanobeads were covalently linked to antigens and used as a tool to simultaneously follow their intracellular transport into the cells and specifically purify the intracellular compartments implicated in antigen processing. The protein content of these vesicles was analysed by 2D-electrophoresis. Furthermore, nanobeads allowed intracellular localisation of the antigen in electron and fluorescence microscopy.

  6. Use of magnetic nanobeads to study intracellular antigen processing

    International Nuclear Information System (INIS)

    Perrin-Cocon, Laure A.; Chesne, Serge; Pignot-Paintrand, Isabelle; Marche, Patrice N.; Villiers, Christian L.

    2001-01-01

    Magnetic nanobeads were covalently linked to antigens and used as a tool to simultaneously follow their intracellular transport into the cells and specifically purify the intracellular compartments implicated in antigen processing. The protein content of these vesicles was analysed by 2D-electrophoresis. Furthermore, nanobeads allowed intracellular localisation of the antigen in electron and fluorescence microscopy

  7. Induction of antigen-specific immunity by pH-sensitive carbonate apatite as a potent vaccine carrier

    Energy Technology Data Exchange (ETDEWEB)

    Hebishima, Takehisa [Viral Infectious Diseases Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Tada, Seiichi [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Takeshima, Shin-nosuke [Viral Infectious Diseases Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Akaike, Toshihiro [Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501 (Japan); Ito, Yoshihiro [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Aida, Yoko, E-mail: aida@riken.jp [Viral Infectious Diseases Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2011-12-02

    Highlights: Black-Right-Pointing-Pointer To develop effective vaccine, we examined the effects of CO{sub 3}Ap as an antigen carrier. Black-Right-Pointing-Pointer OVA contained in CO{sub 3}Ap was taken up by BMDCs more effectively than free OVA. Black-Right-Pointing-Pointer OVA-immunized splenocytes was activated by OVA contained in CO{sub 3}Ap effectively. Black-Right-Pointing-Pointer OVA contained in CO{sub 3}Ap induced strong OVA-specific immune responses to C57BL/6 mice. Black-Right-Pointing-Pointer CO{sub 3}Ap is promising antigen carrier for the achievement of effective vaccine. -- Abstract: The ability of carbonate apatite (CO{sub 3}Ap) to enhance antigen-specific immunity was examined in vitro and in vivo to investigate its utility as a vaccine carrier. Murine bone marrow-derived dendritic cells took up ovalbumin (OVA) containing CO{sub 3}Ap more effectively than free OVA. Interestingly, mice immunized with OVA-containing CO{sub 3}Ap produced OVA-specific antibodies more effectively than mice immunized with free OVA. Furthermore, immunization of C57BL/6 mice with OVA-containing CO{sub 3}Ap induced the proliferation and antigen-specific production of IFN-{gamma} by splenocytes more strongly than immunization with free OVA. Moreover, no significant differences were detected in the induction of delayed-type hypersensitivity responses, an immune reaction involving an antigen-specific, cell-mediated immune response between OVA-containing CO{sub 3}Ap and OVA-containing alumina salt (Alum), suggesting that CO{sub 3}Ap induced cell-mediated immune response to the same degree as Alum, which is commonly used for clinical applications. This study is the first to demonstrate the induction of antigen-specific immune responses in vivo by CO{sub 3}Ap.

  8. Induction of antigen-specific immunity by pH-sensitive carbonate apatite as a potent vaccine carrier

    International Nuclear Information System (INIS)

    Hebishima, Takehisa; Tada, Seiichi; Takeshima, Shin-nosuke; Akaike, Toshihiro; Ito, Yoshihiro; Aida, Yoko

    2011-01-01

    Highlights: ► To develop effective vaccine, we examined the effects of CO 3 Ap as an antigen carrier. ► OVA contained in CO 3 Ap was taken up by BMDCs more effectively than free OVA. ► OVA-immunized splenocytes was activated by OVA contained in CO 3 Ap effectively. ► OVA contained in CO 3 Ap induced strong OVA-specific immune responses to C57BL/6 mice. ► CO 3 Ap is promising antigen carrier for the achievement of effective vaccine. -- Abstract: The ability of carbonate apatite (CO 3 Ap) to enhance antigen-specific immunity was examined in vitro and in vivo to investigate its utility as a vaccine carrier. Murine bone marrow-derived dendritic cells took up ovalbumin (OVA) containing CO 3 Ap more effectively than free OVA. Interestingly, mice immunized with OVA-containing CO 3 Ap produced OVA-specific antibodies more effectively than mice immunized with free OVA. Furthermore, immunization of C57BL/6 mice with OVA-containing CO 3 Ap induced the proliferation and antigen-specific production of IFN-γ by splenocytes more strongly than immunization with free OVA. Moreover, no significant differences were detected in the induction of delayed-type hypersensitivity responses, an immune reaction involving an antigen-specific, cell-mediated immune response between OVA-containing CO 3 Ap and OVA-containing alumina salt (Alum), suggesting that CO 3 Ap induced cell-mediated immune response to the same degree as Alum, which is commonly used for clinical applications. This study is the first to demonstrate the induction of antigen-specific immune responses in vivo by CO 3 Ap.

  9. Progesterone impairs antigen-non-specific immune protection by CD8 T memory cells via interferon-γ gene hypermethylation.

    Directory of Open Access Journals (Sweden)

    Yushi Yao

    2017-11-01

    Full Text Available Pregnant women and animals have increased susceptibility to a variety of intracellular pathogens including Listeria monocytogenes (LM, which has been associated with significantly increased level of sex hormones such as progesterone. CD8 T memory(Tm cell-mediated antigen-non-specific IFN-γ responses are critically required in the host defense against LM. However, whether and how increased progesterone during pregnancy modulates CD8 Tm cell-mediated antigen-non-specific IFN-γ production and immune protection against LM remain poorly understood. Here we show in pregnant women that increased serum progesterone levels are associated with DNA hypermethylation of IFN-γ gene promoter region and decreased IFN-γ production in CD8 Tm cells upon antigen-non-specific stimulation ex vivo. Moreover, IFN-γ gene hypermethylation and significantly reduced IFN-γ production post LM infection in antigen-non-specific CD8 Tm cells are also observed in pregnant mice or progesterone treated non-pregnant female mice, which is a reversible phenotype following demethylation treatment. Importantly, antigen-non-specific CD8 Tm cells from progesterone treated mice have impaired anti-LM protection when adoptive transferred in either pregnant wild type mice or IFN-γ-deficient mice, and demethylation treatment rescues the adoptive protection of such CD8 Tm cells. These data demonstrate that increased progesterone impairs immune protective functions of antigen-non-specific CD8 Tm cells via inducing IFN-γ gene hypermethylation. Our findings thus provide insights into a new mechanism through which increased female sex hormone regulate CD8 Tm cell functions during pregnancy.

  10. T-Helper Type 2 Cells Direct Antigen-Induced Eosinophilic Skin Inflammation in Mice.

    Science.gov (United States)

    Kaminuma, Osamu; Nishimura, Tomoe; Kitamura, Noriko; Saeki, Mayumi; Hiroi, Takachika; Mori, Akio

    2018-01-01

    Eosinophilic inflammation in combination with immunoglobulin E (IgE) production is a characteristic feature of atopic dermatitis. Although activated T-helper type (Th) 2 cells play critical roles in the local accumulation and activation of eosinophils, whether they induce eosinophilic skin inflammation, independent of the IgE-mediated pathway has been unclear. To address the functional role of T cells in allergic skin diseases, we herein transferred Th1/Th2-differentiated or naive DO11.10 T cells into unprimed BALB/c mice. Ovalbumin-specific Th2 cells, as well as eosinophils, accumulated in the skin upon antigen challenge, despite the absence of antigen-specific IgE. Neither antigen-specific Th1 nor naive T cells induced eosinophil accumulation, although Th1 cells by themselves migrated into the skin. Interleukin (IL)-4, IL-5, and eotaxin were specifically produced in the skin of antigen-challenged, Th2 cell-transferred mice, whereas interferon (IFN)-γ and regulated on activation, normal T cell expressed and secreted (RANTES) were preferentially produced in Th1 cells-transferred mice. Production of monocyte chemoattractant protein (MCP)-1 and MCP-3 was enhanced by both Th1 and Th2 cells. The accumulation of eosinophils and Th2 cells in the skin was suppressed by both dexamethasone and FK506, indicating an essential role of Th2 cells in eosinophil recruitment. We conclude that Th2 cells can induce eosinophilic infiltration into the skin in the absence of antigen-specific IgE. Copyright © 2018 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.

  11. Generation of Antigen Microarrays to Screen for Autoantibodies in Heart Failure and Heart Transplantation.

    Science.gov (United States)

    Chruscinski, Andrzej; Huang, Flora Y Y; Nguyen, Albert; Lioe, Jocelyn; Tumiati, Laura C; Kozuszko, Stella; Tinckam, Kathryn J; Rao, Vivek; Dunn, Shannon E; Persinger, Michael A; Levy, Gary A; Ross, Heather J

    2016-01-01

    Autoantibodies directed against endogenous proteins including contractile proteins and endothelial antigens are frequently detected in patients with heart failure and after heart transplantation. There is evidence that these autoantibodies contribute to cardiac dysfunction and correlate with clinical outcomes. Currently, autoantibodies are detected in patient sera using individual ELISA assays (one for each antigen). Thus, screening for many individual autoantibodies is laborious and consumes a large amount of patient sample. To better capture the broad-scale antibody reactivities that occur in heart failure and post-transplant, we developed a custom antigen microarray technique that can simultaneously measure IgM and IgG reactivities against 64 unique antigens using just five microliters of patient serum. We first demonstrated that our antigen microarray technique displayed enhanced sensitivity to detect autoantibodies compared to the traditional ELISA method. We then piloted this technique using two sets of samples that were obtained at our institution. In the first retrospective study, we profiled pre-transplant sera from 24 heart failure patients who subsequently received heart transplants. We identified 8 antibody reactivities that were higher in patients who developed cellular rejection (2 or more episodes of grade 2R rejection in first year after transplant as defined by revised criteria from the International Society for Heart and Lung Transplantation) compared with those who did have not have rejection episodes. In a second retrospective study with 31 patients, we identified 7 IgM reactivities that were higher in heart transplant recipients who developed antibody-mediated rejection (AMR) compared with control recipients, and in time course studies, these reactivities appeared prior to overt graft dysfunction. In conclusion, we demonstrated that the autoantibody microarray technique outperforms traditional ELISAs as it uses less patient sample, has

  12. Generation of Antigen Microarrays to Screen for Autoantibodies in Heart Failure and Heart Transplantation.

    Directory of Open Access Journals (Sweden)

    Andrzej Chruscinski

    Full Text Available Autoantibodies directed against endogenous proteins including contractile proteins and endothelial antigens are frequently detected in patients with heart failure and after heart transplantation. There is evidence that these autoantibodies contribute to cardiac dysfunction and correlate with clinical outcomes. Currently, autoantibodies are detected in patient sera using individual ELISA assays (one for each antigen. Thus, screening for many individual autoantibodies is laborious and consumes a large amount of patient sample. To better capture the broad-scale antibody reactivities that occur in heart failure and post-transplant, we developed a custom antigen microarray technique that can simultaneously measure IgM and IgG reactivities against 64 unique antigens using just five microliters of patient serum. We first demonstrated that our antigen microarray technique displayed enhanced sensitivity to detect autoantibodies compared to the traditional ELISA method. We then piloted this technique using two sets of samples that were obtained at our institution. In the first retrospective study, we profiled pre-transplant sera from 24 heart failure patients who subsequently received heart transplants. We identified 8 antibody reactivities that were higher in patients who developed cellular rejection (2 or more episodes of grade 2R rejection in first year after transplant as defined by revised criteria from the International Society for Heart and Lung Transplantation compared with those who did have not have rejection episodes. In a second retrospective study with 31 patients, we identified 7 IgM reactivities that were higher in heart transplant recipients who developed antibody-mediated rejection (AMR compared with control recipients, and in time course studies, these reactivities appeared prior to overt graft dysfunction. In conclusion, we demonstrated that the autoantibody microarray technique outperforms traditional ELISAs as it uses less patient

  13. Downregulation of integrin β4 decreases the ability of airway epithelial cells to present antigens.

    Directory of Open Access Journals (Sweden)

    Chi Liu

    Full Text Available Airway epithelial cells have been demonstrated to be accessory antigen presentation cells (APC capable of activating T cells and may play an important role in the development of allergic airway inflammation of asthma. In asthmatic airways, loss of expression of the adhesion molecule integrin β4 (ITGB4 and an increase in Th2 inflammation bias has been observed in our previous study. Given that ITGB4 is engaged in multiple signaling pathways, we studied whether disruption of ITGB4-mediated cell adhesion may contribute to the adaptive immune response of epithelial cells, including their ability to present antigens, induce the activate and differentiate of T cells. We silenced ITGB4 expression in bronchial epithelial cells with an effective siRNA vector and studied the effects of ITGB4 silencing on the antigen presentation ability of airway epithelial cells. T cell proliferation and cytokine production was investigated after co-culturing with ITGB4-silenced epithelial cells. Surface expression of B7 homologs and the major histocompatibility complex (MHC class II was also detected after ITGB4 was silenced. Our results demonstrated that silencing of ITGB4 resulted in impaired antigen presentation processes and suppressed T cell proliferation. Meanwhile, decrease in Th1 cytokine production and increase in Th17 cytokine production was induced after co-culturing with ITGB4-silenced epithelial cells. Moreover, HLA-DR was decreased and the B7 homologs expression was different after ITGB4 silencing. Overall, this study suggested that downregulation of ITGB4 expression in airway epithelial cells could impair the antigen presentation ability of these cells, which further regulate airway inflammation reaction in allergic asthma.

  14. The chicken erythrocyte-specific MHC antigen. Characterization and purification of the B-G antigen by monoclonal antibodies

    DEFF Research Database (Denmark)

    Salomonsen, J; Skjødt, K; Crone, M

    1987-01-01

    Mouse monoclonal antibodies with B-G antigen (major histocompatibility complex class IV) specificity were obtained after immunization with erythrocytes or partially purified B-G antigen. The specificities of the hybridoma antibodies were determined by precipitation of B-G antigens from 125I-label...

  15. 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...

  16. Radionuclide-labelled antigens in serological epidemiology

    International Nuclear Information System (INIS)

    Felsenfeld, O.; Parrott, M.W.

    1977-01-01

    The feasibility of tests using radionuclide-labelled antigens in serological surveys was studied, with particular attention to the likely availability of facilities and personnel in the tropics and arctics, where measurements may be disturbed by climatic influences. The methodology required was to be simple, rapid and suitable for examining large numbers of sera, as for epidemological surveys. In the introduction, limitations of labelled antigen tests are discussed, the choice of radionuclide and measurement methods, test procedures and evaluation of results. Collection, preservation and shipment of speciments (serum, faeces, cerebrospinal fluid, sputum, etc.) are described. Experiments with bacteria and bacterial toxins (Enterobacteriaceae, vibrios, staphylococci, meningococci, etc.), with protozoa and metazoa (Entamoeba hystolytica, Schistosoma mansoni, Trypanosoma cruzi, Plasmodia and other parasites), with viruses (vaccinia, adeno-, polio-, and influenza viruses, etc.), and with fungi are discussed

  17. Adoptive Immunotherapy for Hematological Malignancies Using T Cells Gene-Modified to Express Tumor Antigen-Specific Receptors

    Directory of Open Access Journals (Sweden)

    Hiroshi Fujiwara

    2014-12-01

    Full Text Available Accumulating clinical evidence suggests that adoptive T-cell immunotherapy could be a promising option for control of cancer; evident examples include the graft-vs-leukemia effect mediated by donor lymphocyte infusion (DLI and therapeutic infusion of ex vivo-expanded tumor-infiltrating lymphocytes (TIL for melanoma. Currently, along with advances in synthetic immunology, gene-modified T cells retargeted to defined tumor antigens have been introduced as “cellular drugs”. As the functional properties of the adoptive immune response mediated by T lymphocytes are decisively regulated by their T-cell receptors (TCRs, transfer of genes encoding target antigen-specific receptors should enable polyclonal T cells to be uniformly redirected toward cancer cells. Clinically, anticancer adoptive immunotherapy using genetically engineered T cells has an impressive track record. Notable examples include the dramatic benefit of chimeric antigen receptor (CAR gene-modified T cells redirected towards CD19 in patients with B-cell malignancy, and the encouraging results obtained with TCR gene-modified T cells redirected towards NY-ESO-1, a cancer-testis antigen, in patients with advanced melanoma and synovial cell sarcoma. This article overviews the current status of this treatment option, and discusses challenging issues that still restrain the full effectiveness of this strategy, especially in the context of hematological malignancy.

  18. Low antigen dose formulated in CAF09 adjuvant Favours a cytotoxic T-cell response following intraperitoneal immunization in Göttingen minipigs

    DEFF Research Database (Denmark)

    Overgaard, Nana Haahr; Frøsig, Thomas Mørch; Jakobsen, Jeanne Toft

    2017-01-01

    The relationship between the antigen dose and the quality of an immune response generated upon immunization is poorly understood. However, findings show that the immune system is indeed influenced by the antigen dose; hence underlining the importance of correctly determining which dose to use...... in order to generate a certain type of immune response. To investigate this area further, we used Göttingen minipigs asan animal model especially due to the similar body size and high degree of immunome similarity between humans and pigs. In this study, we show that both a humoral and a cell......-mediated immune (CMI) response can be generated following intraperitoneal immunization with tetanus toxoid (TT) formulated in the CAF09 liposomal adjuvant. Importantly, a low antigen dose induced more TT-specific polyfunctional T cells, whereas antigen-specific IgG production was observed upon high...

  19. The Fas/CD95 receptor regulates the death of autoreactive B cells and the selection of antigen-specific B cells

    Directory of Open Access Journals (Sweden)

    Anne-Odile eHUEBER

    2012-07-01

    Full Text Available Cell death receptors have crucial roles in the regulation of immune responses. Here we review recent in vivo data confirming that the Fas death receptor (TNFSR6 on B cells is important for the regulation of autoimmunity since the impairment of only Fas function on B cells results in uncontrolled autoantibody production and autoimmunity. Fas plays a role in the elimination of the non-specific and auto-reactive B cells in germinal center, while during the selection of antigen specific B cells different escape signals ensure the resistance to Fas-mediated apoptosis. Antigen specific survival such as BCR or MHCII signal or coreceptors (CD19 cooperating with BCR inhibits the formation of death inducing signaling complex. Antigen-specific survival can be reinforced by antigen-independent signals of IL4 or CD40 overproducing the anti-apoptotic members of the Bcl-2 family proteins.

  20. 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.

  1. ABO blood group antigens in oral mucosa. What is new?

    DEFF Research Database (Denmark)

    Dabelsteen, Erik

    2002-01-01

    Histo-blood group ABH (O) antigens are major alloantigens in humans. These antigens are widely distributed in human tissues and undergo changes in expression during cellular differentiation and malignant development. The ABH antigens have been characterized as terminal disaccharide determinants...... healing show similarly decreased expression of A/B antigens on migrating epithelial cells. Some studies suggest that the relationship between expression of blood group antigens and cell motility can be explained by different degrees of glycosylation of integrins. Changes in ABO expression in tumours have...

  2. The Antigenic Structure Characterization of Oestrus Ovis Larvae

    Directory of Open Access Journals (Sweden)

    Daniela Moţ

    2012-05-01

    Full Text Available With the aim of proteic components definition from Oestrus ovis larvae, endowed with antigenic properties, able to induce immune responses in vivo and to react in vitro with induced molecular effectors were been performed: electrophoresis in poliacrilamid gel, western blot technique preceded by immunotransfer, immunoassay test. Total soluble larval antigens of O. ovis were been prepared through ultrasonic disintegration, from all three larval stages. Western blot technique allowed and emphasized the specific antigens with a superior sensitivity in comparison with SDS-PAGE electrophoresis. After antigenic characteristics demonstration of investigated larval antigens were been performed the immunoassay test to emphasized the antibodies dozes for O. ovis infestation diagnosis.

  3. 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.

  4. The Leishmania promastigote surface antigen-2 (PSA-2) is specifically recognised by Th1 cells in humans with naturally acquired immunity to L. major

    DEFF Research Database (Denmark)

    Kemp, M; Handman, E; Kemp, K

    1998-01-01

    The promastigote surface antigen-2 (PSA-2) is a Leishmania parasite antigen, which can induce Th1-mediated protection against murine leishmaniasis when used as a vaccine. To evaluate PSA-2 as a human vaccine candidate the specific T-cell response to PSA-2 was characterised in individuals immune......-beta, and little interleukin-4, thereby showing a Th1 cytokine pattern. Parallel cultures showed clear Th1 and Th2 response patterns to purified protein derivative of tuberculin or tetanus toxoid, respectively. Flow cytometric analysis revealed that PSA-2 induced blastogenesis in the CD3 positive population...... and that these cells were the major source of interferon-gamma. The results show that Th1-like cells recognising PSA-2 are expanded during infection by L. major and that they maintain their Th1-like cytokine profile upon reactivation in vitro. Since immunity to cutaneous leishmaniasis is mediated by antigen...

  5. MERS-CoV and H5N1 influenza virus antagonize antigen presentation by altering the epigenetic landscape

    Energy Technology Data Exchange (ETDEWEB)

    Menachery, Vineet D.; Schafer, Alexandra; Burnum-Johnson, Kristin E.; Mitchell, Hugh D.; Eisfeld-Fenney, Amie J.; Walters, Kevin B.; Nicora, Carrie D.; Purvine, Samuel O.; Casey, Cameron P.; Monroe, Matthew E.; Weitz, Karl K.; Stratton, Kelly G.; Webb-Robertson, Bobbie-Jo M.; Gralinski, Lisa; Metz, Thomas O.; Smith, Richard D.; Waters, Katrina M.; Sims, Amy C.; Kawaoka, Yoshihiro; Baric, Ralph

    2018-01-16

    Convergent evolution dictates that diverse groups of viruses will target both similar and distinct host pathways in order to manipulate the immune response and improve infection. In this study, we sought to leverage this uneven viral antagonism to identify critical host factors that govern disease outcome. Utilizing a systems based approach, we examined differential regulation of IFNγ dependent genes following infection with highly pathogenic viruses including influenza (H5N1-VN1203, H1N1-CA04) and coronaviruses (SARS-CoV, MERS-CoV). Categorizing by function, we observed down regulation of genes associated with antigen presentation following both H5N1-VN1203 and MERS-CoV infection. Further examination revealed global down regulation of antigen presentation genes and was confirmed by proteomics for both H5N1-VN1203 and MERS-CoV infection. Importantly, epigenetic analysis suggested that DNA methylation rather than histone modification plays a crucial role in MERS-CoV mediated antagonism of antigen presentation genes; in contrast, H5N1-VN1203 likely utilizes a combination of epigenetic mechanisms to target antigen presentation. Together, the results indicate a common approach utilized by H5N1-VN1203 and MERS-CoV to modulate antigen presentation and the host adaptive immune response.

  6. Polyclonal antibodies for the detection of Trypanosoma cruzi circulating antigens.

    Directory of Open Access Journals (Sweden)

    Edith S Málaga-Machaca

    2017-11-01

    Full Text Available Detection of Trypanosoma cruzi antigens in clinical samples is considered an important diagnostic tool for Chagas disease. The production and use of polyclonal antibodies may contribute to an increase in the sensitivity of immunodiagnosis of Chagas disease.Polyclonal antibodies were raised in alpacas, rabbits, and hens immunized with trypomastigote excreted-secreted antigen, membrane proteins, trypomastigote lysate antigen and recombinant 1F8 to produce polyclonal antibodies. Western blot analysis was performed to determine specificity of the developed antibodies. An antigen capture ELISA of circulating antigens in serum, plasma and urine samples was developed using IgY polyclonal antibodies against T. cruzi membrane antigens (capture antibody and IgG from alpaca raised against TESA. A total of 33 serum, 23 plasma and 9 urine samples were analyzed using the developed test. Among serum samples, compared to serology, the antigen capture ELISA tested positive in 55% of samples. All plasma samples from serology positive subjects were positive in the antigen capture ELISA. All urine positive samples had corresponding plasma samples that were also positive when tested by the antigen capture ELISA.Polyclonal antibodies are useful for detection of circulating antigens in both the plasma and urine of infected individuals. Detection of antigens is direct evidence of the presence of the parasite, and could be a better surrogate of current infection status.

  7. Osteopontin promotes dendritic cell maturation and function in response to HBV antigens

    Directory of Open Access Journals (Sweden)

    Cui GY

    2015-06-01

    Full Text Available Guangying Cui,1,2 Jianing Chen,1,2 Jianqin He,1,2 Chong Lu,1,2 Yingfeng Wei,1,2 Lin Wang,1,2 Xuejun Xu,3 Lanjuan Li,1,2 Toshimitsu Uede,4 Hongyan Diao1,2 1State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 2Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, 3Department of Oral Orthodontics, Affiliated Stomatology Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People’s Republic of China; 4Molecular Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan Purpose: Dendritic cells (DCs play critical roles in promoting innate and adaptive immunity in microbial infection. Functional impairment of DCs may mediate the suppression of viral-specific T-cell immune response in chronic hepatitis B (CHB patients. Osteopontin (OPN is involved in several liver diseases and infectious diseases. However, whether OPN affects DC function in hepatitis B virus (HBV infection is unknown.Methods: Twenty CHB patients and 20 healthy volunteers were recruited. OPN secreted by DCs was compared. Peripheral blood mononuclear cells cultured with OPN antibody were examined to study the costimulatory molecular expression and interleukin (IL-12 production of DCs after HBV antigenic stimulation. OPN-deficient mice were used to investigate the influence of OPN on DC maturation and function after HBV antigenic stimulation in vitro and in vivo. Exogenous OPN was administrated to further verify the functioning of DCs from CHB patients upon HBV antigenic stimulation.Results: We found that OPN production of DCs from CHB patients was significantly lower than those from healthy volunteers. The absence of OPN impaired IL-12 production and costimulatory molecular expression of DCs upon stimulation with HBV antigens. Defective DC function led to reduced activation of Th1 response to

  8. Recognition of melanoma-derived antigens by CTL: possible mechanisms involved in down-regulating anti-tumor T-cell reactivity

    DEFF Research Database (Denmark)

    Rivoltini, L; Loftus, D J; Squarcina, P

    1998-01-01

    Several T cell-recognized epitopes presented by melanoma cells have been identified recently. Despite the large array of epitopes potentially available for clinical use, it is still unclear which of these antigens could be effective in mediating anti-tumor responses when used as a vaccine...

  9. Cellular mechanism of primary anti-Thy-1 antibody responses in vitro induced by uniquely immunogenic thymocyte antigens.

    Science.gov (United States)

    Isobe, K I; Nakashima, I; Nagase, F; Kato, N; Mizoguchi, K; Kawashima, K; Lake, P

    1984-03-01

    Thy-1 antigens are the only cell membrane antigens known to be able to induce primary antibody responses in vitro. We have shown that antigens from the thymocytes of mice and rats were highly immunogenic in cultures of murine spleen cells for the induction of Thy-1.1-specific plaque-forming cell responses, whereas antigens from other tissues, including brains and bone marrow, were poorly immunogenic, if at all. The thymocyte-specific Thy-1 immunogenicity was carried by disrupted cell membranes, and the specific activity for inducing responses was closely linked to Thy-1. We then tried to determine the mechanism of anti-Thy-1 antibody responses in vitro that were induced by the uniquely immunogenic thymocyte antigens. The thymocyte Thy-1 antigens behaved as T cell-independent class 2 (TI-2) antigens: they induced responses in athymic nude mice but not in CBA/N mice with a B cell defect. The apparent TI-2 responses to thymocyte Thy-1 did, however, require Thy-1+ cells in the responder, similar to anti-DNP-Ficoll responses. The full development of the anti-Thy-1 responses required the participation of splenic adherent cells (SAC). Nevertheless, the mechanism of the SAC dependency of anti-Thy-1 responses did not involve antigen presentation to lymphocytes by antigen-pulsed SAC, which contrasted with the finding that the presentation of antigen by live SAC to lymphocytes was indispensable for responses to DNP-Ficoll. The poor Thy-1 responsiveness of SAC-depleted spleen cells was fully restored by the addition of soluble factors (IL 1-like molecules) released from SAC into the culture, which did not replace the SAC-requirement of responses to DNP-Ficoll. It was concluded from these results that Thy-1 or Thy-1-linked structures on thymocyte membranes have an intrinsic activity to directly signal either TI-2 B cells or immature T cells, or both, for activation in the presence of soluble factors released from adherent accessory cells. This conclusion is discussed in

  10. Immunosensing procedures for carcinoembryonic antigen using graphene and nanocomposites.

    Science.gov (United States)

    Luong, John H T; Vashist, Sandeep Kumar

    2017-03-15

    Two-dimensional (2D) graphene, sp 2 -hybridized carbon, and its two major derivatives, graphene oxide (GO) and reduced graphene oxide (rGO) have played an important role in immunoassays (IAs) and immunosensing (IMS) platforms for the detection of carcinoembryonic antigen (CEA), an implicated tumor biomarker found in several types of cancer. The graphene family with high surface area is functionalized to form stable nanocomposites with gold nanoparticles (AuNPs) and electron mediators. The capture anti-CEA antibody (Ab) with high density can be anchored on AuNPs of such composites to provide remarkable detection sensitivity, significantly below the level found in normal subjects and cancer patients. Electrochemical and fluorescence/chemiluminescence-quenching properties of graphene-based nanocomposites are exploited in various detection schemes. Future endeavors are envisioned for the development of an array platform with high-throughput for CEA together with other tumor biomarkers and C-reactive protein, a universal biomarker for infection and inflammation. The ongoing efforts dedicated to the replacement of a lab-based detector by a cellphone with smart applications will further enable cost-effective and frequent monitoring of CEA in order to establish its clinical relevance and provide tools for real-time monitoring of patients during chemotherapy. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. 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.

  12. Alterations in cellular metabolism modulate CD1d-mediated NKT-cell responses.

    Science.gov (United States)

    Webb, Tonya J; Carey, Gregory B; East, James E; Sun, Wenji; Bollino, Dominique R; Kimball, Amy S; Brutkiewicz, Randy R

    2016-08-01

    Natural killer T (NKT) cells play a critical role in the host's innate immune response. CD1d-mediated presentation of glycolipid antigens to NKT cells has been established; however, the mechanisms by which NKT cells recognize infected or cancerous cells remain unclear. 5(')-AMP activated protein kinase (AMPK) is a master regulator of lipogenic pathways. We hypothesized that activation of AMPK during infection and malignancy could alter the repertoire of antigens presented by CD1d and serve as a danger signal to NKT cells. In this study, we examined the effect of alterations in metabolism on CD1d-mediated antigen presentation to NKT cells and found that an infection with lymphocytic choriomeningitis virus rapidly increased CD1d-mediated antigen presentation. Hypoxia inducible factors (HIF) enhance T-cell effector functions during infection, therefore antigen presenting cells pretreated with pharmacological agents that inhibit glycolysis, induce HIF and activate AMPK were assessed for their ability to induce NKT-cell responses. Pretreatment with 2-deoxyglucose, cobalt chloride, AICAR and metformin significantly enhanced CD1d-mediated NKT-cell activation. In addition, NKT cells preferentially respond to malignant B cells and B-cell lymphomas express HIF-1α. These data suggest that targeting cellular metabolism may serve as a novel means of inducing innate immune responses. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Cell mediated immune response in human antirabies revaccination

    Directory of Open Access Journals (Sweden)

    Débora Regina Veiga

    1987-04-01

    Full Text Available The occurrence of secondary cell mediated immune response (CMI in human antirabies immunization was studied. The Puenzalida & Palácios vaccine was used because it is routinely used in Brazil. CMI was evaluated by lymphoblastic transformation indices obtained in whole blood culture in the presence of rabies and control (nervous tissue antigens. Eleven volunteers submitted to revaccination constituted the group under study, while three other volunteers submitted primo vaccination were utilized as control group. A clear secondary CMI to rabies antigen was detected in all the revaccinated volunteers who showed earlier and more intense response than the control group. Response to the control antigen, however, present in all the components of the first group was not detectable in two out of the three primovaccinated and very low in the third one.

  14. Human leukocyte antigen-E mismatch is associated with better hematopoietic stem cell transplantation outcome in acute leukemia patients.

    Science.gov (United States)

    Tsamadou, Chrysanthi; Fürst, Daniel; Vucinic, Vladan; Bunjes, Donald; Neuchel, Christine; Mytilineos, Daphne; Gramatzki, Martin; Arnold, Renate; Wagner, Eva Maria; Einsele, Hermann; Müller, Carlheinz; Schrezenmeier, Hubert; Mytilineos, Joannis

    2017-11-01

    The immunomodulatory role of human leukocyte antigen (HLA)-E in hematopoietic stem cell transplantation (HSCT) has not been extensively investigated. To this end, we genotyped 509 10/10 HLA unrelated transplant pairs for HLA-E , in order to study the effect of HLA-E as a natural killer (NK)-alloreactivity mediator on HSCT outcome in an acute leukemia (AL) setting. Overall survival (OS), disease free survival (DFS), relapse incidence (RI) and non-relapse mortality (NRM) were set as endpoints. Analysis of our data revealed a significant correlation between HLA-E mismatch and improved HSCT outcome, as shown by both univariate (53% vs 38%, P =0.002, 5-year OS) and multivariate (hazard ratio (HR)=0.63, confidence interval (CI) 95%=0.48-0.83, P =0.001) analyses. Further subgroup analysis demonstrated that the positive effect of HLA-E mismatch was significant and pronounced in advanced disease patients (n=120) (5-year OS: 50% vs 18%, P =0.005; HR=0.40, CI 95%=0.22-0.72, P =0.002; results from univariate and multivariate analyses, respectively). The study herein is the first to report an association between HLA-E incompatibility and improved post-transplant prognosis in AL patients who have undergone matched unrelated HSCT. Combined NK and T cell HLA-E-mediated mechanisms may account for the better outcomes observed. Notwithstanding the necessity for in vitro and confirmational studies, our findings highlight the clinical relevance of HLA-E matching and strongly support prospective HLA-E screening upon donor selection for matched AL unrelated HSCTs. Copyright© Ferrata Storti Foundation.

  15. Molecular Characteristics of Carcinoembryonic Antigen and Nonspecific Cross-reacting Antigen(Clinical Application of Tumor Antigen)

    OpenAIRE

    内山, 一晃; Uchiyama, Kazuaki

    1990-01-01

    Carcinoembryonic antigen (CEA) is one of the most famous laboratory tests of tumor markers. CEA was first reported in 1965, but molecular structure of CEA was not clear untill recent years. Amino acid sequence of CEA was reported in 1987, by the success of cDNA clonig of CEA. The CEA molecule is composed of five major domains, called domain N, I, II, III, C from the -NH_2 terminal. But sugar chains of CEA are complicated and have much variety, so there are few informations about them. If CEA ...

  16. New diagnostic antigens for early trichinellosis: the excretory-secretory antigens of Trichinella spiralis intestinal infective larvae.

    Science.gov (United States)

    Sun, Ge Ge; Liu, Ruo Dan; Wang, Zhong Quan; Jiang, Peng; Wang, Li; Liu, Xiao Lin; Liu, Chun Yin; Zhang, Xi; Cui, Jing

    2015-12-01

    The excretory-secretory (ES) antigens from Trichinella spiralis muscle larvae (ML) are the most commonly used diagnostic antigens for trichinellosis, but anti-Trichinella IgG antibodies cannot be detected until 2-3 weeks after infection; there is an obvious window period between Trichinella infection and antibody positivity. Intestinal infective larvae (IIL) are the first invasive stage during Trichinella infection, and their ES antigens are firstly exposed to the immune system and might be the early diagnostic markers of trichinellosis. The aim of this study was to evaluate the early diagnostic values of IIL ES antigens for trichinellosis. The IIL were collected from intestines of infected mice at 6 h postinfection (hpi), and IIL ES antigens were prepared by incubation for 18 h. Anti-Trichinella IgG antibodies in mice infected with 100 ML were detectable by ELISA with IIL ES antigens as soon as 10 days postinfection (dpi), but ELISA with ML ES antigens did not permit detection of infected mice before 12 dpi. When the sera of patients with trichinellosis at 19 dpi were assayed, the sensitivity (100 %) of ELISA with IIL ES antigens was evidently higher than 75 % of ELISA with ML ES antigens (P < 0.05) The specificity (96.86 %) of ELISA with IIL ES antigens was also higher than 89.31 % of ELISA with ML ES antigens (P < 0.05). The IIL ES antigens provided a new source of diagnostic antigens and could be considered as a potential early diagnostic antigen for trichinellosis.

  17. 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...

  18. Abnormal antigens in breast cancer tissues and production of monoclonal antibodies against one of these antigens

    International Nuclear Information System (INIS)

    Mohammed, M. E. A.

    2010-02-01

    Breast cancer is associated with up regulation, down regulation of normal antigens or abnormal antigens. These antigens are very useful candidates as targets for the different breast cancer therapies and for vaccination trials. This study was done to characterize abnormal antigens, extract one of them and to produce monoclonal antibodies against the extracted antigen. One hundred and twenty Sudanese female patients were included in this study after informed consent. The mean age was 47. 2 years (16-80). Two tissue samples were obtained from each patient and they were confirmed as normal and cancerous breast tissues microscopically. 2D PAGE was used to analyze the protein content of samples. LC/MS and nr. fast a database search were used for separation and indentification of the abnormal proteins. Three different patterns of 2D Page results were obtained, the first pattern involved detection of four abnormal proteins in 26.7% of the patient cancerous tissues while they were undetected in the normal tissues of the same patients. In the second 2D PAGE result pattern the cancerous and the normal tissues of 67.5% patients were identical and they did not contain the four abnormal proteins while the third 2D PAGE pattern involved the presence of two abnormal antigens (from the four) in the cancerous tissues of 5.8% of the patients and they were absent from the normal tissues of the same patients. The four abnormal proteins were identified as, human Thioredoxin (D60nmutant), x-ray crystal structure of human galectin-1, retrocopy of tropomyosin 3(rc TPM3) and beta-tropomyosin (isoform 2). The primary and the secondary structures were obtained from the SWISSPROT and the PDB databases. Beta tropomyosin spot was extracted and used as antigen for monoclonal antibody production. Monoclonal antibody against beta- tropomyosin with a concentration of 0.35 mg/ml and a G11 anti beta-tropomyosin hybridoma cell line were produced. The monoclonal antibody was with single bad and

  19. Human leukocyte antigen-E alleles and expression in patients with serous ovarian cancer

    OpenAIRE

    Zheng, Hui; Lu, Renquan; Xie, Suhong; Wen, Xuemei; Wang, Hongling; Gao, Xiang; Guo, Lin

    2015-01-01

    Human leukocyte antigen-E (HLA-E) is one of the most extensively studied non-classical MHC class I molecules that is almost non-polymorphic. Only two alleles (HLA-E*0101 and HLA-E*0103) are found in worldwide populations, and suggested to be functional differences between these variants. The HLA-E molecule can contribute to the escape of cancer cells from host immune surveillance. However, it is still unknown whether HLA-E gene polymorphisms might play a role in cancer immune escape. To explo...

  20. LOCALIZATION OF ANTIGEN IN TISSUE CELLS

    Science.gov (United States)

    Coons, Albert H.; Leduc, Elizabeth H.; Kaplan, Melvin H.

    1951-01-01

    The fate of three proteins, crystalline hen's egg albumin, crystalline bovine plasma albumin, and human plasma γ-globulin, was traced after intravenous injection into mice. This was done by preparing frozen sections of quick-frozen tissue, allowing what foreign protein might be present in the section to react with homologous antibody labelled with fluorescein, and examining the section under the fluorescence microscope. By this means, which employs the serological specificity of the protein as a natural "marker," all three of these proteins were found in the cells of the reticulo-endothelial system, the connective tissue, the vascular endothelium, the lymphocytes of spleen and lymph node, and the epithelium of the kidney tubules, the liver, and in very small amounts in the adrenal. The central nervous system was not studied. All three persisted longest in the reticulo-endothelial system and the connective tissue, and in the doses employed egg white (10 mg.) was no longer detectable after 1 day, bovine albumin (10 mg.) after 2 days, and human γ-globulin (4 mg.) after 6 days, although in a somewhat higher dose (10 mg.) human γ-globulin persisted longer than 8 days. Egg albumin differed from the others in not being detectable in the cells of the renal glomerulus. It was found that each of the three proteins was present in the nuclei of each cell type enumerated above, often in higher concentration than in the cytoplasm. Further, some of the nuclei not only contained antigen, soon after injection, but were also surrounded by a bright ring associated with the nuclear membrane. By means of photographic records under the fluorescence microscope of sections stained for antigen, and direct observation under the light microscope of the same field subsequently stained with hematoxylin and eosin, it could be determined that the antigen was not adsorbed to chromatin or nucleoli, but was apparently in solution in the nuclear sap. PMID:14803641

  1. 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.

  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. High Antigen Dose Is Detrimental to Post-Exposure Vaccine Protection against Tuberculosis

    Directory of Open Access Journals (Sweden)

    Rolf Billeskov

    2018-01-01

    Full Text Available Mycobacterium tuberculosis (Mtb, the etiologic agent of tuberculosis (TB, causes 1.8M deaths annually. The current vaccine, BCG, has failed to eradicate TB leaving 25% of the world’s population with latent Mtb infection (LTBI, and 5–10% of these people will reactivate and develop active TB. An efficient therapeutic vaccine targeting LTBI could have an enormous impact on global TB incidence, and could be an important aid in fighting multidrug resistance, which is increasing globally. Here we show in a mouse model using the H56 (Ag85B-ESAT-6-Rv2660 TB vaccine candidate that post-exposure, but not preventive, vaccine protection requires low vaccine antigen doses for optimal protection. Loss of protection from high dose post-exposure vaccination was not associated with a loss of overall vaccine response magnitude, but rather with greater differentiation and lower functional avidity of vaccine-specific CD4 T cells. High vaccine antigen dose also led to a decreased ability of vaccine-specific CD4 T cells to home into the Mtb-infected lung parenchyma, a recently discovered important feature of T cell protection in mice. These results underscore the importance of T cell quality rather than magnitude in TB-vaccine protection, and the significant role that antigen dosing plays in vaccine-mediated protection.

  4. Role of sustained antigen release from nanoparticle vaccines in shaping the T cell memory phenotype.

    Science.gov (United States)

    Demento, Stacey L; Cui, Weiguo; Criscione, Jason M; Stern, Eric; Tulipan, Jacob; Kaech, Susan M; Fahmy, Tarek M

    2012-06-01

    Particulate vaccines are emerging promising technologies for the creation of tunable prophylactics against a wide variety of conditions. Vesicular and solid biodegradable polymer platforms, exemplified by liposomes and polyesters, respectively, are two of the most ubiquitous platforms in vaccine delivery studies. Here we directly compared the efficacy of each in a long-term immunization study and in protection against a model bacterial antigen. Immunization with poly(lactide-co-glycolide) (PLGA) nanoparticles elicited prolonged antibody titers compared to liposomes and alum. The magnitude of the cellular immune response was also highest in mice vaccinated with PLGA, which also showed a higher frequency of effector-like memory T cell phenotype, leading to an effective clearance of intracellular bacteria. The difference in performance of these two common particulate platforms is shown not to be due to material differences but appears to be connected to the kinetics of antigen delivery. Thus, this study highlights the importance of sustained antigen release mediated by particulate platforms and its role in the long-term appearance of effector memory cellular response. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Poly-ϵ-caprolactone/chitosan nanoparticles provide strong adjuvant effect for hepatitis B antigen.

    Science.gov (United States)

    Jesus, Sandra; Soares, Edna; Borchard, Gerrit; Borges, Olga

    2017-10-01

    This work aims to investigate the adjuvant effect of poly-ϵ-caprolactone/chitosan nanoparticles (NPs) for hepatitis B surface antigen (HBsAg) and the plasmid DNA encoding HBsAg (pRC/CMV-HBs). Both antigens were adsorbed onto preformed NPs. Vaccination studies were performed in C57BL/6 mice. Transfection efficiency was investigated in A549 cell line. HBsAg-adsorbed NPs generated strong anti-HBsAg IgG titers, mainly of IgG1 isotype, and induced antigen-specific IFN-γ and IL-17 secretion by spleen cells. The addition of pRC/CMV-HBs to the HBsAg-adsorbed NPs inhibited IL-17 secretion but had minor effect on IFN-γ levels. Lastly, pRC/CMV-HBs-loaded NPs generated a weak serum antibody response. Poly-ϵ-caprolactone/chitosan NPs provide a strong humoral adjuvant effect for HBsAg and induce a Th1/Th17-mediated cellular immune responses worth explore for hepatitis B virus vaccination.

  6. Enhanced expression of codon optimized Mycobacterium avium subsp. paratuberculosis antigens in Lactobacillus salivarius

    Directory of Open Access Journals (Sweden)

    Christopher D Johnston

    2014-09-01

    Full Text Available It is well documented that open reading frames containing high GC content show poor expression in A+T rich hosts. Specifically, G+C-rich codon usage is a limiting factor in heterologous expression of Mycobacterium avium subsp. paratuberculosis (MAP proteins using Lactobacillus salivarius. However, re-engineering opening reading frames through synonymous substitutions can offset codon bias and greatly enhance MAP protein production in this host. In this report, we demonstrate that codon-usage manipulation of two MAP genes (MAP2121c and MAP3733c can enhance the heterologous expression of two antigens (MMP and MptD respectively, analogous to the form to which they are produced natively by MAP bacilli. When heterologously over-expressed, antigenic determinants were preserved in synthetic MMP proteins as shown by monoclonal antibody mediated ELISA. Moreover, MMP is a membrane protein in MAP, which is also targeted to the cellular surface of recombinant L. salivarius at levels comparable to MAP. Additionally, codon optimised MptD displayed the tendency to associate with the cytoplasmic membrane boundary under confocal microscopy and the intracellularly accumulated protein selectively adhered with the MptD-specific bacteriophage fMptD. This work demonstrates there is potential for L. salivarius as a viable antigen delivery vehicle for MAP, which may provide an effective mucosal vaccine against Johne’s disease.

  7. SNX5 is essential for efficient macropinocytosis and antigen processing in primary macrophages.

    Science.gov (United States)

    Lim, Jet Phey; Teasdale, Rohan D; Gleeson, Paul A

    2012-09-15

    Macropinocytosis mediates the bulk endocytosis of solute molecules, nutrients and antigens. As this endocytic pathway is considered important in functions associated with immune responses, the molecular mechanisms regulating this pathway in immune cells is of particular significance. However, the regulators of macropinocytosis in primary cells remain poorly defined. Members of the sorting nexin (SNX) family have been implicated in macropinosome biogenesis in cultured cells and here we have analyzed the role of two SNX family members, SNX1 and its binding partner SNX5, in macropinocytosis of mouse primary macrophages. We show that endogenous SNX1 and SNX5 are localised to newly-formed macropinosomes in primary mouse macrophages and, moreover, demonstrate that SNX5 plays an essential role in macropinosome biogenesis. Depletion of SNX5 in bone marrow-derived macrophages dramatically decreased both the number and size of macropinosomes. Depletion of SNX5 also resulted in dramatic reduction in uptake and processing of soluble ovalbumin in macrophages, indicating that the majority of antigen uptake and delivery to late endosomes is via macropinocytosis. By contrast, the absence of SNX1 had no effect on endogenous SNX5 localisation and macropinosome biogenesis using macrophages from SNX1 knockout mice. Therefore, SNX5 can function independently of SNX1 and is a modulator of macropinocytosis that influences the uptake and processing of soluble antigen in primary mouse macrophages.

  8. SNX5 is essential for efficient macropinocytosis and antigen processing in primary macrophages

    Directory of Open Access Journals (Sweden)

    Jet Phey Lim

    2012-07-01

    Macropinocytosis mediates the bulk endocytosis of solute molecules, nutrients and antigens. As this endocytic pathway is considered important in functions associated with immune responses, the molecular mechanisms regulating this pathway in immune cells is of particular significance. However, the regulators of macropinocytosis in primary cells remain poorly defined. Members of the sorting nexin (SNX family have been implicated in macropinosome biogenesis in cultured cells and here we have analyzed the role of two SNX family members, SNX1 and its binding partner SNX5, in macropinocytosis of mouse primary macrophages. We show that endogenous SNX1 and SNX5 are localised to newly-formed macropinosomes in primary mouse macrophages and, moreover, demonstrate that SNX5 plays an essential role in macropinosome biogenesis. Depletion of SNX5 in bone marrow-derived macrophages dramatically decreased both the number and size of macropinosomes. Depletion of SNX5 also resulted in dramatic reduction in uptake and processing of soluble ovalbumin in macrophages, indicating that the majority of antigen uptake and delivery to late endosomes is via macropinocytosis. By contrast, the absence of SNX1 had no effect on endogenous SNX5 localisation and macropinosome biogenesis using macrophages from SNX1 knockout mice. Therefore, SNX5 can function independently of SNX1 and is a modulator of macropinocytosis that influences the uptake and processing of soluble antigen in primary mouse macrophages.

  9. Antigen microarrays: descriptive chemistry or functional immunomics?

    Science.gov (United States)

    Prechl, József; Papp, Krisztián; Erdei, Anna

    2010-04-01

    Advances in protein microarray technology allow the generation of high content, reliable information about complex, multilevel protein interaction networks. Yet antigen arrays are used mostly only as devices for parallel immune assays describing multitudes of individual binding events. We propose here that the huge amount of immunological information hidden in the plasma of an individual could be better revealed by combining the characterization of antibody binding to target epitopes with improved estimation of effector functions triggered by these binding events. Furthermore, we could generate functional immune profiles characterizing general immune responsiveness of the individual by designing arrays incorporating epitope collections from diverse subsets of antibody targets. Copyright 2010 Elsevier Ltd. All rights reserved.

  10. Detection of poliovirus antigen by enzyme immunoassay.

    OpenAIRE

    Ukkonen, P; Huovilainen, A; Hovi, T

    1986-01-01

    A solid-phase enzyme immunoassay (EIA) was developed for the detection of poliovirus antigen. Rabbit and guinea pig antisera for the assay were raised against purified poliovirus type 3/Fin (strain 3/Fin/K) isolated from a fecal specimen from a meningitis patient during an outbreak of poliomyelitis in Finland in 1984. The EIA was highly specific for poliovirus type 3, and it was about 30 times more sensitive for strain 3/Fin/K than for strain 3/Saukett used in the inactivated poliovirus vacci...

  11. Galactosylated LDL nanoparticles: a novel targeting delivery system to deliver antigen to macrophages and enhance antigen specific T cell responses.

    Science.gov (United States)

    Wu, Fang; Wuensch, Sherry A; Azadniv, Mitra; Ebrahimkhani, Mohammad R; Crispe, I Nicholas

    2009-01-01

    We aim to define the role of Kupffer cells in intrahepatic antigen presentation, using the selective delivery of antigen to Kupffer cells rather than other populations of liver antigen-presenting cells. To achieve this we developed a novel antigen delivery system that can target antigens to macrophages, based on a galactosylated low-density lipoprotein nanoscale platform. Antigen was delivered via the galactose particle receptor (GPr), internalized, degraded and presented to T cells. The conjugation of fluoresceinated ovalbumin (FLUO-OVA) and lactobionic acid with LDL resulted in a substantially increased uptake of FLUO-OVA by murine macrophage-like ANA1 cells in preference to NIH3T3 cells, and by primary peritoneal macrophages in preference to primary hepatic stellate cells. Such preferential uptake led to enhanced proliferation of OVA specific T cells, showing that the galactosylated LDL nanoscale platform is a successful antigen carrier, targeting antigen to macrophages but not to all categories of antigen presenting cells. This system will allow targeted delivery of antigen to macrophages in the liver and elsewhere, addressing the question of the role of Kupffer cells in liver immunology. It may also be an effective way of delivering drugs or vaccines directly at macrophages.

  12. Tissue distribution of histo-blood group antigens

    DEFF Research Database (Denmark)

    Ravn, V; Dabelsteen, Erik

    2000-01-01

    The introduction of immunohistochemical techniques and monoclonal antibodies to specific carbohydrate epitopes has made it possible to study in detail the tissue distribution of histo-blood group antigens and related carbohydrate structures. The present paper summarizes the available data...... concerning the histological distribution of histo-blood group antigens and their precursor structures in normal human tissues. Studies performed have concentrated on carbohydrate antigens related to the ABO, Lewis, and TTn blood group systems, i.e. histo-blood group antigens carried by type 1, 2, and 3 chain...... carrier carbohydrate chains. Histo-blood group antigens are found in most epithelial tissues. Meanwhile, several factors influence the type, the amount, and the histological distribution of histoblood group antigens, i.e. the ABO, Lewis, and saliva-secretor type of the individual, and the cell- and tissue...

  13. Tissue distribution of histo-blood group antigens

    DEFF Research Database (Denmark)

    Ravn, V; Dabelsteen, Erik

    2000-01-01

    carrier carbohydrate chains. Histo-blood group antigens are found in most epithelial tissues. Meanwhile, several factors influence the type, the amount, and the histological distribution of histoblood group antigens, i.e. the ABO, Lewis, and saliva-secretor type of the individual, and the cell- and tissue......The introduction of immunohistochemical techniques and monoclonal antibodies to specific carbohydrate epitopes has made it possible to study in detail the tissue distribution of histo-blood group antigens and related carbohydrate structures. The present paper summarizes the available data...... concerning the histological distribution of histo-blood group antigens and their precursor structures in normal human tissues. Studies performed have concentrated on carbohydrate antigens related to the ABO, Lewis, and TTn blood group systems, i.e. histo-blood group antigens carried by type 1, 2, and 3 chain...

  14. Strategies to enhance immunogenicity of cDNA vaccine encoded antigens by modulation of antigen processing

    NARCIS (Netherlands)

    Platteel, Anouk C M; Marit de Groot, A; Andersen, Peter; Ovaa, Huib; Kloetzel, Peter M; Mishto, Michele; Sijts, Alice J A M

    2016-01-01

    Most vaccines are based on protective humoral responses while for intracellular pathogens CD8(+) T cells are regularly needed to provide protection. However, poor processing efficiency of antigens is often a limiting factor in CD8(+) T cell priming, hampering vaccine efficacy. The multistage cDNA

  15. Hepatitis B surface antigen incorporated in dissolvable microneedle array patch is antigenic and thermostable.

    Science.gov (United States)

    Poirier, Danielle; Renaud, Frédéric; Dewar, Vincent; Strodiot, Laurent; Wauters, Florence; Janimak, Jim; Shimada, Toshio; Nomura, Tatsuya; Kabata, Koki; Kuruma, Koji; Kusano, Takayuki; Sakai, Masaki; Nagasaki, Hideo; Oyamada, Takayoshi

    2017-11-01

    Alternatives to syringe-based administration are considered for vaccines. Intradermal vaccination with dissolvable microneedle arrays (MNA) appears promising in this respect, as an easy-to-use and painless method. In this work, we have developed an MNA patch (MNAP) made of hydroxyethyl starch (HES) and chondroitin sulphate (CS). In swines, hepatitis B surface antigen (HBsAg) formulated with the saponin QS-21 as adjuvant, both incorporated in HES-based MNAP, demonstrated the same level of immunogenicity as a commercially available aluminum-adjuvanted HBsAg vaccine, after two immunizations 28 days apart. MNAP application was associated with transient skin reactions (erythema, lump, scab), particularly evident when the antigen was delivered with the adjuvant. The thermostability of the adjuvanted antigen when incorporated in the HES-based matrix was also assessed by storing MNAP at 37, 45 or 50 °C for up to 6 months. We could demonstrate that antigenicity was retained at 37 and 45 °C and only a 10% loss was observed after 6 months at 50 °C. Our results are supportive of MNAP as an attractive alternative to classical syringe-based vaccination. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Monoclonal antibodies to Nocardia asteroides and Nocardia brasiliensis antigens.

    OpenAIRE

    Jiménez, T; Díaz, A M; Zlotnik, H

    1990-01-01

    Nocardia asteroides and Nocardia brasiliensis whole-cell extracts were used as antigens to generate monoclonal antibodies (MAbs). Six stable hybrid cell lines secreting anti-Nocardia spp. MAbs were obtained. These were characterized by enzyme-linked immunosorbent assay, Western blot (immunoblot), and immunofluorescence assay. Although all the MAbs exhibited different degrees of cross-reactivity with N. asteroides and N. brasiliensis antigens as well as with culture-filtrate antigens from Myco...

  17. Relations between immune and mediator receptors of mouse lymphocytes

    International Nuclear Information System (INIS)

    Ado, A.D.; Alekseeva, T.A.; Kravchenko, S.A.

    1985-01-01

    This paper examines the action of the specific muscarinic antogonist tritium-quinuclidinyl benzilate (tritium-QNB) on immune rosette formation in mice. It is shown that since the specific muscarini antagonist tritium-QNB inhibits immune rosette formation, this process must be regarded as interconnected with muscarinic receptors of lymphocytes. Interaction of immune (antigen-binding) and mediator receptors, however, is an important factor maintaining immune homeostasis at a certain level

  18. Immunoregulation by Taenia crassiceps and Its Antigens

    Directory of Open Access Journals (Sweden)

    Alberto N. Peón

    2013-01-01

    Full Text Available Taenia crassiceps is a cestode parasite of rodents (in its larval stage and canids (in its adult stage that can also parasitize immunocompromised humans. We have studied the immune response elicited by this helminth and its antigens in mice and human cells, and have discovered that they have a strong capacity to induce chronic Th2-type responses that are primarily characterized by high levels of Th2 cytokines, low proliferative responses in lymphocytes, an immature and LPS-tolerogenic profile in dendritic cells, the recruitment of myeloid-derived suppressor cells and, specially, alternatively activated macrophages. We also have utilized the immunoregulatory capabilities of this helminth to successfully modulate autoimmune responses and the outcome of other infectious diseases. In the present paper, we review the work of others and ourselves with regard to the immune response induced by T. crassiceps and its antigens, and we compare the advances in our understanding of this parasitic infection model with the knowledge that has been obtained from other selected models.

  19. Monoclonal antibodies to carcino-embryonic antigen

    International Nuclear Information System (INIS)

    Teh, Jinghee; McKenzie, I.F.C.

    1990-01-01

    With the aim of producing new MoAb to colorectal carcinoma, immunization with cell suspensions of a fresh colonic tumour was performed and MoAb 17C4 was obtained. To produce other MoAb to colon cancer, an immunization protocol using fresh tumour, colonic cell lines and sera from patients with colonic tumours was employed and resulted in MoAb JGT-13, LK-4 and XPX-13. MoAb I-1 and O-1 were raised against sera from patients with colon cancer to produce MoAb directed against circulating tumour associated antigens. The six antibodies gave a range of reactions with normal and malignant tissues, indicating that they most likely reacted with different epitopes. Thus, apart from the reactions of 17C4, LK-4 and XPX-13 with fresh and formalin-fixed granulocytes, none of the antibodies reacted with formalin-fixed normal tissues. Despite the apparent specificity of these MoAb for colon cancer, serum testing using MoAb gave similar results to carcino-embryonic antigen polyclonal antibodies, that is the MoAb gave no obvious advantage. 9 refs., 1 tab., 3 figs

  20. Glycoconjugates as target antigens in peripheral neuropathies

    Directory of Open Access Journals (Sweden)

    Ljubica Suturkova

    2014-12-01

    Full Text Available Identification and characterization of antigens present at the human peripheral nerve is a great challenge in the field of neuroimmunology. The latest investigations are focused on the understanding of the biology of glycoconjugates present at the peripheral nerve, and their immunological reactivity. Increased titers of antibodies that recognize carbohydrate determinants of glycoconjugates (glycolipids and glycoproteins are associated with distinct neuropathic syndromes. There is considerable cross-reactivity among anti-ganglioside antibodies, resulting from shared oligosaccharide epitopes, possibly explaining the overlap in syndromes observed in many affected patients. Sera from patients with neuropathies (GBS, chronic inflammatory demielynating polyneuropathy - CIDP, multifocal motor neuropathy - MMN, cross-react with glycoproteins isolated from human peripheral nerve and from Campylobacter jejuni O:19. The frequency of occurrence of antibodies against these glycoproteins is different, depending of the type of neuropathy. Identification of the cross-reactive glycoproteins and possible additional auto antigens could be useful in laboratory evaluation of peripheral neuropathies and help to develop a more effective therapeutic approach.

  1. 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.

  2. СAPSULAR ANTIGEN OF YERSINIA PESTIS

    Directory of Open Access Journals (Sweden)

    L. A. Kadnikova

    2015-01-01

    Full Text Available Plague is a zoonosis caused by gram-negative bacteria Yersinia pestis, which, as a rule, is transmitted to humans from septicemic rodents by the bites of infected fleas. This microbe killed more people than all of the wars in the human history. Y. pestis circulation in the natural plague foci is ensured by the whole number of pathogenicity factors with differing functional orientation. This review is devoted to one of them, Y. pestis capsular antigen (F1 or Caf1. The history of its discovery and studying of its genetic control, biosynthesis, isolation and purification, and physicochemical properties are reviewed. Its roles in plague pathogenesis and its application as a main component of plague vaccines are also discussed. Y. pestis capsule under light microscopy is visually amorphous, while high-resolution electron microscopy displays the structure formed from separate fimbria-like cords up to 200 nm long, diverging from the bacterial surface in different directions. At 37°C Y. pestis produce 800–1000 times more capsular antigen than at 28°C. Genes coding for 17.6-kD Caf1 protein, which contains 170 amino acids, are located in caf1 operon of pFra plasmid. Analysis of caf1 operon nucleotide sequence testified its close phylogenetic relationship with the gene clusters coding for pilus adhesins that were secreted with the help of chaperone/usher systems in enterobacteria including six additional adhesins in Y. pestis. Y. pestis multiplication within macrophages is the obligatory stage of plague pathogenesis, and the plague pathogen virulence correlates not with resistance to phagocyte ingesting but with bacterial ability to survive and multiply within phagolysosomes of phagocytes due to neutralization of antibacterial functions of eukaryotic cells. The capsule formed out of the Caf1 aggregates protects Y. pestis from ingestion by naïve host’s phagocytes and prevents from initiation of the alternative pathway of the complement system

  3. T-cell responses against Malaria: Effect of parasite antigen diversity and relevance for vaccine development.

    Science.gov (United States)

    Nlinwe, Omarine Nfor; Kusi, Kwadwo Asamoah; Adu, Bright; Sedegah, Martha

    2018-03-21

    The on-going agenda for global malaria elimination will require the development of additional disease control and prevention measures since currently available tools are showing signs of inadequacy. Malaria vaccines are seen as one such important addition to the control arsenal since vaccines have proven to be highly effective public health tools against important human diseases. Both cell-mediated and antibody responses are generally believed to be important for malaria parasite control, although the exact targets of T and B cell responses against malaria have not been clearly defined. However, our current understanding of the immune response to malaria suggests that T cell responses against multiple antigenic targets may potentially be key for the development of a highly efficacious malaria vaccine. This review takes a comprehensive look at the available literature on T cell-mediated immunity against all human stages of the malaria parasite and the effect of antigen diversity on these responses. The implications of these interrelationships for the development of an effective vaccine for malaria are also highlighted. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. IL-4Rα-associated antigen processing by B cells promotes immunity in Nippostrongylus brasiliensis infection.

    Directory of Open Access Journals (Sweden)

    William G C Horsnell

    2013-10-01

    Full Text Available In this study, B cell function in protective T(H2 immunity against N. brasiliensis infection was investigated. Protection against secondary infection depended on IL-4Rα and IL-13; but not IL-4. Protection did not associate with parasite specific antibody responses. Re-infection of B cell-specific IL-4Rα⁻/⁻ mice resulted in increased worm burdens compared to control mice, despite their equivalent capacity to control primary infection. Impaired protection correlated with reduced lymphocyte IL-13 production and B cell MHC class II and CD86 surface expression. Adoptive transfer of in vivo N. brasiliensis primed IL-4Rα expressing B cells into naïve BALB/c mice, but not IL-4Rα or IL-13 deficient B cells, conferred protection against primary N. brasiliensis infection. This protection required MHC class II compatibility on B cells suggesting cognate interactions by B cells with CD4⁺ T cells were important to co-ordinate immunity. Furthermore, the rapid nature of these protective effects by B cells suggested non-BCR mediated mechanisms, such as via Toll Like Receptors, was involved, and this was supported by transfer experiments using antigen pulsed Myd88⁻/⁻ B cells. These data suggest TLR dependent antigen processing by IL-4Rα-responsive B cells producing IL-13 contribute significantly to CD4⁺ T cell-mediated protective immunity against N. brasiliensis infection.

  5. IL-4Rα-Associated Antigen Processing by B Cells Promotes Immunity in Nippostrongylus brasiliensis Infection

    Science.gov (United States)

    Hoving, Jennifer C.; Nieuwenhuizen, Natalie; McSorley, Henry J.; Ndlovu, Hlumani; Bobat, Saeeda; Kimberg, Matti; Kirstein, Frank; Cutler, Anthony J.; DeWals, Benjamin; Cunningham, Adam F.; Brombacher, Frank

    2013-01-01

    In this study, B cell function in protective TH2 immunity against N. brasiliensis infection was investigated. Protection against secondary infection depended on IL-4Rα and IL-13; but not IL-4. Protection did not associate with parasite specific antibody responses. Re-infection of B cell-specific IL-4Rα−/− mice resulted in increased worm burdens compared to control mice, despite their equivalent capacity to control primary infection. Impaired protection correlated with reduced lymphocyte IL-13 production and B cell MHC class II and CD86 surface expression. Adoptive transfer of in vivo N. brasiliensis primed IL-4Rα expressing B cells into naïve BALB/c mice, but not IL-4Rα or IL-13 deficient B cells, conferred protection against primary N. brasiliensis infection. This protection required MHC class II compatibility on B cells suggesting cognate interactions by B cells with CD4+ T cells were important to co-ordinate immunity. Furthermore, the rapid nature of these protective effects by B cells suggested non-BCR mediated mechanisms, such as via Toll Like Receptors, was involved, and this was supported by transfer experiments using antigen pulsed Myd88−/− B cells. These data suggest TLR dependent antigen processing by IL-4Rα-responsive B cells producing IL-13 contribute significantly to CD4+ T cell-mediated protective immunity against N. brasiliensis infection. PMID:24204255

  6. Bayesian nonparametric clustering in phylogenetics: modeling antigenic evolution in influenza.

    Science.gov (United States)

    Cybis, Gabriela B; Sinsheimer, Janet S; Bedford, Trevor; Rambaut, Andrew; Lemey, Philippe; Suchard, Marc A

    2018-01-30

    Influenza is responsible for up to 500,000 deaths every year, and antigenic variability represents much of its epidemiological burden. To visualize antigenic differences across many viral strains, antigenic cartography methods use multidimensional scaling on binding assay data to map influenza antigenicity onto a low-dimensional space. Analysis of such assay data ideally leads to natural clustering of influenza strains of similar antigenicity that correlate with sequence evolution. To understand the dynamics of these antigenic groups, we present a framework that jointly models genetic and antigenic evolution by combining multidimensional scaling of binding assay data, Bayesian phylogenetic machinery and nonparametric clustering methods. We propose a phylogenetic Chinese restaurant process that extends the current process to incorporate the phylogenetic dependency structure between strains in the modeling of antigenic clusters. With this method, we are able to use the genetic information to better understand the evolution of antigenicity throughout epidemics, as shown in applications of this model to H1N1 influenza. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  7. SPECIFIC CARCINOEMBRYONIC ANTIGENS OF THE HUMAN DIGESTIVE SYSTEM

    Science.gov (United States)

    Gold, Phil; Freedman, Samuel O.

    1965-01-01

    A wide variety of human adult and fetal tissues were studied by immune-diffusion techniques in agar gel to determine whether they contained the tumor-specific antigen(s) previously found in coionic cancers. In the adult tissues it was demonstrated that identical antigens were present in all tested specimens of malignant tumors of the entodermally derived epithelium of the gastrointestinal tract and pancreas, but were absent from all other tested adult tissues. The common antigenic constituents, therefore, represent system-specific cancer antigens of the human digestive system. System-specific cancer antigens have not previously been demonstrated in humans. Experiments with fetal tissues demonstrated that identical antigens were also present in fetal gut, liver, and pancreas between 2 and 6 months of gestation. These components were named "carcinoembryonic" antigens of the human digestive system. On the basis of the present findings and the recent work regarding control of the expression of genetic potentialities in various types of cells, it was concluded that the carcinoembryonic antigens represent cellular constituents which are repressed during the course of differentiation of the normal digestive system epithelium and reappear in the corresponding malignant cells by a process of derepressive-dedifferentiation. PMID:4953873

  8. Identification of protective antigens for vaccination against systemic salmonellosis

    Directory of Open Access Journals (Sweden)

    Dirk eBumann

    2014-08-01

    Full Text Available There is an urgent medical need for improved vaccines with broad serovar coverage and high efficacy against systemic salmonellosis. Subunit vaccines offer excellent safety profiles but require identification of protective antigens, which remains a challenging task. Here, I review crucial properties of Salmonella antigens that might help to narrow down the number of potential candidates from more than 4000 proteins encoded in Salmonella genomes, to a more manageable number of 50-200 most promising antigens. I also discuss complementary approaches for antigen identification and potential limitations of current pre-clinical vaccine testing.

  9. Cancer-germline antigen vaccines and epigenetic enhancers

    DEFF Research Database (Denmark)

    Gjerstorff, Morten Frier; Burns, Jorge; Ditzel, Henrik Jorn

    2010-01-01

    can be achieved using epigenetic modifiers. AREAS COVERED IN THIS REVIEW: We provide an overview of the potential of CG antigens as targets for cancer immunotherapy, including advantages and disadvantages. We also discuss the current state of development of CG antigen vaccines, and the potential...... synergistic effect of combining CG antigen immunotherapeutic strategies with epigenetic modifiers. WHAT THE READER WILL GAIN: The reader will gain an overview of the past, present and future role of CG antigens in cancer immunotherapy. TAKE HOME MESSAGE: Chemoimmunotherapy using epigenetic drugs and CG...

  10. Antigenic subversion: a novel mechanism of host immune evasion by Ebola virus.

    Directory of Open Access Journals (Sweden)

    Gopi S Mohan

    Full Text Available In addition to its surface glycoprotein (GP(1,2, Ebola virus (EBOV directs the production of large quantities of a truncated glycoprotein isoform (sGP that is secreted into the extracellular space. The generation of secreted antigens has been studied in several viruses and suggested as a mechanism of host immune evasion through absorption of antibodies and interference with antibody-mediated clearance. However such a role has not been conclusively determined for the Ebola virus sGP. In this study, we immunized mice with DNA constructs expressing GP(1,2 and/or sGP, and demonstrate that sGP can efficiently compete for anti-GP(12 antibodies, but only from mice that have been immunized by sGP. We term this phenomenon "antigenic subversion", and propose a model whereby sGP redirects the host antibody response to focus on epitopes which it shares with membrane-bound GP(1,2, thereby allowing it to absorb anti-GP(1,2 antibodies. Unexpectedly, we found that sGP can also subvert a previously immunized host's anti-GP(1,2 response resulting in strong cross-reactivity with sGP. This finding is particularly relevant to EBOV vaccinology since it underscores the importance of eliciting robust immunity that is sufficient to rapidly clear an infection before antigenic subversion can occur. Antigenic subversion represents a novel virus escape strategy that likely helps EBOV evade host immunity, and may represent an important obstacle to EBOV vaccine design.

  11. Antigenic subversion: a novel mechanism of host immune evasion by Ebola virus.

    Science.gov (United States)

    Mohan, Gopi S; Li, Wenfang; Ye, Ling; Compans, Richard W; Yang, Chinglai

    2012-01-01

    In addition to its surface glycoprotein (GP(1,2)), Ebola virus (EBOV) directs the production of large quantities of a truncated glycoprotein isoform (sGP) that is secreted into the extracellular space. The generation of secreted antigens has been studied in several viruses and suggested as a mechanism of host immune evasion through absorption of antibodies and interference with antibody-mediated clearance. However such a role has not been conclusively determined for the Ebola virus sGP. In this study, we immunized mice with DNA constructs expressing GP(1,2) and/or sGP, and demonstrate that sGP can efficiently compete for anti-GP(12) antibodies, but only from mice that have been immunized by sGP. We term this phenomenon "antigenic subversion", and propose a model whereby sGP redirects the host antibody response to focus on epitopes which it shares with membrane-bound GP(1,2), thereby allowing it to absorb anti-GP(1,2) antibodies. Unexpectedly, we found that sGP can also subvert a previously immunized host's anti-GP(1,2) response resulting in strong cross-reactivity with sGP. This finding is particularly relevant to EBOV vaccinology since it underscores the importance of eliciting robust immunity that is sufficient to rapidly clear an infection before antigenic subversion can occur. Antigenic subversion represents a novel virus escape strategy that likely helps EBOV evade host immunity, and may represent an important obstacle to EBOV vaccine design.

  12. Several Carcinoembryonic Antigens (CD66) Serve as Receptors for Gonococcal Opacity Proteins

    Science.gov (United States)

    Chen, Tie; Grunert, Fritz; Medina-Marino, Andrew; Gotschlich, Emil C.

    1997-01-01

    Neisseria gonorrhoeae (GC) is a human pathogen that adheres to and invades genital surfaces. Although pili are required for the initial adherence, the interaction of GC with epithelial cells is also promoted by a family of outer membrane proteins, the opacity (Opa) proteins such as OpaA protein from strain MS11. Studies have demonstrated that the interaction of the OpaA GC with epithelial cells involves binding to heparan sulfate attached to syndecan receptors. However, other Opa proteins interact with CEA gene family member 1 (CGM1) or biliary glycoprotein (BGP), members of the CD66 antigen family. In this study, we demonstrate that, in addition, the 180-kD carcinoembryonic antigen (CEA) is a receptor for Opa proteins. This conclusion was based on the following observations. First, transfected HeLa cells expressing CEA (HeLaCEA) and the CEA-expressing colon cancer cell line (LS 174T) bound and subsequently engulfed the Opa+ bacteria. These interactions were inhibited by anti-CEA antibody, but could not be inhibited by addition of heparin. Furthermore, OpaI E. coli directly bound purified CEA. We also compared the adherence and invasion by Opa+ bacteria of CD66 transfected HeLa cells: HeLa-BGPa, HeLa-CGM6, HeLa-NCA, HeLa-CGM1a, HeLa-CEA, and HeLa-Neo serving as negative control. Using OpaI as the prototype, the relative ability of the transfected HeLa cell lines to support adherence was (CEA = BGPa >CGM1a >NCA >>CGM6 = Neo). The ability to mediate invasion of the transfectant cells was (CGM1a >CEA >BGPa >NCA >CGM6 = Neo). Among the Opa proteins tested, OpaC proved to be bifunctional, able to mediate adherence to both syndecan receptors and to CD66 antigens. PMID:9151893

  13. O antigen modulates insect vector acquisition of the bacterial plant pathogen Xylella fastidiosa.

    Science.gov (United States)

    Rapicavoli, Jeannette N; Kinsinger, Nichola; Perring, Thomas M; Backus, Elaine A; Shugart, Holly J; Walker, Sharon; Roper, M Caroline

    2015-12-01

    Hemipteran insect vectors transmit the majority of plant pathogens. Acquisition of pathogenic bacteria by these piercing/sucking insects requires intimate associations between the bacterial cells and insect surfaces. Lipopolysaccharide (LPS) is the predominant macromolecule displayed on the cell surface of Gram-negative bacteria and thus mediates bacterial interactions with the environment and potential hosts. We hypothesized that bacterial cell surface properties mediated by LPS would be important in modulating vector-pathogen interactions required for acquisition of the bacterial plant pathogen Xylella fastidiosa, the causative agent of Pierce's disease of grapevines. Utilizing a mutant that produces truncated O antigen (the terminal portion of the LPS molecule), we present results that link this LPS structural alteration to a significant decrease in the attachment of X. fastidiosa to blue-green sharpshooter foreguts. Scanning electron microscopy confirmed that this defect in initial attachment compromised subsequent biofilm formation within vector foreguts, thus impairing pathogen acquisition. We also establish a relationship between O antigen truncation and significant changes in the physiochemical properties of the cell, which in turn affect the dynamics of X. fastidiosa adhesion to the vector foregut. Lastly, we couple measurements of the physiochemical properties of the cell with hydrodynamic fluid shear rates to produce a Comsol model that predicts primary areas of bacterial colonization within blue-green sharpshooter foreguts, and we present experimental data that support the model. These results demonstrate that, in addition to reported protein adhesin-ligand interactions, O antigen is crucial for vector-pathogen interactions, specifically in the acquisition of this destructive agricultural pathogen. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. The challenge of producing skin test antigens with minimal resources suitable for human application against a neglected tropical disease; leprosy.

    Directory of Open Access Journals (Sweden)

    Becky L Rivoire

    Full Text Available True incidence of leprosy and its impact on transmission will not be understood until a tool is available to measure pre-symptomatic infection. Diagnosis of leprosy disease is currently based on clinical symptoms, which on average take 3-10 years to manifest. The fact that incidence, as defined by new case detection, equates with prevalence, i.e., registered cases, suggests that the cycle of transmission has not been fully intercepted by implementation of multiple drug therapy. This is supported by a high incidence of childhood leprosy. Epidemiological screening for pre-symptomatic leprosy in large endemic populations is required to facilitate targeted chemoprophylactic interventions. Such a test must be sensitive, specific, simple to administer, cost-effective, and easy to interpret. The intradermal skin test method that measures cell-mediated immunity was explored as the best option. Prior knowledge on skin testing of healthy subjects and leprosy patients with whole or partially fractionated Mycobacterium leprae bacilli, such as Lepromin or the Rees' or Convit' antigens, has established an acceptable safety and potency profile of these antigens. These data, along with immunoreactivity data, laid the foundation for two new leprosy skin test antigens, MLSA-LAM (M. leprae soluble antigen devoid of mycobacterial lipoglycans, primarily lipoarabinomannan and MLCwA (M. leprae cell wall antigens. In the absence of commercial interest, the challenge was to develop these antigens under current good manufacturing practices in an acceptable local pilot facility and submit an Investigational New Drug to the Food and Drug Administration to allow a first-in-human phase I clinical trial.

  15. Presensitization to Ascaris antigens promotes induction of mite-specific IgE upon mite antigen inhalation in mice

    OpenAIRE

    Suzuki, Mayu; Hara, Mutsuko; Ichikawa, Saori; Kamijo, Seiji; Nakazawa, Takuya; Hatanaka, Hideki; Akiyama, Kazuo; Ogawa, Hideoki; Okumura, Ko; Takai, Toshiro

    2016-01-01

    Background: Patients with house dust mite (HDM) allergy or Ascariasis produce serum IgE specific to the antigens of HDM or nematode Ascaris, respectively. Although human IgE cross-reactivity has been reported between HDM and Ascaris antigens, it remains unclear whether it contributes to the pathogenesis of allergic diseases. We herein investigated the induction of cross-reactive antibodies and T cells in mice and effects of airway exposure to HDM antigens after preimmunization with Ascaris an...

  16. Antigenic determinants of prostate-specific antigen (PSA) and development of assays specific for different forms of PSA.

    OpenAIRE

    Nilsson, O.; Peter, A.; Andersson, I.; Nilsson, K.; Grundstr?m, B.; Karlsson, B.

    1997-01-01

    Monoclonal antibodies were raised against prostate-specific antigen (PSA) by immunization with purified free PSA, i.e. not in complex with any protease inhibitor (F-PSA) and PSA in complex with alpha1-anti-chymotrypsin (PSA-ACT). Epitope mapping of PSA using the established monoclonal antibody revealed a complex pattern of independent and partly overlapping antigenic domains in the PSA molecule. Four independent antigenic domains and at least three partly overlapping domains were exposed both...

  17. Induction of protective immunity against Schistosoma mansoni infection by antigens purified from PIII, a fraction of adult worm, associated to the downregulation of granuloma formation

    Directory of Open Access Journals (Sweden)

    Gustavson Shauma

    1998-01-01

    Full Text Available This study was performed in order to define Schistosoma mansoni antigens able to function as modulator agents in BALB/c mice granulomatous hypersensitivity to parasite egg. The antigens P-24, P-35 and P-97 were purified by affinity chromatography from a fraction of S. mansoni adult worm antigenic preparation, denominated PIII, involved in the inhibition of granulomatous response to eggs. Immunization of mice with these antigens, in the presence of Corynebacterium parvum and Al(OH3 as adjuvant, induced a significant protection degree against challenge infection, as observed by the decrease on worm burden recovered from portal system. In vitro blastogenesis assays revealed that purified antigens were able to induce significant proliferation of spleen cells from S. mansoni-infected mice. This protection was correlated to significant decrease in granuloma size induced by PIII. From these results, we concluded that PIII preparation contains antigens capable of mediating protective anti-parasite immunity and down-regulating granulomatous hypersensitivity to S. mansoni eggs.

  18. Centrosomal localisation of the cancer/testis (CT) antigens NY-ESO-1 and MAGE-C1 is regulated by proteasome activity in tumour cells.

    Science.gov (United States)

    Pagotto, Anna; Caballero, Otavia L; Volkmar, Norbert; Devalle, Sylvie; Simpson, Andrew J G; Lu, Xin; Christianson, John C

    2013-01-01

    The Cancer/Testis (CT) antigen family of genes are transcriptionally repressed in most human tissues but are atypically re-expressed in many malignant tumour types. Their restricted expression profile makes CT antigens ideal targets for cancer immunotherapy. As little is known about whether CT antigens may be regulated by post-translational processing, we investigated the mechanisms governing degradation of NY-ESO-1 and MAGE-C1 in selected cancer cell lines. Inhibitors of proteasome-mediated degradation induced the partitioning of NY-ESO-1 and MAGE-C1 into a detergent insoluble fraction. Moreover, this treatment also resulted in increased localisation of NY-ESO-1 and MAGE-C1 at the centrosome. Despite their interaction, relocation of either NY-ESO-1 or MAGE-C1 to the centrosome could occur independently of each other. Using a series of truncated fragments, the regions corresponding to NY-ESO-1(91-150) and MAGE-C1(900-1116) were established as important for controlling both stability and localisation of these CT antigens. Our findings demonstrate that the steady state levels of NY-ESO-1 and MAGE-C1 are regulated by proteasomal degradation and that both behave as aggregation-prone proteins upon accumulation. With proteasome inhibitors being increasingly used as front-line treatment in cancer, these data raise issues about CT antigen processing for antigenic presentation and therefore immunogenicity in cancer patients.

  19. The extended family of CD1d-restricted T cells: sifting through a mixed bag of TCRs, antigens and functions

    Directory of Open Access Journals (Sweden)

    Elodie eMacho-Fernandez

    2015-07-01

    Full Text Available Natural killer T (NKT cells comprise a family of specialized T cells that recognize lipid antigens presented by CD1d. Based on their T cell receptor (TCR usage and antigen-specificities, CD1d-restricted NKT cells have been divided into two main subsets: type I NKT cells that use a canonical invariant TCR α-chain and recognize α-galactosylceramide (α-GalCer, and type II NKT cells that use a more diverse αβ TCR repertoire and do not recognize α-GalCer. In addition, α-GalCer-reactive NKT cells that use non-canonical αβ TCRs and CD1d-restricted T cells that use γδ or δ/αβ TCRs have recently been identified, revealing further diversity among CD1d-restricted T cells. Importantly, in addition to their distinct antigen specificities, functional differences are beginning to emerge between the different members of the CD1d-restricted T cell family. In this review, while using type I NKT cells as comparison, we will focus on type II NKT cells and the other non-invariant CD1d-restricted T cell subsets, and discuss our current understanding of the antigens they recognize, the formation of stimulatory CD1d/antigen complexes, the modes of TCR-mediated antigen recognition, and the mechanisms and consequences of their activation that underlie their function in antimicrobial responses, antitumor immunity, and autoimmunity.

  20. The Extended Family of CD1d-Restricted NKT Cells: Sifting through a Mixed Bag of TCRs, Antigens, and Functions.

    Science.gov (United States)

    Macho-Fernandez, Elodie; Brigl, Manfred

    2015-01-01

    Natural killer T (NKT) cells comprise a family of specialized T cells that recognize lipid antigens presented by CD1d. Based on their T cell receptor (TCR) usage and antigen specificities, CD1d-restricted NKT cells have been divided into two main subsets: type I NKT cells that use a canonical invariant TCR α-chain and recognize α-galactosylceramide (α-GalCer), and type II NKT cells that use a more diverse αβ TCR repertoire and do not recognize α-GalCer. In addition, α-GalCer-reactive NKT cells that use non-canonical αβ TCRs and CD1d-restricted T cells that use γδ or δ/αβ TCRs have recently been identified, revealing further diversity among CD1d-restricted T cells. Importantly, in addition to their distinct antigen specificities, functional differences are beginning to emerge between the different members of the CD1d-restricted T cell family. In this review, while using type I NKT cells as comparison, we will focus on type II NKT cells and the other non-invariant CD1d-restricted T cell subsets, and discuss our current understanding of the antigens they recognize, the formation of stimulatory CD1d/antigen complexes, the modes of TCR-mediated antigen recognition, and the mechanisms and consequences of their activation that underlie their function in antimicrobial responses, anti-tumor immunity, and autoimmunity.

  1. Whole blood transcriptional profiling reveals significant down-regulation of human leukocyte antigen class I and II genes in essential thrombocythemia, polycythemia vera and myelofibrosis

    DEFF Research Database (Denmark)

    Skov, Vibe; Riley, Caroline Hasselbalch; Thomassen, Mads

    2013-01-01

    be down-regulation of major histocompatibility (MHC) class I and II genes, which are used by tumor cells to escape antitumor T-cell-mediated immune responses. We have performed whole blood transcriptional profiling of genes encoding human leukocyte antigen (HLA) class I and II molecules, β2-microglobulin...... and members of the antigen processing machinery of HLA class I molecules (LMP2, LMP7, TAP1, TAP2 and tapasin). The findings of significant down-regulation of several of these genes may possibly be of major importance for defective tumor immune surveillance. Since up-regulation of HLA genes is recorded during...

  2. Lectin inhibits antigen-antibody reaction in a glycoform-specific manner: Application for detecting α2,6sialylated-carcinoembryonic antigen.

    Science.gov (United States)

    Ito, Hiromi; Hoshi, Kyoka; Osuka, Fumihiko; Gotoh, Mitsukazu; Saito, Takuro; Hojo, Hiroshi; Suzuki, Rei; Ohira, Hiromasa; Honda, Takashi; Hashimoto, Yasuhiro

    2016-12-01

    Carcinoembryonic antigen (CEA) is a glycoprotein marker, which is widely used for diagnosing various cancers, especially colon adenocarcinoma. In addition, CEA mediates homotypic adhesion of colon adenocarcinoma cells, which appears to favor hematogenous metastasis. CEA carries α2,6sialyl residues on its N-glycans whereas a normal counterpart, normal fecal antigen-2, does α2,3sialyl residues, suggesting that cancer-specific  α2,6sialylation on CEA may play a role for cell invasion and metastasis. A simple and rapid estimation of α2,6sialyled CEA in detergent extracts from formalin-fixed colon adenocarcinoma by "lectin inhibition" is reported. In the lectin inhibition method, Sambucus sieboldiana Agglutinin (SSA) lectin, an α2,6sialic acid binder, was used as a glycoform-specific inhibitor for antigen-antibody reaction in ELISA. Detergent extracts from colon adenocarcinoma showed a fair amount of ELISA signal in the absence of SSA whereas the signal was markedly reduced (45≈74%) in the presence of SSA, suggesting that the extracts contains α2,6sialyled CEA. The presence of α2,6sialyled CEA in the extracts was confirmed by lectin microarray, in which SSA, Sambucus nigra agglutinin, and Trichosanthes japonica agglutinin I lectins were used as α2,6sialyl binders. Thus lectin inhibition is a simple and rapid method for detecting α2,6sialyled CEA even in crude detergent extracts from formalin-fixed adenocarcinoma tissue. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Endothelial cells present antigens in vivo

    Directory of Open Access Journals (Sweden)

    Tellides George

    2004-03-01

    Full Text Available Abstract Background Immune recognition of vascular endothelial cells (EC has been implicated in allograft rejection, protection against pathogens, and lymphocyte recruitment. However, EC pervade nearly all tissues and predominate in none, complicating any direct test of immune recognition. Here, we examined antigen presentation by EC in vivo by testing immune responses against E. coli β-galactosidase (β-gal in two lines of transgenic mice that express β-gal exclusively in their EC. TIE2-lacZ mice express β-gal in all EC and VWF-lacZ mice express β-gal in heart and brain microvascular EC. Results Transgenic and congenic wild type FVB mice immunized with β-gal expression vector DNA or β-gal protein generated high titer, high affinity antisera containing comparable levels of antigen-specific IgG1 and IgG2a isotypes, suggesting equivalent activation of T helper cell subsets. The immunized transgenic mice remained healthy, their EC continued to express β-gal, and their blood vessels showed no histological abnormalities. In response to β-gal in vitro, CD4+ and CD8+ T cells from immunized transgenic and FVB mice proliferated, expressed CD25, and secreted IFN-γ. Infection with recombinant vaccinia virus encoding β-gal raised equivalent responses in transgenic and FVB mice. Hearts transplanted from transgenic mice into FVB mice continued to beat and the graft EC continued to express β-gal. These results suggested immunological ignorance of the transgene encoded EC protein. However, skin transplanted from TIE2-lacZ onto FVB mice lost β-gal+ EC and the hosts developed β-gal-specific antisera, demonstrating activation of host immune effector mechanisms. In contrast, skin grafted from TIE2-lacZ onto VWF-lacZ mice retained β-gal+ EC and no antisera developed, suggesting a tolerant host immune system. Conclusion Resting, β-gal+ EC in transgenic mice tolerize specific lymphocytes that would otherwise respond against β-gal expressed by EC within

  4. Use of antigenic cartography in vaccine seed strain selection.

    Science.gov (United States)

    Fouchier, Ron A M; Smith, Derek J

    2010-03-01

    Human influenza A viruses are classic examples of antigenically variable pathogens that have a seemingly endless capacity to evade the host's immune response. The viral hemagglutinin (HA) and neuraminidase (NA) proteins are the main targets of our antibody response to combat infections. HA and NA continuously change to escape from humoral immunity, a process known as antigenic drift. As a result of antigenic drift, the human influenza vaccine is updated frequently. The World Health Organization (WHO) coordinates a global influenza surveillance network that, by the hemagglutination inhibition (HI) assay, routinely characterizes the antigenic properties of circulating strains in order to select new seed viruses for such vaccine updates. To facilitate a quantitative interpretation and easy visualization of HI data, a new computational technique called "antigenic cartography" was developed. Since its development, antigenic cartography has been applied routinely to assist the WHO with influenza surveillance activities. Until recently, antigenic variation was not considered a serious issue with influenza vaccines for poultry. However, because of the diversification of the Asian H5N1 lineage since 1996 into multiple genetic clades and subclades, and because of the long-term use of poultry vaccines against H5 in some parts of the world, this issue needs to be re-addressed. The antigenic properties of panels of avian H5N1 viruses were characterized by HI assay, using mammalian or avian antisera, and analyzed using antigenic cartography methods. These analyses revealed antigenic differences between circulating H5N1 viruses and the H5 viruses used in poultry vaccines. Considerable antigenic variation was also observed within and between H5N1 clades. These observations have important implications for the efficacy and long-term use of poultry vaccines.

  5. Recombinant Salivary Proteins of Phlebotomus orientalis are Suitable Antigens to Measure Exposure of Domestic Animals to Sand Fly Bites.

    Directory of Open Access Journals (Sweden)

    Michal Sima

    2016-03-01

    Full Text Available Certain salivary proteins of phlebotomine sand flies injected into the host skin during blood-feeding are highly antigenic and elicit strong antibody-mediated immune responses in repeatedly-exposed hosts. These antibodies can be measured by enzyme-linked immuno sorbent assays (ELISAs using salivary gland homogenates (SGHs as the source of antigens and serve as a markers for exposure to biting sand flies. Large-scale screening for anti-sand fly saliva antibodies requires replacement of SGH with recombinant salivary proteins. In East Africa, Phlebotomus orientalis is the main vector of Leishmania donovani, a trypanosomatid parasite causing visceral leishmaniasis. We tested recombinant salivary proteins derived from Ph. orientalis saliva to study exposure of domestic animals to this sand fly species.Antigenic salivary proteins from Ph. orientalis were identified by immunoblot and mass spectrometry. Recombinant apyrase rPorSP15, yellow-related protein rPorSP24, ParSP25-like protein rPorSP65, D7-related protein rPorSP67, and antigen 5-related protein rPorSP76 were tested using ELISA with sera of domestic animals from L. donovani foci in Ethiopia where Ph. orientalis is present. Our results highlighted recombinant yellow-related protein rPorSP24 as the most promising antigen, displaying a high positive correlation coefficient as well as good sensitivity and specificity when compared to SGH. This recombinant protein was the most suitable one for testing sera of dogs, sheep, and goats. In addition, a different antigen, rPorSP65 was found efficacious for testing canine sera.Recombinant salivary proteins of Ph. orientalis, specifically rPorSP24, were shown to successfully substitute SGH in serological experiments to measure exposure of domestic animals to Ph. orientalis, the vector of L. donovani. The results suggest that rPorSP24 might be a suitable antigen for detecting anti-Ph. orientalis antibody-mediated reactions also in other host species.

  6. Recombinant Salivary Proteins of Phlebotomus orientalis are Suitable Antigens to Measure Exposure of Domestic Animals to Sand Fly Bites.

    Science.gov (United States)

    Sima, Michal; Ferencova, Blanka; Warburg, Alon; Rohousova, Iva; Volf, Petr

    2016-03-01

    Certain salivary proteins of phlebotomine sand flies injected into the host skin during blood-feeding are highly antigenic and elicit strong antibody-mediated immune responses in repeatedly-exposed hosts. These antibodies can be measured by enzyme-linked immuno sorbent assays (ELISAs) using salivary gland homogenates (SGHs) as the source of antigens and serve as a markers for exposure to biting sand flies. Large-scale screening for anti-sand fly saliva antibodies requires replacement of SGH with recombinant salivary proteins. In East Africa, Phlebotomus orientalis is the main vector of Leishmania donovani, a trypanosomatid parasite causing visceral leishmaniasis. We tested recombinant salivary proteins derived from Ph. orientalis saliva to study exposure of domestic animals to this sand fly species. Antigenic salivary proteins from Ph. orientalis were identified by immunoblot and mass spectrometry. Recombinant apyrase rPorSP15, yellow-related protein rPorSP24, ParSP25-like protein rPorSP65, D7-related protein rPorSP67, and antigen 5-related protein rPorSP76 were tested using ELISA with sera of domestic animals from L. donovani foci in Ethiopia where Ph. orientalis is present. Our results highlighted recombinant yellow-related protein rPorSP24 as the most promising antigen, displaying a high positive correlation coefficient as well as good sensitivity and specificity when compared to SGH. This recombinant protein was the most suitable one for testing sera of dogs, sheep, and goats. In addition, a different antigen, rPorSP65 was found efficacious for testing canine sera. Recombinant salivary proteins of Ph. orientalis, specifically rPorSP24, were shown to successfully substitute SGH in serological experiments to measure exposure of domestic animals to Ph. orientalis, the vector of L. donovani. The results suggest that rPorSP24 might be a suitable antigen for detecting anti-Ph. orientalis antibody-mediated reactions also in other host species.

  7. Facts on the fragmentation of antigens in presenting cells, on the association of antigen fragments with MHC molecules in cell-free systems, and speculation on the cell biology of antigen processing

    DEFF Research Database (Denmark)

    Werdelin, O; Mouritsen, S; Petersen, B L

    1988-01-01

    The processing of a protein antigen is a multi-step event taking place in antigen-presenting cells. Processing is a prerequisite for the recognition of most antigens by T lymphocytes. The antigen is ingested by endocytosis, transported to an acid cellular compartment and subjected to proteolytic...... fragmentation. Some of the antigen fragments bind to MHC class II molecules and are transported to the surface of the antigen-presenting cell where the actual presentation to T lymphocytes occurs. The nature of the processed antigen, how and where it is derived and subsequently becomes associated with MHC...

  8. A novel merozoite surface antigen of Plasmodium falciparum (MSP-3 identified by cellular-antibody cooperative mechanism antigenicity and biological activity of antibodies

    Directory of Open Access Journals (Sweden)

    Claude Oeuvray

    1994-01-01

    Full Text Available We report the identification of a 48kDa antigen targeted by antibodies which inhibit Plasmodium falciparum in vitro growth by cooperation with blood monocytes in an ADCI assay correlated to the naturally acquired protection. This protein is located on the surface of the merozoite stage of P. falciparum, and is detectable in all isolates tested. Epidemiological studies demonstrated that peptides derived from the amino acid sequence of MSP-3 contain potent B and T-cell epitopes recognized by a majority of individuals living in endemic areas. Moreover human antibodies either purified on the recombinant protein, or on the synthetic peptide MSP-3b, as well as antibodies raised in mice, were all found to promote parasite killing mediated by monocytes.

  9. Spinal cord injury, immunodepression, and antigenic challenge.

    Science.gov (United States)

    Held, Katherine S; Lane, Thomas E

    2014-10-01

    The inability to effectively control microbial infection is a leading cause of morbidity and mortality in individuals affected by spinal cord injury (SCI). Available evidence from clinical studies as well as animal models of SCI demonstrate that increased susceptibility to infection is derived from disruption of central nervous system (CNS) communication with the host immune system that ultimately leads to immunodepression. Understanding the molecular and cellular mechanisms governing muted cellular and humoral responses that occur post-injury resulting in impaired host defense following infection is critical for improving the overall quality of life of individuals with SCI. This review focuses on studies performed using preclinical animal models of SCI to evaluate how injury impacts T and B lymphocyte responses following either viral infection or antigenic challenge. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. 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.

  11. An O antigen capsule modulates bacterial pathogenesis in Shigella sonnei.

    Science.gov (United States)

    Caboni, Mariaelena; Pédron, Thierry; Rossi, Omar; Goulding, David; Pickard, Derek; Citiulo, Francesco; MacLennan, Calman A; Dougan, Gordon; Thomson, Nicholas R; Saul, Allan; Sansonetti, Philippe J; Gerke, Christiane

    2015-03-01

    Shigella is the leading cause for dysentery worldwide. Together with several virulence factors employed for invasion, the presence and length of the O antigen (OAg) of the lipopolysaccharide (LPS) plays a key role in pathogenesis. S. flexneri 2a has a bimodal OAg chain length distribution regulated in a growth-dependent manner, whereas S. sonnei LPS comprises a monomodal OAg. Here we reveal that S. sonnei, but not S. flexneri 2a, possesses a high molecular weight, immunogenic group 4 capsule, characterized by structural similarity to LPS OAg. We found that a galU mutant of S. sonnei, that is unable to produce a complete LPS with OAg attached, can still assemble OAg material on the cell surface, but a galU mutant of S. flexneri 2a cannot. High molecular weight material not linked to the LPS was purified from S. sonnei and confirmed by NMR to contain the specific sugars of the S. sonnei OAg. Deletion of genes homologous to the group 4 capsule synthesis cluster, previously described in Escherichia coli, abolished the generation of the high molecular weight OAg material. This OAg capsule strongly affects the virulence of S. sonnei. Uncapsulated knockout bacteria were highly invasive in vitro and strongly inflammatory in the rabbit intestine. But, the lack of capsule reduced the ability of S. sonnei to resist complement-mediated killing and to spread from the gut to peripheral organs. In contrast, overexpression of the capsule decreased invasiveness in vitro and inflammation in vivo compared to the wild type. In conclusion, the data indicate that in S. sonnei expression of the capsule modulates bacterial pathogenesis resulting in balanced capabilities to invade and persist in the host environment.

  12. An O antigen capsule modulates bacterial pathogenesis in Shigella sonnei.

    Directory of Open Access Journals (Sweden)

    Mariaelena Caboni

    2015-03-01

    Full Text Available Shigella is the leading cause for dysentery worldwide. Together with several virulence factors employed for invasion, the presence and length of the O antigen (OAg of the lipopolysaccharide (LPS plays a key role in pathogenesis. S. flexneri 2a has a bimodal OAg chain length distribution regulated in a growth-dependent manner, whereas S. sonnei LPS comprises a monomodal OAg. Here we reveal that S. sonnei, but not S. flexneri 2a, possesses a high molecular weight, immunogenic group 4 capsule, characterized by structural similarity to LPS OAg. We found that a galU mutant of S. sonnei, that is unable to produce a complete LPS with OAg attached, can still assemble OAg material on the cell surface, but a galU mutant of S. flexneri 2a cannot. High molecular weight material not linked to the LPS was purified from S. sonnei and confirmed by NMR to contain the specific sugars of the S. sonnei OAg. Deletion of genes homologous to the group 4 capsule synthesis cluster, previously described in Escherichia coli, abolished the generation of the high molecular weight OAg material. This OAg capsule strongly affects the virulence of S. sonnei. Uncapsulated knockout bacteria were highly invasive in vitro and strongly inflammatory in the rabbit intestine. But, the lack of capsule reduced the ability of S. sonnei to resist complement-mediated killing and to spread from the gut to peripheral organs. In contrast, overexpression of the capsule decreased invasiveness in vitro and inflammation in vivo compared to the wild type. In conclusion, the data indicate that in S. sonnei expression of the capsule modulates bacterial pathogenesis resulting in balanced capabilities to invade and persist in the host environment.

  13. Imputing amino acid polymorphisms in human leukocyte antigens.

    Directory of Open Access Journals (Sweden)

    Xiaoming Jia

    Full Text Available DNA sequence variation within human leukocyte antigen (HLA genes mediate susceptibility to a wide range of human diseases. The complex genetic structure of the major histocompatibility complex (MHC makes it difficult, however, to collect genotyping data in large cohorts. Long-range linkage disequilibrium between HLA loci and SNP markers across the major histocompatibility complex (MHC region offers an alternative approach through imputation to interrogate HLA variation in existing GWAS data sets. Here we describe a computational strategy, SNP2HLA, to impute classical alleles and amino acid polymorphisms at class I (HLA-A, -B, -C and class II (-DPA1, -DPB1, -DQA1, -DQB1, and -DRB1 loci. To characterize performance of SNP2HLA, we constructed two European ancestry reference panels, one based on data collected in HapMap-CEPH pedigrees (90 individuals and another based on data collected by the Type 1 Diabetes Genetics Consortium (T1DGC, 5,225 individuals. We imputed HLA alleles in an independent data set from the British 1958 Birth Cohort (N = 918 with gold standard four-digit HLA types and SNPs genotyped using the Affymetrix GeneChip 500 K and Illumina Immunochip microarrays. We demonstrate that the sample size of the reference panel, rather than SNP density of the genotyping platform, is critical to achieve high imputation accuracy. Using the larger T1DGC reference panel, the average accuracy at four-digit resolution is 94.7% using the low-density Affymetrix GeneChip 500 K, and 96.7% using the high-density Illumina Immunochip. For amino acid polymorphisms within HLA genes, we achieve 98.6% and 99.3% accuracy using the Affymetrix GeneChip 500 K and Illumina Immunochip, respectively. Finally, we demonstrate how imputation and association testing at amino acid resolution can facilitate fine-mapping of primary MHC association signals, giving a specific example from type 1 diabetes.

  14. Essential Contribution of CD4+ T Cells to Antigen-Induced Nasal Hyperresponsiveness in Experimental Allergic Rhinitis.

    Directory of Open Access Journals (Sweden)

    Tomoe Nishimura

    Full Text Available Nasal hyperresponsiveness (NHR is a characteristic feature of allergic rhinitis (AR; however, the pathogenesis of NHR is not fully understood. In this study, during the establishment of an experimental AR model using ovalbumin-immunized and -challenged mice, augmentation of the sneezing reaction in response to nonspecific proteins as well as a chemical stimulant was detected. Whether NHR is independent of mast cells and eosinophils was determined by using mast cell- and eosinophil-deficient mice. NHR was suppressed by treatment with anti-CD4 antibody, suggesting the pivotal contribution of CD4+ T cells. Furthermore, antigen challenge to mice to which in vitro-differentiated Th1, Th2, and Th17 cells but not naïve CD4+ T cells had been adoptively transferred led to the development of equivalent NHR. Since antigen-specific IgE and IgG were not produced in these mice and since antigen-specific IgE-transgenic mice did not develop NHR even upon antigen challenge, humoral immunity would be dispensable for NHR. CD4+ T cells play a crucial role in the pathogenesis of AR via induction of NHR, independent of IgE-, mast cell-, and eosinophil-mediated responses.

  15. Identification of DRG-1 As a Melanoma-Associated Antigen Recognized by CD4+ Th1 Cells.

    Directory of Open Access Journals (Sweden)

    Yukiko Kiniwa

    Full Text Available Immunotherapy has emerged as a promising strategy for the treatment of metastatic melanoma. Clinical studies have demonstrated the feasibility of cancer immunotherapy using tumor antigens recognized by CD8(+ T cells. However, the overall immune responses induced by these antigens are too weak and transient to induce tumor regression in the majority of patients who received immunization. A growing body of evidence suggests that CD4(+ T helper (Th cells play an important role in antitumor immunity. Therefore, the identification of MHC class II-restricted tumor antigens capable of stimulating CD4(+ T cells may provide opportunities for developing effective cancer vaccines. To this end, we describe the identification of developmentally regulated GTP-binding protein 1 (DRG-1 as a melanoma-associated antigen recognized by HLA-DR11-restricted CD4(+ Th1 cells. Epitope mapping analysis showed that the DRG1248-268 epitope of DRG-1 was required for T cell recognition. Reverse transcription-polymerase chain reaction revealed that DRG-1 was highly expressed in melanoma cell lines but not in normal tissues. DRG-1 knockdown by lentiviral-based shRNA suppressed melanoma cell proliferation and soft agar colony formation. Taken together, these data suggest that DRG-1 plays an important role in melanoma cell growth and transformation, indicating that DRG1 may represent a novel target for CD4(+ T cell-mediated immunotherapy in melanoma.

  16. Age-Associated Decline in Thymic B Cell Expression of Aire and Aire-Dependent Self-Antigens

    Directory of Open Access Journals (Sweden)

    Sergio Cepeda

    2018-01-01

    Full Text Available Although autoimmune disorders are a significant source of morbidity and mortality in older individuals, the mechanisms governing age-associated increases in susceptibility remain incompletely understood. Central T cell tolerance is mediated through presentation of self-antigens by cells constituting the thymic microenvironment, including epithelial cells, dendritic cells, and B cells. Medullary thymic epithelial cells (mTECs and B cells express distinct cohorts of self-antigens, including tissue-restricted self-antigens (TRAs, such that developing T cells are tolerized to antigens from peripheral tissues. We find that expression of the TRA transcriptional regulator Aire, as well as Aire-dependent genes, declines with age in thymic B cells in mice and humans and that cell-intrinsic and cell-extrinsic mechanisms contribute to the diminished capacity of peripheral B cells to express Aire within the thymus. Our findings indicate that aging may diminish the ability of thymic B cells to tolerize T cells, revealing a potential mechanistic link between aging and autoimmunity.

  17. The Antigenic Structure of Zika Virus and Its Relation to Other Flaviviruses: Implications for Infection and Immunoprophylaxis

    Science.gov (United States)

    Stiasny, Karin

    2017-01-01

    SUMMARY Zika virus was discovered ∼70 years ago in Uganda and maintained a low profile as a human disease agent in Africa and Asia. Only recently has it caused explosive outbreaks in previously unaffected regions, first in Oceania and then in the Americas since 2015. Of special concern is the newly identified link between congenital malformations (especially microcephaly) and Zika virus infections during pregnancy. At present, it is unclear whether Zika virus changed its pathogenicity or whether the huge number of infections allowed the recognition of a previously cryptic pathogenic property. The purpose of this review is to discuss recent data on the molecular antigenic structure of Zika virus in the context of antibody-mediated neutralization and antibody-dependent enhancement (ADE) of infection, a phenomenon that has been implicated in the development of severe disease caused by the related dengue viruses. Emphasis is given to epitopes of antibodies that potently neutralize Zika virus and also to epitopes that provide antigenic links to other important human-pathogenic flaviviruses such as dengue, yellow fever, West Nile, Japanese encephalitis, and tick-borne encephalitis viruses. The antigenic cross talk between Zika and dengue viruses appears to be of special importance, since they cocirculate in many regions of endemicity and sequential infections are likely to occur frequently. New insights into the molecular antigenic structure of Zika virus and flaviviruses in general have provided the foundation for great progress made in developing Zika virus vaccines and antibodies for passive immunization. PMID:28179396

  18. Lym-1 Chimeric Antigen Receptor T Cells Exhibit Potent Anti-Tumor Effects against B-Cell Lymphoma.

    Science.gov (United States)

    Zheng, Long; Hu, Peisheng; Wolfe, Brandon; Gonsalves, Caryn; Ren, Luqing; Khawli, Leslie A; Kaslow, Harvey R; Epstein, Alan L

    2017-12-20

    T cells expressing chimeric antigen receptors (CARs) recognizing CD19 epitopes have produced remarkable anti-tumor effects in patients with B-cell malignancies. However, cancer cells lacking recognized epitopes can emerge, leading to relapse and death. Thus, CAR T cells targeting different epitopes on different antigens could improve immunotherapy. The Lym-1 antibody targets a conformational epitope of Human Leukocyte Antigen-antigen D Related (HLA-DR) on the surface of human B-cell lymphomas. Lym-1 CAR T cells were thus generated for evaluation of cytotoxic activity towards lymphoma cells in vitro and in vivo. Human T cells from healthy donors were transduced to express a Lym-1 CAR, and assessed for epitope-driven function in culture and towards Raji xenografts in NOD-scidIL2Rgamma null (NSG) mice. Lym-1 CAR T cells exhibited epitope-driven activation and lytic function against human B-cell lymphoma cell lines in culture and mediated complete regression of Raji/Luciferase-Green fluorescent protein (Raji/Luc-GFP) in NSG mice with similar or better reactivity than CD19 CAR T cells. Lym-1 CAR transduction of T cells is a promising immunotherapy for patients with Lym-1 epitope positive B-cell malignancies.

  19. A novel plasmid-encoded serotype conversion mechanism through addition of phosphoethanolamine to the O-antigen of Shigella flexneri.

    Directory of Open Access Journals (Sweden)

    Qiangzheng Sun

    Full Text Available Shigella flexneri is the major pathogen causing bacillary dysentery in developing countries. S. flexneri is divided into at least 16 serotypes based on the combination of antigenic determinants present in the O-antigen. All the serotypes (except for serotype 6 share a basic O-unit containing one N-acetyl-d-glucosamine and three l-rhamnose residues, whereas differences between the serotypes are conferred by phage-encoded glucosylation and/or O-acetylation. Serotype Xv is a newly emerged and the most prevalent serotype in China, which can agglutinate with both MASF IV-1 and 7,8 monoclonal antibodies. The factor responsible for the presence of MASF IV-1 (E1037 epitope has not yet been identified. In this study, we analyzed the LPS structure of serotype Xv strains and found that the MASF IV-1 positive phenotype depends on an O-antigen modification with a phosphoethanolamine (PEtN group attached at position 3 of one of the rhamnose residues. A plasmid carried gene, lpt-O (LPS phosphoethanolamine transferase for O-antigen, mediates the addition of PEtN for serotype Xv and other MASF IV-1 positive strains. These findings reveal a novel serotype conversion mechanism in S. flexneri and show the necessity of further extension of the serotype classification scheme recognizing the MASF IV-1 positive strains as distinctive subtypes.

  20. Lym-1 Chimeric Antigen Receptor T Cells Exhibit Potent Anti-Tumor Effects against B-Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Long Zheng

    2017-12-01

    Full Text Available T cells expressing chimeric antigen receptors (CARs recognizing CD19 epitopes have produced remarkable anti-tumor effects in patients with B-cell malignancies. However, cancer cells lacking recognized epitopes can emerge, leading to relapse and death. Thus, CAR T cells targeting different epitopes on different antigens could improve immunotherapy. The Lym-1 antibody targets a conformational epitope of Human Leukocyte Antigen-antigen D Related (HLA-DR on the surface of human B-cell lymphomas. Lym-1 CAR T cells were thus generated for evaluation of cytotoxic activity towards lymphoma cells in vitro and in vivo. Human T cells from healthy donors were transduced to express a Lym-1 CAR, and assessed for epitope-driven function in culture and towards Raji xenografts in NOD-scidIL2Rgammanull (NSG mice. Lym-1 CAR T cells exhibited epitope-driven activation and lytic function against human B-cell lymphoma cell lines in culture and mediated complete regression of Raji/Luciferase-Green fluorescent protein (Raji/Luc-GFP in NSG mice with similar or better reactivity than CD19 CAR T cells. Lym-1 CAR transduction of T cells is a promising immunotherapy for patients with Lym-1 epitope positive B-cell malignancies.

  1. Chemical camouflage of antigenic determinants: stealth erythrocytes.

    Science.gov (United States)

    Scott, M D; Murad, K L; Koumpouras, F; Talbot, M; Eaton, J W

    1997-07-08

    In a number of clinical circumstances it would be desirable to artificially conceal cellular antigenic determinants to permit survival of heterologous donor cells. A case in point is the problem encountered in transfusions of patients with rare blood types or chronically transfused patients who become allosensitized to minor blood group determinants. We have tested the possibility that chemical modification of the red blood cell (RBC) membrane might serve to occlude antigenic determinants, thereby minimizing transfusion reactions. To this end, we have covalently bound methoxy(polyethylene glycol) (mPEG) to the surface of mammalian RBC via cyanuric chloride coupling. Human RBC treated with this technique lose ABO blood group reactivity as assessed by solution-phase antisera agglutination. In accord with this, we also find a profound decrease in anti-blood group antibody binding. Furthermore, whereas human monocytes avidly phagocytose untreated sheep RBC, mPEG-derivatized sheep RBC are ineffectively phagocytosed. Surprisingly, human and mouse RBC appear unaffected by this covalent modification of the cell membrane. Thus, mPEG-treated RBC are morphologically normal, have normal osmotic fragility, and mPEG-derivatized murine RBC have normal in vivo survival, even following repeated infusions. Finally, in preliminary experiments, mPEG-modified sheep RBC intraperitoneally transfused into mice show significantly improved (up to 360-fold) survival when compared with untreated sheep RBC. We speculate that similar chemical camouflage of intact cells may have significant clinical applications in both transfusion (e.g., allosensitization and autoimmune hemolytic disease) and transplantation (e.g., endothelial cells and pancreatic beta cells) medicine.

  2. Distinct patterns of blood-stage parasite antigens detected by plasma IgG subclasses from individuals with different level of exposure to Plasmodium falciparum infections

    Directory of Open Access Journals (Sweden)

    Højrup Peter

    2010-10-01

    Full Text Available Abstract Background In endemic regions naturally acquired immunity against Plasmodium falciparum develops as a function of age and exposure to parasite infections and is known to be mediated by IgG. The targets of protective antibodies remain to be fully defined. Several immunoepidemiological studies have indicated an association of cytophilic anti-parasite IgG with protection against malaria. It has been hypothesized that the initial antibody responses against parasite antigens upon first few Plasmodium falciparum infections is dominated by non-protective IgG2/IgG4 and IgM antibodies, which then gradually develop into protective response dominated by cytophilic IgG1 and IgG3 antibodies. Methods Naturally occurring IgG antibodies against P. falciparum blood-stage antigens were analysed from plasma samples collected from four groups of individuals differing in age and level of exposure to P. falciparum infections. Western Blot profiling of blood-stage parasite antigens displaying reactivity with individual plasma samples in terms of their subclass specificities was conducted. Parasite antigens detected by IgG were grouped based on their apparent molecular sizes resolved by SDS-PAGE as high molecular weight (≥ 70 kDa or low molecular weight (P. falciparum infections. Results IgG4 and IgM antibodies in plasma samples from all groups detected very few parasite antigens. IgG2 antibodies from all groups detected a common pattern of high molecular weight parasite antigens. Cytophilic IgG subclasses in plasma samples from individuals with higher levels of exposure to P. falciparum infections distinctly detected higher numbers of low molecular weight parasite antigens. Conclusions In the present study, there was no evidence for switching of antibody responses from non-cytophilic to cytophilic subclasses against blood-stage parasite antigens as a likely mechanism for induction of protective immunity against malaria.

  3. Antigen-Experienced CD4lo T Cells Are Linked to Deficient Contraction of the Immune Response in Autoimmune Diabetes

    Directory of Open Access Journals (Sweden)

    Sean Linkes

    2010-01-01

    Full Text Available Following proper activation, naïve “CD4lo” T cells differentiate into effector T cells with enhanced expression of CD4 -“CD4hi” effectors. Autoimmune diabetes-prone NOD mice display a unique set of antigen-experienced “CD4lo” T cells that persist after primary stimulation. Here, we report that a population of such cells remained after secondary and tertiary TCR stimulation and produced cytokines upon antigenic challenge. However, when NOD blasts were induced in the presence of rIL-15, the number of antigen-experienced “CD4lo” T cells was significantly reduced. Clonal contraction, mediated in part by CD95-dependent activation-induced cell death (AICD, normally regulates the accumulation of “CD4hi” effectors. Interestingly, CD95 expression was dramatically reduced on the AICD-resistant NOD “CD4lo” T cells. Thus, while autoimmune disease has often been attributed to the engagement of robust autoimmunity, we suggest that the inability to effectively contract the immune response distinguishes benign autoimmunity from progressive autoimmune diseases that are characterized by chronic T cell-mediated inflammation.

  4. The CD3-zeta chimeric antigen receptor overcomes TCR Hypo-responsiveness of human terminal late-stage T cells.

    Directory of Open Access Journals (Sweden)

    Gunter Rappl

    Full Text Available Adoptive therapy of malignant diseases with tumor-specific cytotoxic T cells showed remarkable efficacy in recent trials. Repetitive T cell receptor (TCR engagement of target antigen, however, inevitably ends up in hypo-responsive cells with terminally differentiated KLRG-1(+ CD57(+ CD7(- phenotype limiting their therapeutic efficacy. We here revealed that hypo-responsiveness of CMV-specific late-stage CD8(+ T cells is due to reduced TCR synapse formation compared to younger cells. Membrane anchoring of TCR components contributes to T cell hypo-responsiveness since dislocation of galectin-3 from the synapse by swainsonine restored both TCR synapse formation and T cell response. Transgenic expression of a CD3-zeta signaling chimeric antigen receptor (CAR recovered hypo-responsive T cells to full effector functions indicating that the defect is restricted to TCR membrane components while synapse formation of the transgenic CAR was not blocked. CAR engineered late-stage T cells released cytokines and mediated redirected cytotoxicity as efficiently as younger effector T cells. Our data provide a rationale for TCR independent, CAR mediated activation in the adoptive cell therapy to avoid hypo-responsiveness of late-stage T cells upon repetitive antigen encounter.

  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. 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

  7. Antigenic analysis of some Nigerian street rabies virus using ...

    African Journals Online (AJOL)

    The authors studied 12 street rabies virus isolates from 3 states of Nigeria using both the anti-nucleocapsid and anti-glycoprotein monoclonal antibodies and cross-protection tests. It was observed that all the viruses were rabies having divergent antigenic presentation. Also noticed was an antigenic shift when the viruses ...

  8. Expression of Treponema pallidum Antigens in Escherichia coli

    Science.gov (United States)

    Walfield, Alan M.; Hanff, Philip A.; Lovett, Michael A.

    1982-04-01

    Treponema pallidum DNA was cloned in a bacteriophage. Clones were screened for expression of Treponema pallidum antigens by an in situ radio-immunoassay on nitrocellulose, with the use of subsequent reactions with syphilitic serum and radioiodinated Staphylococcus aureus protein A. One clone, which gave a strong signal, codes for at least seven antigens that react specifically with human antibodies to Treponema pallidum.

  9. Dissecting antigen processing and presentation routes in dermal vaccination strategies

    NARCIS (Netherlands)

    Platteel, Anouk C M; Henri, Sandrine; Zaiss, Dietmar M; Sijts, Alice J A M

    2017-01-01

    The skin is an attractive site for vaccination due to its accessibility and presence of immune cells surveilling this barrier. However, knowledge of antigen processing and presentation upon dermal vaccination is sparse. In this study we determined antigen processing routes that lead to CD8(+) T cell

  10. The prevalence of hepatitis B virus E antigen among Ghanaian ...

    African Journals Online (AJOL)

    We studied the prevalence of hepatitis B virus 'e' antigen (HBeAg) among individuals determined to be hepatitis B virus (HBV) surface antigen- positive and analyzed the gender/age category associated with more active HBV infection and whether alteration in the levels of alanine aminotransferase could be associated with ...

  11. ABO blood group antigens in oral mucosa. What is new?

    DEFF Research Database (Denmark)

    Dabelsteen, Erik

    2002-01-01

    healing show similarly decreased expression of A/B antigens on migrating epithelial cells. Some studies suggest that the relationship between expression of blood group antigens and cell motility can be explained by different degrees of glycosylation of integrins. Changes in ABO expression in tumours have...

  12. 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 ...

  13. Protein modeling of apical membrane antigen-1(AMA-1) of ...

    African Journals Online (AJOL)

    Apical membrane Antigen-1(AMA-1), an asexual blood stage antigen of Plasmodium cynomolgi, is an important candidate for testing as a component of malarial vaccine. The degree of conservation of. AMA-1 sequences implies a conserved function for this molecule across different species of Plasmodium. Since the AMA-1 ...

  14. Identification of Surface Exposed Elementary Body Antigens of ...

    African Journals Online (AJOL)

    This study sought to identify the surface exposed antigenic components of Cowdria ruminantium elementary body (EB) by biotin labeling, determine effect of reducing and non-reducing conditions and heat on the mobility of these antigens and their reactivity to antibodies from immunized animals by Western blotting.

  15. A Survey of ABO, Rhesus (D) Antigen and Haemoglobin Genes ...

    African Journals Online (AJOL)

    Summary: A survey of ABO and Rhesus (Rh D) antigens and variants of haemoglobin genes (HbGen) in Oyo state was carried out. This longitudinal study involved the determination of ABO and Rh(D) antigens in 3241 and HbGen in 2622 male and female adults (aged 26-65years) respectively using standard methods.

  16. Antigen Loss Variants: Catching Hold of Escaping Foes.

    Science.gov (United States)

    Vyas, Maulik; Müller, Rolf; Pogge von Strandmann, Elke

    2017-01-01

    Since mid-1990s, the field of cancer immunotherapy has seen steady growth and selected immunotherapies are now a routine and preferred therapeutic option of certain malignancies. Both active and passive cancer immunotherapies exploit the fact that tumor cells express specific antigens on the cell surface, thereby mounting an immune response specifically against malignant cells. It is well established that cancer cells typically lose surface antigens following natural or therapy-induced selective pressure and these antigen-loss variants are often the population that causes therapy-resistant relapse. CD19 and CD20 antigen loss in acute lymphocytic leukemia and chronic lymphocytic leukemia, respectively, and lineage switching in leukemia associated with mixed lineage leukemia (MLL) gene rearrangements are well-documented evidences in this regard. Although increasing number of novel immunotherapies are being developed, majority of these do not address the control of antigen loss variants. Here, we review the occurrence of antigen loss variants in leukemia and discuss the therapeutic strategies to tackle the same. We also present an approach of dual-targeting immunoligand effectively retargeting NK cells against antigen loss variants in MLL-associated leukemia. Novel immunotherapies simultaneously targeting more than one tumor antigen certainly hold promise to completely eradicate tumor and prevent therapy-resistant relapses.

  17. Detection of Rabies antigen in brains of suspected Rabid dogs ...

    African Journals Online (AJOL)

    Objective: To detect the presence of rabies antigen in brains of suspected rabid dogs. Materials and Methods: Ninety six (96) brain specimens from suspected rabid dogs were examined for the presence of rabies antigen using Seller's staining technique and enzyme immunoassay. Results: The two techniques were both ...

  18. Oral vaccination of animals with antigens encapsulated in alginate microspheres.

    Science.gov (United States)

    Bowersock, T L; HogenEsch, H; Suckow, M; Guimond, P; Martin, S; Borie, D; Torregrosa, S; Park, H; Park, K

    1999-03-26

    Most infectious diseases begin at a mucosal surface. Prevention of infection must therefore consider ways to enhance local immunity to prevent the attachment and invasion of microbes. Despite this understanding, most vaccines depend on parenterally administered vaccines that induce a circulating immune response that often does not cross to mucosal sites. Administration of vaccines to mucosal sites induces local immunity. To be effective requires that antigen be administered often. This is not always practical depending on the site where protection is needed, nor comfortable to the patient. Not all mucosal sites have inductive lymphoid tissue present as well. Oral administration is easy to do, is well accepted by humans and animals and targets the largest inductive lymphoid tissue in the body in the intestine. Oral administration of antigen requires protection of antigen from the enzymes and pH of the stomach. Polymeric delivery systems are under investigation to deliver vaccines to the intestine while protecting them from adverse conditions that could adversely affect the antigens. They also can enhance delivery of antigen specifically to the inductive lymphoid tissue. Sodium alginate is a readily available, inexpensive polymer that can be used to encapsulate a wide variety of antigens under mild conditions. Orally administered alginate microspheres containing antigen have successfully induced immunity in mice to enteric (rotavirus) pathogens and in the respiratory tract in cattle with a model antigen (ovalbumin). This delivery system offers a safe, effective means of orally vaccinating large numbers of animals (and perhaps humans) to a variety of infectious agents.

  19. Protein antigen adsorption to the DDA/TDB liposomal adjuvant

    DEFF Research Database (Denmark)

    Hamborg, Mette; Jorgensen, Lene; Bojsen, Anders Riber

    2013-01-01

    Understanding the nature of adjuvant-antigen interactions is important for the future design of efficient and safe subunit vaccines, but remains an analytical challenge. We studied the interactions between three model protein antigens and the clinically tested cationic liposomal adjuvant composed...

  20. Pneumocystis carinii from pigs and humans are antigenically distinct

    DEFF Research Database (Denmark)

    Christensen, C B; Settnes, Osvald Peter; Bille-Hansen, Vivi

    1996-01-01

    The antigens of Pneumocystis carinii cysts isolated from pigs and humans were compared by the Western immunoblotting technique. Convalescent pig serum reacted with two antigens (approximately 78 kDa and 32.5 kDa) of porcine P. carinii cysts, whereas convalescent serum from humans did not react...

  1. 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...

  2. Histoplasmin reaction. Comparison of a polysaccharide antigen to the filtrate antigen

    Directory of Open Access Journals (Sweden)

    Sérgio Di Camilo FAVA

    1997-09-01

    Full Text Available This work was planned by taking into account all the knowledge accumulated from the immunological study of paracoccidioidomycosis. It aimed at comparing a polysaccharide antigen from Histoplasma capsulatum to a classic histoplasmin with the help of intradermal tests of delayed type of hypersensitivity. Tests were applied to 115 individuals in Santo Amaro, a town in the state of São Paulo. Positive results using classic histoplasmin were obtained in 46.0% cases whereas positive results using the polysaccharide antigen at its hightest concentration were obtained in 51.30% cases. The major conclusion in this investigation is that it is possible to use the polysaccharide antigen as histoplasmin instead of the filtrate antigenO estudo envolve a comparação entre o antígeno polissacarídico de Histoplasma capsulatum com a histoplasmina clássica em inquérito epidemiológico, através de provas intradérmicas de hipersensibilidade do tipo tardio, realizado em 115 indivíduos da região de Santo Amaro. Os resultados revelaram 46,0% de provas positivas com a histoplasmina clássica e 51,30% de resultados positivos com o antígeno polissacarídico em sua maior concentração. A principal conclusão da pesquisa: é possível utilizar o antígeno polissacarídico como histoplasmina, em substituição ao antígeno filtrado

  3. Mosaic VSGs and the scale of Trypanosoma brucei antigenic variation.

    Directory of Open Access Journals (Sweden)

    James P J Hall

    Full Text Available A main determinant of prolonged Trypanosoma brucei infection and transmission and success of the parasite is the interplay between host acquired immunity and antigenic variation of the parasite variant surface glycoprotein (VSG coat. About 0.1% of trypanosome divisions produce a switch to a different VSG through differential expression of an archive of hundreds of silent VSG genes and pseudogenes, but the patterns and extent of the trypanosome diversity phenotype, particularly in chronic infection, are unclear. We applied longitudinal VSG cDNA sequencing to estimate variant richness and test whether pseudogenes contribute to antigenic variation. We show that individual growth peaks can contain at least 15 distinct variants, are estimated computationally to comprise many more, and that antigenically distinct 'mosaic' VSGs arise from segmental gene conversion between donor VSG genes or pseudogenes. The potential for trypanosome antigenic variation is probably much greater than VSG archive size; mosaic VSGs are core to antigenic variation and chronic infection.

  4. The susceptibility to cytotoxic T lymphocyte mediated lysis of chemically induced sarcomas from immunodeficient and normal mice

    DEFF Research Database (Denmark)

    Svane, I M; Engel, A M; Thomsen, Allan Randrup

    1997-01-01

    the sensitivity to CTL mediated lysis and surface expression of the MHC class I molecule Ld of the tumour cells. Tumour cells incapable of in vitro presentation of viral antigen to specific cytotoxic T cells originated from tumours known from previous experiments to be readily accepted after transplantation...... tested for susceptibility to cytolysis by virus specific cytotoxic T cells. Tumour cells originating from tumours induced in immunocompetent C.B.-17 mice presented virus antigen more efficiently than tumour cells from immunodeficient SCID mice. No significant difference in virus antigen presentation...... was found between tumours from nude and nu/+ BALB/c mice. The sensitivity of target cells from the individual tumours to cytotoxic T lymphocyte (CTL) mediated lysis correlated negatively with their sensitivity to natural killer (NK) cell mediated lysis. There was a positive correlation between...

  5. Tripeptidyl Peptidase II Mediates Levels of Nuclear Phosphorylated ERK1 and ERK2

    NARCIS (Netherlands)

    Wiemhoefer, Anne; Stargardt, Anita; van der Linden, Wouter A; Renner, Maria C; van Kesteren, Ronald E; Stap, Jan; Raspe, Marcel A; Tomkinson, Birgitta; Kessels, Helmut W; Ovaa, Huib; Overkleeft, Herman S; Florea, Bogdan; Reits, Eric A

    Tripeptidyl peptidase II (TPP2) is a serine peptidase involved in various biological processes, including antigen processing, cell growth, DNA repair, and neuropeptide mediated signaling. The underlying mechanisms of how a peptidase can influence this multitude of processes still remain unknown. We

  6. Tripeptidyl Peptidase II Mediates Levels of Nuclear Phosphorylated ERK1 and ERK2

    NARCIS (Netherlands)

    Wiemhoefer, Anne; Stargardt, Anita; van der Linden, Wouter A.; Renner, Maria C.; van Kesteren, Ronald E.; Stap, Jan; Raspe, Marcel A.; Tomkinson, Birgitta; Kessels, Helmut W.; Ovaa, Huib; Overkleeft, Herman S.; Florea, Bogdan; Reits, Eric A.

    2015-01-01

    Tripeptidyl peptidase II (TPP2) is a serine peptidase involved in various biological processes, including antigen processing, cell growth, DNA repair, and neuropeptide mediated signaling. The underlying mechanisms of how a peptidase can influence this multitude of processes still remain unknown. We

  7. The small GTPase, Rap1, mediates CD31-induced integrin adhesion

    NARCIS (Netherlands)

    Reedquist, K. A.; Ross, E.; Koop, E. A.; Wolthuis, R. M.; Zwartkruis, F. J.; van Kooyk, Y.; Salmon, M.; Buckley, C. D.; Bos, J. L.

    2000-01-01

    Integrin-mediated leukocyte adhesion is a critical aspect of leukocyte function that is tightly regulated by diverse stimuli, including chemokines, antigen receptors, and adhesion receptors. How cellular signals from CD31 and other adhesion amplifiers are integrated with those from classical

  8. Antigenic Relationships among Human Pathogenic Orientia tsutsugamushi Isolates from Thailand.

    Directory of Open Access Journals (Sweden)

    Sarah L James

    2016-06-01

    Full Text Available Scrub typhus is a common cause of undiagnosed febrile illness in certain tropical regions, but can be easily treated with antibiotics. The causative agent, Orientia tsutsugamushi, is antigenically variable which complicates diagnosis and efforts towards vaccine development.This study aimed to dissect the antigenic and genetic relatedness of O. tsutsugamushi strains and investigate sero-diagnostic reactivities by titrating individual patient sera against their O. tsutsugamushi isolates (whole-cell antigen preparation, in homologous and heterologous serum-isolate pairs from the same endemic region in NE Thailand. The indirect immunofluorescence assay was used to titrate Orientia tsutsugamushi isolates and human sera, and a mathematical technique, antigenic cartography, was applied to these data to visualise the antigenic differences and cross-reactivity between strains and sera. No functional or antigen-specific analyses were performed. The antigenic variation found in clinical isolates was much less pronounced than the genetic differences found in the 56kDa type-specific antigen genes. The Karp-like sera were more broadly reactive than the Gilliam-like sera.Antigenic cartography worked well with scrub typhus indirect immunofluorescence titres. The data from humoral responses suggest that a Karp-like strain would provide broader antibody cross-reactivity than a Gilliam-like strain. Although previous exposure to O. tsutsugamushi could not be ruled out, scrub typhus patient serum antibody responses were characterised by strong homologous, but weak heterologous antibody titres, with little evidence for cross-reactivity by Gilliam-like sera, but a broader response from some Karp-like sera. This work highlights the importance of antigenic variation in O. tsutsugamushi diagnosis and determination of new serotypes.

  9. Strategies for Designing and Monitoring Malaria Vaccines Targeting Diverse Antigens

    Science.gov (United States)

    Barry, Alyssa E.; Arnott, Alicia

    2014-01-01

    After more than 50 years of intensive research and development, only one malaria vaccine candidate, “RTS,S,” has progressed to Phase 3 clinical trials. Despite only partial efficacy, this candidate is now forecast to become the first licensed malaria vaccine. Hence, more efficacious second-generation malaria vaccines that can significantly reduce transmission are urgently needed. This review will focus on a major obstacle hindering development of effective malaria vaccines: parasite antigenic diversity. Despite extensive genetic diversity in leading candidate antigens, vaccines have been and continue to be formulated using recombinant antigens representing only one or two strains. These vaccine strains represent only a small fraction of the diversity circulating in natural parasite populations, leading to escape of non-vaccine strains and challenging investigators’ abilities to measure strain-specific efficacy in vaccine trials. Novel strategies are needed to overcome antigenic diversity in order for vaccine development to succeed. Many studies have now cataloged the global diversity of leading Plasmodium falciparum and Plasmodium vivax vaccine antigens. In this review, we describe how population genetic approaches can be applied to this rich data source to predict the alleles that best represent antigenic diversity, polymorphisms that contribute to it, and to identify key polymorphisms associated with antigenic escape. We also suggest an approach to summarize the known global diversity of a given antigen to predict antigenic diversity, how to select variants that best represent the strains circulating in natural parasite populations and how to investigate the strain-specific efficacy of vaccine trials. Use of these strategies in the design and monitoring of vaccine trials will not only shed light on the contribution of genetic diversity to the antigenic diversity of malaria, but will also maximize the potential of future malaria vaccine candidates. PMID

  10. Neonatal exposure to fecal antigens reduces intestinal inflammation.

    Science.gov (United States)

    Sydora, Beate C; McFarlane, Sarah M; Doyle, Jason S G; Fedorak, Richard N

    2011-04-01

    A role for bacterial antigens in the pathogenesis of inflammatory bowel disease (IBD) has been established in enhanced humoral and cellular immune response to ubiquitous antigens of the enteric flora. However, we have recently shown that bacterial antigens in the absence of live bacteria cannot initiate an intestinal inflammation in IBD-prone interleukin (IL)-10 gene-deficient mice. The objective was to investigate whether neonatal exposure to antigens of their own endogenous flora can tolerize mice to bacterial antigens. IL-10 gene-deficient neonates were injected intraperitoneally within 72 hours of birth with a sterile solution of bacterial lysates prepared from fecal material of either conventionally raised mice (contains bacterial antigens) or axenic mice (lacks bacterial antigens). The onset of intestinal inflammation was monitored as the appearance of occult blood in the stool in weekly hemoccult analysis. Mice were sacrificed between age 15 and 19 weeks and tested for histopathologic injury, intestinal inflammation, and systemic response to bacterial antigens. In mice neonatally exposed to bacterial antigens the onset of intestinal inflammation was delayed and the incidence of histopathologic injury at age 18 weeks was reduced. In addition, mice injected with lysates from conventionally raised mice exhibited decreased release of proinflammatory cytokines (interferon gamma [IFN-γ] and IL-17) in intestinal tissue and demonstrated reduced bacteria-stimulated systemic responses when compared to mice injected with lysates derived from bacteria-free, axenic mice. Neonatal intraperitoneal injection of antigens from the commensal flora causes long-lasting changes in systemic and mucosal immune responses resulting in delayed onset of intestinal inflammation and injury in IBD-prone IL-10 gene-deficient mice. Copyright © 2010 Crohn's & Colitis Foundation of America, Inc.

  11. Strategies for designing and monitoring malaria vaccines targeting diverse antigens

    Directory of Open Access Journals (Sweden)

    Alyssa E Barry

    2014-07-01

    Full Text Available After more than 50 years of intensive research and development, only one malaria vaccine candidate, RTS,S, has progressed to Phase 3 clinical trials. Despite only partial efficacy, this candidate is now forecast to become the first licensed malaria vaccine. Hence, more efficacious second-generation malaria vaccines that can significantly reduce transmission are urgently needed. This review will focus on a major obstacle hindering development of effective malaria vaccines: parasite antigenic diversity. Despite extensive genetic diversity in leading candidate antigens, vaccines have been and continue to be formulated using recombinant antigens representing only one or two strains. These vaccine strains represent only a small fraction of the diversity circulating in natural parasite populations, leading to escape of non-vaccine strains and challenging investigators’ abilities to measure strain-specific efficacy in vaccine trials. Novel strategies are needed to overcome antigenic diversity in order for vaccine development to succeed. Many studies have now catalogued the global diversity of leading Plasmodium falciparum and Plasmodium vivax vaccine antigens. In this review, we describe how population genetic approaches can be applied to this rich data source to predict the alleles that best represent antigenic diversity, polymorphisms that contribute to it, and to identify key polymorphisms associated with antigenic escape. We also suggest an approach to summarise the known global diversity of a given antigen to predict antigenic diversity, how to select variants that best represent the strains circulating in natural parasite populations and how to investigate the strain-specific efficacy of vaccine trials. Use of these strategies in the design and monitoring of vaccine trials will not only shed light on the contribution of genetic diversity to the antigenic diversity of malaria, but will also maximise the potential of future malaria vaccine

  12. Nordic Mediation Reseach

    DEFF Research Database (Denmark)

    A presentation of 12 studies on mediation from researchers from Denmark, Finland, Norway and Sweden.......A presentation of 12 studies on mediation from researchers from Denmark, Finland, Norway and Sweden....

  13. The kinetics of antibody binding to Plasmodium falciparum VAR2CSA PfEMP1 antigen and modelling of PfEMP1 antigen packing on the membrane knobs

    DEFF Research Database (Denmark)

    Joergensen, Lars M; Salanti, Ali; Dobrilovic, Tina

    2010-01-01

    ABSTRACT: BACKGROUND: Infected humans make protective antibody responses to the PfEMP1 adhesion antigens exported by Plasmodium falciparum parasites to the erythrocyte membrane, but little is known about the kinetics of this antibody-receptor binding reaction or how the topology of PfEMP1...... on the parasitized erythrocyte membrane influences antibody association with, and dissociation from, its antigenic target. METHODS: A Quartz Crystal Microbalance biosensor was used to measure the association and dissociation kinetics of VAR2CSA PfEMP1 binding to human monoclonal antibodies. Immuno......-fluorescence microscopy was used to visualize antibody-mediated adhesion between the surfaces of live infected erythrocytes and atomic force microscopy was used to obtain higher resolution images of the membrane knobs on the infected erythrocyte to estimate knob surface areas and model VAR2CSA packing density on the knob...

  14. Evaluation of Hepatitis C Virus Core Antigen Assays in Detecting Recombinant Viral Antigens of Various Genotypes ▿

    Science.gov (United States)

    Saeed, Mohsan; Suzuki, Ryosuke; Kondo, Madoka; Aizaki, Hideki; Kato, Takanobu; Mizuochi, Toshiaki; Wakita, Takaji; Watanabe, Haruo; Suzuki, Tetsuro

    2009-01-01

    A single substitution within the hepatitis C virus core antigen sequence, A48T, which is observed in ∼30% of individuals infected with genotype 2a virus, reduces the sensitivity of a commonly used chemiluminescence enzyme immunoassay. Quantitation of the antigen is improved by using a distinct anticore antibody with a different epitope. PMID:19812276

  15. Brain antigens in functionally distinct antigen-presenting cell populations in cervical lymph nodes in MS and EAE

    NARCIS (Netherlands)

    M. van Zwam (Marloes); R. Huizinga (Ruth); M.J. Melief (Marie-José); A.F. Wierenga-Wolf (Annet); M. van Meurs (Marjan); J.S. Voerman (Jane); K.P.H. Biber (Knut); H.W.G.M. Boddeke (Hendrikus); U.E. Höpken (Uta); C. Meisel (Christian); I. Bechmann (Ingo); R.Q. Hintzen (Rogier); B.A. 't Hart (Bert); S. Amor (Sandra); J.D. Laman (Jon); L.A. Boven (Leonie)

    2009-01-01

    textabstractDrainage of central nervous system (CNS) antigens to the brain-draining cervical lymph nodes (CLN) is likely crucial in the initiation and control of autoimmune responses during multiple sclerosis (MS). We demonstrate neuronal antigens within CLN of MS patients. In monkeys and mice with

  16. mediation: R Package for Causal Mediation Analysis

    Directory of Open Access Journals (Sweden)

    Dustin Tingley

    2014-09-01

    Full Text Available In this paper, we describe the R package mediation for conducting causal mediation analysis in applied empirical research. In many scientific disciplines, the goal of researchers is not only estimating causal effects of a treatment but also understanding the process in which the treatment causally affects the outcome. Causal mediation analysis is frequently used to assess potential causal mechanisms. The mediation package implements a comprehensive suite of statistical tools for conducting such an analysis. The package is organized into two distinct approaches. Using the model-based approach, researchers can estimate causal mediation effects and conduct sensitivity analysis under the standard research design. Furthermore, the design-based approach provides several analysis tools that are applicable under different experimental designs. This approach requires weaker assumptions than the model-based approach. We also implement a statistical method for dealing with multiple (causally dependent mediators, which are often encountered in practice. Finally, the package also offers a methodology for assessing causal mediation in the presence of treatment noncompliance, a common problem in randomized trials.

  17. Case of rhesus antigen weak D type 4.2. (DAR category detection

    Directory of Open Access Journals (Sweden)

    L. L. Golovkina

    2015-01-01

    Full Text Available Serological methods of Rhesus antigens identification in humans cannot identify D-antigen variants. In this article the serological characteristics of Rhesus antigen D weak type 4.2. (Category DAR are described.

  18. Bayesian Mediation Analysis

    Science.gov (United States)

    Yuan, Ying; MacKinnon, David P.

    2009-01-01

    In this article, we propose Bayesian analysis of mediation effects. Compared with conventional frequentist mediation analysis, the Bayesian approach has several advantages. First, it allows researchers to incorporate prior information into the mediation analysis, thus potentially improving the efficiency of estimates. Second, under the Bayesian…

  19. Antigen cross-priming of cell-associated proteins is enhanced by macroautophagy within the antigen donor cell

    Directory of Open Access Journals (Sweden)

    Matthew eAlbert

    2012-03-01

    Full Text Available Phagocytosis of dying cells constitutes an importance mechanism of antigen capture for the cross-priming of CD8+ T cells. This process has been shown to be critical for achieving tumor and viral immunity. While most studies have focused on the mechanisms inherent in the dendritic cell that account for exogenous antigen accessing MHC I, several recent reports have highlighted the important contribution made by the antigen donor cell. Specifically, the cell stress and cell death pathways that precede antigen transfer are now known to impact cross-presentation and cross-priming. Herein, we review the current literature regarding a role for macro-autophagy within the antigen donor cell. Further examination of this point of immune regulation is warranted and may contribute to a better understanding of how to optimize immunotherapy for treatment of cancer and chronic infectious disease.

  20. Whole blood assay to access T cell-immune responses to Mycobacterium tuberculosis antigens in healthy Brazilian individuals

    Directory of Open Access Journals (Sweden)

    Paulo RZ Antas

    2004-02-01

    Full Text Available The production of interferon gamma (IFNgamma guarantees effective T cell-mediated immunity against Mycobacterium tuberculosis infection. In the present study, we simply compare the in vitro immune responses to Mycobacterium antigens in terms of IFNg production in a total of 10 healthy Brazilian volunteers. Whole blood and mononuclear cells were cultivated in parallel with PPD, Ag85B, and M. bovis hsp65, and five-days supernatants were harvested for cytokine detection by ELISA. The inter-assay result was that the overall profile of agreement in response to antigens was highly correlated (r² = 0.9266; p = 0.0102. Potential analysis is in current progress to dictate the usefulness of this method to access the immune responses also in tuberculosis patients and its contacts.

  1. The Leishmania promastigote surface antigen-2 (PSA-2) is specifically recognised by Th1 cells in humans with naturally acquired immunity to L. major

    DEFF Research Database (Denmark)

    Kemp, M; Handman, E; Kemp, K

    1998-01-01

    The promastigote surface antigen-2 (PSA-2) is a Leishmania parasite antigen, which can induce Th1-mediated protection against murine leishmaniasis when used as a vaccine. To evaluate PSA-2 as a human vaccine candidate the specific T-cell response to PSA-2 was characterised in individuals immune...... to cutaneous leishmaniasis. Peripheral blood mononuclear cells from Sudanese individuals with a past history of self-healing cutaneous leishmaniasis proliferated vigorously in response to PSA-2 isolated from Leishmania major, whereas the antigen did not activate cells from presumably unexposed Danes....... Peripheral blood mononuclear cells from individuals with previous L. major infection had varying proliferative responses to PSA-2 derived from L. donovani promastigotes. Peripheral blood mononuclear cells activated by PSA-2 from L. major produced high amounts of interferon-gamma and tumour necrosis factor...

  2. Quantitation of MHC antigen expression on colorectal tumours and its association with tumour progression.

    OpenAIRE

    Durrant, L. G.; Ballantyne, K. C.; Armitage, N. C.; Robins, R. A.; Marksman, R.; Hardcastle, J. D.; Baldwin, R. W.

    1987-01-01

    A flow cytometric technique has been established for accurately quantitating the cell surface density of MHC antigens and the percentage of cells expressing MHC antigens in 38 colorectal tumours. Thirty-four percent of tumours were partially or completely negative for HLA-ABC antigen expression. Although the quantity of HLA-ABC antigens varied widely, there was no correlation between the density of HLA-ABC antigens, or the percentage of cells expressing these antigens and clinicopathological ...

  3. A Diet, Physical Activity, and Mediation Intervention in Men With Rising Prostate-Specific Antigen (PSA)

    National Research Council Canada - National Science Library

    Hebert, James

    2004-01-01

    ... physical activity and mindfulness-based stress reduction. This randomized trial will enroll 60 men with rising PSA levels along with a partner of their choice, half of whom will be randomized to the intervention and half to usual care...

  4. Antigen 43-mediated autotransporter display, a versatile bacterial cell surface presentation system

    DEFF Research Database (Denmark)

    Kjærgaard, Kristian; Hasman, Henrik; Schembri, Mark

    2002-01-01

    to the outer membrane and secretion through the cell envelope is contained within the protein itself. Ag43 consists of two subunits (alpha and beta), where the beta-subunit forms an integral outer membrane translocator to which the alpha-subunit is noncovalently attached. The simplicity of the Ag43 system...... makes it ideally suited as a surface display scaffold. Here we demonstrate that the Ag43 alpha-module can accommodate and display correctly folded inserts and has the ability to display entire functional protein domains, exemplified by the FimH lectin domain. The presence of heterologous cysteine...... bridges does not interfere with surface display, and Ag43 chimeras are correctly processed into alpha- and beta-modules, offering optional and easy release of the chimeric alpha-subunits. Furthermore, Ag43 can be displayed in many gram-negative bacteria. This feature is exploited for display of our...

  5. Prostate-specific membrane antigen (PSMA)-mediated laminin proteolysis generates a pro-angiogenic peptide

    Czech Academy of Sciences Publication Activity Database

    Conway, R. E.; Rojas, C.; Alt, J.; Nováková, Zora; Richardson, S. M.; Rodrick, T. C.; Fuentes, J. L.; Richardson, N. H.; Attalla, J.; Stewart, S.; Fahmy, B.; Bařinka, Cyril; Ghosh, M.; Shapiro, L. H.; Slusher, B. S.

    2016-01-01

    Roč. 19, č. 4 (2016), s. 487-500 ISSN 0969-6970 R&D Projects: GA ČR GAP301/12/1513; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : TUMOR-ASSOCIATED NEOVASCULATURE * BASEMENT-MEMBRANE * DISTINCT ANTITUMOR PROPERTIES Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 5.253, year: 2016

  6. Yersinia enterocolitica YopP inhibits MAP kinase-mediated antigen uptake in dendritic cells

    Czech Academy of Sciences Publication Activity Database

    Autenrieth, S. E.; Adkins, Irena; Rösemann, R.; Gunst, D.; Zahir, N.; Kracht, M.; Ruckdeschel, K.; Wagner, H.; Borgmann, S.; Autenrieth, I. B.

    2007-01-01

    Roč. 9, č. 2 (2007), s. 425-437 ISSN 1462-5814 Institutional research plan: CEZ:AV0Z50200510 Keywords : yersinia enterocolitica * dendritic cells * immunity Subject RIV: EC - Immunology Impact factor: 5.293, year: 2007

  7. General gauge mediation

    International Nuclear Information System (INIS)

    Meade, Patrick; Seiberg, Nathan; Shih, David

    2009-01-01

    We give a general definition of gauge mediated supersymmetry breaking which encompasses all the known gauge mediation models. In particular, it includes both models with messengers as well as direct mediation models. A formalism for computing the soft terms in the generic model is presented. Such a formalism is necessary in strongly-coupled direct mediation models where perturbation theory cannot be used. It allows us to identify features of the entire class of gauge mediation models and to distinguish them from specific signatures of various subclasses. (author)

  8. 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.

  9. 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.

  10. Microglial MHC antigen expression after ischemic and kainic acid lesions of the adult rat hippocampus

    DEFF Research Database (Denmark)

    Finsen, B.R.; Jørgensen, Martin Balslev; Diemer, Nils Henrik

    1993-01-01

    Leukocyte common antigen, macrophages, blood-brain barrier, neural degeneration, fascia dentata, neuropathology......Leukocyte common antigen, macrophages, blood-brain barrier, neural degeneration, fascia dentata, neuropathology...

  11. Molecular interplay between T-Antigen and splicing factor, arginine/serine-rich 1 (SRSF1) controls JC virus gene expression in glial cells.

    Science.gov (United States)

    Craigie, Michael; Regan, Patrick; Otalora, Yolanda-Lopez; Sariyer, Ilker Kudret

    2015-11-24

    Human polyomavirus JCV is the etiologic agent of progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease characterized by lytic infection of glial cells in the central nervous system. PML is seen primarily in immunosuppressed patients and is mainly classified as an AIDS-defining disease. In addition to structural capsid proteins, JCV encodes multiple regulatory proteins, including T-antigen and agnoprotein, which are required for functional lytic infection. Previous studies have suggested that molecular interaction between viral proteins and host factors play an important role in reactivation of JCV and progression of the viral life cycle in glial cells. Recently, serine/arginine rich splicing factor 1 (SRSF1), a cellular alternative splicing factor, was identified as a strong negative regulator of JCV in glial cells. SRSF1 inhibits JCV gene expression and viral replication by directly interacting with viral promoter sequences. Here, we have investigated possible impact of JCV regulatory proteins, T-antigen and agnoprotein, on SRSF1-mediated suppression of JCV gene expression in glial cells. Reporter gene analysis has suggested that T-antigen rescues viral transcriptional suppression mediated by SRSF1. Further analyses have revealed that T-antigen promotes viral gene expression by suppressing SRSF1 gene transcription in glial cells. A subsequent ChIP analysis revealed that T-antigen associates with the promoter region of SRSF1 to induce the transcriptional suppression. These findings have revealed a molecular interplay between cellular SRSF1 and viral T-antigen in controlling JCV gene expression, and may suggest a novel mechanism of JCV reactivation in patients who are at risk of developing PML.

  12. In vasculitis of small muscular arteries, activation of vessel-infiltrating CD8 T cells seems to be antigen-independent.

    Science.gov (United States)

    Kobayashi, Mikiko; Ogawa, Eisaku; Okuyama, Ryuhei; Kanno, Hiroyuki

    2018-02-01

    The etiology of polyarteritis nodosa (PAN) and localized PAN is still unknown, although a T cell-mediated immune mechanism has been considered. CD8 T cells participate not only in the antigen-dependent adaptive immune system, but also in the antigen-independent innate immune system. Non-antigen-activated CD8 T cells express a unique phenotype: granzyme B (GrB) positive /CD25 negative /programmed death-1 (PD-1) negative. The aims of this study were to assess the participation of T cells, especially innate CD8 T cells, in the development of vasculitis. Twenty-eight consecutive cases of skin biopsy specimens with cutaneous vasculitis of small muscular arteries (CVSMA) were retrieved. The series comprises of 21 cases of cutaneous arteritis, three cases of PAN, and four cases of rheumatoid vasculitis. Cases of antineutrophil cytoplasmic antibody-associated vasculitis were excluded. The phenotypes of infiltrating lymphocytes in vasculitis lesions were evaluated by immunohistochemistry. In most cases of CVSMA, the number of CD8 T cells infiltrating the intima was higher than that of CD4 T cells, and significant numbers of GrB-positive cells, which represent activated CD8 T cells, were observed. However, GrB/CD25-double-positive cells, which correspond to antigen-activated T cells, were very few in a small number of cases. Cells positive for PD-1, which is also expressed on antigen-activated CD8 T cells, were not detected. We conclude that a T cell-mediated immune mechanism, involving cytotoxic CD8 T cells, may play a role in the development of CVSMA. Low expression of CD25 in activated CD8 T cells suggests that activation was antigen-independent.

  13. Lymphocyte transformation assay for C neoformans antigen is not reliable for detecting cellular impairment in patients with neurocryptococcosis.

    Science.gov (United States)

    Rocha, Katya C; Pinhal, Cinthia; Cavalcanti, Sônia; Vidal, Monica S M; Toscano, Matheus; Moraes-Vasconcelos, Dewton; Duarte, Alberto J S; Fonseca, Fernando L A; de Abreu, Luiz Carlos; Valenti, Vitor E; Grumach, Anete S G

    2012-10-30

    Cryptococcus neoformans causes meningitis and disseminated infection in healthy individuals, but more commonly in hosts with defective immune responses. Cell-mediated immunity is an important component of the immune response to a great variety of infections, including yeast infections. We aimed to evaluate a specific lymphocyte transformation assay to Cryptococcus neoformans in order to identify immunodeficiency associated to neurocryptococcosis (NCC) as primary cause of the mycosis. Healthy volunteers, poultry growers, and HIV-seronegative patients with neurocryptococcosis were tested for cellular immune response. Cryptococcal meningitis was diagnosed by India ink staining of cerebrospinal fluid and cryptococcal antigen test (Immunomycol-Inc, SP, Brazil). Isolated peripheral blood mononuclear cells were stimulated with C. neoformans antigen, C. albicans antigen, and pokeweed mitogen. The amount of 3H-thymidine incorporated was assessed, and the results were expressed as stimulation index (SI) and log SI, sensitivity, specificity, and cut-off value (receiver operating characteristics curve). We applied unpaired Student t tests to compare data and considered significant differences for p<0.05. The lymphotoxin alpha showed a low capacity with all the stimuli for classifying patients as responders and non-responders. Lymphotoxin alpha stimulated by heated-killed antigen from patients with neurocryptococcosis was not affected by TCD4+ cell count, and the intensity of response did not correlate with the clinical evolution of neurocryptococcosis. Response to lymphocyte transformation assay should be analyzed based on a normal range and using more than one stimulator. The use of a cut-off value to classify patients with neurocryptococcosis is inadequate. Statistical analysis should be based on the log transformation of SI. A more purified antigen for evaluating specific response to C. neoformans is needed.

  14. Designing malaria vaccines to circumvent antigen variability✩

    Science.gov (United States)

    Ouattara, Amed; Barry, Alyssa E.; Dutta, Sheetij; Remarque, Edmond J.; Beeson, James G.; Plowe, Christopher V.

    2016-01-01

    Prospects for malaria eradication will be greatly enhanced by an effective vaccine, but parasite genetic diversity poses a major impediment to malaria vaccine efficacy. In recent pre-clinical and field trials, vaccines based on polymorphic Plasmodium falciparum antigens have shown efficacy only against homologous strains, raising the specter of allele-specific immunity such as that which plagues vaccines against influenza and HIV. The most advanced malaria vaccine, RTS,S, targets relatively conserved epitopes on the P. falciparum circumsporozoite protein. After more than 40 years of development and testing, RTS,S, has shown significant but modest efficacy against clinical malaria in phase 2 and 3 trials. Ongoing phase 2 studies of an irradiated sporozoite vaccine will ascertain whether the full protection against homologous experimental malaria challenge conferred by high doses of a whole organism vaccine can provide protection against diverse strains in the field. Here we review and evaluate approaches being taken to design broadly cross-protective malaria vaccines. PMID:26475447

  15. Designing malaria vaccines to circumvent antigen variability.

    Science.gov (United States)

    Ouattara, Amed; Barry, Alyssa E; Dutta, Sheetij; Remarque, Edmond J; Beeson, James G; Plowe, Christopher V

    2015-12-22

    Prospects for malaria eradication will be greatly enhanced by an effective vaccine, but parasite genetic diversity poses a major impediment to malaria vaccine efficacy. In recent pre-clinical and field trials, vaccines based on polymorphic Plasmodium falciparum antigens have shown efficacy only against homologous strains, raising the specter of allele-specific immunity such as that which plagues vaccines against influenza and HIV. The most advanced malaria vaccine, RTS,S, targets relatively conserved epitopes on the P. falciparum circumsporozoite protein. After more than 40 years of development and testing, RTS,S, has shown significant but modest efficacy against clinical malaria in phase 2 and 3 trials. Ongoing phase 2 studies of an irradiated sporozoite vaccine will ascertain whether the full protection against homologous experimental malaria challenge conferred by high doses of a whole organism vaccine can provide protection against diverse strains in the field. Here we review and evaluate approaches being taken to design broadly cross-protective malaria vaccines. Copyright © 2015. Published by Elsevier Ltd.

  16. Immunization with viral antigens: Infectious haematopoietic necrosis

    Science.gov (United States)

    Winton, J.R.; Midtlyng, Paul J.; Brown, F.

    1997-01-01

    Infectious haematopoietic necrosis (IHN) is one of the most important viral diseases of salmonids, especially among juvenile fish where losses can be high. For over 20 years, researchers have tested a variety of preparations for control of IHN. Early vaccines consisted of killed virus and were effective when delivered by injection, but too costly to be practical on a large scale. Attenuated vaccines were developed by serial passage in cell culture and by monoclonal antibody selection. These offered excellent protection and were cost-effective, but residual virulence and uncertainty about their effects on other aquatic species made them poor candidates for licensing. Subunit vaccines using part of the IHNV glycoprotein gene cloned into E. coli or into an attenuated strain of A. salmonicida have been tested, appeared safe and were inexpensive. These vaccines were reported to provide some protection when delivered by immersion. Information on the location of antigenic sites on the glycoprotein led to trials using synthetic peptides, but these did not seem to be economically viable. Recently, plasmid vectors encoding the glycoprotein gene under control of a cytomegalovirus promoter were developed for genetic immunization. The constructs were highly protective when delivered by injection, but a more practical delivery system is needed. Thus, while several vaccine strategies have been tried in order to stimulate specific immunity against IHN, more research is needed to develop a commercially viable product for control of this important disease.

  17. Assaying Carcinoembryonic Antigens by Normalized Saturation Magnetization

    Science.gov (United States)

    Huang, Kai-Wen; Chieh, Jen-Jie; Shi, Jin-Cheng; Chiang, Ming-Hsien

    2015-07-01

    Biofunctionalized magnetic nanoparticles (BMNs) that provide unique advantages have been extensively used to develop immunoassay methods. However, these developed magnetic methods have been used only for specific immunoassays and not in studies of magnetic characteristics of materials. In this study, a common vibration sample magnetometer (VSM) was used for the measurement of the hysteresis loop for different carcinoembryonic antigens (CEA) concentrations ( Φ CEA) based on the synthesized BMNs with anti-CEA coating. Additionally, magnetic parameters such as magnetization ( M), remanent magnetization ( M R), saturation magnetization ( M S), and normalized parameters (Δ M R/ M R and Δ M S/ M S) were studied. Here, Δ M R and Δ M s were defined as the difference between any ΦCEA and zero Φ CEA. The parameters M, Δ M R, and Δ M S increased with Φ CEA, and Δ M S showed the largest increase. Magnetic clusters produced by the conjugation of the BMNs to CEAs showed a Δ M S greater than that of BMNs. Furthermore, the relationship between Δ M S/ M S and Φ CEA could be described by a characteristic logistic function, which was appropriate for assaying the amount of CEAs. This analytic Δ M S/ M S and the BMNs used in general magnetic immunoassays can be used for upgrading the functions of the VSM and for studying the magnetic characteristics of materials.

  18. MutLα and Proliferating Cell Nuclear Antigen Share Binding Sites on MutSβ*

    Science.gov (United States)

    Iyer, Ravi R.; Pluciennik, Anna; Genschel, Jochen; Tsai, Miaw-Sheue; Beese, Lorena S.; Modrich, Paul

    2010-01-01

    MutSβ (MSH2-MSH3) mediates repair of insertion-deletion heterologies but also triggers triplet repeat expansions that cause neurological diseases. Like other DNA metabolic activities, MutSβ interacts with proliferating cell nuclear antigen (PCNA) via a conserved motif (QXX(L/I)XXFF). We demonstrate that MutSβ-PCNA complex formation occurs with an affinity of ∼0.1 μm and a preferred stoichiometry of 1:1. However, up to 20% of complexes are multivalent under conditions where MutSβ is in molar excess over PCNA. Conformational studies indicate that the two proteins associate in an end-to-end fashion in solution. Surprisingly, mutation of the PCNA-binding motif of MutSβ not only abolishes PCNA binding, but unlike MutSα, also dramatically attenuates MutSβ-MutLα interaction, MutLα endonuclease activation, and bidirectional mismatch repair. As predicted by these findings, PCNA competes with MutLα for binding to MutSβ, an effect that is blocked by the cell cycle regulator p21CIP1. We propose that MutSβ-MutLα interaction is mediated in part by residues ((L/I)SRFF) embedded within the MSH3 PCNA-binding motif. To our knowledge this is the first case where residues important for PCNA binding also mediate interaction with a second protein. These findings also indicate that MutSβ- and MutSα-initiated repair events differ in fundamental ways. PMID:20154325

  19. The Leishmania promastigote surface antigen-2 (PSA-2) is specifically recognised by Th1 cells in humans with naturally acquired immunity to L. major.

    Science.gov (United States)

    Kemp, M; Handman, E; Kemp, K; Ismail, A; Mustafa, M D; Kordofani, A Y; Bendtzen, K; Kharazmi, A; Theander, T G

    1998-03-01

    The promastigote surface antigen-2 (PSA-2) is a Leishmania parasite antigen, which can induce Th1-mediated protection against murine leishmaniasis when used as a vaccine. To evaluate PSA-2 as a human vaccine candidate the specific T-cell response to PSA-2 was characterised in individuals immune to cutaneous leishmaniasis. Peripheral blood mononuclear cells from Sudanese individuals with a past history of self-healing cutaneous leishmaniasis proliferated vigorously in response to PSA-2 isolated from Leishmania major, whereas the antigen did not activate cells from presumably unexposed Danes. Peripheral blood mononuclear cells from individuals with previous L. major infection had varying proliferative responses to PSA-2 derived from L. donovani promastigotes. Peripheral blood mononuclear cells activated by PSA-2 from L. major produced high amounts of interferon-gamma and tumour necrosis factor-beta, and little interleukin-4, thereby showing a Th1 cytokine pattern. Parallel cultures showed clear Th1 and Th2 response patterns to purified protein derivative of tuberculin or tetanus toxoid, respectively. Flow cytometric analysis revealed that PSA-2 induced blastogenesis in the CD3 positive population and that these cells were the major source of interferon-gamma. The results show that Th1-like cells recognising PSA-2 are expanded during infection by L. major and that they maintain their Th1-like cytokine profile upon reactivation in vitro. Since immunity to cutaneous leishmaniasis is mediated by antigen-specific Th1-like cells, PSA-2 might be considered a vaccine candidate for human leishmaniasis.

  20. Generation of competent bone marrow-derived antigen presenting cells from the deer mouse (Peromyscus maniculatus

    Directory of Open Access Journals (Sweden)

    Farrell Regina M

    2004-09-01

    Full Text Available Abstract Background Human infections with Sin Nombre virus (SNV and related New World hantaviruses often lead to hantavirus cardiopulmonary syndrome (HCPS, a sometimes fatal illness. Lungs of patients who die from HCPS exhibit cytokine-producing mononuclear infiltrates and pronounced pulmonary inflammation. Deer mice (Peromyscus maniculatus are the principal natural hosts of SNV, in which the virus establishes life-long persistence without conspicuous pathology. Little is known about the mechanisms SNV employs to evade the immune response of deer mice, and experimental examination of this question has been difficult because of a lack of methodologies for examining such responses during infection. One such deficiency is our inability to characterize T cell responses because susceptible syngeneic deer mice are not available. Results To solve this problem, we have developed an in vitro method of expanding and generating competent antigen presenting cells (APC from deer mouse bone marrow using commercially-available house mouse (Mus musculus granulocyte-macrophage colony stimulating factor. These cells are capable of processing and presenting soluble protein to antigen-specific autologous helper T cells in vitro. Inclusion of antigen-specific deer mouse antibody augments T cell stimulation, presumably through Fc receptor-mediated endocytosis. Conclusions The use of these APC has allowed us to dramatically expand deer mouse helper T cells in culture and should permit extensive characterization of T cell epitopes. Considering the evolutionary divergence between deer mice and house mice, it is probable that this method will be useful to other investigators using unconventional models of rodent-borne diseases.

  1. Non-classical antigen processing pathways are required for MHC class II-restricted direct tumor recognition by NY-ESO-1-specific CD4+ T cells

    Science.gov (United States)

    Matsuzaki, Junko; Tsuji, Takemasa; Luescher, Immanuel; Old, Lloyd J.; Shrikant, Protul; Gnjatic, Sacha; Odunsi, Kunle

    2014-01-01

    Tumor antigen-specific CD4+ T cells that directly recognize cancer cells are important for orchestrating antitumor immune responses at the local tumor sites. However, the mechanisms of direct MHC class II (MHC-II) presentation of intracellular tumor antigen by cancer cells are poorly understood. We found that two functionally distinct subsets of CD4+ T cells were expanded after HLA-DPB1*04 (DP04)-binding NY-ESO-1157–170 peptide vaccination in ovarian cancer patients. While both subsets similarly recognized exogenous NY-ESO-1 protein pulsed on DP04+ target cells, only one type recognized target cells with intracellular expression of NY-ESO-1. The tumor-recognizing CD4+ T cells more efficiently recognized the short 8–9-mer peptides than the non-tumor-recognizing CD4+ T cells. In addition to endosomal/lysosomal proteases that are typically involved in MHC-II antigen presentation, several pathways in the MHC class I presentation pathways such as the proteasomal degradation and transporter-associated with antigen-processing (TAP)-mediated peptide transport were also involved in the presentation of intracellular NY-ESO-1 on MHC-II. The presentation was inhibited significantly by primaquine, a small molecule that inhibits endosomal recycling, consistent with findings that pharmacological inhibition of new protein synthesis enhances antigen presentation. Together, our data demonstrated that cancer cells selectively present peptides from intracellular tumor antigens on MHC-II by multiple non-classical antigen-processing pathways. Harnessing direct tumor-recognizing ability of CD4+ T cells could be a promising strategy to enhance antitumor immune responses in the immunosuppressive tumor microenvironment. PMID:24764581

  2. Nonclassical antigen-processing pathways are required for MHC class II-restricted direct tumor recognition by NY-ESO-1-specific CD4(+) T cells.

    Science.gov (United States)

    Matsuzaki, Junko; Tsuji, Takemasa; Luescher, Immanuel; Old, Lloyd J; Shrikant, Protul; Gnjatic, Sacha; Odunsi, Kunle

    2014-04-01

    Tumor antigen-specific CD4(+) T cells that directly recognize cancer cells are important for orchestrating antitumor immune responses at the local tumor sites. However, the mechanisms of direct MHC class II (MHC-II) presentation of intracellular tumor antigen by cancer cells are poorly understood. We found that two functionally distinct subsets of CD4(+) T cells were expanded after HLA-DPB1*04 (DP04)-binding NY-ESO-1157-170 peptide vaccination in patients with ovarian cancer. Although both subsets recognized exogenous NY-ESO-1 protein pulsed on DP04(+) target cells, only one type recognized target cells with intracellular expression of NY-ESO-1. The tumor-recognizing CD4(+) T cells more efficiently recognized the short 8-9-mer peptides than the non-tumor-recognizing CD4(+) T cells. In addition to endosomal/lysosomal proteases that are typically involved in MHC-II antigen presentation, several pathways in the MHC class I presentation pathways, such as the proteasomal degradation and transporter-associated with antigen-processing-mediated peptide transport, were also involved in the presentation of intracellular NY-ESO-1 on MHC-II. The presentation was inhibited significantly by primaquine, a small molecule that inhibits endosomal recycling, consistent with findings that pharmacologic inhibition of new protein synthesis enhances antigen presentation. Together, our data demonstrate that cancer cells selectively present peptides from intracellular tumor antigens on MHC-II by multiple nonclassical antigen-processing pathways. Harnessing the direct tumor-recognizing ability of CD4(+) T cells could be a promising strategy to enhance antitumor immune responses in the immunosuppressive tumor microenvironment.

  3. Dissolving microneedle delivery of nanoparticle-encapsulated antigen elicits efficient cross-priming and Th1 immune responses by murine Langerhans cells.

    Science.gov (United States)

    Zaric, Marija; Lyubomska, Oksana; Poux, Candice; Hanna, Mary L; McCrudden, Maeliosa T; Malissen, Bernard; Ingram, Rebecca J; Power, Ultan F; Scott, Christopher J; Donnelly, Ryan F; Kissenpfennig, Adrien

    2015-02-01

    Dendritic cells (DCs) of the skin have an important role in skin-mediated immunity capable of promoting potent immune responses. We availed of polymeric dissolving microneedle (MN) arrays laden with nano-encapsulated antigen to specifically target skin DC networks. This modality of immunization represents an economic, efficient, and potent means of antigen delivery directly to skin DCs, which are inefficiently targeted by more conventional immunization routes. Following MN immunization, Langerhans cells (LCs) constituted the major skin DC subset capable of cross-priming antigen-specific CD8+ T cells ex vivo. Although all DC subsets were equally efficient in priming CD4+ T cells, LCs were largely responsible for orchestrating the differentiation of CD4+ IFN-γ- and IL-17-producing effectors. Importantly, depletion of LCs prior to immunization had a profound effect on CD8+ CTL responses in vivo, and vaccinated animals displayed reduced protective anti-tumor and viral immunity. Interestingly, this cross-priming bias was lost following MN immunization with soluble antigen, suggesting that processing and cross-presentation of nano-particulate antigen is favored by LCs. Therefore, these studies highlight the importance of LCs in skin immunization strategies and that targeting of nano-particulate immunogens through dissolvable polymeric MNs potentially provides a promising technological platform for improved vaccination strategies.

  4. Regulation of major histocompatibility complex class II antigens on human alveolar macrophages by granulocyte–macrophage colony-stimulating factor in the presence of glucocorticoids

    Science.gov (United States)

    Caulfield, J J; Fernandez, M H; Sousa, A R; Lane, S J; Lee, T H; Hawrylowicz, C M

    1999-01-01

    Alveolar macrophages (AM) present antigen poorly to CD4+ T cells and respond weakly to interferon-γ (IFN-γ) for up-regulation of major histocompatibility complex (MHC) class II and costimulatory molecule expression. In atopic asthma, however, AM exhibit enhanced antigen-presenting cell (APC) activity. Since granulocyte–macrophage colony-stimulating factor (GM-CSF) is increased in the airways of asthmatic patients, we have investigated its role in modulating the APC function of AM. The effects of glucocorticoids were also studied since earlier studies showed optimal induction of MHC antigens on monocytes by GM-CSF in their presence. GM-CSF in the presence, but not the absence, of dexamethasone enhanced the expression of HLA-DR, -DP and -DQ antigens by AM. However AM and monocytes differed in the optimal concentration of steroid required to mediate this effect (10−10 m and 10−7 m, respectively). Induction of MHC antigens was glucocorticoid specific and independent of IFN-γ. These studies suggest the existence of an IFN-γ-independent pathway of macrophage activation, which may be important in regulating APC function within the lung. PMID:10469240

  5. IL-10 polymorphism and cell-mediated immune response to Chlamydia trachomatis

    DEFF Research Database (Denmark)

    Öhman, H.; Tiitinen, A; Halttunen, M.

    2006-01-01

    background. To study a relationship between interleukin-10 (IL-10) promoter -1082 polymorphism and cell-mediated immune response during C trachomatis infection in vitro, lymphocyte proliferation and cytokine (IL-10, IFN-gamma, TNF-alpha, IL-2, IL-4 and IL-5) secretion were analysed in subjects with different...... IL-10 genotypes. Enhanced IL-10 secretion and reduced antigen-specific lymphocyte proliferative and IFN-gamma responses were found in subjects with IL-10 -1082 GG genotype when compared to those with -1082 AA genotype. CD14+ monocytes were main source of IL-10 indicating that these cells...... are important regulators of the antigen-specific cell-mediated responses during active C trachomatis infection. We conclude that impaired cell-mediated response to C trachomatis is associated with IL-10 genotype in subjects with high IL-10 producing capacity. A comparison of immune markers between subjects...

  6. Boosting antibody responses by targeting antigens to dendritic cells.

    Science.gov (United States)

    Caminschi, Irina; Shortman, Ken

    2012-02-01

    Delivering antigens directly to dendritic cells (DCs) in situ, by injecting antigens coupled to antibodies specific for DC surface molecules, is a promising strategy for enhancing vaccine efficacy. Enhanced cytotoxic T cell responses are obtained if an adjuvant is co-administered to activate the DC. Such DC targeting is also effective at enhancing humoral immunity, via the generation of T follicular helper cells. Depending on the DC surface molecule targeted, antibody production can be enhanced even in the absence of adjuvants. In the case of Clec9A as the DC surface target, enhanced antibody production is a consequence of the DC-restricted expression of the target molecule. Few other cells absorb the antigen-antibody construct, therefore, it persists in the bloodstream, allowing sustained antigen presentation, even by non-activated DCs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Use of Recombinant Antigens for the Diagnosis of Invasive Candidiasis

    Directory of Open Access Journals (Sweden)

    Ana Laín

    2008-01-01

    Full Text Available Invasive candidiasis is a frequent and often fatal complication in immunocompromised and critically ill patients. Unfortunately, the diagnosis of invasive candidiasis remains difficult due to the lack of specific clinical symptoms and a definitive diagnostic method. The detection of antibodies against different Candida antigens may help in the diagnosis. However, the methods traditionally used for the detection of antibodies have been based on crude antigenic fungal extracts, which usually show low-reproducibility and cross-reactivity problems. The development of molecular biology techniques has allowed the production of recombinant antigens which may help to solve these problems. In this review we will discuss the usefulness of recombinant antigens in the diagnosis of invasive candidiasis.

  8. Detection of dentin antigenic fractions by salivary immunoglobulin G ...

    African Journals Online (AJOL)

    Detection of dentin antigenic fractions by salivary immunoglobulin G in patients undergoing orthodontic treatment. TMP Soares da Costa, S de Paula Ramos, MM Hidalgo, A Consolaro, SA Khan, EN Itano ...

  9. DNA encoding individual mycobacterial antigens protects mice against tuberculosis

    Directory of Open Access Journals (Sweden)

    C.L. Silva

    1999-02-01

    Full Text Available Over the last few years, some of our experiments in which mycobacterial antigens were presented to the immune system as if they were viral antigens have had a significant impact on our understanding of protective immunity against tuberculosis. They have also markedly enhanced the prospects for new vaccines. We now know that individual mycobacterial protein antigens can confer protection equal to that from live BCG vaccine in mice. A critical determinant of the outcome of immunization appears to be the degree to which antigen-specific cytotoxic T cells are generated by the immune response. Our most recent studies indicate that DNA vaccination is an effective way to establish long-lasting cytotoxic T cell memory and protection against tuberculosis.

  10. Goodbye warts, hello vitiligo: Candida antigen-induced depigmentation.

    Science.gov (United States)

    Wilmer, Erin N; Burkhart, Craig N; Morrell, Dean S

    2013-01-01

    Depigmentation after the use of topical immune modulators is a rare but reported event. Herein we present what is to our knowledge the first case of vitiligo at a site of Candida antigen injection. © 2012 Wiley Periodicals, Inc.

  11. Antigen excess in modern immunoassays: to anticipate on the unexpected.

    Science.gov (United States)

    Jacobs, Joannes F M; van der Molen, Renate G; Bossuyt, Xavier; Damoiseaux, Jan

    2015-02-01

    Immunoassays measuring sera with high analyte concentration may be prone to an artifact that causes underestimation of the analyte concentration. This phenomenon is generally described as antigen excess or the prozone effect. Characteristically, serum with high concentrations of a certain analyte can give a false negative/low result when tested at the recommended dilution, but reacts strongly positive upon further dilution. Increased insight of the antigen excess mechanisms and tools to prevent it has reduced the analytical problems caused by prozone effects in daily laboratory practice. However, misinterpretation of laboratory results caused by antigen excess does still occur, in virtually any type of immunoassay. Awareness by the laboratory specialist of the mechanisms underlying antigen excess in the different immunoassays, strategies to detect it, and adequate communication with clinicians can help to avoid reporting false negative test-results. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. 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

  13. Seroprevalence of hepatitis B surface antigen among pregnant ...

    African Journals Online (AJOL)

    Seroprevalence of hepatitis B surface antigen among pregnant women attending the Hospital for Women & Children in Koutiala, Mali. Brett MacLean, Rosanna F Hess, Edward Bonvillain, Joseph Kamate, Daoda Dao, Amy Cosimano, Shannon Hoy ...

  14. Critical role for Sec22b-dependent antigen cross-presentation in antitumor immunity.

    Science.gov (United States)

    Alloatti, Andrés; Rookhuizen, Derek C; Joannas, Leonel; Carpier, Jean-Marie; Iborra, Salvador; Magalhaes, Joao G; Yatim, Nader; Kozik, Patrycja; Sancho, David; Albert, Matthew L; Amigorena, Sebastian

    2017-08-07

    CD8 + T cells mediate antigen-specific immune responses that can induce rejection of solid tumors. In this process, dendritic cells (DCs) are thought to take up tumor antigens, which are processed into peptides and loaded onto MHC-I molecules, a process called "cross-presentation." Neither the actual contribution of cross-presentation to antitumor immune responses nor the intracellular pathways involved in vivo are clearly established because of the lack of experimental tools to manipulate this process. To develop such tools, we generated mice bearing a conditional DC-specific mutation in the sec22b gene, a critical regulator of endoplasmic reticulum-phagosome traffic required for cross-presentation. DCs from these mice show impaired cross-presentation ex vivo and defective cross-priming of CD8 + T cell responses in vivo. These mice are also defective for antitumor immune responses and are resistant to treatment with anti-PD-1. We conclude that Sec22b-dependent cross-presentation in DCs is required to initiate CD8 + T cell responses to dead cells and to induce effective antitumor immune responses during anti-PD-1 treatment in mice. © 2017 Alloatti et al.

  15. Immune Responses to Tissue-Restricted Nonmajor Histocompatibility Complex Antigens in Allograft Rejection

    Directory of Open Access Journals (Sweden)

    Ankit Bharat

    2017-01-01

    Full Text Available Chronic diseases that result in end-stage organ damage cause inflammation, which can reveal sequestered self-antigens (SAgs in that organ and trigger autoimmunity. The thymus gland deletes self-reactive T-cells against ubiquitously expressed SAgs, while regulatory mechanisms in the periphery control immune responses to tissue-restricted SAgs. It is now established that T-cells reactive to SAgs present in certain organs (e.g., lungs, pancreas, and intestine are incompletely eliminated, and the dysregulation of peripheral immuneregulation can generate immune responses to SAgs. Therefore, chronic diseases can activate self-reactive lymphocytes, inducing tissue-restricted autoimmunity. During organ transplantation, donor lymphocytes are tested against recipient serum (i.e., cross-matching to detect antibodies (Abs against donor human leukocyte antigens, which has been shown to reduce Ab-mediated hyperacute rejection. However, primary allograft dysfunction and rejection still occur frequently. Because donor lymphocytes do not express tissue-restricted SAgs, preexisting Abs against SAgs are undetectable during conventional cross-matching. Preexisting and de novo immune responses to tissue-restricted SAgs (i.e., autoimmunity play a major role in rejection. In this review, we discuss the evidence that supports autoimmunity as a contributor to rejection. Testing for preexisting and de novo immune responses to tissue-restricted SAgs and treatment based on immune responses after organ transplantation may improve short- and long-term outcomes after transplantation.

  16. Engineering tolerance using biomaterials to target and control antigen presenting cells.

    Science.gov (United States)

    Tostanoski, Lisa H; Gosselin, Emily A; Jewell, Christopher M

    2016-05-01

    Autoimmune diseases occur when cells of the adaptive immune system incorrectly recognize and attack "self" tissues. Importantly, the proliferation and differentiation of these cells is triggered and controlled by interactions with antigen presenting cells (APCs), such as dendritic cells. Thus, modulating the signals transduced by APCs (e.g., cytokines, costimulatory surface proteins) has emerged as a promising strategy to promote tolerance for diseases such as multiple sclerosis, type 1 diabetes, and lupus. However, many approaches have been hindered by non-specific activity of immunosuppressive or immunoregulatory cues, following systemic administration of soluble factors via traditional injections routes (e.g., subcutaneous, intravenous). Biomaterials offer a unique opportunity to control the delivery of tolerogenic signals in vivo via properties such as controlled particle size, tunable release kinetics, and co-delivery of multiple classes of cargo. In this review, we highlight recent reports that exploit these properties of biomaterials to target APCs and promote tolerance via three strategies, i) passive or active targeting of particulate carriers to APCs, ii) biomaterial-mediated control over antigen localization and processing, and iii) targeted delivery of encapsulated or adsorbed immunomodulatory signals. These reports represent exciting advances toward the goal of more effective therapies for autoimmune diseases, without the broad suppressive effects associated with current clinically-approved therapies.

  17. Mechanisms of naturally acquired immunity to P. falciparum and approaches to identify merozoite antigen targets.

    Science.gov (United States)

    Healer, Julie; Chiu, Chris Y; Hansen, Diana S

    2017-11-16

    Malaria is one the most serious infectious diseases with over 200 million clinical cases annually. Most cases of the severe disease are caused by Plasmodium falciparum. The blood stage of Plasmodium parasite is entirely responsible for malaria-associated pathology. The population most susceptible to severe malaria are children under the age of 5, with low levels of immunity. It is only after many years of repeated exposure that individuals living in endemic areas develop clinical immunity. This form of protection prevents clinical episodes by substantially reducing parasite burden. Naturally acquired immunity predominantly targets blood-stage parasites with antibody responses being the main mediators of protection. The targets of clinical immunity are the extracellular merozoite and the infected erythrocyte surface, with the extremely diverse PfEMP1 proteins the main target here. This observation provides a strong rationale that an effective anti-malaria vaccine targeting blood-stage parasites is achievable. Thus the identification of antigenic targets of naturally acquired immunity remains an important step towards the formulation of novel vaccine combinations before testing their efficacy in clinical trials. This review summarizes the main findings to date defining antigenic targets present on the extracellular merozoite associated with naturally acquired immunity to P. falciparum malaria.

  18. Permeation of antigen protein-conjugated nanoparticles and live bacteria through microneedle-treated mouse skin

    Directory of Open Access Journals (Sweden)

    Kumar A

    2011-06-01

    Full Text Available Amit Kumar, Xinran Li, Michael A Sandoval, B Leticia Rodriguez, Brian R Sloat, Zhengrong CuiUniversity of Texas at Austin, College of Pharmacy, Pharmaceutics Division, Austin, TX, USABackground: The present study was designed to evaluate the extent to which pretreatment with microneedles can enhance skin permeation of nanoparticles in vitro and in vivo. Permeation of live bacteria, which are physically nanoparticles or microparticles, through mouse skin pretreated with microneedles was also studied to evaluate the potential risk of microbial infection.Methods and results: It was found that pretreatment of mouse skin with microneedles allowed permeation of solid lipid nanoparticles, size 230 nm, with ovalbumin conjugated on their surface. Transcutaneous immunization in a mouse skin area pretreated with microneedles with ovalbumin nanoparticles induced a stronger antiovalbumin antibody response than using ovalbumin alone. The dose of ovalbumin antigen determined whether microneedle-mediated transcutaneous immunization with ovalbumin nanoparticles induced a stronger immune response than subcutaneous injection of the same ovalbumin nanoparticles. Microneedle treatment permitted skin permeation of live Escherichia coli, but the extent of the permeation was not greater than that enabled by hypodermic injection.Conclusion: Transcutaneous immunization on a microneedle-treated skin area with antigens carried by nanoparticles can potentially induce a strong immune response, and the risk of bacterial infection associated with microneedle treatment is no greater than that with a hypodermic injection.Keywords: antibody responses, safety of microneedles, transepidermal water loss

  19. Permeation of antigen protein-conjugated nanoparticles and live bacteria through microneedle-treated mouse skin

    Science.gov (United States)

    Kumar, Amit; Li, Xinran; Sandoval, Michael A; Rodriguez, B Leticia; Sloat, Brian R; Cui, Zhengrong

    2011-01-01

    Background: The present study was designed to evaluate the extent to which pretreatment with microneedles can enhance skin permeation of nanoparticles in vitro and in vivo. Permeation of live bacteria, which are physically nanoparticles or microparticles, through mouse skin pretreated with microneedles was also studied to evaluate the potential risk of microbial infection. Methods and results: It was found that pretreatment of mouse skin with microneedles allowed permeation of solid lipid nanoparticles, size 230 nm, with ovalbumin conjugated on their surface. Transcutaneous immunization in a mouse skin area pretreated with microneedles with ovalbumin nanoparticles induced a stronger antiovalbumin antibody response than using ovalbumin alone. The dose of ovalbumin antigen determined whether microneedle-mediated transcutaneous immunization with ovalbumin nanoparticles induced a stronger immune response than subcutaneous injection of the same ovalbumin nanoparticles. Microneedle treatment permitted skin permeation of live Escherichia coli, but the extent of the permeation was not greater than that enabled by hypodermic injection. Conclusion: Transcutaneous immunization on a microneedle-treated skin area with antigens carried by nanoparticles can potentially induce a strong immune response, and the risk of bacterial infection associated with microneedle treatment is no greater than that with a hypodermic injection. PMID:21753877

  20. H-2 restriction: Independent recognition of H-2 and foreign antigen by a single receptor

    Science.gov (United States)

    Siliciano, Robert F.; Zacharchuk, Charles M.; Shin, Hyun S.

    1980-01-01

    We describe two situations in which the recognition of hapten can compensate for the lack of recognition of appropriate H-2 gene products in hapten-specific, H-2 restricted, T lymphocyte-mediated cytolysis. First, we show that although recognition of appropriate H-2 gene products is essential for the lysis of target cells bearing a low hapten density, significant hapten-specific lysis of H-2 inappropriate target cells is observed at high levels of target cell derivatization. Secondly, we show that hapten-conjugated anti-H-2 antibody inhibits cytolysis poorly even though its binding to target cell H-2 antigens is equivalent to that of underivatized antibody. These results suggest that hapten and H-2 are recognized independently and are therefore inconsistent with the altered-self model. Although our data do not exclude the dual-recognition model, we prefer to interpret them within the framework of a single-receptor model in which hapten and H-2 are recognized independently by receptors of identical idiotype on the T cell. We postulate that the affinity of these receptors for the relevant H-2 gene product is low enough so that the T cell is not activated by encounters with normal-self cells expressing that H-2 gene product. However, when self cells express in addition a foreign antigen that can also be recognized by the same receptor, then the force of T cell-target cell interaction may be increased sufficiently to activate T cell effector function. PMID:6966404